Principles of Cancer Biotherapy...method of treatment complementing cancer destruction as mechanisms...

Principles of Cancer Biotherapy

5th Edition

Principles of Cancer Biotherapy5th Edition

Edited by

Robert K. OldhamHematology-Oncology Associates of Southeast Missouri HospitalSoutheast Medical PlazaCape Girardeau, MOUSA

Robert O. DillmanHoag Cancer CenterNewport Beach, CAUSAUniversity of CaliforniaIrvine, CAUSA

Robert K. Oldham Robert O. DillmanHematology-Oncology Associates Hoag Cancer Center of Southeast Missouri Hospital Newport Beach, CASoutheast Medical Plaza USACape Girardeau, MO University of CaliforniaUSA Irvine, CA USA

ISBN 978-90-481-2277-6 e-ISBN 978-90-481-2289-9DOI 10.1007/978-90-481-229-9Springer Dordrecht Heidelberg London New York

Library of Congress Control Number: 2009929387

First edition published 1987 by Raven PressSecond edition published 1993 by Williams & WilkinsThird and Fourth edition published 1998 Kluwer Academic Publishers© Springer Science+Business Media B.V. 2009No part of this work may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, microfi lming, recording or otherwise, without written permission from the Publisher, with the exception of any material sup-plied specifi cally for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work.

Printed on acid-free paper

Springer is part of Springer Science+Business Media (www.springer.com)

Preface

The idea for the fi rst edition of Principles of Cancer Biotherapy was formulated in the early 1980s. As the founding director of the Biological Response Modifi ers Program for the National Cancer Institute from 1980-1984, one of us (rko) envisioned a textbook that would embody the principles of the then fl edgling fourth modal-ity of cancer treatment - biotherapy. Contributing authors were solicited in 1985, and the fi rst edition came off the presses in 1987. Principles represented the fi rst compre-hensive textbook on the use of cancer biotherapy and summarized the work done in this fi eld through 1986.

The second edition of Principles was published in 1991 about the time biotherapy was more broadly recog-nized as the fourth major cancer treatment modality. Subsequent textbooks by DeVita, Hellman and Rosenberg [1] in 1991, Mitchell [2] in 1993 and Rosenberg [3] in 2000 validated the importance of this modality in cancer care.

This third edition was published in 1998 and con-fi rmed the tremendous progress that had been made in the previous fi ve years using biologicals in cancer treat-ment. It was generally agreed that biopharmaceuticals were producing major opportunities for new cancer therapies. Cancer biotherapy was emerging as a more specifi c and targeted form of systemic cancer treatment. Cancer growth control was also becoming an effective method of treatment complementing cancer destruction as mechanisms of cancer treatment and “cure”.

The fourth edition of Principles was published in 2003. It was apparent that biotherapy and the use of bio-pharmaceuticals had not only become recognized as the fourth modality of cancer treatment, it was clear that biopharmaceuticals had become the dominant form of new cancer therapeutics which in the future will replace less selective, more toxic forms of therapy.

For years, the chemical manipulation of small mole-cules has been pursued in drug development. We now have all the tools for the biological manipulation of natu-ral substances for therapeutic use. In fact, as we better understand the interaction between biological molecules and their receptors, it is clear that biological manipula-tion and chemical manipulation are coming together to bring molecular medicine to the bedside. Many biologi-cal molecules are large and have functions other than

those mediated by their active sites. There is increasing evidence that drug development will focus on the inter-action between the smaller active regions of these large biological molecules and their receptors. This opens up a broad fi eld of molecular design for extending and improving the therapeutic activities of natural biological molecules. This has recently been extended to small molecules interacting with DNA/RNA (anti-sense), with enzymes such as tyrosine kinase and with growth and vascular factor receptors. The last decade has been extraordinarily productive in the development of new anticancer drugs through chemical and biological manip-ulation of these natural molecules. Thus, the body itself has become the “medicine cabinet” of the future.

In the 1990s and beyond into this millennium, medi-cine will face extraordinary demands. While technol-ogy brings us tremendous opportunity, it also highlights problems in our medical care system. Most new tech-nology is expensive and, as it comes from the laboratory to the clinic, is by its very nature untried and unproven. Our medical care system involves a private and govern-ment insurance reimbursement system that favors pay-ing for marginally effective medical care of the past rather than innovative medical treatments of the future. Such a system is inhibitory to the development of effec-tive new anti-cancer medicines.

To more rapidly and effi ciently exploit the opportuni-ties in cancer biotherapy in the future, patients, employ-ers, insurers, universities, and government must come together and redefi ne the system of reimbursement to maximize the patient’s opportunity for access to new and potentially effective cancer therapies. To simply reimburse for old ineffective or marginally effective treatment is not the answer. Provisions must be made to fund clinical research and afford these new approaches broader use at the bedside. We must develop methods to allow our patients access to the opportunities of the future, while maintaining solid support for effective therapies of the past. No longer is it acceptable to pay only for medical care that utilizes old technology, such as chemotherapy, that is approved but only marginally effective. Across the broad spectrum of human malig-nancies, most chemotherapeutic drugs are toxic and of limited medical value. We must support clinical research

v

vi Preface

in its efforts to bring newer methods of cancer treatment to the clinic, methods that are less toxic and more effective.

We believe cancer biotherapy will ultimately replace much of what we utilize today in cancer treatment. In light of this view, we want to thank all the authors for their dedication to purpose in writing this fi fth edition of Principles. This book summarizes an evolving science and a rapidly changing medical practice. As we progress into the millennium, it now becomes possible to envision a much more diversifi ed system of cancer research and treatment that will afford greater opportunities for our patients. As indicated in some of the chapters in Principles, there is increasing evidence that our historical “kill and cure” outlook in cancer treatment is in need of modifi ca-tion. Some forms of cancer biotherapy use the strategy of tumor growth stabilization and control through con-tinued biological therapy over a longer period of time, akin to the use of insulin in the treatment of diabetes.

These chapters illustrate some of these new methods of thinking and illustrate new strategies for the treatment and control of cancer. It is always diffi cult to move from past dogmas to future opportunities, but this fi fth edi-tion of Principles of Cancer Biotherapy illustrates why it is so important for researchers, regulators and clinicians to explore and apply these new opportunities in cancer biotherapy to the benefi t of our patients.

Robert K. Oldham, M.D. Robert O. Dillman MD

References1. DeVita VT Jr, Hellman S, Rosenberg SA. Biologic Therapy of

Cancer. J.B. Lippincott, 1991.2. Mitchell MS. Biological Approaches to Cancer Treatment.

McGraw-Hill, 1993.3. Rosenberg SA. Principles and Practices of the Biologic Therapy of

Cancer. J.B. Lippincott, 2000.

Contents

Preface vRobert K. Oldham

Contributors ix

1. Cancer biotherapy: general principles 1Robert K. Oldham

2. The pathogenesis of cancer metastasis: relevance to therapy 17Sun-Jin Kim, Cheryl Hunt Baker, Yasuhiko Kitadai, Toru Nakamura, Toshio Kuwai, Takamitsu Sasaki, Robert Langley, and Isaiah J. Fidler

3. Developmental therapeutics and the design of clinical trials 41Robert K. Oldham

4. Recombinant proteins and genomics in cancer therapy 53Kapil Mehta, Bulent Ozpolat, Kishorchandra Gohil, and Bharat B. Aggarwal

5. Current concepts in immunology 85Robert K. Oldham

6. Therapeutic approaches to cancer-associated immune suppression 101Robert K. Oldham

7. Cancer vaccines 147Kenneth A. Foon and Malek M. Safa

8. Cytokines 155Walter M. Lewko and Robert K. Oldham

9. Interferons: therapy for cancer 277David Goldstein, Robert Jones, Richard V. Smalley, and Ernest C. Borden

10. Monoclonal antibody therapy 303Robert O. Dillman

11. Immunotoxins 407Arthur E. Frankel, Jung-Hee Woo, and David M. Neville

12. Drug Immunoconjugates 451Malek Safa, Kenneth A. Foon, and Robert K. Oldham

13. Targeted radionuclide therapy of cancer 463John M. Pagel, Otto C. Boerman, Hazel B. Breitz, and Ruby Meredith

vii

14. Stem cell/bone marrow transplantation as biotherapy 497 Robert K. Oldham

15. Cellular immunotherapy (CI), where have we been and where are we going? 505 John R. Yannelli

16. Growth and differentiation factors as cancer therapeutics 527 Kapil Mehta, Robert K. Oldham, and Bulent Ozpolat

17. Granulocyte colony-stimulating factor: biology and clinical potential 569 MaryAnn Foote and George Morstyn

18. Granulocyte-macrophage colony-stimulating factor 581 Maryann Foote and George Morstyn

19. Cancer gene therapy 589 Donald J. Buchsbaum, C. Ryan Miller, Lacey R. Mcnally, and Sergey A. Kaliberov

20. Regulatory process for approval of biologicals for cancer therapy 613 Antonio J. Grillo-López

21.1. Cancer biotherapy: 2009 disease-related activity 631 Robert K. Oldham and Robert O. Dillman

21.2. Biological therapy of melanoma 633 Robert K. Oldham

21.3. Biological therapy of genitourinary cancer 645 Robert K. Oldham

21.4. Biological therapy of colon cancer 659 Robert O. Dillman

21.5. Biological therapy of breast cancer 669 Robert O. Dillman

21.6. Biological therapy of lung cancer 679 Robert O. Dillman

21.7. Biological therapy of B and T cell lymphoproliferative disorders 693 Robert O. Dillman

21.8. Biological therapy of multiple myeloma 711 Robert K. Oldham

21.9. Biological therapy of squamous cell cancers of the head and neck 713 Robert O. Dillman

21.10. Biological therapy of glioblastoma 723 Robert O. Dillman

22. Speculations for 2009 and beyond 733 Robert K. Oldham

Index 739

viii Contents

Contributors

Robert K. OldhamHematology-Oncology Associates of Southeast Missouri HospitalSoutheast Medical PlazaCape Girardeau, MOUSA

Robert O. DillmanHoag Cancer CenterNewport Beach, CAUSAUniversity of California Irvine, CAUSA

Sun-Jin KimDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Cheryl Hunt BakerDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Yasuhiko KitadaiDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Toru NakamuraDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Toshio KuwaiDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Takamitsu SasakiDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Robert LangleyDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Isaiah J. FidlerDepartment of Cancer BiologyM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Kapil MehtaDepartment of Experimental TherapeuticsM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Bulent OzpolatDepartment of Experimental TherapeuticsM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

ix

Kishorchandra GohilDepartment of Internal MedicineThe University of CaliforniaDavis, CAUSA

Bharat B. AggarwalDepartment of Experimental TherapeuticsM. D. Anderson Cancer CenterThe University of Texas Houston, TX USA

Kenneth A. FoonDepartment of Hematological MalignanciesNevada Cancer InstituteLas Vegas, NV USA

Malek M. SafaDivision of Hematology / OncologyUniversity of CincinnatiCincinnati, OHUSA

Walter M. LewkoCancer Cellular Therapeutics, Inc.Cape Girardeau, MOUSA

David GoldsteinDepartment of Medical OncologyPrince of Wales HospitalRandwick, Sydney Australia

Robert JonesCentre for Oncology and Applied PharmacologyCRUK Beatson LaboratoriesGlasgow, ScotlandUK

Richard V. Smalley (deceased)Synertron Inc.Madison, WIUSA

Arthur E. FrankelCancer Research Institute of Scott &WhiteTemple, TXUSA

Jung-Hee WooCancer Research Institute of Scott &WhiteTemple, TXUSA

David M. NevilleAngimmune LLC, Bethesda, MD USA

John M. PagelThe Fred Hutchinson Cancer Research CenterSeattle, WAUSA

Otto C. BoermanUniversity Medical CenterNijmegenThe Netherlands

Hazel B. BreitzPoniard Pharmaceuticals, Inc.Seattle, WAUSA

Ruby F. MeredithDepartment of Radiation OncologyUniversity of Alabama BirminghamBirmingham, AlabamaUSA

John R. YannelliDepartment of Microbiology, Immunology and Molecular GeneticsMarkey Cancer Center University of Kentucky, School of MedicineLexington, KentuckyUSA

MaryAnn FooteThousand Oaks, CA USA

Dr George MorstynDepartment of MicrobiologyMonash UniversityVictoria Australia

x Contributors

Contributors xi

Donald J. BuchsbaumDepartment of Radiation OncologyUniversity of Alabama at BirminghamBirmingham, ALUSA

Lacey R. McNallyDepartment of RadiologyUniversity of Alabama at BirminghamBirmingham, ALUSA

Sergey A. KaliberovDepartment of Radiation OncologyUniversity of Alabama at BirminghamBirmingham, ALUSA

C. Ryan MillerDepartment of PathologyUniversity of North CarolinaChapel Hill, NCUSA

Antonio J. Grillo-LópezRancho Santa Fé, CAUSA

R.K. Oldham and R.O. Dillman (eds.), Principles of Cancer Biotherapy, 1© Springer Science + Business Media B.V. 2009

The term biotherapy encompasses the therapeutic use of any biological substance, but more specifi cally, it con-notes the use of products of the mammalian genome. With modern techniques of genetic engineering, the mammalian genome represents the new “medicine cabi-net.” Biological response modifi ers (BRM) are agents and approaches whose mechanisms of action involve the individual’s own biological responses. Biologicals and BRM work through diverse mechanisms in the biother-apy of cancer. They may (a) augment the host’s defenses through the administration of cells, natural biologicals, or the synthetic derivatives thereof as effectors or mediators (direct or indirect) of an antitumor response; (b) increase the individual’s antitumor responses through augmenta-tion or restoration of effector mechanisms, or decrease a component of the host’s reaction that is deleterious; (c) augment the individual’s responses using modifi ed tumor cells or vaccines to stimulate a greater response, or increase tumor cell sensitivity to an existing bio logical response; (d) decrease transformation and/or increase dif-ferentiation or maturation of tumor cells; (e) interfere with growth-promoting factors and angiogenesis induc-ing factors produced by tumor cells; (f) decrease or arrest the tendency of tumor cells to metastasize to other sites; (g) increase the ability of the patient to tolerate damage by cytotoxic modalities of cancer treatment; and/or (h) use biological molecules to target and bind to cancer cells and induce more effective cytostatic or cytocidial antitu-mor activity.

While several of these approaches involve the aug-mentation or use of biological responses, an understand-ing of the biological properties of immune response molecules, growth and maturation factors, and other biological substances will assist in the development of specifi c molecular entities that can act on biological responses and/or act directly on tumor cells. Thus, one can visualize the development of biological approaches with response-modifying as well as direct cytolytic, cytostatic, growth-inhibiting (antiproliferative), or mat-urational effects on tumor cells.

Biotherapy is the fourth modality of cancer therapy and can be effective alone or in association with surgery, radiotherapy, and chemotherapy. To put bio therapy into perspective, it is important to dispel a historical miscon-

ception associated with immunotherapy: biotherapy can be effective against clinically apparent, even bulky, can-cer, and treatment should not be restricted to situations where the tumor cell mass is imperceptible [64, 71]. Thus, the clinical trial designs for biotherapy can be similar to those used previously for other modalities of cancer treatment, as long as one measures both pharma-cokinetics and the biological responses affected by these approaches [65]. Testing is continuing for biotherapy using the interferons, lymphokines, chemokines and cytokines, growth and maturation factors, angiostatic factors, monoclonal antibodies and their immunoconju-gates, vaccines, and cellular therapy [68].

Historical PerspectivesThe use of chemical and biological compounds to mod-ulate biological responses has been under active investi-gation for over 30 years. Although various chemicals, bacterial extracts, and viruses have been found to modu-late immune responses in experimental animals, and, to a more limited extent, in humans, these “nonspecifi c” immunomodulators have not been highly effective in clinical trials [71]. Molecular biologists have recently developed techniques for the isolation of genes and their subsequent translation into appropriate production sys-tems. These methods make available virtually unlimited quantities of highly purifi ed biological compounds for experimental and therapeutic use. As a result, several classes of biologicals are being evaluated in preclinical models and clinical trials (Table 1).

The continued investigation of nonspecifi c immuno-modulators and adjuvants, as well as the recent advent of genetically engineered biologicals, makes the need for predictive preclinical assays of biological activity and effi cacy apparent [33]. In vitro assays of biological activity (bioassays) are generally used to defi ne and quantitate the activity of a given biological substance. Subsequently, fl ow cytometry, immunoperoxidase staining, enzyme-linked immunosorbent assays (ELISA), tetramer assays, radioimmunoassays (RIA), and variations of these methods allow the precise determination of levels of these molecules and activities in appropriate fl uids and tissues.

1 Cancer biotherapy: general principles

ROBERT K. OLDHAM


Finally, there is the need to assess the in vivo activity of these materials in preclinical models to develop predic-tive assays for clinical effi cacy and provide information useful in the rational selection of agents and the design of clinical trials [33, 54].

Given the variability in the biological behavior of cancer and its interface with the human outbred host, it is not surprising that trials of nonspecifi c and specifi c immunotherapy, as translated from artifi cially con-structed animal models, have not been uniformly suc-cessful in cancer treatment [4, 33]. Naturally occurring cancers arise in a particular organ from one cell or a few cells under some carcinogenic stimulus. In humans, these initial foci of cancer cells may grow – and some-times lie dormant – over very long periods of time (from 1% to 30% of the human life span) before there is clini-cal evidence of cancer. Dissemination of cells from the initial focus may occur at any time during the develop-ment of the primary tumor. Subsequently, growth and metastasis occur over periods of months to years from primary and secondary foci, causing complex biological interactions to occur.

In contrast, experimentally induced cancer is an arti-fi cial (even artifactual) situation. A short-duration, high-dose carcinogen may be used to induce cancer quickly so that experiments can proceed rapidly. In transplant-able models, the tumor cells are injected into young, normal, syngeneic animals, thereby circumventing the infl uences of environmental or genetic factors that may be operative in the natural host during tumor develop-ment. Many of the experimental models are transplant-able tumors that have been maintained for decades and have only the most remote relevance to cancer in humans. The injection represents a single, instantaneous point source for a defi ned tumor load that has been manipulated in vitro. Regardless of whether that tumor load is 10 or 106 cells, it is being placed artifi cially in a single site and allowed to grow and metastasize from that selected and artifi cial, single site. Thus, these trans-plantable cancers are simply not analogous to clinical

cancer and the conclusions drawn from them are unlikely to be broadly applicable to human cancers [33].

The modern era of cancer treatment began in the 1950s with the recognition that most cancers were sys-temic problems. It became obvious that lymphatic and blood-borne metastases often occurred simultaneously with local growth and regional spread. The early success of chemotherapy in leukemia and lymphoma prompted a massive and enthusiastic search for chemicals that might have cytolytic or cytostatic effects on cancer cells. Millions of compounds have been “screened” for antitu-mor activity [11], and this effort has given clinicians less than 75 “approved and active” anticancer chemotherapy drugs [84]. In addition, there are about 15 approved hor-monal agents, ten targeted small molecules, and 25 bio-logical drugs. There is now widespread recognition that only a few drugs in cancer treatment can effectively pal-liate and sometimes cure [19]. The development of three modalities (surgery, radiotherapy and chemotherapy) and their subsequent integration into what is now multi-modal cancer treatment has been summarized [18, 20]. Between 1975 and 1990 a plateau was reached in cancer treatment. New surgical techniques (e.g., debulking, intra- operative methods for radiotherapy, and catheter isolation/ infusion for chemotherapy) and new methods of radiotherapy (e.g., neutrons, protons, interstitial ther-apy, isotopes) continue to be developed, but these two modalities are primarily useful in local and regional can-cer treatment. There has been continued, but slow, prog-ress in the treatment of highly replicative, drug-sensitive malignancies over the past 15 years. It is now apparent that further progress with chemotherapy will depend on a greater understanding of the metabolic and enzymatic processes of cancer cells and the differences between these and normal cells. In addition, there are the prob-lems of drug resistance, selectivity of action, and drug delivery. Cancer cells are more like than unlike normal cells with respect to chemotherapy sensitivity but they are more likely to become chemotherapy resistant with drug exposure. Many chemotherapeutic agents are highly cytolytic, but the problems of normal tissue tox-icity, drug delivery, and tumor-cell resistance remain [19, 46]. Thus, cancer remains a systemic problem, and further systemic but more selective approaches are required for more effective treatment [20].

In addition to standard chemotherapy drugs that are approved and in clinical use, there are approximately 15 hormonal drugs available. These are primarily used in breast cancer and prostate cancer, and many are varia-tions on the theme of blocking hormonal receptors. The evolution in this area has been primarily testing new

Table 1. Biologicals and BRM

Immunomodulators (chemicals, bacterial extracts, viruses, etc.)Lymphokines/cytokines α, β, γ-interferon; IL-1–32, tumor

necrosis factor (TNF); etc.Growth/maturation factors (CSF, IL-2, EPO, etc.)Effector cells (cytotoxic and helper T cells, NK, and LAK cells,

gene-engineered cells, etc.)Tumor-associated antigens and gene-engineered cellular

vaccinesMonoclonal antibodiesImmunoconjugates

Robert K. Oldham 3

hormonal agents for superiority in therapy and for lesser degrees of toxicity when used in large-scale trials against hormonally sensitive tumors.

Then newest area of drug development is in targeted therapy. Here, small molecules are tested for the ability to block a particular receptor, enzyme, or target which may be involved in cell replication or cell metabolism. Eight targeted agents are currently available in the clinic, and a very large number of these small molecules are currently in clinical trials, most of which are variations on the theme of blocking a particular receptor or enzyme system with many of these drugs being multifunctional in that they can block more than one receptor or system.

The scientifi c basis for biotherapy as the fourth modal-ity of cancer treatment is now fi rm [21–23, 68, 70, 81, 82, 94, 97]. Historically, there was an attempt to establish immunotherapy in this role. Whereas immunotherapy was reproducible under specifi c experimental protocols, it was not strikingly effective in animals bearing palpable tumors and did not translate well to patients. Given the observation that immunotherapy was more effective with small tumor burdens, investigators began to study both “specifi c” and “nonspecifi c” immunotherapy as treatment for minimal residual disease. Although it became widely accepted that the treatment of animals with minimal residual disease was analogous to the postsurgical treat-ment of cancer in humans, this analogy was often stretched beyond reason. Immunotherapy in young, nor-mal, syngeneic animals was often begun on the day of the tumor transplant (or within 1 or 2 days), using a trans-plant of a very small number of tumor cells (1–1,000) to a single site. In many of these studies, and in studies in which the tumor was surgically resected and no evident disease remained, the effects of immunotherapy were rea-sonably reproducible; the therapy was most benefi cial when the tumor mass was less than 106 cells.

These experimental results produced a dogma that immunological manipulation or immunotherapy could work only when the tumor cell mass was imperceptible [4, 71]. This posed real problems for clinical immuno-therapy, since the tumor cell mass at clinical diagnosis or after surgery is usually three orders of magnitude (or more) greater than 106 cells. Despite the obvious diffi -culties with the experimental models and the translation to humans, clinicians began larger scale immunotherapy trials in the 1970s. The results of initial, small, uncon-trolled trials were often reported as positive. Larger, ran-domized, controlled studies were done to confi rm the effi cacy of a particular immunotherapeutic regimen in a particular type of cancer. Although some of the con-trolled studies were positive, most yielded marginal or

negative results. Thus, immunotherapy had a poor image by the end of the 1970s [71, 109].

Immunotherapy failed to establish itself as a major mode of cancer treatment for several reasons. One impor-tant factor was the lack of defi nition and purity of immu-notherapeutic agents. Many of the nonspecifi c approaches involved the use of complex chemicals, bacteria, viruses, and poorly defi ned extracts in an attempt to “stimulate” the immune response. Thus, molecular defi nition of the actual stimulating entity was not available. Given the lack of analogy between model systems and humans, the poorly characterized reagents, and the problems of vari-ability in experimental procedures, the lack of demon-strable clinical effi cacy was predictable [71].

Immunotherapy is not an appropriate term for the modern use of biologicals and BRM in medicine. Biological control mechanisms should be envisioned on a much broader basis than the immune system. While immunotherapy remains a subcategory of biotherapy, growth and differentiation factors, chemokines and angiostatic factors, the use of synthetically derived molecular analogs, and the pharmacological exploita-tion of biological molecules is much broader than immunotherapy (Table 1) [68].

Certain specifi c developments led to biotherapy becoming the fourth modality of cancer therapy. Advances in molecular biology have given scientists the capability to clone individual genes and produce signifi -cant quantities of highly purifi ed genomic products as medicines. Unlike extracted and purifi ed biological molecules, available in small quantities as semi-purifi ed mixtures, the products of cloned genes have a level of purity on a par with drugs. They can be analyzed alone or in combination as to their effects in cancer biology. In addition, progress in nucleic acid sequencing and trans-lation, protein sequencing and synthesis, the isolation and purifi cation of biological products, and mass cell culture has given the scientifi c community the opportu-nity to alter nucleic acids and proteins at the nucleotide or amino acid level to mani pulate then optimize their biological activity [42]. The elucidation of the human genome and the encoded products broadened the oppor-tunities for advancements in biotherapy.

As a result of gene cloning, a major approach in can-cer treatment has evolved. Interleukin-2 can be used to stimulate the growth of a broad range of lymphocytes (T, NK, and LAK cells). This has given clinicians the ability to have large quantities of specifi c subclasses of effector cells for cancer treatment. Emerging evidence suggests that these effector cells can be helpful in the regional and systemic treatment of advanced, bulky


cancer. It was the availability of Interleukin-2 that allowed this technology to prosper [83]. In addition, IL-2 is now being used as the T cell growth factor for gene engineered lymphocytes containing new genes to enhance their cancer treatment capacity [80, 103].

Another major technical advance was the discovery of hybridomas. A major limitation on the use of anti-bodies had been the inability to make reproducible high-titer, specifi c antisera and to defi ne these preparations on a molecular basis. Immunoglobulin reagents can now be produced with the same level of molecular purity as cloned gene products and drugs. Processes to easily “humanize” antibodies have produced therapeutic anti-bodies with excellent specifi city, low immuno genicity and optimal pharmacokinetics. These antibodies are also powerful tools in the isolation and purifi cation of tumor-associated antigens, lymphokines/cytokines, and other biologicals, which can then be used in biotherapy. The advances in molecular biology and hybridoma tech-nology have eclipsed previous techniques for the isola-tion and purifi cation of biological molecules [63, 77].

Technical advances in instrumentation, computers, and computer software have been critically important in the isolation and purifi cation of biological molecules. The construction of nucleotide or amino acid sequences to fi t any biological message is now possible. While this synthetic capability is currently limited to smaller gene products, techniques by which analysis and con-struction of nucleotide sequences will occur in an auto-mated way, making enormously complex molecules possible to synthesize and manufacture, are rapidly becoming available.

Preclinical ModelsBiological Activity in Preclinical ModelsCentral to the identifi cation of biotherapy that might be useful in cancer patients is the recognition that, in the main, the challenge in humans is the eradication of metastases. Metastases can result from the dissemina-tion of different subpopulations of cells within the pri-mary neoplasm [32]. This may explain the observation that cells within a metastasis can be antigenically dis-tinct from those that predominate in the parental tumor [32]. Metastases may also emanate from other metasta-ses. The implications of cellular heterogeneity as it relates to the outcome of the specifi c immunotherapy are obvious. In addition, normal animals are not com-parable to animals or humans bearing autochthonous

neoplasms [33]. There may exist in animals and in humans specifi c or nonspecifi c defects important in the development of their auto chthonous tumors. Corrections of such defects may require a form of biotherapy totally different from that required to assist the normal host in controlling a transplanted cancer.

Model Screening CriteriaTheoretically, an ideal procedure for screening new bio-logicals should employ a system of sequential and pro-gressively more demanding protocols designed to select a maximum number of effective agents.

The term screening denotes a series of sequential assays through which promising agents are tested for therapeutic potential. For some biotherapies, a general screening procedure may be inappropriate. For exam-ple, the activity of a monoclonal antibody with antitu-mor specifi city would not be detected by use of the general screen of biological activity. Design consider-ations for general screening in biotherapy have been extensively reviewed [33, 54, 56, 61]. A step-by-step approach to the screening of potential BRM was devel-oped to defi ne their effects on T-cell, B-cell, NK-cell, and macrophage functions. A progressive in vitro and then in vivo sequence allows the variables of dose, schedule, route, duration and maintenance of activity, adjuvanticity, and synergistic potential to be explored in an orderly fashion [33]. Unfortunately, the screening program was used only briefl y by the NCI and no replacement program is now in use.

Evaluation of Screening ProgramsScreening programs for chemotherapeutic agents were initiated in the mid-1950s, and attempts have been made to randomly examine thousands of compounds for antitumor activity [11]. Such large screening pro-grams are empirically rather than rationally based, and are no longer appropriate [4, 5, 20, 33, 71]. Whether induced or transplantable animal tumor systems are valid models for testing therapeutic approaches for human cancer has been a controversial issue [33]. In patients, therapy successful against one type of can-cer may not be successful against another type, or even for another patient with the same histological type of cancer. Unlike the model systems, in which treatment can be given with precise timing relative to the meta-static phase of a resected tumor or injected tumor cells, cancer diagnosis in humans is generally late, and micro-metastases (and often macro-metastases) have become

Robert K. Oldham 5

well established before treatment can be initiated. Thus, screening programs can only provide tentative indica-tions on agents and approaches of interest.

Biotherapy: Specifi c Agents and ApproachesNonspecifi c ImmunomodulatorsSince the early 1900s, immunotherapy with bacterial or viral products has been utilized with the hope of “non-specifi cally” stimulating the host’s immune response [71]. These agents had been useful as adjuvants and as nonspecifi c stimulants in animal tumor models, but human trials have been disappointing.

Perhaps purifi ed viruses or specifi c chemicals will lead to the development of more effective adjuvants or stimu-

lants of the immune response. Bacillus Calmette-Guerin (BCG) and other whole organisms were used early in immunotherapy. The use of a purifi ed derivative of bacte-rial components, such as muramyl di- or tripeptide, “pack-aged” in liposomes as a method to stimulate macrophages to greater anticancer activity has also been tried. Such adjuvants may prove useful with genetically engineered or synthetic tumor-associated antigens, active specifi c immunotherapy, or immunoprophylaxis.

Multiple agents that appear capable of augmenting one or more immune functions already exist. Several of these have been associated with prolongation of sur-vival in prospectively randomized trials involving patients with a wide variety of malignancies (Table 2). Although some of these agents have produced modest clinical benefi ts, and do represent a potential method of immune augmentation, it is doubtful that they will have a major role in future cancer therapy. Great problems

Table 2. Biologicals and biological response modifi ers

Immunomodulating agentsAlkyl lysophospholipids (ALP)AzimexonBCGBestatinBrucella abortusCornyebacterium parvumCimetidineSodium diethyldithiocarbamate (DTC)EndotoxinGlucan‘Immune’ RNAsKrestinLentinanT-cell growth factors (‘TCGF’ – interleukin 2 [IL-2])LevamisoleMuramyldipeptide (MDP), tripeptide (MTP)Maleic anhydride-divinyl ether (MVE-2)Mixed bacterial vaccines (MBV)Nocardia rubra cell wall skeletons (CWS)Picibanil (OK432)Prostaglandin inhibitors (aspirin, indomethacin)ThiobendazoleTuftsin

Interferons and interferon inducersInterferons (α, β, γ)Poly IC-LCPoly A-UGE-132Brucella abortusTiloroneVirusesPyrimidinones

ThymosinsThymosin alpha-1Thymosin fraction 5Other thymic factors

Lymphokines, cytokines, growth/maturation factorsAntigrowth factorsChalonesColony-stimulating factors (CSF)Growth factors (transforming growth factor, TGF)Lymphocyte activation factor (LAF-interleukin 1 [IL-1])Lymphotoxins (TNF, α, β, LT)Macrophage activation factors (MAF)Macrophage chemotactic factorMacrophage cytotoxic factor (MCF)Macrophage growth factor (MGF)Migration inhibitory factor (MIF)Maturation factorsInterleukin 3–18, etc.Thymocyte mitogenic factor (TMF)Transfer factorTransforming growth factor (TFR, α, β)

AntigensTumor-associated antigensMolecular vaccinesCell-engineered cellular vaccines

Effector cellsMacrophagesNK cellsCytotoxic T cellsLAK cellsT helper cells

Miscellaneous approachesAllogeneic immunizationLiposome-encapsulated biologicalsBone-marrow transplantation and reconstitutionPlasmapheresis and ex vivo treatments (activation

columns, immunoabsorbents, and ultrafi ltration)Virus infection of cells (oncolysates)


exist for most of the agents, including lack of chemical defi nition, low purity, and poor reproducibility from one lot to another. An additional problem has been the inability to defi ne clearly a mechanism of action for these agents in humans. The preclinical screening established by the Biological Response Modifi ers Program (BRMP) of the National Cancer Institute was one mechanism to do this [31]. Data from this type of screening with subsequent phase I and phase II clinical data could have provided interesting insights and cor-relations [98, 104, 105]. Unfortunately, this approach has been abandoned.

The ability to specifi cally control and manipulate immune responses with highly purifi ed, defi ned mole-cules obtained by genetic engineering is the future. Thus, it seems probable that nonspecifi c immuno therapy as a sole modality has become obsolete, although as adjuvants some may fi nd a role in active specifi c immu-notherapy (Chapter 6).

Active Specifi c ImmunotherapyThere has been a substantial effort to produce active immunization of autochthonous or syngeneic hosts with irradiated or chemically modifi ed tumor cells in an attempt to use active specifi c immunotherapy (AST) [46]. Inherent is the assumption that tumor cells express immu-nogenic tumor-associated antigens (TAA). Treatment of tumor cells with a variety of unrelated agents, such as irradiation, mitomycin, lipophilic agents, neurominidase, viruses, or admixtures of cells with bacterial or chemical adjuvants, has produced non-tumoroigenic tumor cell preparations that are immunogenic upon injection into syngeneic hosts (Table 3).

AST using BCG-tumor cell (“antigens”) vaccines has been reevaluated using a syngeneic guinea pig hepato-carcinoma. The defi nition of several variables of vac-cine preparation, such as a ratio of bacterial organisms to viable, metabolically active tumor cells, the proce-dures of tumor cell dissociation and cryobiologic pres-ervation, and the irradiation attenuation of cells, has resulted in the development of an effective non-tumori-genic vaccine. It has proven effective in both micro- and macro-metastatic disease [47].

The nature of the anatomic alteration in metastatic nodules after AST was explored using a specifi c monoclonal antibody to assess vascular permeability within these tumor nodules [50, 51]. Immunohistologic analysis demonstrated signifi cantly more antibody in tumors from vaccinated animals than in comparable tumors from unvaccinated guinea pigs. These data sup-port the hypo thesis that the anatomic characteristics of tumor foci restrict drug and antibody access, thus pro-

tecting tumors not only from immunotherapy but from other forms of treatment as well [45].

Table 3. Studies of immunotherapy with random designs

Specifi c cancer and type of immunotherapy

Positive studies

Equivocal studies

Negative studies

LeukemiaBCG/AML +BCG/Cells/AML + +MER/AML +CP/Cells/AML +

All/Hodgkin’sNHL/MMLev/ALL +BDG/NHL +Lev/MM +

Lung cancerIT BCG + +IP BCG + +IP BCG & Lev +IP CP +Lev + +Thy Fr V +BCG/Cells +TAA/Freund’sAdjuvant +

Breast cancerPoly A/Poly U +BCG + +Lev +

Colon cancerBCG +MER +CP +Lev +

MelanomaIL/BCG +BCG/BCG + Cells + +BCG + +CP +Lev +

Genitourinary cancerIC BCG/bladder +BCG/prostate +

Gynecological cancerCP/cervix +CP/ovary +BCG/ovary +

Other cancersLev/H & N +CP/H & N +BCG/Cells/Sarcoma +MER/Neuroblastoma +

Robert K. Oldham 7

The regulation of the blood supply to neoplastic tissue may be unique in comparison to normal tissue. Tumor metastatic nodules may have a vascular “barrier,” which contributes to a limitation in delivery for chemothera-peutic agents, monoclonal antibodies, and immune effector cells. Such vascular barriers may provide an environment in which some tumor cells survive blood-borne chemotherapeutic and biologic agents. Thus, solid tumor nodules may serve as “pharmacologic sanctuaries,” allowing even drug-sensitive tumor cells to continue to grow [45–47].

Hanna and co-workers [47] demonstrated that strategi-cally timed chemotherapy subsequent to immunotherapy can effectively double the number of survivors attainable with immunotherapy alone. This effect was not drug spe-cifi c. These results suggest a new basis for AST in the treat-ment of solid tumors. Infl ammatory disruption of anatomic barriers of metastatic nodules combined with strategically administered chemo therapy or biotherapy may prove use-ful in the design of future biotherapy trials in humans.

Another approach used more recently involves the deliv-ery of lymphokines and cytokines, such as interleukins, colony stimulating factors, tumor necrosis factor, lympho-toxins, macrophage cytotoxic factors, and activated com-plexes (such as those generated by plasma perfusion over protein A columns) to the tumor and its vascular bed. These substances are known to have powerful effects on tumor vasculature and cellular infi ltrations, something leading to tumor necrosis. This approach may, in addition, increase the access of antibody, immunoconjugates, drugs, and acti-vated cells to the cancer nodule [45].

A more recent method to infl uence the blood supply of tumor nodules has been the use of a monoclonal anti-body, Bevacizumab, which targets the vascular endothe-lial growth factor (VEGF) receptor. Bevacizumab is primarily used with chemotherapy, and it may be there are similar mechanisms at play with regard to increasing chemotherapy drug access to tumor nodules by the use of a monoclonal antibody targeting the VEGF receptor [38, 49, 52].

A major limitation of AST has been the availability of purifi ed TAA. Whereas whole cell vaccine preparations contain viable, non-tumorigenic cells prepared from individual tumors, purifi ed TAA is now prompting large-scale immunization. TAA purifi cation and characteriza-tion followed by genetic engineering of the antigen for vaccine production is underway and several purifi ed antigens are in clinical trials, especially in melanoma. Alternatively, synthetic peptide sequences of the active portion of TAA may prove useful in the near future. Even the combining site of antibody to TAA has recently been suggested as a potential vaccine. These technologies

are now undergoing extensive preclinical and clinical evaluation (see Chapter 7).

Thymic FactorsIt has been known for years that thymic extracts have immunological activity [40, 41]. Thymosin fraction 5 and thymosin alpha-1 have received the most attention in the laboratory and the clinic. Thymosin fraction 5 is an extract containing a variety of thymic polypeptides, and alpha-1 is a synthetic polypeptide component present in many thy-mic extracts. Thymic preparations have been shown to enhance and suppress immune responses in both intact and thymectomized animals. Many investigators have reported that the thymosins can correct selected immuno-defi ciency states, both natural and experimentally induced. There have also been reports that thymic factors can aug-ment suppressed or depressed T-cell responses in patients with cancer. Studies in preclinical screening have demon-strated stimulation of T-cell activity [99], but clinical stud-ies have not shown striking effects [25, 98, 99], and none have been approved for clinical use.

Recombinant DNA TechnologyRecombinant DNA technology, commonly referred to as genetic engineering, has provided us with the tool for the biosynthesis and subsequent mass production of a sig-nifi cant number of biologicals [8, 29, 39]. This is highly relevant to lymphokines/cytokines as well as growth and maturation factors, and should revolutionize the treat-ment of cancer over the next 10 years. The process involves the incorporation (recombination) of a segment of a DNA molecule containing a desired gene into a vec-tor, usually a plasmid, which in turn is inserted into a host organism, usually an Escherichia coli, although other bacteria, yeasts, insects, and mammalian cells have been utilized. The cells are cloned and the cells produc-ing the desired protein or polypeptide are selected. This clone is mass produced using fermentation techniques, and the protein molecule is harvested and purifi ed. The resultant product is a highly purifi ed (95–99%) protein solution, and has a high specifi c activity (i.e., biological activity per weight of protein).

The relevant DNA can be obtained by a variety of methods. Once messenger RNA (mRNA) is isolated, complementary DNA (cDNA) can be produced through the use of reverse transcriptase. Alternatively, an artifi cial DNA molecule can be constructed once the nucleotide or amino acid sequence is known. This can be used to isolate the complementary sequence, which is then isolated and cloned. RNA molecules can also be used in cell-free systems


to produce these biologicals. There are over 200 restric-tion enzymes that can cut desired fragments of DNA and lead to their isolation. These enzymes can uniquely cleave a DNA molecule at specifi c, predictable sites relative to the nucleotide sequence. These fragments are then incor-porated into the plasmid, and combine with plasmid DNA. Plasmids have a symbiotic relationship with selected bacteria inducing resistance to a variety of anti-biotics, which allows for selection of engineered clones. A number of alpha interferons, as well as beta and gamma interferon, have been genetically engineered [24, 39, 106, 111]; multiple interleukins, colony-stimulating factors, and tumor necrosis factor have been cloned [107]. The number of cloned biological products increases yearly (see Chapter 4). These biological products and their receptors (Table 4) are rapidly being translated into high-quality pharmaceuticals for clinical testing and approval for general use.

Lymphokines/CytokinesLymphokines and cytokines are molecules secreted by a variety of cells (Table 4). They provide one means through which the cells involved in the immune process communicate with one another and direct the overall process [40]. Lymphokines/cytokines with specifi c effects on cell proliferation have been identifi ed and may prove useful as anticancer agents. Interleukins (IL) 1–32 are among the multiple lymphokines that appear to be involved in a cascade phenomenon leading to the induction of a variety of immune responses [86]. Other examples include multiple subclasses of colony-stimu-lating factors (CSF) chemokines and ligands. The list of lymphokines/cytokines is long, and the potential for therapeutic manipulation is great [73, 74]. The identifi -cation of these biological activities is the start of a pro-cess that should ultimately provide us with the knowledge and the tools to identify more accurately and control a number of immune responses. Physicians may then be able to manipulate the immune system (Fig. 1) intelli-gently, in favor of the host. Further, by selective activation

and subsequent cloning in vitro, T-cell lines with spe-cifi c cytotoxic and helper capabilities can be obtained and utilized in autologous and allogeneic adoptive immunotherapy [16, 27, 93, 103, 112].

Many investigators have held the rather simplistic view that the immune system (Fig. 1) might be manipu-lated in vivo and corrected to better deal with the cancer problem. Evidence to date suggests that the pharmaco-logic use of biologicals, in rather high doses, is a more effective method for cancer treatment, with immunoac-tivation and immunomodulation, playing the dominant roles [69, 70].

Another specifi c use of lymphokines may be in the pharmacological regulation of tumors of the lymphoid sys-tem. Although many of these tumors are considered to be generally unresponsive to normal growth- controlling mechanisms mediated by lymphokines, it is possible that large quantities of pure lymphokines administered as medicinals, or the use of certain molecular analogs of these naturally occurring lymphokines, may be useful in the treatment of lymphoid malignancies.

The use of certain lymphokines/cytokines has been extended to other cancers, in that in vitro observations suggest an antiproliferative activity in some solid tumors. These antiproliferative effects might be maxi-mized by testing the tumor cells of each patient to “cus-tom tailor” the treatment rather than giving these biologicals as general treatment, as has been done with anticancer drugs [70].

IL-1, originally known as lymphocyte activating fac-tor, is a macrophage-derived cytokine that has an enhancing effect on murine thymocyte proliferation. Both IL-1 and viable macrophages are necessary for the initial step in activation of IL-2 (Fig. 2). Cloning of IL-1 and IL-2 has made large quantities of highly purifi ed materials available for clinical studies.

Preclinical studies with IL-2 have been oriented around in vitro cell production protocols and induction or mainte-nance of antitumor T-cell effects in vivo [15, 16, 67, 70]. IL-2 has been used to activate peripheral blood cells and initially stimulated much interest [93, 104]. These acti-vated cells are generally more cytotoxic against cancer cells than normal cells; however, their lineage can be T cell or NK cell (LAK cells) depending on the technique employed. This approach, though expensive and techni-cally demanding, illustrates that cellular therapy is feasible and can be effective [67, 70, 85, 103].

A lymphotoxic product of antigen/mitogen- stimulated leukocytes was called lymphotoxin [92]. Lymphotoxin may be a principle effector of delayed hypersensitivity and, although confl icting data have been reported, may also be involved in the cytoxic reactions of T-cell-mediated

Table 4. Clinical lymphokines/cytokines

Colony-stimulating factorsErythropoietinInterferons: α, β, γInterleukins 1–32, etc.Lymphotoxincs: α, β (TNF)Macrophage-activating factorsThymosinsTransfer factor(s)

Robert K. Oldham 9

lysis and NK- or K-cell lysis. Depending upon the type of tumor cell involved, the in vitro effect of lymphoto-xin may be either cytolytic or cytostatic. Mouse tumor cells are frequently killed by homo logous and heterolo-gous lymphotoxins, whereas in other species reversible inhibition of tumor cell proliferation is more common [48].

Human lymphotoxin is of at least two species, alpha and beta [30, 37, 60, 88, 108]. Alpha lymphotoxin is tumor necrosis factor (TNF). Both have been cloned, and TNF has undergone rather extensive clinical trials [31, 91, 101]. While some antitumor responses have been seen, the lymphotoxins have not been highly effi cacious as single agents in the treatment of advanced human tumors and the toxicity of systemic administration has been unacceptable. Continued trials are underway com-bining lymphotoxins such as TNF with other lym-phokine/cytokines and with chemotherapy. Targeted delivery of these molecules may prove more effi cacious since they have high toxicity administered intravenously with what is probably minimal delivery to the tumor cell

site [60, 28]. Thus, intratumoral and regional perfusion studies with TNF have yielded positive results in patients with melanoma and sarcoma [17, 53, 59, 60, 90].

There is now evidence that the combined use of various lymphokines may produce enhanced anti proliferative effects. Selective assays for lymphokine antiproliferative cocktails may prove useful in “tailoring” such preparations for individual patients [6, 95, 97, 102, 100, 110].

More than 100 biological molecules have already been described and named as lymphokines/cytokines (Table 5). Biologicals such as the interferons, lymphotoxins, TNF, CSF, IL-1–22 are now under evaluation (see Chapter 8). The studies require quantities of material obtained through genetic engineering, using sensitive and rapid assay procedures to monitor production, purifi cation, and bioavailability.

InterferonsInterferons are small, biologically active proteins with antiviral, antiproliferative, and immunomodulatory

Figure 1. Immune response


activities (see Chapter 9). Each interferon has distinctive capabilities in altering a variety of immunological and biological responses. As a class, the interferons appear to have some growth- regulating capacity in that antiproliferative effects are measur-able with in vitro assays and in animal model systems. The relative effi cacy of the mixtures of natural inter-ferons that occur after virus stimulation as compared to the cloned interferons remains to be precisely deter-mined. There are more than 20 interferon molecules (and theoretically hundreds of recombinant hybrids there from), and efforts are underway altering individ-ual interferon molecules in specifi c ways, so the range of biological activities of the interferons as antiviral agents, as immunomodulating agents, and as antipro-liferative agents may be very broad [66, 69].

In addition to antiviral and antiproliferative activity, the interferons have profound effects on the immune system. Low doses enhance antibody formation and lymphocyte blastogenesis, while higher doses inhibit

these functions. Low to moderate doses may inhibit delayed hypersensitivity while enhancing macrophage phagocytosis and cytotoxicity, natural killer activity, and surface antigen expression. Interferons prolong and inhibit cell division (both transformed and normal cells). In addition, interferons stimulate the induction of sev-eral intracellular enzyme systems with resultant pro-found effect on macromolecular activities and protein synthesis.

We can draw some preliminary conclusions about interferon therapy for human cancer [9, 36, 43, 44, 57, 69, 96] (Tables 6 and 7). One is that the Cantell, lym-phoblastoid, and recombinant alpha-interferons are surprisingly similar, both quantitatively and qualita-tively, in their toxicity, antitumor effi cacy, and other biologic effects. Second, objectively defi ned antitumor responses in phase I alpha-interferon trials (mostly involving lymphoma, myeloma, Kaposi’s sarcoma, melanoma, and renal cancer) were observed in approx-imately 10% of all patients treated. That level of activ-ity may not seem impressive, but it does exceed the average response rate of 1–2% in phase I trials of che-motherapeutic agents. We should also note that very few responses in patients with tumors of the breast, colon, lung, or lower genitourinary system have been seen with alpha- interferon as a single agent. Overall, even though interferons have toxicities, they were more tolerable and less permanent than those observed in early-phase chemotherapy testing.

A third impression, suggested by increased response rates with higher alpha-interferon doses, is that interferons may produce their acute antitumor effect by a direct cytostatic action, rather than an indirect immu-nomodulatory mechanism [12, 23, 57, 66, 69, 72, 98]. Finally, clinical experience with beta- and gamma- interferons indicated that both produce response rates and response patterns similar to those obtained with alpha-interferon, although beta- interferon is only approved for multiple sclerosis and gamma only for chronic granulomatous disease. What is clear from the current preclinical and clinical studies is that the inter-ferons have antitumor activity even in bulky, drug-resis-tant cancers [102]. Clinical activity has been seen most reproducibly in several lymphomas and leukemias (Table 6), but responses in many other tumor types with approval in melanoma and renal cancer [36].

Growth and Maturation FactorsUsing technology similar to that employed for lymphokine/cytokines, scientists have cloned and pro-duced a variety of growth and maturation factors. The

Figure 2. Model for interleukin stimulation of T-cell immune responses

Monocytic Macrophage

Ag StimulatedT Cell

? CSF

Activated Macrophage

IL-1

Activated T cells Ag Stimulated T cell

IL-2

Effector T cell Precursor

Mature Effector T Cells

Robert K. Oldham 11

clinical trials have focused mainly on erythropoietin and the colony-stimulating factors. The former is a drug now approved for use in refractory anemia, and GM-CSF and GCSF are approved for the treatment of bone marrow dysplasia and chemotherapy-induced marrow suppres-sion. Oprelvekim to stimulate platelet production is now approved. These factors are reviewed in later chapters, but it should be noted that they represent only the early beginnings of the very broad fi eld of growth and matu-

ration factors (See Chapter 16). It is now clear that a variety of biological substances up- and down-regulate growth of both normal and neo plastic cells. These sub-stances may stimulate or inhibit growth and may change the maturation cycle of various normal and neoplastic cells. Contained within this broad category of factors are the tumor growth factors, colony-stimulating fac-tors, and a variety of still to be defi ned factors important in the regulation of cell growth and maturation. Future

Helper factorsLAF (lymphocyte-activating factor, IL-1)NMF (normal macrophage factor)BAF (B-cell-activating factor)TRF (T-cell-replacing factor)MP (mitogenic protein)TDF (thymus differentiation factor)TransferrinMF (mitogenic [blastogenic] factor)NSF (nonspecifi c factor)TDEF (T-cell-derived enhancing factor)TEF (thymus extracted factor)Complement componentsDSRF (defi cient serum-restoring factor)

Suppressor factorsInhibitor(s) of DNA synthesisAIM (antibody-inhibitory material)IDA (inhibitor of DNA synthesis)LTF (lymphoblastogenesis inhibition factor)FIF (feedback inhibition factor)MIFIF (Mif inhibition factor)SIRS (soluble immune response suppressor)IRF (immunoregulatory gamma-globulin)ChalonesIF (interferons)AFP (alpha-fetoprotein)LDL (low-density lipoproteins)CRP (C-reactive protein)Fibrinogen degradation productsNIP (normal immunosuppressive protein)LMWS (low-molecular-weight suppressor)HSF (histamine-induced suppressor factor)TCSF (T-cell suppressive factor)

Factors acting on infl ammatory cellsMIF (migration inhibitory factor)MCF (macrophage chemotactic factor)MSF (macrophage slowing factor)MEF (migration enhancement factor)MAF (macrophage activating factor)MFF (macrophage fusion factor)PRS (pyrogen-releasing substance)LIF (leukocyte inhibition factor)NCF (neutrophil chemotactic factor)PAR (products of antigenic recognition)BCF (basophil chemotactic factor)ECF (eosinophil chemotactic factor)

ESP (eosinophil stimulation factor)LCF (lymphocyte chemotactic factor)LTF (lymphocyte trapping factor)

Factors acting on vascular endotheliumSRF (skin reactive factor)TPF (thymic permeability factor)LNPF (lymph node permeability factor)LNAF (lymph node activating factor)AIPF (anaphylactoid infl ammation promoting factor)IVPF (increased vascular permeability factor)

Factors acting on other cellsInterferonsTMIF (tumor cell migration inhibition factor)OAF (osteoclast activating factor)Fibroblast chemotactic factorPyrogensFAF (fi broblast activating factor)

Growth-stimulating factorsBCGF (B-cell growth factor)BCDF (B-cell differentiation factor)MGF (macrophage growth factor)MF (mitogeni [blastogenic] factor)LIAF (lymphocyte-induced angiogenesis factor)CSF (colony-stimulating factor)TDF (thymus differentiation factor)Thymopoietin, thymosinTCGF (T-cell growth factor, IL-2)IL-3 (interleukin 3)EGF (epidermal growth factor)

Direct-acting factorsLysosomal enzymesCTF (cytotoxic factors)MTF or MCF (macrophage toxic [cytotoxic] factor)SMC (specifi c macrophage cytotoxin)MCF (macrophage cytolytic factor)ACT (adherent cell toxin)Chromosomal breakage factorsMicrobicidal factorsLT (lymphotoxin)PIF (proliferation inhibitory factor)CIF (cloning inhibition factor)IDS (inhibitor of DNA synthesis)Transforming factorsTNF (tumor necrosis factor)

Table 5. Antigen-nonspecifi c mediators,a unrestricted by MHC

a These names/factors are based on biological activity. Several may represent the activity of a single molecule.


therapeutic use of these factors may regulate growth and spread of cancer. Such a chronic growth restraining strategy may not “cure” cancer; rather treatment may be more analogous to using insulin in diabetes. This is a fi eld that is under going explosive growth and should be watched carefully over the coming decade for molecules with therapeutic activity.

Monoclonal AntibodiesThe advent of hybridoma technology in the late 1970s made available an important tool for the production of monoclonal antibodies for therapeutic trials [10] (see Chapter 10). These antibodies are now being produced in huge quantities and in highly purifi ed form for cancer treatment. The humanization of murine antibody combin-ing sites has yielded a whole new class of therapeutic anti-bodies [84]. They will undoubtedly defi ne a new range of

antigens on the cell surfaces, which will improve our understanding of cell differentiation and of cancer biol-ogy. Major problems in understanding the biology of the cancer cell have been the diffi culties of isolating, purify-ing, and characterizing tumor- associated antigens (TAA). The use of monoclonal antibody technology will improve the defi nition of the neoplastic cell surface and identify its differences from the normal counterpart. This will be of great value in cancer diagnosis and histopathologic classifi cation, and will be useful in the imaging of tumor cell masses and in the therapy of cancer [1, 7, 13, 14, 32, 33, 34, 35, 50, 51, 55, 63, 75, 84, 89]. Finally, antibodies may be a useful reagent in treating certain immune defi -ciencies and in altering immune responses. The removal of T cells from bone marrow to improve bone marrow transplantation techniques is an example of using anti-body as a BRM [63]. A more recent example is the use of anti-CTLA-4 antibodies to regulate the immune response. Two monoclonal antibodies are in develop-ment that have infl uence on T-regulatory cells, which infl uence the immune response to cancer. It is already clear that this class of monoclonal antibodies can infl u-ence T-regulatory cells in a yet undefi ned manner, such that regression of bulky melanoma can occur. At the same time, they give a range of interesting toxicities with regard to uveitis, colitis, and depigmentation syndromes relative to their use in melanoma [26].

In spite of encouraging data from the use of anti-bodies and, especially, immunoconjugates to target toxic substances to cancer, the heterogeneity of cancer is an important consideration [2, 71–78, 87]. If a sin-gle antibody or a fi xed combination of a few antibod-ies covering only a portion of the tumor cells is used, and if that preparation does not eliminate the true rep-licating cell population (stem cell) from the patient’s tumor population, eventual outgrowth of viable, per-haps resistant cells is inevitable. Therefore, it seems logical to proceed with attempts to type human tumors and to deliver toxic substances to them utilizing “cock-tails” of antibodies suffi cient to cover all the tumor cells suspected of replication in each patient. This type of approach may require a considerable amount of testing for each patient and a “typing” of one or more tumors from each patient [3, 58, 62, 78, 79, 87]. Such approaches may be more individually designed than is easily approachable through the product devel-opment paradigm that has been used in the develop-ment of new anticancer drugs. If however, the spectrum of human tumor heterogeneity is great, the goal of the ideal antibody conjugated to the ideal toxic agent may not be achievable.

Table 6. Apha-interferon activitya

ActiveHairy-cell leukemiaChronic myelogenous leukemiaMyeloproliferative disordersNon-Hodgkin’s lymphomaCutaneous T-cell lymphomaKaposi’s sarcomaMultiple myelomaMelanomaRenal cell carcinomaBladder cancer (intravesical)

InactiveBreast cancerColon cancerLung cancerProstate cancerAcute myelogenous leukemia

a As a single agent.

Table 7. Malignancies: Summary of responses to alpha-interferon with date of FDA approvalTumor type Response rate (%) ApprovedMultiple myeloma 18–27Hairy cell leukemia 80–90 1986Low-grade lymphoma 38–73 1997High-grade lymphoma 0–10Kaposi’s sarcoma 25–40 1988Chronic myelogenous leukemia

80–90 1995

Melanoma 20–30 1995Renal cancer 10–20

Robert K. Oldham 13

Future PerspectivesHow rapidly will biotherapy develop and what role will it have in cancer treatment in the next decade? It is cer-tain that we now have much more powerful tools for improving cancer therapy in the future. We now have the techniques to decipher the major problems in cancer biology down to the genetic level. These techniques, along with the recognition that biotherapy can provide increased selectivity in cancer treatment, support the belief that new and highly effective approaches are near. Biotherapy provides an additional technique, which may work effectively in combination with surgery or radiotherapy (to decrease the local and regional tumor) or with chemotherapy (to reduce the systemic tumor burden). It may work very effectively via antibodies in directing radioisotopes selectively to the tumor site, and with chemotherapy, toxins, and other cytostatic or cyto-toxic molecules in directing the agent to the tumor bed, enhancing activity and selectivity.

The use of biotherapy is at an early stage. We have already seen that highly purifi ed biologicals can be effec-tive in patients with clinically apparent, even advanced, bulky cancer. Clinical studies with alpha- interferon have demonstrated the responsiveness of radiation- and drug-resistant lymphoma, melanoma, and renal carcinoma. IL-2 with effector cells or alone (in high doses) produces partial and complete remissions in melanoma and kidney cancer. These results, along with the clinical results using monoclonal antibody alone and conjugated to toxic sub-stances in selected cancers (lymphoma, melanoma, gas-trointestinal, leukemia and breast cancer), confi rm the concept that we need not think of biotherapy as a tool that can be used only in patients with undetectable and mini-mal residual tumor burdens [84]. While this modality may work best with minimal tumor burdens (a situation that is also true for chemotherapy), biotherapy can be used as a single modality in clinically apparent disease. It may be even more effective in multimodality treatment regimens. Biotherapy offers the hope for selective treat-ment to enhance the therapeutic/toxic ratio and lessen the problem of nonspecifi c toxicity, a major impediment to the development of more effective cancer treatment.

This decade will provide many opportunities to pursue new approaches in cancer treatment. These approaches will employ new techniques in the laboratory and clinic, requiring special training and expertise. The medical oncologist trained in the administration of che-motherapy drugs, is not necessarily well prepared to give biologicals for cancer treatment. Biotherapy uses biological substances that are often active on, or work in

association with, the immune system. The tremendous diversity of this system is best understood by clinical immunologists and cell biologists who are well suited to assist in the translation of biotherapeutic approaches to the clinic.

Given these new techniques and new approaches, we must redesign many of the mechanisms for develop-mental therapeutics [59]. It may well be that the speci-fi city of biologicals will require that biotherapy be developed in an individualistic fashion and applied to each patient in a specifi c, personalized way. This con-cept was conceptualized in 1977 by the Nobel laureate Sir Peter Medawar:

The cure of cancer is never going to be found. It is far more likely that each tumor in each patient is going to present a unique research problem for which laboratory workers and clinicians between them will have to work out a unique solution.

References 1. Abrams P, Oldham RK. Monoclonal antibody therapy of solid

tumors. In: Foon KA, Morgan AC, Jr., eds. Monoclonal antibody therapy of human cancer. The Hague: Martinus Nijihoff, 1985; 103–120.

2. Abrams PG, Morgan AC, Schroff RW, et al. Monoclonal antibod-ies in cancer therapy: Drug-antibody conjugates. In: Reisfeld RA, Sell S, eds. Localization and biodistribution studies of a monoclo-nal antibody in patients with melanoma. New York: Alan R. Liss, 1985; 27:233–236.

3. Avner BP, Liao SK, Avner B, et al. Therapeutic murine monoclo-nal antibodies developed for individual cancer patients. J Biol Response Modif 1989; 8(1):25–36.

4. Baldwin, RW. Relevant animal models for immunotherapy. Cancer Immunol Immunother 1976; 1:97–206.

5. Balkwill FR, Burke F. The cytokine network. Immunol Today 1989; 10(9):29–304.

6. Balkwill FR, Lee A, Aldam G, et al. Human tumor xenografts treated with recombinant human tumor necrosis factor alone or in combination with interferons. Cancer Res 1986; 46:3990–3993.

7. Bernhard MI, Foon KA, Oeltmann TN, et al. Guinea pig line 10 hepatocarcinoma model: characterization of monoclonal antibody and in vivo effect of unconjugated antibody and antibody conjugated to diphtheria toxin A chain. Cancer Res 1983; 43:4420–4428.

8. Bollon AP, Barron EA, Berent SL, et al. Recombinant DNA tech-niques: Isolation, cloning and expression of genes. In: Bollon AP, ed. Recombinant DNA products: Insulin interferon and growth hormone. Boca Raton, Florida: CRC Press, 1984; 1–35.

9. Bonnem EM, Spregel RJ. Interferon-alpha: Current status and future promise. J Biol Response Modif 1984; 3:580.

10. Boss BD, Langman R, Trowbridge I, Dulbecco R, eds. Monoclonal antibodies and cancer. New York: Academic Press, 1983; 1–200.

11. Boyd MR. Status of the NCI preclinical antitumor drug discovery screen. Prin Pract Oncol Suppl 1989; 3(10):1–12.

12. Bunn PA, Foon KA, Ihde DC, et al. Recombinant leukocyte A interferon: An active agent in advanced cutaneous T-cell lympho-mas. Ann Intern Med 1984; 101:484–487.


13. Carrasquillo JA, Bunn PA, Jr., Kennan AM, et al. Radioimmunodetection of cutaneous T-cell lymphoma with 111In-T101 monoclonal antibody. New Engl J Med 1986; 315:673–680.

14. Carrasquillo JA, Abrams PG, Schroff R, et al. Effect of antibody dose on the imaging and biodistribution of indium-111 9.2.27 anti-melanoma monoclonal antibody. J Nucl Med 1988; January, 29(1):39–47.

15. Cheever MA, Greenberg PD, Fefer A, Gillis S. Augmentation of the antitumor therapeutic effi cacy of long-term cultured T lympho-cytes by in vivo administration of purifi ed interleukin-2. J Exp Med 1982; 155:968–980.

16. Cheever MA, Greenberg PD, Fefer A. Potential for specifi c cancer therapy with immune T lymphocytes. J Biol Response Modif 1984; 3:113–127.

17. Cumberlin R, DeMoss E, Lassus M, Friedman M. Isolation perfu-sion for malignant melanoma of the extremity: A review. J Clin Oncol 1985; 3:1022–1031.

18. DeVita VT. Progress in cancer management: Keynote address. Cancer 1983; 51:2401–2409.

19. DeVita VT. The relationship between tumor mass and resistance to chemotherapy: Implication for surgical adjuvant treatment of can-cer. Cancer 1983; 51:1209–1220.

20. DeVita VT, Hellman S, Rosenberg SA, eds. Important advances in oncology 1989. New York: J.B. Lippincott, 1995; 1–118.

21. DeVita VT, Jr., Hellman S, Rosenberg SA, eds. In: Biologic ther-apy of cancer, second edition. Philadelphia, Pennsylvania: J.B. Lippincott, 1995; 295–327.



24. Devos R, Cheroutre H, Taya Y, et al. Molecular cloning of human immune interferon cDNA and its expression in eukaryotic cells. Nucl Acids Res 1982; 10:2487–2501.

25. Dillman RO, Beauregard JC, Mendelsohn J, et al. Phase I trials of thymosin fraction 5 and thymosin alpha-1. J Biol Response Modif 1982; 1:35–41.

26. Dudley ME, Wunderlich JR, Yang JC, et al. Adoptive cell transfer therapy following non-ablative but lymphodepleting chemother-apy for the treatment of patients with refractory metastatic mela-noma. J Clin Onc 2005; 23:2346–2357.

27. Eberlein TJ, Rosenstein M, Spiess P, et al. Adoptive chemoimmu-notherapy of a synergeneic murine lymphoma with long-term lym-phoid cell lines expanded in T-cell growth factor. Cancer Immunol Immunother 1982; 13:5–13.

28. Eggermont AM, Schraffordt Koops H, Klausner JM, et al. Isolated limb perfusion with tumor necrosis factor and for limb salvage in 186 patients with locally advanced extremity sarco-mas. The cumulative multicenter Euro experience. Ann Surg Dec, 1996; v.224(6).

29. Emery AEH. Recombinant DNA technology. Lancet 1981; 2:1406–1409.

30. Evans CH, Lymphotoxin: An immunologic hormone with anticar-cinogenic and antitumor activity. Cancer Immunol Immunother 1982; 12:181–190.

31. Feinberg B, Kurzrock R, Talpaz M, et al. A phase I trial of intrave-nously-administered recombinant tumor necrosis factor-alpha in cancer patients. J Clin Oncol 1988; 6:1328–1334.

32. Fidler IJ, Gersten DM, Hart IR. The biology of cancer invasion and metastasis. Adv Cancer Res 1978; 28:149–250.

33. Fidler IJ, Berendt M, Oldham RK. The rationale for and design of screening assays for the assessment of biological response modi-fi ers for cancer treatment. J Biol Response Modif 1982; 1:15–26.

34. Foon KA, Bernhard MI, Oldham RK. Monoclonal antibody ther-apy: Assessment by animal tumor models. J Biol Response Modif 1982; 1:277–304.

35. Foon KA, Schroff R, Bunn PA, et al. Effects of monoclonal anti-body therapy in patients with chronic lymphocytic leukemia. Blood 1984; 64:1085–1093.

36. Foon KA, Sherwin SA, Abrams PG, et al. Treatment of advanced non-Hodgkin’s lymphoma with recombinant leukocyte A inter-feron. N Engl J Med 1984; 311:1148–1152.

37. Gamm H, Lindemann A, Mertelsmann R, Herrmann F. Phase I trial of recombinant human tumour necrosis factor α in patients with advanced malignancy. Eur J Cancer 1991; 27:856–863.

38. Giantonio BJ, Catalano PJ, Meropol NJ, et al. Bevacizumab in combination with oxaliplatin, fl uorouracil and leucovorin (FLOFOX4) for previously treated metastatic colorectal cancer: Results from the Eastern Cooperative Oncology Group Study E3200. J Clin Oncol 2007; 25:1539–1544.

39. Goeddel DV, Yelverton E, Ullrich A, et al. Human leucocyte inter-feron produce by E. coli is biologically active. Nature 1980; 287:411–416.

40. Goldstein AL, Chirigos MA, eds. Lymphokines and thymic hor-mones; their potential utilization in cancer therapeutics. Progress in cancer research and therapy, vol. 20. New York: Raven Press, 1981.

41. Goldstein AL, Chirigos MA. In: Progress in cancer research and therapy, vol. 20. New York: Raven Press, 1982; 1–324.

42. Gray PSW, Leung DW, Pennica D, et al. Expression of human immune interferon cDNA in E. coli and monkey cells. Nature 1982; 295:503–508.

43. Grem JL, Hoth D, Hamilton MJ, et al. An overview of the current status and future direction of clinical trials of 5-fl uorouracil and folinic acid. Cancer Treat Rep 1987; 71:1249–1264.

44. Grem JL, McAtee N, Murphy RF, et al. A pilot study of interferon alfa-2a in combination with fl uorouracil plus high-dose leucovorin in metastatic gastrointestinal carcinoma. J Clin Oncol 1991; 9:1811–1820.

45. Hanna MG, Key ME, Oldham RK. Biology of cancer therapy: Some new insights into adjuvant treatment of metastatic solid tumors. J Biol Response Modif 1983; 4:295–309.

46. Hanna MG, Jr., Brandhorst JS, Peters LC. Active specifi c immuno-therapy of residual micrometastasis: An evaluation of sources, doses and ratios of BCG with tumor cells. Cancer Immunol Immunother 1979; 7:165–174.

47. Hanna MG, Jr., Key ME. Immunotherapy of metastases enhances subsequent chemotherapy. Science 1982; 217:367–370.

48. Haranaka K. Macrophage Symposium 1987, Tumor Necrosis Factor. Japan, January 5–8, 1987.

49. Hurwitz H, Fehrenbacher L, Novotny W, et al. Bevacizumab plus irinotecan, fl uorouracil and leucovorin for metastatic colorectal cancer. N Engl J Med 2004; 350:2335–2342.

50. Hwang KM, Foon KA, Cheung PH, et al. Selective antitumor effect on L-10 hepatocarcinoma cella of a potent immunoconjugate composed of the A chain of abrin and a monoclonal antibody to a hepatoma-associated antigen. Cancer res 1984; 44:4578–4586.

51. Hwang KM, Keenan AM, Frincke J, et al. Dynamic interaction of 111 indium-labeled monoclonal antibodies with surface of solid tumors visualized in vivo by external scintigraphy. J Natl Cancer Inst 1986; 76:849–855.

52. Kavvinaran FF, Hambleton J, Mass RD, et al. Combined analysis of effi cacy: The addition of bevacizumab to fl uorouracil/leucovorin

Robert K. Oldham 15

improves survival for patients with metastatic colorectal cancer. J Clin Oncol 2005; 23:3706–3712.

53. Kahn JO, Kaplan LD, Volberding PA, et al. Intralesional recombi-nant tumor necrosis factor-α for AIDS-associated Kaposi’s sar-coma. A randomized, double-blind trial. J Acquir Immune Defi c Syndr 1989; 2:217–223.

54. Kallman RF, ed. Rodent tumor models in experimental cancer therapy. New York: Pergamon Press, 1987; 1–310.

55. Key ME, Bernhard MI, Hoyer LC, et al. Guinea pig 10 hepatocar-cinoma model for monoclonal antibody serotherapy: In vivo local-ization of a monoclonal antibody in normal and malignant tissues. J Immunol 1983; 139:1451–1457.

56. Key ME, Brandhorst JS, Hanna MC, Jr. Synergistic effects of active specifi c immunotherapy and chemotherapy in guinea pigs with disseminated cancer. J Immunol 1983; 130:2987–2992.

57. Kirkwood JM, Ernstoff MS. Interferon in the treatment of human cancer. J Clin Oncol 1984; 2:336–352.

58. Liao SK, Meranda C, Avner BP, et al. Immunohistochemical phe-notyping of human solid tumors with monoclonal antibodies in devising biotherapeutic strategies. Cancer Immunol Immunother 1989; 28:77–86.

59. Lienard D, Ewalenko P, Delmitti JJ, et al. High-dose recombinant tumor necrosis factor alpha in combination with interferon gamma and melphalan in isolation perfusion of the limbs for melanoma and sarcoma. J Clin Oncol 1992; 10:52–60.

60. Mavligit GM, Zukiwski AA, Charnsargavej C. Regional biologic therapy: Hepatic arterial infusion of recombinant human tumor necro-sis factor in patients with liver metastases. Cancer 1992; 69:557–561.

61. McCormick DL, Adamowski CB, Fiks A, Moon RC. Lifetime dose-response relationships for mammary tumor induction by a single administration of N-methyl-N-nitrosourea. Cancer Res 1981; 41:1690–1694.

62. Ogden JR, Leung K, Kundra SA, et al. Immunoconjugates of dox-orubicin and murine antihuman breast carcinoma monoclonal anti-bodies prepared via an n-hydroxysuccinimide active ester intermediate of cis-aconityl-doxorubicin: Preparation and in vitro cytotoxicity. Mol Biother 1989; 1(3):170–174.

63. Oldham, RK. Monoclonal antibodies in cancer therapy. J Clin Oncol 1983; 1:582–590.

64. Oldham RK. Biologicals: New horizons in pharmaceutical devel-opment. J Biol Response Modif 1983; 2:199–206.

65. Oldham RK. Biologicals and biological response modifi ers: New strategies for clinical trials. In: Finter NB, Oldham RK, eds. Interferons IV. Amsterdam: Elsevier Science, 1985; 235–249.

66. Oldham RK. Interferon: A model for future biological. In: Burke D, Cantell K, Gresser I, DeMaeyer E, Landy M, Revel M, Vilcek J, eds. Interferon VI. New York: Academic Press, 1985; 127–143.

67. Oldham RK. In vivo effects of interleukin 2. J Biol Response Modif 1984; 3:455–532.

68. Oldham RK. Biologicals and biological response modifi ers: The fourth modality of cancer treatment. Cancer Treatment Rep 1984; 68:221–232.

69. Oldham RK. Biologicals for cancer treatment: Interferons. Hospital Pract 1985; 20:72–91.

70. Oldham RK. Biotherapy: The fourth modality of cancer treatment. J Cell Physiol Suppl 1986; 4:91–99.

71. Oldham RK, Smalley RV. Immunotherapy: The old and the new. J Biol Response Modif 1983; 2:1–37.

72. Oldham RK, Smalley RV. The role of interferon in the treatment of cancer. In: Zoon KC, Noguchi PC, Lui T-Y, eds. Interferon: Research, clinical application and regulatory consideration. Amsterdam: Elsevier Science, 1984; 191–205.

73. Oldham RK, Smalley RV. Biological and biological response modifi ers. In: DeVita VT, Hellman S, Rosenberg SA, eds. Cancer: Principles and practice of oncology. Philadelphia, Pennsylvania: J.B. Lippincott, 1985; 2223–2245.

74. Oldham RK, Thurman GB, Talmadge JE, et al. Lymphokines, monoclonal antibodies and other biological response modifi ers in the treatment of cancer. Cancer 1984; 54:2795–2810.

75. Oldham RK, Foon KA, Morgan AC, et al. Monoclonal antibody therapy of malignant melanoma: In vivo localization in cutaneous metastasis after intravenous administration. J Clin Oncol 1984; 2:1235–1242.

76. Oldham RK. Perspectives on the use of immunotoxins in clinical medicine. In: Vogel C-W, ed. Immunoconjugates: Antibody con-jugates in radioimaging and therapy of cancer. New York, Oxford University Press. 1987; 281–289.

77. Oldham RK. Therapeutic monoclonal antibodies: Effects of tumor cell heterogeneity. In: Therapeutic monoclonal antibodies: Effects of tumor cell heterogeneity. S. Karger Ag. Cancer Treatment Symposium (Germany), 1988.

78. Oldham RK, Lewis M, Orr DW, et al. Adriamycin custom-tailored immunoconjugates in the treatment of human malignancies. Mol Biother 1988; 1(2):103–113.

79. Oldham RK, Lewis M, Orr DW, et al. Individually specifi ed drug immunoconjugates in cancer treatment. In: Ceriani RL, ed. Breast cancer immunodiagnosis and immunotherapy. New York: Plenum Publishing 1990; 219–230.

80. Oldham RK. Gene therapy and cancer: Is it for everyone? Cancer Investigation 1992; 10(6):607–609.

81. Oldham RK. Cancer biotherapy: 1993 to the millennium and more! Cancer Biother 1993; 8(1):1–2.

82. Oldham RK. Cancer biotherapy: The fi rst year. Cancer Biother 1994; 9(3):179–181.

83. Oldham RK, Lewko W, Good R, et al. Growth of tumor derived activated T-cells for the treatment of cancer. Cancer Biother 1994; 9(3):211–224.

84. Oldham RK, Dillman RO. JCO 2008; 26(11):1774–1777. 85. Lewko WM, Hall PB, Oldham RK. Growth of tumor- dervice

activated T cells for the treatment of advanced cancer. Can Bio and Radio 2000; 15(4):357–366.

86. Oppenheim JJ, Stadler BM, Siraganian RP, et al. Lymphokines: Their role in lymphocyte responses properties of interleukin 1. Fed Proc 1982; 41:257–262.

87. Orr DW, Oldham RK, Lewis M, et al. Phase I trial of mitomycin-c immunoconjugate cocktails in human malignancies. Mol Biother 1989; 1(4):229–240.

88. Palladino MA, Shalaby MR, Kramer SM, et al. Characterization of the antitumor activities of human tumor necrosis factor-alpha, and the comparison with other cytokines: Induction of tumor specifi c immunity. J Immunol 1987; 138:4023–4032.

89. Paranasivam G, Pearson JW, Bohn W, et al. Immunotoxins of a human melanoma-associated antigen: Comparison of gelonin with ricin and other a-chain conjugates. Cancer Res 1987; 47:3169–3173.

90. Pfreundschuh MG, Steinmetz HT, Tuschen R, et al. Phase I study of intratumoral application of recombinant human tumor necrosis factor. Eur J Cancer Clin Oncol 1989; 25:379–388.

91. Regenass U, Muller M, Curschellas E, Matter A. Anti-tumor effects of tumor necrosis factor in combination with chemothera-peutic agents. Int J Cancer 1987; 39:266–273.

92. Rosenau W. Lymphotoxin: Properties, role and mode of action. Int J Immunopharm 1981; 3:1–8.

93. Rosenberg SA, Lotze MT, Muul LM, et al. Observations on the systemic administration of autologous lymphokine-activated killer cells and recombinant interleukin-2 to patients with metastatic cancer. N Engl J Med 1985; 313:1485–1492.

94. Rosenberg SA. Principles and practices of the biologic therapy of cancer. Philadelphia, Pennsylvania: J.B. Lippincott, 2001.


95. Schiller JH, Witt PL, Storer B, et al. Clinical and biologic effects of combination therapy with gamma-interferon and tumor necrosis factor. Cancer 1992; 69:562–571.

96. Sherwin SA, Knost JA, Fein S, et al. A multiple dose Phase I trial of recombinant leukocyte A interferon in cancer patients. J Am Med Assoc 1982; 248:2461–2466.

97. Smalley RV, Long CW, Sherwin SA, Oldham RK. Biological response modifi ers: Current status and prospects as anticancer agents. In: Herberman RB, ed. Basic and clinical tumor immu-nology. The Hague: Martinus Hijhoff, 1983; 257–300.

98. Smalley RV, Oldham RK. Biological response modifi ers: Preclinical evaluation and clinical activity. CRC Crit Rev Oncol/Hematol 1984; 1:259–280.

99. Smalley RV, Talmadge JA, Oldham RK, Thurman GB. The thy-mosins: Preclinical and clinical studies with fraction V and alpha-1. Cancer Treatment Rev 1984; 11:69–84.

100. Smith JW, Urba WJ, Clark JW, et al. Phase I evaluation of recombinant tumor necrosis factor given in combination with recombinant interferon-gamma. J Immunother 1991; 10:355–362.

101. Spriggs DR, Sherman ML, Michie H, et al. Recombinant human tumor necrosis factor administered as a 24-hour intravenous infu-sion. A Phase I and Pharmacologic Study. J Natl Cancer Inst 1988; 80:1039–1044.

102. Stevenson HC, Ochs JJ, Halverson L, et al. Recombinant alpha interferon in retreatment of two patients with pulmonary lym-phoma, dramatic responses with resolution of pulmonary compli-cations. Am J Med 1984; 77:355–358.

103. Stevenson HC, eds. Adoptive cellular immunotherapy of cancer. New York: Marcel Dekker, 1989; 1–236.

104. Stringfellow DA, Smalley RV. Interferon inducers for clinical use. In: Finter N, Oldham RK, eds. In vivo application of interferons. Amsterdam: Elsevier Science, 1984.

105. Talmadge JE, Maluish AE, Collins M, et al. Immuno modulation and antitumor effects of MVE-2 in mice. J Biol Response Modif 1984; 3:634–652.

106. Taniguchi T, Mantei N, Schwarzstein M, et al. Human leukocyte and fi broblast interferons are structurally related. Nature 1980; 285:2848–2852.

107. Tanguichi T, Matsui H, Fujita T, et al. Structure and expression of cloned cDNA for human interleukin-2. Nature 1983; 302: 305–310.

108. Taguchi T. Phase I study of recombinant human tumor necrosis factor (rHu-TNF:PT-050). Cancer Detect Prev 1988; 12:561–572.

109. Terry MD, Rosenberg SA, eds. Immunotherapy of cancer. New York: Excerpta Medica, 1982; 1–398.

110. Wadler S, Lembersky B, Atkins M, et al. Phase II trial of fl uo-rouracil and recombinant interferon alfa-2a in patients with colorectal carcinoma: An Eastern Cooperative Oncology Group study. J Clin Oncol 1991; 9:1806–1810.

111. Weissman C, Nagata S, Boll W, et al. Structure and expression of human alpha interferon genes. In: Miwa M, et al., eds. Primary and tertiary structure of nucleic acids and cancer research. Tokyo: Japan Science Society Press, 1982; 1–22.

112. West WH, Tauer KW, Yannelli JR, et al. Constant infusion recombinant interleukin-2 in adoptive immunotherapy of advanced cancer. N Engl J Med 1987; 316(15):898–905.

R.K. Oldham and R.O. Dillman (eds.), Principles of Cancer Biotherapy, 17© Springer Science + Business Media B.V. 2009

IntroductionMetastasis, the spread of malignant tumor cells from a primary neoplasm to distant parts of the body where they multiply to form new growths, is a major cause of death from cancer. The treatment of cancer poses a major problem to clinical oncologists, because by the time many cancers are diagnosed, metastasis may already have occurred, and the presence of multiple metastases makes complete eradication by surgery, radiation, drugs, or biotherapy nearly impossible. Metastases can be located in different organs and in different locations within the same organ. These aspects signifi cantly infl uence the response of tumor cells to therapy and the effi ciency of anticancer drugs, which must be delivered to tumor lesions to destroy cells without leading to undesirable side effects. Similarly, immune effector cells of current biotherapeu-tic regimens may not reach or localize in metastases with different organs.

Exacerbating the problems of treating metastatic dis-ease is the fact that tumor cells in different metastases and in some instances even in different regions within a single metastasis may respond differently to treatment. Tumor cell resistance to current therapeutic modalities is the single most important reason for the lack success in treating many types of solid neoplasms. In part, the emergence of treatment-resistant tumor cells is due to the heterogeneous nature of malignant neoplasms. This diversity, which permits selected variants to develop from the parent tumor, implies not only that the primary tumor and metastases can differ in their response to treatment, but also that individual metastases can differ markedly from one another.

Insight into the molecular mechanisms that regulate the pathogenesis of cancer metastasis as well as a better understanding of the interaction between metastatic cells and the host microenvironment should provide a foundation for the design of new therapeutic approaches. Moreover, the development of adequate models that allow for the isolation and characterization of cells possessing metastatic potential will be invaluable in the

design of more effective therapeutic modalities. In this chapter, we discuss the biology of cancer metastasis with special emphasis on recent data demonstrating that the microenvironment of different organs can infl uence the biological behavior of tumor cells at different steps of the metastatic process and the development of bio-logic diversity in malignant neoplasms. These fi ndings have obvious implications for the therapy of neoplasms in general and metastases in particular.

The Pathogenesis of Cancer MetastasisThe process of cancer metastasis is dynamic, complex and consists of multiple, sequential, and interrelated steps shown schematically in Fig. 1. To produce a clini-cally relevant lesion, metastatic cells must survive all the steps of the process. If the disseminating tumor cell fails to complete any one of these steps, it will fail to produce a metastasis. Thus, the successful metastatic cell has been likened to a decathlon champion who must be profi cient in all ten events to be successful, not just a few [58]. The outcome of this process depends on both the intrinsic properties of the tumor cells and their inter-actions with host factors [48, 56, 57, 99].

The essential steps in the formation of a metastasis are: (1) After the initial transforming event, either uni-cellular or multicellular, growth of neoplastic cells must be progressive, with nutrients for the expanding tumor mass initially supplied by simple diffusion. (2) Extensive vascularization must occur if a tumor mass is to exceed 1–2 mm in diameter. The synthesis and secretion of proangiogenic angiogenesis factor probably plays a key role in establishing a neocapillary network from the surrounding host tissue. (3) Local invasion of the host stroma by some tumor cells could occur by several nonmutually exclusive mechanisms. (4) Thin-walled venules, like lymphatic channels, offer very little resis-tance to penetration by tumor cells and provide the most

2 The pathogenesis of cancer metastasis: relevance to therapy

SUN-JIN KIM, CHERYL HUNT BAKER, YASUHIKO KITADAI, TORU NAKAMURA, TOSHIO KUWAI, TAKAMITSU SASAKI, ROBERT LANGLEY, AND ISAIAH J. FIDLER


common pathways for tumor cell entry into the circula-tion. Although clinical observations have suggested that carcinomas frequently metastasize and grow via the lymphatic system, whereas malignant tumors of mesen-chymal origin more often spread by the hematogenous route, the presence of numerous venolymphatic anasto-moses invalidates this concept. (5) Detachment and embo-lization of small tumor cell aggregates occurs next, the vast majority of circulating tumor cells being rapidly destroyed. (6) Once the tumor cells have survived the circulation, they must (7) arrest in the capillary beds of organs, either by adhering to capillary endothelial cells or by adhering to subendothelial basement membrane, which may be exposed. (8) Extravasation occurs next, probably by the same mechanisms that infl uence initial invasion. (9) Proliferation within the organ parenchyma completes the metastatic process (10). To continue

growing, the micrometastases must develop a vascular network and continue to evade the host immune system. Moreover, the cells can invade, penetrate blood vessels, and enter the circulation to produce additional metasta-ses (Fig. 1).

Neovascularization-AngiogenesisOxygen can diffuse from capillaries for only 150–200 μm. When distances of cells from a blood supply exceed this, cell death follows [80]. Thus, the expansion of tumor masses beyond 1 mm in diameter depends on neovascu-larization, i.e., angiogenesis [78, 79]. The formation of new vasculature consists of multiple, interdependent steps. It begins with local degradation of the basement

Figure 1. The pathogenesis of cancer metastasis

THE PATHOGENESIS OF A METASTASIS

ANGIOGENESISTRANSFORMATION MOTILITY & INVASION

Capillaries,Venules, lymphatic vessels

ADHERENCE

ARREST INCAPILLARY

BEDS EMBOLISM &CIRCULATION

EXTRAVASATIONINTO ORGAN

PARENCHYMARESPONSE TO

MICROENVIRONMENT

TUMOR CELLPROLIFERATION

& ANGIOGENESISMETASTASES

METASTASIS OFMETASTASES

TRANSPORT

MULTICELL AGGREGATES (lymphocytes,platelets)

Sun-Jin Kim et al. 19

membrane surrounding capillaries, followed by invasion of the surrounding stroma and migration of endothelial cells in the direction of the angiogenic stimulus. Proli-feration of endothelial cells occurs at the leading edge of the migrating column, and the endothelial cells begin to organize into three-dimensional structures to form new capillary tubes. Differences in cellular composi-tion, vascular permeability, blood vessel stability, and growth regulation distinguish vessels in neoplasms from those in normal tissue [1, 3, 79, 156].

The onset of angiogenesis involves a change in the local equilibrium between proangiogenic and antiangiogenic molecules [55]. Some of the common proangiogenic factors include bFGF, which induces the proliferation of a variety of cells and has also been shown to stimulate endothelial cells to migrate, to increase production of proteases, and to undergo morphogenesis [80]. Likewise, VEGF/VPF has been shown to induce the proliferation of endothelial cells, to increase vascular permeability, and to induce production of urokinase plasminogen acti-vator by endothelial cells [46]. Additional proangiogenic factors include IL-8 [268], platelet-derived endothelial cell growth factor, which has been shown to stimulate endothelial cell DNA synthesis and to induce production of FGF, hepatocyte growth factor (HGF), or scatter fac-tor, that increases endothelial cell migration, invasion, and the production of proteases, and platelet-derived growth factor (PDGF). The production of bFGF, VEGF, and IL-8 by tumor or host cells or the release of proan-giogenic molecules from the extracellular matrix is known to induce the growth of endothelial cells and formation of blood vessels. Further, the organ microen-vironment can directly contribute to the induction and maintenance of the proangiogenic factors bFGF [226, 227] and IL-8 [228].

The production of angiogenic molecules, e.g., VEGF, bFGF, and IL-8 by melanoma cells is regulated by com-plex interactions with keratinocytes in the skin [106]. Reports from our laboratory showed that IL-8 is an important molecule in melanoma growth and progres-sion. Constitutive expression of IL-8 directly correlated with the metastatic potential of human melanoma cells. Further, IL-8 induced proliferation, migration, and inva-sion of endothelial cells and, hence, neovascularization [97]. Several organ-derived cytokines (produced by infl a-mmatory cells) are known to induce expression of IL-8 in normal and transformed cells [106]. Since IL-8 expres-sion in melanocytes and melanoma cells can be induced by infl ammatory signals, the question of whether specifi c organ microenvironments could infl uence the expression of IL-8 was analyzed. Melanoma cells were implanted into the subcutis, the spleen (to produce liver metastasis),

and intravenously (to produce lung metastasis) of athy-mic nude mice. Subcutaneous tumors, lung lesions, and liver lesions expressed high, intermediate, and no IL-8, respectively, at both the mRNA and protein levels. Melanoma cells established from the tumors growing in vivo exhibited similar levels of IL-8 mRNA transcripts as continuously cultured cells, thus demonstrating that the differential expression of IL-8 was not due to the selection of a subpopulation of cells [97].

IL-8 expression can be upregulated by coculturing melanoma cells with keratinocytes (skin) and inhibited by coculturing melanoma cells with hepatocytes (liver). We also investigated the effects of two cytokines pro-duced by keratinocytes (IL-1, IFN-β) and two cytokines produced by hepatocytes (TGF-α, TGF-β) on the regu-lation of IL-8 in human melanoma cells. IL-1 upregu-lated the expression of IL-8 in human melanoma cells at both the mRNA and protein levels in a dose- and time-dependent manner in the presence of de novo protein synthesis. IFN-β did not affect constitutive IL-8 mRNA and protein production in human melanoma cells, but it did block the induction of IL-8 by IL-1. TGF-β inhib-ited the expression of IL-8, while TGF-α had no effect on IL-8 expression [226].

Patients with renal cell carcinoma exhibit high levels of bFGF in the serum or the urine that inversely correlates with survival [181, 184]. Human renal cancer cells implanted into the kidney of nude mice were highly meta-static to the lung, whereas renal cancer cells implanted subcutaneously remain local [227]. The subcutaneous or intramuscular tumors expressed a lower level of mRNA transcripts for bFGF than did tumor cells growing in cul-ture, whereas the renal tumors had 20 times higher levels of bFGF mRNA and protein levels as compared with the cultured cells. A histopathologic examination of the tumors demonstrated that the subcutaneous tumors had few blood vessels, whereas the renal tumors had many [227, 228].

Direct correlation between the level of bFGF and advanced disease was also reported for patients diagnosed with colon carcinoma. Patients with Duke’s C or D tumors had markedly higher levels of bFGF in the blood than patients with Duke’s B. In situ hybridization analysis revealed that bFGF was overexpressed at the tumor periphery associated with cell division. Northern blot analysis detected no mRNA transcripts for bFGF [129]. In a follow-up study of patients with colon cancer, bFGF expression was found to be highest in the primary tumors of patients who presented with metastatic disease and therefore identify a cohort of patients who appeared to be free of metastatic disease at the time of surgery (low bFGF expression) as compared to another cohort of patients who did develop metastatic disease (high bFGF) [130].


Tumor Cell InvasionTo reach blood vessels or lymphatics, tumor cells must penetrate host stroma that includes basement membrane. The interaction with the basement membrane consists of attachment, matrix dissolution, motility and penetration [154]. At least three nonmutually excluding mechanisms can be involved in tumor cell invasion of tissues. First, mechanical pressure produced by rapidly proliferating neoplasms may force cords of tumor cells along tissue planes of least resistance [154, 155]. Second, increased cell motility can contribute to tumor cell invasion. Most tumor cells possess the necessary cytoplasmic machinery for active locomotion and increased tumor cell motility is preceded by a loss of cell-to-cell cohesive forces. In epithelial cells, the loss of cell-to-cell contact is associated with downregulation of the expression of E-cadherin, a cell surface glycoprotein involved in calcium-dependent homotypic cell-to-cell cohesion. Reduced levels of E-cadherin are associated with a decrease in cellular/tissue differentiation and increased grade in carcinomas [120]. Many differentiated carcinomas express higher levels of E-cadherin mRNA, as do adjacent normal epi-thelial cells, whereas poorly differentiated carcinomas do not. Mutations in the E-cadherin gene and abnormal-ities of α-catenin, which is an E-cadherin-associated protein, have been associated with the transition of cells from the noninvasive to the invasive phenotype [261]. Third, invasive tumor cells secrete enzymes capable of degrading basement membranes, which constitute a barrier between epithelial cells and the stroma. Epithelial cells and stromal cells produce a complex mixture of col-lagens, proteoglycans, and other molecules, which contains ligands for adhesion receptors and is permeable to mole-cules but not to cells [230].

To invade the basement membrane, a tumor cell must fi rst attach to extracellular matrix (ECM) components by a receptor-ligand interaction. One group of such cell surface receptors are the integrins which specifi cally bind cells to laminin, collagen, or fi bronectin [218]. Many integrins that bind to different components of the ECM are expressed on the surface of human carcinoma cells. Tumor progression has been associated with a gradual decrease of integrin expression suggesting that the loss of integrins, coupled with the loss of E-cadherin, may facilitate detachment from a primary neoplasm.

Subsequent to binding, tumor cells can degrade connective-tissue ECM and basement membrane compo-nents [177]. The production of enzymes such as type IV collagenase (gelatinase, matrix metalloproteinase) and heparinase in metastatic tumor cells correlates with invasive capacity of human carcinoma cells. Type IV collagenolytic

metalloproteinases with apparent molecular masses of 98, 92, 80, 68, and 64-kDa have been detected in highly meta-static cells. Poorly metastatic cells, on the other hand, appear to secrete very low amounts of only the 92-kDa metalloproteinase [171, 172].

Lymphatic MetastasisEarly clinical observations led to the impression that carcinomas spread mainly by the lymphatic route and mesenchymal tumors spread mainly by means of the bloodstream. We now know, however, that the lymphatic and vascular systems have numerous connections and that disseminating tumor cells may pass from one system to the other [27]. For these reasons, the division of metastasis into lymphatic spread and hematogenous spread is arbitrary. During invasion, tumor cells can easily penetrate small lymphatic vessels and be passively transported in the lymph. Tumor emboli may be trapped in the fi rst lymph node encountered on their route, or they may bypass regional draining lymph nodes to form distant nodal metastases (“skip metastasis”). Although this phenomenon was recognized in the late 1800s [193], its implications for treatment were frequently ignored in the development of surgical approaches to treat cancers [263, 264].

Regional lymph nodes (RLN) in the area of a primary neoplasm may become enlarged as a result of hyperplasia or growth of tumor cells in the node. Although the use of morphologic criteria for assessing prognoses based on lymph node appearance is debatable, lymphocyte-depleted lymph nodes are believed to indicate a less favorable prognosis than those demonstrating reactive morphologic characteristics [16]. Hyperplastic responses could indicate reactivity to autochthonous tumors, and this could benefi t the host.

Whether the RLN can retain tumor cells and serve as a temporary barrier for cell dissemination is controver-sial. In most experimental animal systems used to inves-tigate this question, normal lymph nodes were subjected to a sudden challenge with a large number of tumor cells, a situation that may not be analogous to RLN at the early stages of cancer spread in humans, when small numbers of cancer cells continuously enter the lymphatics. This issue is important because of practical considerations for surgical management of such neoplasms as cutaneous melanoma. It raises the question, is elective prophylactic lymph node dissection appropriate for the treatment of micrometastases? The biologic justifi cation for elective lymph node dissection in patients with melanoma presumes that metastasis of some cutaneous melanomas

Date post:	20-Sep-2020
Category:	Documents
Upload:	others
View:	0 times
Download:	0 times

Principles of Cancer Biotherapy...method of treatment complementing cancer destruction as mechanisms...

Documents