ONCOLOGY FOCUSED IMMUNOTHERAPY COMPANY

Targeting Cancer Survivorship

FORWARD LOOKING STATEMENT

This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, statements about future expectations, plans and prospects for the development and commercialization of the Company's product candidates, including patient enrollment in our clinical trials, present or future licensing, collaborative or financing arrangements, expected outcomes with regulatory agencies, and projected market opportunities for product candidates are subject to a number of risks, uncertainties and assumptions, including those identified under Risk Factors in the Companys most recently filed Annual Report on Form 10-K and Quarterly Report on Form 10-Q and in other filings the Company periodically makes with the SEC. Actual results may differ materially from those contemplated by these forward-looking statements. The Company does not undertake to update any of these forward-looking statements to reflect a change in its views or events or circumstances that occur after the date of this presentation.

2

LATE-PHASE, ONCOLOGY FOCUSED IMMUNOTHERAPY COMPANY

Targeted, 1st in Class therapies for prevention of cancer recurrence

Focused in large markets in areas of major unmet medical need Phase 3, PRESENT, breast cancer

clinical trial ongoing under SPA

Pioneering immunotherapy technology for cancer Induce, activate and cause

proliferation of Cytotoxic T-Cells Proven Mechanism of Action

through Expansion of Tumor Specific CTLs

3

0

5

10

15

20

25

0.5 1.5 2.5 3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5Year

Haza

rd o

f rec

urre

nce

by y

early

inte

rval Total

Node 0Node 1-3Node (4+)Tumour size (3cm)ER+ER-PremenPostmen

Source: Early Breast Cancer Trialists Collaborative Group. Lancet. 1998;351:1451 ; Update of Houghton. J Clin Oncol. 2005; 23(16S):24s. Abstract 582 Saphner et al., J Clin Oncol. 14: 2738-2746, 1996

DEVELOPMENT PIPELINE

Product Therapeutic Area Phase 1 Phase 2 Phase 3 BLA / NDA

Immunotherapy: Breast Cancer

NeuVax (nelipepimut-S) Node-positiveHER2 IHC 1+/2+

NeuVax + Herceptin Node-positive or node negative/triple negative HER2 IHC 1+/2+

NeuVax + Herceptin High risk, node-positive or negative, HER2 IHC 3+

NeuVax Ductal Carcinoma in Situ (DCIS)

Immunotherapy: Gastric Cancer

NeuVax Gastric, HER2 IHC 1+/2+/3+

Immunotherapy: Gynecological Cancer

GALE-301 Ovarian & Endometrial

GALE-301 + GALE-302 Ovarian & Breast

Hematology

GALE-401 (Anagrelide CR) MPN-related thrombocytosis

PRESENT

*NeuVax is an investigational product. Efficacy has not been established. Herceptin is a registered trademark of Genentech.

Ongoing Planned

VADIS

4

2b

Adds ~10k patients>$3B

Combo: High risk, HER2 3+

NEUVAX:SIGNIFICANT U.S. COMMERCIAL OPPORTUNITY

5

adds ~10k patients>$2.5B

Combo Node Pos or NegHER2 1+, 2+

HLA-A2, A3, A24, A26

PRESENT50-60k patients

>$2B

Source: Global Data 2015/Medtrack. Pricing estimates based on a 20% premium to the current average annual price of Herceptin (U.S. Dollars).

REDEFINING THE STANDARD OF CARE

6

NOVEL DEVELOPMENT STRATEGY: SECONDARY PREVENTION IN CANCER SURVIVORS

7

RECEIVES PRIMARY TREATMENT

Surgery Chemotherapy and/or Radiation

Disease freesurvivor

Breast: HER2, 1+/2+25% recurrence rate in 3 yrs

No FDA Approved targeted therapies

Breast: HER2, 3+ High Risk20% recurrence rate

DECLAREDTO PREVENT RECURRENCE / METASTATIC DISEASE

Breast: Ductal Carcinoma in Situ8-10% progression to invasive

Ovarian Cancer~50% recurrence rate in 1 yr

No FDA Approved targeted therapies

Watch & Wait, or

Repetitive therapies

TOLD

PREVENTING RECURRENCE: UNMET MEDICAL NEED

NEUVAX PHASE 3 PRESENT TRIAL DEMOGRAPHIC:

Node positive, Stage 2a - 3a, HER2 1+/2+, HLA A2/A3

Local or Metastatic recurrent disease =

8

Poor prognosis and/or Death

Patients have a ~25% Recurrence Rate

Prevention of recurrences saves lives!

Sources: 1 http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-survival-by-stage; 2 Sledge GW Jr: Curing Metastatic Breast Cancer. J Oncol Pract 12:6-10, 2016

5 year survival rate of metastatic cancer = 22%1

Low Tumor volume equates to improved overall survival 2

Occult tumor cells micrometastasis macrometastisis metastatic disease

http://www.cancer.org/cancer/breastcancer/detailedguide/breast-cancer-survival-by-stage

UNIQUELY POSITIONED

14.5 million cancer survivors in US (NCI Cancer Survivorship)

Projected to 19 million survivors in 2024

Increase in survival due to decades of productive research, improved screening/prevention, and effective treatments

Survival leads to patients living longer 64% alive after 5 years of diagnosis 41% alive after 10 years of diagnosis 15% alive after 20 years or longer

Galena peptide vaccines NeuVax and GALE-301 are uniquely positioned to maintain survivorship

9Source: DeSantis CE et al. CA Cancer J Clin 2014: 64:252-271

CANCER IMMUNOTHERAPY WITH INNOVATIVE TECHNOLOGY

Overcoming Cancer by Activating and Expanding Cytotoxic T-Cells

10

FIRST-IN-CLASS, TARGETED IMMUNOTHERAPY PIPELINE

11

Harnessing the power of the

immune system in the adjuvant setting

Exploits specificity of natural immune surveillance

Adjuvant patients have healthy immune systems

Systemic protection

Goal is to prevent recurrence

Recurrences are almost always fatal

Minimal toxicity and improved safety profile

Boosters provide long term protective effect

Well-validated targets

HER2

Folate binding protein (FBP)

Current Programs

NeuVax (nelipepimut-S)

Breast: HER2 1+, 2+ and 3+; DCIS

Gastric trial planned

GALE-301 & GALE-302

Ovarian

Adjuvant Setting = Minimal Residual Disease

T-Cell

Activating Receptors Inhibitory Receptors

CD28

OX40

GITR

CD122

CD27

CD360

HVEM

CD137

CTLA-4

PD-1

TIM-3

BTLA

VISTA

LAG-3

IMMUNO-ONCOLOGY:UNLOCKING THE POWER OF THE T-CELL

12

Checkpoint inhibitors

Indirect Immune Modulators

Co-stimulators

Immune Inhibitory Enzymes

CAR TTechnology

TCRTechnology

T-Cell

Activating Receptors Inhibitory Receptors

CD28

OX40

GITR

CD122

CD27

CD360

HVEM

CD137

CTLA-4

PD-1

TIM-3

BTLA

VISTA

LAG-3

LACK OF REACTIVE T-CELLS MAY RENDER SOME TOOLS INEFFECTIVE IN MANY CANCERS

13

Checkpoint inhibitors

Indirect Immune Modulators

Co-stimulators

Immune Inhibitory Enzymes

T-Cell

CD28OX40

GITR

CD122

CD27

CD360

HVEM

CD137

CTLA-4

PD-1

TIM-3

BTLA

VISTA

LAG-3

Activating Receptors Inhibitory Receptors

OUR VACCINES STIMULATE T-CELL PROLIFERATION AND EXPANSION

14

T cells

Checkpoint inhibitors

Indirect Immune Modulators

Co-stimulators

Immune Inhibitory Enzymes

T cells

T cells

T cells

T cells

T cells

T cells

T cells

T cells

T cells

GALE-301

NEUVAX (nelipepimut-S)

Targeting HER2

NEUVAX: HER2 IMMUNODOMINANT PEPTIDE

NeuVax contains the immunodominant peptide derived from the extracellular region of the HER2 protein

Peptide (aa 369-377) immunotherapy administered as intradermal injection

MHC Class I: HLA A2/A3

16

K I F G S L A F L

ELICITS A STRONG CD8+ T-CELL RESPONSE

NeuVax binds to antigen presenting cells (APCs)

NeuVax stimulates APCs to activate CD8+ cytotoxic T lymphocytes (CTLs)

CTLs rapidly replicate to seek out and destroy HER2 expressing tumor cells and micro-metastases

Booster series maintains long term immunologic response

Demonstrated inter- and intra-antigenic epitope spreading

17Sources: Peoples GE, et al (2005) JCO, 23(300, 7536-7545; Mittendorf EA, et al (2006) Surgery, 139(3): 407-418. Peoples, et al, ASCO 2012 Poster Presentation

0.4

1.8

0.70.5

0.0

0.5

1.0

1.5

2.0

2.5

% N

euVa

xsp

ecifi

c C

D8+

T c

ells

NeuVax Specific CD-8 CTLs: Pre-, Post, Mean and Long-Term (6 months)

Pre Max Mean Long-Term

POSITIVE SAFETY PROFILE

NeuVax is well-tolerated in multiple clinical trials

Phase 1/2 showed predominantly Grade 1/2 Adverse Events caused by GM-CSF(n=53) Injection site reactions in nearly all patients

demonstrating the activated dendritic cells Systemic toxicities caused by GM-CSF Fatigue (64%) Headache (42%) Myalgia/Other Pain (30%)

August 2015 Independent Data Monitoring Committee

(IDMC) recommended to the Company that it can reduce the cardiac toxicity monitoring in its Phase 3 PRESENT clinical trial

18Sources: Choy, et al, poster presentation 33rd Annual Chemotherapy Foundation

Symposium: Nov 2015; Mittendorf- Annals of Oncology 25: 17351742, 2014

NEUVAX: SN-33 PHASE 2 HER2 IHC 1+/2+

19Source: 2012 San Antonio Breast Cancer Poster, Mazanet, et al.

PHASE 3, PRESENT TRIAL

Prevention of Recurrence in Early-Stage, Node Positive Breast Cancer with Low to Intermediate Her2 Expression with NeuVax Treatment Trial being run under FDA-approved SPA

Enrollment completed in April 2015 (n=758) Adjuvant breast cancer patients, Node Positive, HER2 1+/2+, HLA A2/A3+

Patient friendly regimen via intradermal injection Primary Vaccine Series injection once a month for 6 months Booster Series injection once every 6 months

Upcoming Key Milestones Interim safety/futility analysis: 2Q16 Primary Endpoint: 2018

20

PHASE 3 PRESENT TRIAL PER SPA

1 2 3 4

Interim analysis by DSMB at n=70 events

Endpoint DFS at n=141 events /36 months

Dosing by Month + 1 booster dose every 6 months thereafter

5 6

Adjuvant breast cancer patients, randomized 1:1

Double blind

Node positive

HLA A2/A3+

HER2 IHC 1+/2+

Stratified by stage, type of surgery, hormone receptor, and menopausal status

Enrollment complete: n=758 Patients

Study Population + GM-CSF

Placebo + GM-CSF

21

Prevention of Recurrence in Early-Stage, Node Positive Breast Cancer with Low to Intermediate Her2 Expression with NeuVax Treatment

PRESENT INTERIM ANALYSIS

70 Events Confirmed by the EAC

Endpoint Adjudication Committee confirms 70 events

Independent team of 2 Oncologists and 1 Radiologist

Galena Compiles

Data

Prepares a detailed review on 70 patients with events and overall safety data set (n=758)

Submits to IDMC

IDMC Evaluates

Evaluates 70 patients with events and overall safety data set (n=758)

Makes recommendation on futility and continuation of trial

Interim Analysis Results

Estimated timing: End of Q2

22

PRIMARY PREVENTIONExpansion potential for safe vaccine in DCIS

METASTATIC DISEASEExpansion potential in combination with checkpoint inhibitors /immune modulators

NEUVAX: ACROSS THE BREAST CANCER TREATMENT SPECTRUM

23

PROOF OF CONCEPT: Established in population with no standard of care treatment options

SECONDARY PREVENTION

IDEAL SETTING: Adjuvant treatment in patient population with no evidence of disease

MOST ADVANCED: PRESENT is the largest and only Phase 3 breast cancer vaccine trial

NEUVAX: DEVELOPMENT COLLABORATIONS

Phase Treatment HER2 Status Indication Trial StatusProtocol Defined

# of PatientsCollaborations

3Single agent

PRESENTStudy

1+, 2+BREAST

Node PositiveHLA A2+, A3+

Enrolled13 countries~140 centers

700(enrolled 758)

2bCombination

with trastuzumab

1+, 2+

BREAST Node Positive or High Risk Node Negative

HLA A2+, A3+, A24+, A26+

EnrollingU.S. only

33 centers300

2Combination

with trastuzumab

3+ high risk

BREASTNode PositiveHLA A2+, A3+

EnrollingU.S. only

28 centers100

2 Single agentVADIS Study1+,

2+,3+

BREASTDuctal Carcinoma in

Situ (DCIS)HLA A2+

PlannedU.S. only4 centers

48

2 Single agent 1+, 2+,3+GASTRIC

HLA A2+, A3+Planned

India Only 50

24

Targeting Folate Binding Protein

GALE-301 & GALE-302

GALE-301 & GALE-302

26Source: U.S. Ovarian Cancer http://seer.cancer.gov/statfacts/html/ovary.html

Targeted cancer immunotherapy

Folate Binding Protein (FBP) is over-expressed (20-80 fold) in >90% of ovarian and endometrial cancers

FBP has very limited tissue distribution and expression in non-malignant tissue making it an ideal immunotherapy target

Current treatments are generic Carboplatin and paclitaxel High recurrence rate

Most patients relapse with poor prognosis

GALE-301: OPTIMAL DOSE GROUP SHOWS PRELIMINARY EFFICACY

Source: Peoples, et. al, Poster Presentation, European Cancer Congress 2015 27

Phase 1/2a trial ongoing Phase 1: Determined optimal dose and

demonstrated safety and potent immune response

Phase 2a Preliminary data in 1000 mcg dose group:

At 12 months median follow-up:

Vaccine group: 2 clinical recurrences (13.3%) n=15

Control group: 12 recurrences (55%) n=22

Two year DFS estimate in 1000 mcg dose group is 85.7% vaccine vs. 33.6% control (p

GALE-301 & GALE 302: PHASE 1DELAYED-TYPE HYPERSENSITIVITY

28

LEGENDEE = E39 (GALE-301) x 6 inoculations (n=12)EE = E39 (GALE-301) x 3 inoculations followed by E39 (GALE-302) x 3 inoculations (n=14)EE = E39 (GALE-302) x 3 inoculations followed by E39 (GALE-301) x 3 inoculations (n=13)

R0 = baseline (pre-vaccination)RC1 = 1 month after completion of the PVSRC6 = 6 months after completion of the PVS and pre-booster

Source: Mittendorf et. al., Poster Presentation, Society of the Immunotherapy of Cancer 2015

GALE-401

Anagrelide Controlled Release (CR)

GALE-401 ANAGRELIDE CONTROLLED RELEASE (CR)

Anagrelide

Active ingredient Reduces the elevated platelet count and the risk of thrombosis in patients with

myeloproliferative neoplasms (MPNs) MPNs are hematological malignancies in which the bone marrow cells develop and function

abnormally

Immediate Release

Approved for the treatment of patients with thrombocythemia, secondary to MPNs IR formulation can cause unacceptable side effects believed to be Cmax-related and has largely

limited the use due to early treatment withdrawal

GALE-401

Controlled Release (CR) formulation may decrease the frequency or severity of side effects Phase 2, Proof-of-Concept Trial Results

Well tolerated with primarily Grade 1 and 2 toxicities Efficacy compares favorably to historical anagrelide IR

30

CORPORATE OVERVIEW

31

1st IN CLASS PROGRAMS WITH EXPANSION OPPORTUNITIES

Mid-stage clinical trials have proven T-cell generation NeuVax (nelipepimut-S) Phase 2 trial demonstrated 2% of the patients

T-Cells become CD8+, HER2 directed

GALE-301 Phase 1/2: Two year DFS estimate in optimal dose group is 85.7% vaccine vs. 33.6% control (p

LEADERSHIP TEAM

33

Mark W. Schwartz, Ph.D., President & CEOApthera, Bayhill Therapeutics, Calyx Therapeutics, Trega Biosciences, Incyte Genomics, DuPont Diagnostics

Bijan Nejadnik, M.D., Executive Vice President, Chief Medical Officer Jazz Pharmaceuticals, Johnson & Johnson, Stanford, Johns Hopkins, UC Davis

Remy Bernarda, SVP, Investor Relations & Corporate CommunicationsIR Sense, Hana Biosciences, Knight Equity Markets, Bear Stearns, Goldman Sachs

Gavin Choy, Pharm.D., SVP, Clinical Sciences & OperationsOtsuka, Astex, SuperGen, Hana Biosciences, Gilead, Stanford University Medical Center, Department of Veteran Affairs

Tom Knapp, Esq., Interim General Counsel Sucampo, Exemplar Law Partners, NorthWestern Energy, Paul Hastings, The Boeing Company

Joe Lasaga, VP, Business Development & Alliance ManagementNektar Therapeutics, Rigel

Pat Murphy, VP, Regulatory Affairs & ComplianceNektar Therapeutics, Bayhill Therapeutics, Berlex Laboratories, Serono, Parexel, Biogen

2016 MILESTONES

34

PROGRAM MILESTONEPROJECTED

DATE

NeuVax(nelipepimut-S)

PRESENT: Achieve 70 Qualifying DFS Events Fast Track Designation Initiate DCIS trial Q2

PRESENT: Interim analysis Q2

Combo H&N 1+/2+ Interim safety data Q4

Combo H&N 1+/2+ A24/A26 data Q4

GALE-301GALE-302

Present 301/302 booster data Present GALE-301 Phase 2a two year data Q4

GALE-401 (anagrelide CR)

Present combined safety data Q2

Confirmation of 505(b)2 pathway 2H

Publish final Phase 2 report Q4

FINANCIAL OVERVIEW

Cash Position (as of March 31, 2016) $34.7 million

Debt Financing (May 10, 2016) + $23.4 million

Payoff Remaining Oxford Debt (May 10, 2016) - $3.1 million

Q2 Projected Operating Burn $13 - $15 million

Includes legal settlement & fees ~$4-$5 million

Future Projected Quarterly Burn $9 - $11 million

Shares Outstanding 182 million

Market Cap (as of June 2, 2016) ~$375 million

35

WHY WERE HERE

36Source: E75 vaccine's final tests start in S.A. By Don Finley, January 22, 2012; Photo credit: Kin Man Hui/San Antonio Express-News/ZUMAPress

I've had several friends who've had (breast cancer) and thenit came back and they had to go through treatment again. So this would be wonderful, not to have to come back.

First NeuVax Phase 3 patient

THANK YOU

NASDAQ: GALE

ONCOLOGY FOCUSED IMMUNOTHERAPY COMPANYFORWARD LOOKING STATEMENTLATE-PHASE, ONCOLOGY FOCUSED IMMUNOTHERAPY COMPANYDEVELOPMENT PIPELINENEUVAX:SIGNIFICANT U.S. COMMERCIAL OPPORTUNITYREDEFINING THE STANDARD OF CARENOVEL DEVELOPMENT STRATEGY: SECONDARY PREVENTION IN CANCER SURVIVORSPREVENTING RECURRENCE: UNMET MEDICAL NEEDUNIQUELY POSITIONEDCancer Immunotherapy with Innovative TechnologyFIRST-IN-CLASS, TARGETED IMMUNOTHERAPY PIPELINEIMMUNO-ONCOLOGY:UNLOCKING THE POWER OF THE T-CELLLACK OF REACTIVE T-CELLS MAY RENDER SOME TOOLS INEFFECTIVE IN MANY CANCERSOUR VACCINES STIMULATE T-CELL PROLIFERATION AND EXPANSIONNEUVAX (nelipepimut-S)NEUVAX: HER2 IMMUNODOMINANT PEPTIDE ELICITS A STRONG CD8+ T-CELL RESPONSEPOSITIVE SAFETY PROFILENEUVAX: SN-33 PHASE 2 HER2 IHC 1+/2+PHASE 3, PRESENT TRIALPHASE 3 PRESENT TRIAL PER SPAPRESENT INTERIM ANALYSISNEUVAX: ACROSS THE BREAST CANCER TREATMENT SPECTRUMNEUVAX: DEVELOPMENT COLLABORATIONSGALE-301 & GALE-302GALE-301 & GALE-302GALE-301: OPTIMAL DOSE GROUP SHOWS PRELIMINARY EFFICACYGALE-301 & GALE 302: PHASE 1DELAYED-TYPE HYPERSENSITIVITYGALE-401GALE-401 ANAGRELIDE CONTROLLED RELEASE (CR)CORPORATE OVERVIEW1st IN CLASS PROGRAMS WITH EXPANSION OPPORTUNITIESLEADERSHIP TEAM2016 MILESTONESFINANCIAL OVERVIEWWHY WERE HERETHANK YOU