A Multicenter Randomized Controlled Trial of Rituximab versus Cyclosporine in the Treatment of Idiopathic Membranous Nephropathy (MENTOR)
Fernando C. Fervenza a Pietro A. Canetta b Sean J. Barbour c Richard A. Lafayette d Brad H. Rovin e Nabeel Aslam f Michelle A. Hladunewich g Maria V. Irazabal a Sanjeev Sethi h Debbie S. Gipson i Heather N. Reich g Paul Brenchley j Matthias Kretzler k Jai Radhakrishnan b Lee A. Hebert e Patrick E. Gipson i Leslie F. Thomas l Ellen T. McCarthy m Gerald B. Appel b J. Ashley Jefferson n Alfonso Eirin a John C. Lieske a Marie C. Hogan a Eddie L. Greene a John J. Dillon a Nelson Leung a John R. Sedor o Dana V. Rizk p Samuel S. Blumenthal q Lada B. Lasic r Luis A. Juncos s Dollie F. Green t James Simon u Amy N. Sussman v David Philibert w Daniel C. Cattran g for the Mentor Consortium group
a Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minn. , b Division of Nephrology, Columbia University, New York, N.Y. , USA; c Division of Nephrology, University of British Columbia, Vancouver, B.C. , Canada; d Division of Nephrology and Hypertension, Stanford University Medical Center, Sanford, Calif. , e Division of Nephrology, Ohio State University, Columbus, Ohio , f Division of Nephrology and Hypertension, Mayo Clinic, Jacksonville, Fla. , USA; g University Health Network, Toronto General Hospital, Toronto, Ont. , Canada; h Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minn. , USA; i Division of Nephrology, University of Michigan, Ann Arbor, Mich. , j Manchester Royal Infirmary, Manchester , UK; k Internal Medicine/Nephrology and Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, Mich., l Division of Nephrology and Hypertension, Mayo Clinic, Scottsdale, Ariz. , m Division of Nephrology and Hypertension, University of Kansas Medical Center, Kansas City, Kans. , and n Division of Nephrology, University of Washington Medical Center, Seattle, Wash. , o Department of Medicine and Physiology & Biophysics, Case Western Reserve University, Cleveland, Ohio, p Division of Nephrology, University of Alabama, Birmingham, Ala., q Division of Nephrology, Medical College of Wisconsin, Milwaukee, Wis., r Division of Nephrology, New York University, New York, N.Y., s Division of Nephrology, University of Mississippi Medical Center, Jackson, Miss., t Division of Nephrology and Hypertension, University of Miami, Miami, Fla., u Department of Nephrology and Hypertension, Cleveland Clinic, Cleveland, Ohio, v Division of Nephrology, University of Arizona, Tucson, Ariz., USA; w Centre Hospitalier Universitaire de Québec, Quebec City, Que., Canada
Abstract
Background: Idiopathic membranous nephropathy re-mains the leading cause of nephrotic syndrome in Cauca-sian adults. Immunosuppressive therapy with cyclosporine
Received: January 29, 2015 Accepted after revision: April 17, 2015 Published online: June 12, 2015
Dr. Fernando C. Fervenza Division of Nephrology and Hypertension, Mayo Clinic 200 First Street SW Rochester, MN 55905 (USA) E-Mail fervenza.fernando @ mayo.edu
Dr. Daniel C. CattranUniversity Health Network, Toronto General Hospital610 University Avenue, Toronto, ON M5G 2M9 (Canada)E-Mail daniel.cattran @ uhn.ca
Idiopathic membranous nephropathy (IMN) is a common immune-mediated glomerular disease and re-mains the leading cause of nephrotic syndrome (NS) in Caucasian adults [1] . Although in most patients the dis-ease progresses relatively slowly, approximately 40% of patients eventually develop End Stage Renal Disease (ESRD) [2] . Because of its frequency, it remains the 2nd or 3rd most common cause of a primary glomerulopathy leading to ESRD [3] . Patients with IMN who remain ne-phrotic are also at increased risk for thromboembolic [4] and cardiovascular events to occur [5, 6] .
There is no standard specific treatment for IMN. Ini-tial therapy should be supportive and involves restricting dietary protein and sodium intake, controlling blood pressure, hyperlipidemia, and edema. Reducing protein intake to about 0.6–0.8 g/kg ideal body weight per day tends to decrease proteinuria [7] . Angiotensin-converting- enzyme inhibitor (ACEi) and/or angiotensin receptor blockers (ARBs) are effective anti-hypertensive agents that may also reduce proteinuria in both diabetic and non-diabetic chronic nephropathy patients and slow pro-gression of renal disease independent of blood pressure control [8] . However, evidence that such therapy is ben-eficial in IMN is weak and largely inferential [9–16] . Tak-en together, in the past decade, relatively little progress has been made in the treatment of patients with IMN, and up to 40% of the patients will still progress to ESRD. Agents that result in a higher response and lower relapse rates, as well as fewer adverse effects, are therefore need-ed.
To date, the best proven therapy for patients with IMN consists of the combined use of corticosteroids and cyclo-phosphamide (CYC). However, the potential side effects with the use of 9 g of methylprednisolone mandated by this protocol as well as the potential risk of other serious side effects associated with the use of cytotoxic agents (such as bone marrow toxicity, severe infections, gonadal dysfunction) [17, 18] combined with the long-term risk of malignancy associated with CYC [19–22] has left many physicians reluctant to use this regimen. For these rea-sons, the majority of the academic centers in the United States have considered CYC treatments too toxic and rel-egated the use of Ponticelli’s protocol to rescue therapy in patients who have failed less toxic immunosuppressive therapies.
Cyclosporine (CSA) is a calcineurin inhibitor that ex-erts its immunosuppressive effect by blocking the pro-duction of interleukin-2, interleukin-3 and interferon-γ, resulting in a reduction of T-lymphocyte helpers/induc-ers and cytotoxic cell function [23] . This immunosup-pressive effect is probably not the only anti-proteinuric effect of CSA since it is known to have both hemodynam-ic effects and to act on the podocyte structure [24, 25] . CSA has been used successfully in patients with IMN and NS resistant to corticosteroids and/or cytotoxic drugs and has been tried in some of the glomerular disorders even before exposure to cytotoxic therapy because of its sig-nificantly different side-effect profile [13, 26–31] . How-ever, CSA is a potent immunosuppressive agent and is associated with significant risk of both short- and long-term toxicity. In a majority of cases, these adverse effects
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Trial of Rituximab versus Cyclosporine in Idiopathic Membranous Nephropathy
NephronDOI: 10.1159/000430849
3
are associated with both daily dose and total exposure. Precise incidences of these toxicities are hard to ascertain from the literature, given the rarity of studies where these agents are used as monotherapy and their use for a lim-ited duration as proposed in this trial. However, there is undoubtedly an acute effect on filtration function and de-layed effects on renal vasculature that have been well doc-umented and a recent review summarized both short- and long-term toxicities associated with this agent [32] . Hypertension, overgrowth of body hair and gingiva hy-perplasia, mild tremor, infections, elevated bilirubin lev-els and mild nausea represent the most frequently ob-served short-term adverse effects related to CSA [32] . These are seen in up to 20 to 30% of the treated popula-tion and may require additional anti-hypertension drugs and/or dose reduction [33] .
A New Approach to Therapy: The Case for Targeting B-Cells In IMN, experimental data suggest that B-cells abnor-
malities are involved in the pathogenesis of the disease [34–36] . Given the key role of IgG antibodies in IMN [37] , it is reasonable to postulate that suppression of an-tibody production that targets glomerular antigens by depleting B-cells may improve or even resolve the glo-merular pathology. Indeed, CYC works mainly by deplet-ing B-cells [35, 38] . However, CYC-depletion is non-se-lective and may account for the significant toxicity ob-served with its use. This concept led to the seminal study by Remuzzi et al. to use selective B-cell targeting with Rituximab (RTX), a monoclonal antibody that specifical-ly targets CD20 on the surface of B-cells, in patients with IMN [39] .
Subsequently, we conducted a pilot trial in 15 newly-biopsied patients with IMN and persistent proteinuria >5 g/24 h despite ACEi/ARB blockade [40] . Patients were treated with RTX (1 g) on days 1 and 15. At 6 months, patients who remained with proteinuria >3 g/24 h re-ceived a second identical course of RTX. In the fourteen patients who completed 12 months follow-up, complete remission (CR) was achieved in 2 patients and partial re-mission (PR) in 7 patients. At 18-month follow-up, 3 of these 7 PR patients achieved CR of their proteinuria. Five patients did not respond. There were a limited number of minor side effects.
Based on these results, we conducted an additional study based on the premise that in patients with MN, 4 weekly doses of RTX would result in more effective B-cell depletion and a higher remission rate while still maintaining the same safety profile as patients treated
with RTX dosed at 1 g × 2 [41] . Twenty patients with IMN and proteinuria >5 g/24 h received RTX (375 mg/m 2 × 4), with retreatment at 6 months regardless of proteinuria response. Of 18 patients who completed 24-month fol-low-up, 4 had CR, 12 PR, and 2 did not respond. One pa-tient relapsed from a CR. Serum RTX levels using the 4 dose regimen were similar to those obtained with 2 doses of RTX. Four doses of RTX did result in more effective B-cell depletion but proteinuria reduction at 12 months was basically identical to the results obtained using RTX 1,000 mg on days 1 and 15. Thus, we concluded that the two dose regimen with retreatment at 6 months should be used in a randomized-control trial comparing RTX to CSA (the standard of care for IMN in the North America). Thus, we designed a clinical trial to test the hypothesis that RTX will prove at least non-inferior to CSA, both in the production of short- and long-term control of the NS and be safer than any of the other current regimens used to treat IMN. This treatment could then potentially rep-resent the new standard of care for patients with MN.
Anti-PLA2R Levels and Response to Treatment Recent studies indicate that autoantibodies to the M-
type phospholipase A2 receptor (PLA2R) may represent a specific marker for IMN [42–47] related to its pathobi-ology as well as clinical outcomes. This autoantibody has been found in greater than 70% of IMN patients [48] . When the analysis is limited to new-onset, nephrotic pa-tients with IMN, this sensitivity increases even further. We also have studied whether the immunologic changes in serum anti-PLA2R levels parallel the clinical reduction in proteinuria in our 2 cohorts of MN patients treated with RTX [49] . We found that post-RTX anti-PLA2R lev-els correlated with and preceded clinical response to RTX, suggesting that monitoring anti-PLA2R autoantibody levels may provide a window onto the immunologic ef-fects of treatment on the course of IMN, and allow a more specific and an earlier means of determining treatment effectiveness compared to the clinical response of de-creasing proteinuria.
We intend to explore the correlation of anti-PLA2R and disease activity by carefully looking at anti-PLA2R titer in response to RTX/CSA and the achievement of partial or complete remission (see supplemental in-formation on MENTOR remission cohort; for online suppl. material, see www.karger.com/doi/10.1159/000 430849). However, in order to avoid bias in the treat-ment of these patients, investigators will be blind to the results of anti-PLA2R antibodies until the study is com-pleted.
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Fervenza et al. NephronDOI: 10.1159/000430849
4
Design and Methods
Trial Aims and Hypothesis The specific aims of this Phase III trial are to test the hypothesis (1) that B-cell targeting with RTX is non-inferior to CSA in in-
ducing long-term remission (CR or PR) of proteinuria in patients with IMN.
(2) that B-cell targeting with RTX reduces the number of re-lapses (efficacy in sustaining remission) and increases the time to relapse when compared with treatment with CSA.
(3) that B-cell targeting with RTX is as effective as CSA in in-ducing CR or PR of proteinuria in patients with IMN during the active treatment phase.
(4) that B-cell targeting with RTX has a better side-effect profile and improved quality of life when compared with treatment with CSA in patients with IMN.
Protection for Human Subjects This clinical trial will be conducted in accordance with the Dec-
laration of Helsinki, and consistent with Good Clinical Practice and all applicable regulatory requirements. The study protocol has been reviewed and approved by the National Institutes of Diabetes, Digestive and Kidney Disease.
Patient Recruitment Inclusion and exclusion criteria are listed in table 1 . The study
population will be comprised of individuals with biopsy-proven IMN. The total study size will be 126 patients, enrolled among up to 25 participating sites. Potential candidates for the study will be identified by the investigators using existing databases and clinical trial networks.
Run-In Phase – Common Therapy for Both Arms The purpose of the run-in phase is to determine if an individ-
ual’s IMN can be adequately controlled through conservative, non-immunosuppressive treatment. If proteinuria can be brought below 5 g/24 h after 3 months or more of conservative therapy, the individual will not be eligible for randomized.
Blood Pressure Control and Angiotensin-II Blockade. The target blood pressure (<130/80 mm Hg in >75% of the readings; but not <100 mm Hg systolic) is chosen based on recent recommendations by the JNC VII [50] . The first step will be the introduction of an ACEi. Because this part of the study aims to maximize Ang II blockade, ACEi dose will be increased every 2 weeks until the max-imum tolerated/FDA approved dose is achieved or until intolera-ble side effects occur. Once ACEi dose has been maximized and there are no observable side-effects and/or blood pressure is not at target, an ARB will be added. The ARB dose will be increased every 2 weeks to achieve the maximum-tolerated or maximum-ap-proved dosage.
Concomitant Treatment. At the start of the run-in/conservative phase of the study, patients will be started on atorvastatin 10 mg/day. The dose should not be increased above the maximum of 40 mg/day. Patients will remain at the highest tolerated dose for the entire duration of the study. Serum lipids will be measured at Time 0 and every 3 months thereafter. Patients will be instructed to follow a low-salt diet (2–3 g/day), advised of a dietary protein target intake of 0.8–1.0 g/kg ideal body weight/day of high quality protein, and encouraged to maintain the same diet throughout the duration of the study. Patients with proteinuria >10 g/24 h and serum albu-min <2 g/dl will be considered for prophylactic anticoagulation.
Randomization and Treatment Groups Once all entry criteria have been satisfied and confirmed, pa-
tients will be randomized to treatment with RTX or CSA ( fig. 1 ). RTX. Patients randomized to the RTX arm will receive 1,000 mg
IV on days 1 and 15. Patients who achieve CR (defined as per table 2) at 6 months will not be retreated. A second course of RTX 1,000 mg IV will be administered at study month 6 for individuals who have not achieved a CR, but have achieved at least a ≥ 25% reduc-tion compared to their central laboratory baseline (Time 0) pro-teinuria. Dosing at study month 6 will be independent of CD19/20+ B-cell count. If after 6 months the reduction in proteinuria is less than 25% compared to baseline, the RTX treatment will not be re-peated, and the patient will exit from the study and will be consid-ered a failure of therapy. Patients randomized to receive RTX will
Table 1. Inclusion and exclusion trial criteria for patients
Inclusion criteria Exclusion criteria
–––
–
–
–
–
IMN diagnosed by renal biopsy. Age 18–80 years inclusive.If female, must be post-menopausal, surgically sterile or practicing a medically approved method of contraception.Patient must be off prednisone or mycophenolate mofetil for >1 month and alkylating agents for >6 months. Treatment with an ACEi and/or ARB, for ≥3 months prior to randomization and adequate blood pressure control or If patient is intolerant to even a very low dose of either ACEi or ARB therapy.Proteinuria ≥5 g/24 h using the average from two 24-hour urine collections collected within 14 days of each other despite Ang II blockade for ≥3 months as described above.Estimated GFR ≥40 ml/min/1.73 m2 while taking ACEi/ARB therapy or quantified endogenous creatinine clearance ≥40 ml/min based on a 24 h urine collection.
–
–
––
Patients with presence of active infection or a secondary cause of IMN (e.g. hepatitis B, SLE, medications, malignancies). Type 1 or 2 diabetes mellitus: to exclude proteinuria secondary to diabetic nephropathy. Patients who have recent history of steroid induced diabetes but no evidence on renal biopsy performed within 6 months of entry into the study are potentially eligible for enrollment.Pregnancy or breast feeding.History of resistance to CSA or other calcineurin inhibitors, RTX or alkylating agents. Patients who previously responded to CSA/CNI, RTX or alkylating agents with either a CR or PR but relapsed off CSA/CNI after 3 months, or relapsed off RTX or alkylating agent after 6 months, are eligible.
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Trial of Rituximab versus Cyclosporine in Idiopathic Membranous Nephropathy
NephronDOI: 10.1159/000430849
5
be started on single strength Bactrim (80 mg TMP/400 mg SMX) q.d. (or its equivalent) for pneumocystis pneumonia prophylaxis. This treatment will continue for at least the first 12 months and will be discontinued once B-cells (CD19/20+) have recovered.
The numbers of CD19/20+ B-cells in the peripheral blood will be quantified by flow cytometry using peripheral blood leukocytes. Flow cytometry will be performed before RTX treatment and at regular intervals following administration of RTX (see table 3 ; test schedule and monitoring for RTX treatment arm). These assays will allow us to follow the level of B-cell depletion, kinetics of B-cell reconstitution and the composition of cells that repopulate the B-cell pool after treatment with RTX as well as help in ensuring dosing adequacy in these patients.
CSA. Patients randomized to the CSA monotherapy arm will be started at a dose of CSA 3.5 mg/kg/day p.o. divided into 2 equal doses given at 12 h intervals. Target trough CSA blood levels, as determined in whole blood by HPLC, are 125–175 ng/ml. Patients will have their doses adjusted according to their blood levels of CSA as monitored every 2 weeks ± 3 days until the target trough level is reached. After reaching the target, CSA trough levels will continue to be checked as per the visit schedule ( table 4 ). If a CR is achieved by six months, CSA will be tapered by approximately 1/3 of the maintenance dose monthly and hence discontinued after two months. If there has been at least an equal to or >25% reduction compared to their central laboratory baseline (Time 0) proteinuria, CSA will be continued for an additional six months. A persistent and otherwise unexplained increase in serum creatinine >30% will
prompt an approximate 25% dose reduction of CSA, aiming for a corresponding 25% reduction in the CSA trough level. If with this dose reduction the creatinine does not return to within 30% of baseline levels within 3 weeks, then a second dose reduction of ap-proximately 25% with a similar reduction in CSA trough level will be implemented. If the creatinine does not fall to within 30% of baseline values with this second dose reduction, the drug will be discontinued. If after 6 months the reduction in proteinuria is less than 25% compared to baseline, the drug will be discontinued, and the patient will exit from the study and will be considered a failure of therapy. At the end of 12 months, CSA will be tapered by 1/3 of the maintenance dose monthly and hence discontinued at the end of 2 months. Serum potassium and serum creatinine levels will be checked at the initiation of CSA in conjunction with blood draw for CSA level. If the CSA dose is changed during treatment, potassium, creatinine and CSA levels will be rechecked every 2 weeks ± 3 days post increase/decrease in CSA dosage until levels are stable and at target. The use of corticosteroids is not allowed.
Outcomes Primary Endpoint. CR or PR at 24 months after randomization
will be the primary endpoint. Secondary Endpoints. (1) Relapse state at month 24 after ran-
domization (Urine Protein (UP) >3.5 g/24 h after earlier CR or PR). (2) Auto-antibodies to the M-type phospholipase A2 receptor (PLA2R) levels. (3) Quality of life as measured by modified KDQOL. (4) Adverse events. (5) ESRD. (6) CR or PR, and CR
Table 2. Definition of remission status
Remission status Proteinuria (UP g/24 h) after treatment
Complete remission UP ≤0.3 g/24 h and serum albumin ≥3.5 g/dlPartial remission Reduction in baseline UP of ≥50% plus final UP ≤3.5 g/24 h but >0.3 g/24 hNon-response Reduction in baseline UP of <25% (includes increase in UP) after 6 months of immunosuppressionRelapse Development of nephrotic range proteinuria following CR or PR, i.e. >3.5 g/24 h
Membranous nephropathy
RTX
At 6 months At 6 months
6 months
NR (<25% inproteinuria) CRPR
Observation
Observation for 12 months
Rx stops at 12 months
Retreat at6 monthsFailure
CSA
Exit
NR(<25%) CRPR
Observation
Observation for 12 months
Rx stops at 12 months
Continue RxFailure
Exit
Fig. 1. Schematic representation of the study design: patients will be randomized to a 12-month treatment period with IV RTX or oral cyclosporine. The efficacy of treatment will be assessed by the remission status (based on changes in proteinuria) at 24 months from randomization. Patient safety will be assessed via the collection of adverse event data and evaluation of pre- and posttreatment laboratory data. At the 6-month post-randomization visit, pa-tients who have been randomized to either CSA or RTX but who do not have a reduc-tion in proteinuria ≥ 25% will be considered treatment failures and exit the study. RTX = Rituximab; CSA = cyclosporine; NR = no response; PR = partial remission; CR = complete remission; Rx = treatment.
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Fervenza et al. NephronDOI: 10.1159/000430849
6
Ta
ble
3. T
est s
ched
ule a
nd m
onito
ring
for r
RTX
trea
tmen
t arm
Tests
/ass
essm
ents
Scre
enT0
Day
1 15
2890
/3
m18
0/6
m18
119
527
0/9
m30
0/10
m36
5/12
m42
5/14
m48
5/16
m54
5/18
m60
5/20
m66
5/22
m73
0/24
m79
0/26
m85
0/28
m91
0/30
m97
0/32
m1,
030/
34 m
1,09
5/36
m
Rand
omiz
atio
nX
Hist
ory/
exam
XX
XX
XX
XX
CBC
with
diff
eren
tial
XX
XX
XX
XX
BUN
, Cr,
lyte
s (in
clud
ing
pota
ssiu
m)/
albu
min
X
XX
XX
XX
X
PBFC
XX
XX3
Seru
m Ig
G, I
gA an
d Ig
MX
XX
X
Lipi
d pa
nel
XX
XX
HA
CAX
XX
Seru
m p
regn
ancy
XX
X
Urin
e pre
gnan
cyX
XX
X
Ant
i-PLA
2R an
tibod
ies
XX
XX
XXd
Xxc,
dXc,
dX
Xc, d
Xc, d
XXc,
dXc,
dXc,
dXc,
dXc,
dXc,
d
DN
A sa
mpl
eX
Gen
e exp
ress
ion
XX
X
UA
XX
XX
X
Upr
ot/U
crea
24
hX
XXX
XXX
XXXX
XX
Upr
ot/U
crea
(spo
t urin
e)Xd
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
24 h
crea
tinin
e for
CrC
lX
XX
XX
24 h
urin
e ure
aX
XX
X
24 h
urin
ary
Na+
XX
XX
Pre-
infu
sion
med
icat
ion
(i.e.
tyle
nol,
bena
dryl
)X
XX
X
Pre-
infu
sion
med
icat
ion
(i.e.
met
hylp
redn
isolo
ne)
XX
Ritu
xim
ab in
fusio
nX
XX
X
Qua
lity
of li
fe-K
DQ
OL
XX
XX
Adv
erse
even
tsX
XX
XX
XX
XX
XX
m =
Mon
ths;
PBFC
= p
erip
hera
l blo
od fl
ow cy
tom
etry
, qua
ntita
te B
and
T ce
ll su
bset
s; H
ACA
= h
uman
anti-
chim
eric
antib
odie
s, pr
e-in
fusio
n on
day
s 1 an
d at
6 m
onth
s and
9 m
onth
s. 3 In
th
e rar
e cas
e whe
re B
-cel
ls (C
D19
/20+
) are
not
repl
ete a
t mon
th 1
2, P
BFC
will
be r
epea
ted
at m
onth
18.
c For
par
ticip
ants
in th
e MEN
TOR
rem
issio
n co
hort
who
are i
n PR
or C
R at
12
mon
ths
or h
ave a
≥50
% re
duct
ion
in p
rote
inur
ia fr
om b
asel
ine b
y 12
mon
ths.
d For
par
ticip
ants
in th
e MEN
TOR
rem
issio
n co
hort
who
are i
n CR
at 6
mon
ths.
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Trial of Rituximab versus Cyclosporine in Idiopathic Membranous Nephropathy
NephronDOI: 10.1159/000430849
7
Ta
ble
4. T
est s
ched
ule a
nd m
onito
ring
for c
CSA
trea
tmen
t arm
Tests
/ass
essm
ents
Scre
enT0
Day
15
2890
/3
m18
0/6
m21
0/7
m24
0/8
m27
0/9
m30
0/10
m33
0/11
m36
5/12
m39
5/13
m42
5/14
m45
5/15
m48
5/16
m51
5/17
m54
5/18
m60
5/20
m66
5/22
m73
0/24
m85
0/28
m97
0/32
m1,
095/
36 m
Rand
omiz
atio
nX
Hist
ory/
exam
XX
XX
XX
XX
CBC
with
diff
eren
tial
XX
XX
XX
XX
BUN
, Cr,
lyte
s, al
bum
in (i
nclu
ding
po
tass
ium
)
XX
XX
XX
XX
CPK
XX
CSA
leve
l†X
XX
XX
X
Lipi
d pa
nel
XX
XX
Seru
m p
regn
ancy
XX
X
Ant
i-PLA
2R
antib
odie
sX
XX
XXd
XdX
XdXd
XXc
Xc, d
XcXc,
dXc
XXc,
dXc,
dX
Xc, d
Xc, d
Xc, d
DN
A sa
mpl
eX
Gen
e exp
ress
ion
XX
X
Pota
ssiu
m an
d Cr
1X
X
UA
XX
XX
X
Upr
ot/U
crea
24
hX
XXX
XXX
XXXX
XX
Upr
ot/U
crea
(s
pot u
rine)
dXd
XdXd
XdXc
Xc, d
XcXc,
dXc
Xc, d
Xc, d
Xc, d
Xc, d
Xc, d
24 h
crea
tinin
e for
Cr
ClX
XX
XX
24 h
urin
e ure
aX
XX
X
24 h
urin
ary
Na+
XX
XX
Qua
lity
of li
fe-K
DQ
OL
X
XX
X
Adv
erse
even
tsX
XX
XX
XX
XX
Disp
ense
/re
turn
med
icat
ion
XX
XX
XXa
XaXa
Xa, b
1 Pot
assiu
m, C
r che
cked
at 2
wee
ks ±
3 d
ays p
ost C
SA in
itiat
ion.
If C
SA is
incr
ease
d or
dec
reas
ed d
urin
g tr
eatm
ent,
pota
ssiu
m, C
r and
CSA
will
be r
eche
cked
afte
r 2 w
eeks
± 3
day
s. † Pati
ent
will
hav
e blo
od le
vels
of C
SA m
onito
red
ever
y 2
wee
ks ±
3 d
ays u
ntil
targ
et is
reac
hed
and
then
as p
er ab
ove s
ched
ule.
a Onl
y fo
r par
ticip
ants
who
cont
inue
on
CSA
at 6
mon
ths.
b Te
leph
one o
r in
-clin
ic v
isit t
o co
nfirm
succ
essfu
l dow
n-tit
ratio
n of
CSA
for p
atie
nts w
ho co
ntin
ue o
n m
edic
atio
n to
12
mon
ths (
if by
pho
ne, m
edic
atio
n sh
ould
be r
etur
ned
at 1
8-m
onth
visi
t). c F
or p
artic
i-pa
nts i
n th
e MEN
TOR
rem
issio
n co
hort
who
are
in P
R or
CR
at 1
2 m
onth
s or h
ave a
≥50
% re
duct
ion
in p
rote
inur
ia fr
om b
asel
ine b
y 12
mon
ths.
d For
par
ticip
ants
in th
e MEN
TOR
rem
issio
n co
hort
who
are i
n CR
at 6
mon
ths.
m =
Mon
ths.
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Fervenza et al. NephronDOI: 10.1159/000430849
8
alone at 6, 12, 18, and 24 months after randomization. (7) Time to CR or PR. (8) The effect of treatment on renal function, as assessed by slope of creatinine clearance from baseline to 24 months.
Patient Monitoring and Evaluation Patients will be followed for 2 years following randomization to
monitor the occurrence of adverse events, late remissions, relapses, glomerular filtration rate changes and development of ESRD. The first 12 months of the study will be considered the treatment period, while the remaining 12 months will be considered an observational period including the period of tapering to discontinuation in the CSA arm. Patients who cannot tolerate the medications and/or who are treatment failures at 6 months will exit the study at 6 months.
In addition, and as part of our ancillary studies (see supplemen-tal information), a remission cohort (including patients in PR or CR at 12 months or CR at 6 months as well as those who are not in remission, but have a ≥ 50% reduction in proteinuria from baseline by month 12) will be followed for an additional 12 months of ob-servation beyond the previous end point of observation of 24 months, to monitor for relapses and changes in PLA2R.
Anti-PLA2R Assay. Serum samples from all 126 subjects will be collected at the screening visit, Time 0, and months 3, 6, 9, 12, 18, and 24. The sera will be tested in batches for reactivity toward im-mobilized recombinant PLA2R by ELISA, with appropriate posi-tive and negative controls.
Pharmaceutical Logistics RTX will be provided free of charge by Genentech, Inc. (San Fran-
cisco, Calif., USA). Although CSA is recognized by insurance service providers as standard treatment for patients with IMN, participants randomized to the CSA arm will receive the drug free of charge. Neoral brand (Novartis) is the preferred CSA product for this trial.
Statistical Methods and Analysis Sample Size Estimation. RTX will be considered non-inferior to
CSA if the response rate of the RTX arm is at the most 15% worse than that of the CSA arm. The preliminary data has indicated that CSA is effective in inducing a CR/PR of proteinuria in between 60 and 75% of MN cases [28, 33] . However, NS relapses may be as high as 50% once CSA is discontinued [51] . Thus, we estimate a CR/PR rate in patients treated with CSA of 30–50% at 24 months after randomization [51] . Similar remission and relapse rates with the use of tacrolimus have been reported by Praga et al. [52]. In this latter study, almost half of the MN patients had a relapse of the NS after tacrolimus was discontinued [52] . On the other hand, based on the long-term follow-up on the 35 patients treated with RTX from our 2 studies, we estimate the relapse rate to be <10% at 24 months [40, 41] . To be conservative for the sample size estimation, we considered a maintained CR/PR rate at the low end of our pre-vious experience, 55% CR/PR for RTX at 24 months and at the high end of our experience with CSA (CNI therapy) CR/PR for CSA of 45%. We propose a non-inferiority trial with non-inferiority mar-gin δ = 15%, with the null hypothesis of πRTX – πcyclosprine <δ, where πRTX and πcyclosprine are the proportions of patients with CR/PR at 24 months in treatment arms of RTX and CSA, respec-tively. Under these assumptions, and a one-sided alpha of 0.025, enrollment of 63 evaluable patients per study arm is required to achieve 80% power to show that the RTX is not inferior.
Statistical and Analytical Plan. Frequency distributions will be used to describe categorical values and basic summary statistics to
describe continuous values. Duplicate urine measurements will be averaged. The Chi-square test and logistic regression will be used to compare the percent of patients with remission, adjusting for treatment center and baseline proteinuria (UP <8 g/24 h vs. ≥ 8 g/ 24 h). Odds ratios and associated 95% confidence intervals will be estimated. The formal test for the primary endpoint will be based on the significance of the treatment group factor in the logistic re-gression model for UP failure at month 24. The Wilcoxon rank-sum test and ordinal logistic regression will be used to compare the ordered remission status outcome (1 = CR, 2 = PR, 3 = NR) be-tween treatment groups. Longitudinal methods for categorical outcomes will be used to compare remission status profiles be-tween treatment arms. All tests will be two-sided with alpha level 0.05.
For repeated measures, individual rates of change will be esti-mated using within-patient linear regression analyses. Because of the nonlinearity of the changes in proteinuria, log transformation estimates will be used. Renal function readings will be censored at the initiation of dialysis or renal transplant. Additionally, mixed effects models, assuming a random center effect, and a random slope of creatinine clearance and/or reciprocal of creatinine and intercept for each patient will be fit using data from all visits. Treat-ment group comparisons regarding quality-of-life scales will be done using repeated measures analyses and mixed effects models.
Adverse events (both patient and event counts) will be tabu-lated by body system, severity and, for each severity, by investiga-tor-assessed relationship to study drug. Group comparisons for adverse events with 4 or more occurrences will be done using Chi-square or Fisher’s exact test. The last RTX injection is at 6 months and the tapering of CSA will be completed by the end of month 14. Hence, the adverse events analyses will focus on events through month 18, allowing these additional months for potential lingering CSA or RTX complications.
The analysis of the primary endpoint (CR or PR at month 24) will be intent-to-treat (ITT), and will include all randomized sub-jects in the analysis. For those without a 24-month visit, the 18-month visit results will be used if available; otherwise, they will be assumed to have failed at 24 months. Per protocol (PP) analyses will also be done including only those subjects who receive a full course of study medication and who have a 24-month visit.
Statistical analysis will be performed using JMP software pack-age version 8.0 (SAS Institute Inc., Cary, N.C., USA).
Discussion
The MENTOR trial is designed to test the hypothesis that RTX is non-inferior to CSA in inducing long-term remission of proteinuria, and safer than any of the other current regimens used to treat IMN.
There is growing evidence implicating abnormalities in B-cells in the pathogenesis of the disease [34–36] . Pilot studies support the efficacy of RTX in IMN; yet no evi-dence that RTX has beneficial effects on hard renal end points is currently available. The primary clinical end-points in this study are CR or PR at 24 months after ran-domization. Furthermore, we will evaluate the effect of
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Trial of Rituximab versus Cyclosporine in Idiopathic Membranous Nephropathy
NephronDOI: 10.1159/000430849
9
treatment on renal function, quality of life, adverse events, and anti-PLA2R levels. Therefore, this trial will provide significant information regarding the treatment of pa-tients with IMN and provide insight into the risks and benefits of rituximab and CSA therapy in IMN.
Cost estimates are also worth addressing. In the United States, the cost of 2 doses of RTX, 1,000 mg each is ∼ US$15,000, while the cost of CSA/TAC is approximately US$800/month. However, this cost calculations do not take into consideration the added cost of monitoring renal function, serum potassium, CSA/TAC levels, the need for additional anti-hypertensive therapy, as well as the time-/work hours cost involved with the need for frequent mon-itoring patients on CSA/TAC therapy. Nor does any of the current literature compare the quality of the patients’ life between these two therapies. Considering that >50% of the patients become calcineurin dependent, it can be argued that RTX may be more expensive upfront but the long-term treatment costs compared to CSA are similar. Fur-thermore, if a B-cell driven approach proves successful in future RTC trials, it could be argued that RTX not only would be less expensive but also associated with an im-provement in the quality of life due to avoidance of twice daily medication intake for extended periods of time.
Although this is an open-label study with neither pa-tients nor physicians blinded, with the exception of qual-ity-of-life measures, all endpoints are based on objective
(laboratory) criteria. Documentation of CSA levels will ensure that patients are taking the drug at the appropriate time and achieving the prescribed levels indicated in the protocol. Furthermore, the investigators will be blinded to the results, with the required exception of the Data Safety Monitor Board.
Acknowledgments
This study is supported by the Fulk Foundation and Genen-tech, Incorporated.
Trial Status
Recruitment began in November, 2011. Patient recruitment for the study is currently ongoing. Estimated study completion date of primary trial is September, 2016.
Trial Registration
ClinicalTrials.gov NCT01180036. Registered: August 10, 2010.
Competing Interests
F.C. Fervenza has received unrestricted research grant support from Genentech, Inc., the maker of rituximab.
References
1 Medawar W, Green A, Campbell E, Carmody M, Donohoe J, Doyle G, Walshe JJ: Clinical and histopathologic findings in adults with the nephrotic syndrome. Ir J Med Sci 1990; 159: 137–140.
2 Ruggenenti P, Chiurchiu C, Brusegan V, Ab-bate M, Perna A, Filippi C, Remuzzi G: Ritux-imab in idiopathic membranous nephropa-thy: a one-year prospective study. J Am Soc Nephrol 2003; 14: 1851–1857.
3 Cattran DC: Membranous nephropathy: quo vadis? Kidney Int 2002; 61: 349–350.
4 Wagoner RD, Stanson AW, Holley KE, Win-ter CS: Renal vein thrombosis in idiopathic membranous glomerulopathy and nephrotic syndrome: incidence and significance. Kid-ney Int 1983; 23: 368–374.
5 Ordoñez JD, Hiatt RA, Killebrew EJ, Fireman BH: The increased risk of coronary heart dis-ease associated with nephrotic syndrome. Kidney Int 1993; 44: 638–642.
6 Wheeler DC, Bernard DB: Lipid abnormali-ties in the nephrotic syndrome: causes, conse-quences, and treatment. Am J Kidney Dis 1994; 23: 331–346.
7 Giordano M, De Feo P, Lucidi P, DePascale E, Giordano G, Cirillo D, Dardo G, Signorelli SS, Castellino P: Effects of dietary protein restric-tion on fibrinogen and albumin metabolism in nephrotic patients. Kidney Int 2001; 60: 235–242.
8 Jafar TH, Stark PC, Schmid CH, Landa M, Maschio G, de Jong PE, de Zeeuw D, Shahinfar S, Toto R, Levey AS: Progression of chronic kidney disease: The role of blood pressure con-trol, proteinuria, and angiotensin-converting enzyme inhibition: a patient-level meta-analy-sis. Ann Intern Med 2003; 139: 244–252.
9 Apperloo AJ, de Zeeuw D, de Jong PE; AIPRD Study Group: Short-term antiproteinuric re-sponse to antihypertensive treatment predicts long-term GFR decline in patients with non-diabetic renal disease. Kidney Int Suppl 1994; 45:S174–S178.
10 Rossing P, Hommel E, Smidt UM, Parving HH: Reduction in albuminuria predicts di-minished progression in diabetic nephropa-thy. Kidney Int Suppl 1994; 45:S145–S149.
11 Gansevoort RT, Heeg JE, Vriesendorp R, de Zeeuw D, de Jong PE: Antiproteinuric drugs
in patients with idiopathic membranous glo-merulopathy. Nephrol Dial Transplant 1992; 7(suppl 1):91–96.
12 Ruggenenti P, Mosconi L, Vendramin G, Moriggi M, Remuzzi A, Sangalli F, Remuzzi G: ACE inhibition improves glomerular size selectivity in patients with idiopathic mem-branous nephropathy and persistent nephrot-ic syndrome. Am J Kidney Dis 2000; 35: 381–391.
13 Ambalavanan S, Fauvel JP, Sibley RK, Myers BD: Mechanism of the antiproteinuric effect of cyclosporine in membranous nephropathy. J Am Soc Nephrol 1996; 7: 290–298.
14 Rostoker G, Ben Maadi A, Remy P, Lang P, Lagrue G, Weil B: Low-dose angiotensin-con-verting-enzyme inhibitor captopril to reduce proteinuria in adult idiopathic membranous nephropathy: a prospective study of long-term treatment. Nephrol Dial Transplant 1995; 10: 25–29.
15 du Buf-Vereijken PW, Branten AJ, Wetzels JF: Idiopathic membranous nephropathy: outline and rationale of a treatment strategy. Am J Kidney Dis 2005; 46: 1012–1029.
Dow
nloa
ded
by:
Ver
lag
S. K
AR
GE
R A
G, B
AS
EL
172.
16.6
.51
- 6/
17/2
015
8:40
:31
AM
Fervenza et al. NephronDOI: 10.1159/000430849
10
16 Troyanov S, Wall CA, Miller JA, Scholey JW, Cattran DC; Toronto Glomerulonephritis Registry Group: Idiopathic membranous ne-phropathy: definition and relevance of a par-tial remission. Kidney Int 2004; 66: 1199–1205.
17 Mok CC, Ying KY, Ng WL, Lee KW, To CH, Lau CS, Wong RW, Au TC: Long-term out-come of diffuse proliferative lupus glomeru-lonephritis treated with cyclophosphamide. Am J Med 2006; 119: 355.e25–e33.
18 Meistrich ML, Parchuri N, Wilson G, Kurdo-glu B, Kangasniemi M: Hormonal protection from cyclophosphamide-induced inactiva-tion of rat stem spermatogonia. J Androl 1995; 16: 334–341.
19 Baltus JA, Boersma JW, Hartman AP, Van-denbroucke JP: The occurrence of malignan-cies in patients with rheumatoid arthritis treated with cyclophosphamide: a controlled retrospective follow-up. Ann Rheum Dis 1983; 42: 368–373.
20 Grünwald HW, Rosner F: Acute leukemia and immunosupressive drug use: a review of patients undergoing immunosuppressive therapy for non-neoplastic diseases. Arch In-tern Med 1979; 139: 461–466.
21 Smith AG, Prentice AG, Lucie NP, Browning JD, Dagg JH, Rowan RM: Acute myelogenous leukaemia following cytotoxic therapy: five cases and a review. Q J Med 1982; 51: 227–240.
22 Faurschou M, Sorensen IJ, Mellemkjaer L, Loft AG, Thomsen BS, Tvede N, Baslund B: Malignancies in Wegener’s granulomatosis: incidence and relation to cyclophosphamide therapy in a cohort of 293 patients. J Rheuma-tol 2008; 35: 100–105.
23 Kshirsagar AV, Nachman PH, Falk RJ: Alter-native therapies and future intervention for treatment of membranous nephropathy. Se-min Nephrol 2003; 23: 362–372.
25 Faul C, Donnelly M, Merscher-Gomez S, Chang YH, Franz S, Delfgaauw J, Chang JM, Choi HY, Campbell KN, Kim K, Reiser J, Mundel P: The actin cytoskeleton of kidney podocytes is a direct target of the antiprotein-uric effect of cyclosporine A. Nat Med 2008; 14: 931–938.
26 Rostoker G, Belghiti D, Ben Maadi A, Rémy P, Lang P, Weil B, Lagrue G: Long-term cyclo-sporin a therapy for severe idiopathic mem-branous nephropathy. Nephron 1993; 63: 335–341.
27 Cattran DC, Appel GB, Hebert LA, Hunsicker LG, Pohl MA, Hoy WE, Maxwell DR, Kunis CL: A randomized trial of cyclosporine in pa-tients with steroid-resistant focal segmental glomerulosclerosis. North America nephrotic syndrome study group. Kidney Int 1999; 56: 2220–2226.
28 Cattran DC, Appel GB, Hebert LA, Hunsicker LG, Pohl MA, Hoy WE, Maxwell DR, Kunis CL; North America Nephrotic Syndrome Study Group: Cyclosporine in patients with steroid-resistant membranous nephropathy:
a randomized trial. Kidney Int 2001; 59: 1484–1490.
29 Guasch A, Suranyi M, Newton L, Hall BM, Myers BD: Short-term responsiveness of membranous glomerulopathy to cyclospo-rine. Am J Kidney Dis 1992; 20: 472–481.
30 Yao X, Chen H, Wang Q, Tang Z, Hu W, Yin G, Liu Z, Li L: Cyclosporin A treatment for idiopathic membranous nephropathy. Chin Med J (Engl) 2001; 114: 1305–1308.
31 Alexopoulos E, Papagianni A, Tsamelashvili M, Leontsini M, Memmos D: Induction and long-term treatment with cyclosporine in membranous nephropathy with the nephrot-ic syndrome. Nephrol Dial Transplant 2006; 21: 3127–3132.
32 Goumenos DS: What have we learned from the use of ciclosporin A in the treatment of nephrotic patients with idiopathic membra-nous nephropathy? Expert Opin Pharmaco-ther 2008; 9: 1695–1704.
33 Cattran DC, Alexopoulos E, Heering P, Hoy-er PF, Johnston A, Meyrier A, Ponticelli C, Saito T, Choukroun G, Nachman P, Praga M, Yoshikawa N: Cyclosporin in idiopathic glo-merular disease associated with the nephrotic syndrome: workshop recommendations. Kidney Int 2007; 72: 1429–1447.
34 Kerjaschki D, Neale TJ: Molecular mecha-nisms of glomerular injury in rat experimen-tal membranous nephropathy (Heymann ne-phritis). J Am Soc Nephrol 1996; 7: 2518–2526.
35 Cupps TR, Edgar LC, Fauci AS: Suppression of human B lymphocyte function by cyclo-phosphamide. J Immunol 1982; 128: 2453–2457.
36 Zhu LP, Cupps TR, Whalen G, Fauci AS: Se-lective effects of cyclophosphamide therapy on activation, proliferation, and differentia-tion of human B cells. J Clin Invest 1987; 79: 1082–1090.
37 Beck LH Jr, Bonegio RG, Lambeau G, Beck DM, Powell DW, Cummins TD, Klein JB, Salant DJ: M-type phospholipase A2 receptor as target antigen in idiopathic membranous nephropathy. N Engl J Med 2009; 361: 11–21.
38 Zhu LP, Cupps TR, Whalen G, Fauci AS: Se-lective effects of cyclophosphamide therapy on activation, proliferation, and differentia-tion of human B cells. J Clin Invest 1987; 79: 1082–1090.
39 Remuzzi G, Chiurchiu C, Abbate M, Bruse-gan V, Bontempelli M, Ruggenenti P: Ritux-imab for idiopathic membranous nephropa-thy. Lancet 2002; 360: 923–924.
40 Fervenza FC, Cosio FG, Erickson SB, Specks U, Herzenberg AM, Dillon JJ, Leung N, Co-hen IM, Wochos DN, Bergstralh E, Hladune-wich M, Cattran DC: Rituximab treatment of idiopathic membranous nephropathy. Kid-ney Int 2008; 73: 117–125.
41 Fervenza FC, Abraham RS, Erickson SB, Iraz-abal MV, Eirin A, Specks U, Nachman PH, Bergstralh EJ, Leung N, Cosio FG, Hogan MC, Dillon JJ, Hickson LJ, Li X, Cattran DC; Mayo Nephrology Collaborative Group: Rituximab therapy in idiopathic membra-
nous nephropathy: a 2-year study. Clin J Am Soc Nephrol 2010; 5: 2188–2198.
42 Hofstra JM, Beck LH Jr, Beck DM, Wetzels JF, Salant DJ: Anti-phospholipase A2 receptor antibodies correlate with clinical status in id-iopathic membranous nephropathy. Clin J Am Soc Nephrol 2011; 6: 1286–1291.
43 Hofstra JM, Debiec H, Short CD, Pellé T, Kle-ta R, Mathieson PW, Ronco P, Brenchley PE, Wetzels JF: Antiphospholipase A2 receptor antibody titer and subclass in idiopathic membranous nephropathy. J Am Soc Nephrol 2012; 23: 1735–1743.
44 Kanigicherla D, Gummadova J, McKenzie EA, Roberts SA, Harris S, Nikam M, Poulton K, Mc-William L, Short CD, Venning M, Brenchley PE: Anti-PLA2R antibodies measured by ELISA predict long-term outcome in a prevalent popu-lation of patients with idiopathic membranous nephropathy. Kidney Int 2013; 83: 940–948.
45 Bech AP, Hofstra JM, Brenchley PE, Wetzels JF: Association of anti-PLA2R antibodies with outcomes after immunosuppressive therapy in idiopathic membranous nephropathy. Clin J Am Soc Nephrol 2014; 9: 1386–1392.
46 Hoxha E, Thiele I, Zahner G, Panzer U, Har-endza S, Stahl RA: Phospholipase A2 receptor autoantibodies and clinical outcome in pa-tients with primary membranous nephropa-thy. J Am Soc Nephrol 2014; 25: 1357–1366.
47 Ruggenenti P, Debiec H, Ruggiero B, Chianca A, Pellé T, Gaspari F, Suardi F, Gagliardini E, Orisio S, Benigni A, Ronco P, Remuzzi G: An-ti-phospholipase A2 receptor antibody titer predicts post-rituximab outcome of membra-nous nephropathy. J Am Soc Nephrol 2015;pii:ASN.2014070640.
48 Beck LH Jr, Bonegio RG, Lambeau G, Beck DM, Powell DW, Cummins TD, Klein JB, Salant DJ: M-type phospholipase A2 receptor as target antigen in idiopathic membranous nephropathy. N Engl J Med 2009; 361: 11–21.
49 Beck LH Jr, Fervenza FC, Beck DM, Bonegio RG, Malik FA, Erickson SB, Cosio FG, Cat-tran DC, Salant DJ: Rituximab-induced de-pletion of anti-PLA2R autoantibodies pre-dicts response in membranous nephropathy. J Am Soc Nephrol 2011; 22: 1543–1550.
50 Chobanian AV, Bakris GL, Black HR, Cush-man WC, Green LA, Izzo JL Jr, Jones DW, Materson BJ, Oparil S, Wright JT Jr, Roccella EJ; National Heart, Lung, and Blood Institute Joint National Committee on Prevention, De-tection, Evaluation, and Treatment of High Blood Pressure; National High Blood Pres-sure Education Program Coordinating Com-mittee: The seventh report of the joint nation-al committee on prevention, detection, evalu-ation, and treatment of high blood pressure: the JNC 7 report. JAMA 2003; 289: 2560–2572.
52 Praga M, Barrio V, Juárez GF, Luño J; Grupo Español de Estudio de la Nefropatía Membra-nosa: Tacrolimus monotherapy in membra-nous nephropathy: a randomized controlled trial. Kidney Int 2007; 71: 924–930.
