UC Irvine
UC Irvine Previously Published Works
Title
Rindopepimut with temozolomide for patients with newly diagnosed, EGFRvIII-expressing
glioblastoma (ACT IV): a randomised, double-blind, international phase 3 trial.
Permalink
https://escholarship.org/uc/item/2sg9m5wp
Journal
The Lancet. Oncology, 18(10)
ISSN
1470-2045
Authors
Weller, Michael
Butowski, Nicholas
Tran, David D
et al.
Publication Date
2017-10-01
DOI
10.1016/s1470-2045(17)30517-x
Peer reviewed
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1373
Articles
Rindopepimut with temozolomide for patients with newly
diagnosed, EGFRvIII-expressing glioblastoma (ACT IV):
a randomised, double-blind, international phase 3 trial
Michael Weller, Nicholas Butowski, David D Tran, Lawrence D Recht, Michael Lim, Hal Hirte, Lynn Ashby, Laszlo Mechtler, Samuel A Goldlust,
Fabio Iwamoto, Jan Drappatz, Donald M O’Rourke, Mark Wong, Mark G Hamilton, Gaetano Finocchiaro, James Perry, Wolfgang Wick,
Jennifer Green, Yi He, Christopher D Turner, Michael J Yellin, Tibor Keler, Thomas A Davis, Roger Stupp, and John H Sampson, for the ACT IV trial
investigators*
Summary
Background Rindopepimut (also known as CDX-110), a vaccine targeting the EGFR deletion mutation EGFRvIII,
consists of an EGFRvIII-specific peptide conjugated to keyhole limpet haemocyanin. In the ACT IV study, we aimed
to assess whether or not the addition of rindopepimut to standard chemotherapy is able to improve survival in patients
with EGFRvIII-positive glioblastoma.
Methods In this randomised, double-blind, phase 3 trial, we recruited patients aged 18 years and older with glioblastoma
from 165 hospitals in 22 countries. Eligible patients had newly diagnosed glioblastoma confirmed to express EGFRvIII
by central analysis, and had undergone maximal surgical resection and completion of standard chemoradiation
without progression. Patients were stratified by European Organisation for Research and Treatment of Cancer recursive
partitioning analysis class, MGMT promoter methylation, and geographical region, and randomly assigned (1:1) with
a prespecified randomisation sequence (block size of four) to receive rindopepimut (500 µg admixed with 150 µg
GM-CSF) or control (100 µg keyhole limpet haemocyanin) via monthly intradermal injection until progression or
intolerance, concurrent with standard oral temozolomide (150–200 mg/m² for 5 of 28 days) for 6–12 cycles or longer.
Patients, investigators, and the trial funder were masked to treatment allocation. The primary endpoint was overall
survival in patients with minimal residual disease (MRD; enhancing tumour <2 cm² post-chemoradiation by central
review), analysed by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01480479.
Findings Between April 12, 2012, and Dec 15, 2014, 745 patients were enrolled (405 with MRD, 338 with significant
residual disease [SRD], and two unevaluable) and randomly assigned to rindopepimut and temozolomide (n=371) or
control and temozolomide (n=374). The study was terminated for futility after a preplanned interim analysis. At final
analysis, there was no significant dierence in overall survival for patients with MRD: median overall survival was
20·1 months (95% CI 18·5–22·1) in the rindopepimut group versus 20·0 months (18·1–21·9) in the control group
(HR 1·01, 95% CI 0·79–1·30; p=0·93). The most common grade 3–4 adverse events for all 369 treated patients in the
rindopepimut group versus 372 treated patients in the control group were: thrombocytopenia (32 [9%] vs 23 [6%]),
fatigue (six [2%] vs 19 [5%]), brain oedema (eight [2%] vs 11 [3%]), seizure (nine [2%] vs eight [2%]), and headache
(six [2%] vs ten [3%]). Serious adverse events included seizure (18 [5%] vs 22 [6%]) and brain oedema (seven [2%]
vs 12 [3%]). 16 deaths in the study were caused by adverse events (nine [4%] in the rindopepimut group and seven [3%]
in the control group), of which one—a pulmonary embolism in a 64-year-old male patient after 11 months of
treatment—was assessed as potentially related to rindopepimut.
Interpretation Rindopepimut did not increase survival in patients with newly diagnosed glioblastoma. Combination
approaches potentially including rindopepimut might be required to show ecacy of immunotherapy in glioblastoma.
Funding Celldex Therapeutics, Inc.
Introduction
Glioblastoma is the most common malignant primary
brain tumour in adults. Its annual incidence is more
than three per 100 000 people worldwide without
major regional variation, and men are aected more
frequently than women.
1
The standard of care—maximum
feasible surgical resection followed by radiotherapy with
concomitant and maintenance temozolomide chemo-
therapy—generally leads to a median overall survival of
about 15 months.
2,3
The tumour-treating fields device, recently reported to
extend survival to 20·5 months, represents an additional
treatment option for glioblastoma.
4
Treatment at
recurrence, which might include second surgery, re-
irradiation, alkylating chemotherapy using nitrosoureas
such as lomustine or temozolomide rechallenge, or
antiangiogenic therapy using bevacizumab, is less well
standardised and has not shown a significant improvement
in survival in a randomised trial. Poor prognostic factors
include poor performance status, older age, incomplete
Lancet Oncol 2017; 18: 1373–85
Published Online
August 22, 2017
http://dx.doi.org/10.1016/
S1470-2045(17)30517-X
See Comment page 1294
*Investigators who participated
in this trial are listed in the
appendix
Department of Neurology
(Prof M Weller MD) and
Department of Oncology
(Prof R Stupp MD), University
Hospital and University of
Zurich, Zurich, Switzerland;
Department of Neurological
Surgery, University of
California, San Francisco, CA,
USA (N Butowski MD);
Washington University,
St Louis, MO, USA
(D D Tran MD); Stanford
University Medical Center, Palo
Alto, CA, USA (L D Recht MD);
The Johns Hopkins Hospital,
Baltimore, MD, USA
(M Lim MD); Juravinski Cancer
Centre, Hamilton, ON, Canada
(H Hirte MD); Barrow
Neurological Institute,
Phoenix, AZ, USA (L Ashby MD);
DENT Neurologic Institute,
Buffalo, NY, USA
(L Mechtler, MD); John Theurer
Cancer Center, Hackensack, NJ,
USA (S A Goldlust MD);
Columbia University Medical
Center, New York, NY, USA
(F Iwamoto MD); University of
Pittsburgh Medical Center,
Pittsburgh, PA, USA
(J Drappatz MD); Department
of Neurosurgery, Perelman
School of Medicine, University
of Pennsylvania, Philadelphia,
PA, USA (D M O’Rourke MD);
Westmead Hospital,
Westmead, NSW, Australia
(M Wong MD); University of
Calgary, Department of Clinical
Neurosciences, Division of
Neurosurgery, Foothills
Hospital, Calgary, AB, Canada
(Prof M G Hamilton MD);
Fondazione IRCCS Istituto
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Neurologico Carlo Besta, Milan,
Italy (G Finocchiaro, MD);
Sunnybrook Health Sciences
Centre, Toronto, ON, Canada
(Prof J Perry MD); The University
of Heidelberg and German
Cancer Research Center,
Heidelberg, Germany
(Prof W Wick MD); Celldex
Therapeutics, Inc, Hampton,
NJ, USA (J Green BS, Y He PhD,
C D Turner MD, M J Yellin MD,
T Keler PhD, T A Davis MD); and
The Preston Robert Tisch Brain
Tumor Center, Duke University
Medical Center, Durham, NC,
USA (Prof J H Sampson MD)
Correspondence to:
Dr Michael Weller, Department of
Neurology, University Hospital
and University of Zurich,
8091 Zurich, Switzerland
michael.weller@usz.ch
See Online for appendix
resection, and an unmethylated promoter of the DNA
repair gene, O⁶-methylguanine-DNA methyltransferase
(MGMT). Novel treatment approaches to glioblastoma are
therefore urgently needed, and immunotherapy has now
become the major area of clinical research.
The EGFR gene is amplified in more than 40% of
glioblastomas, and EGFR amplification is frequently
associated with a deletion mutation aecting exons 2–7,
referred to as EGFRvIII or delta-EGFR. EGFRvIII
expression occurs in roughly 20–30% of all glio-
blastomas.
5–7
The potential immunogenicity of the
EGFRvIII mutation, first recognised several decades ago,
resulted in the development of rindopepimut—a peptide
vaccine containing the specific novel aminoacid sequence
created by the EGFRvIII deletion mutation conjugated to
keyhole limpet haemocyanin. Rindopepimut has been
explored in two small single-group phase 2 trials,
ACTIVATE
8
and ACT II,
9
as well as a larger phase 2 trial
ACT III,
6
which was initially planned as an open-label,
randomised phase 3 trial but was converted to a
single-group design after near-complete voluntary attrition
of the first 16 patients randomly assigned to receive temo-
zolomide alone.
In these trials, about 100 patients with
EGFRvIII-expressing glioblastoma who had received a
gross total resection and had no evidence of progression
after radiotherapy with concomitant temozolomide were
given rindopepimut alone (ACTIVATE) or rindopepimut
with adjuvant temo zolomide (ACT II and ACT III). The
results of these three trials showed a consistent and
encouraging progression-free survival in the range of
15 months from diagnosis and overall survival of
24 months from diagnosis, which compared favourably
with contemporary patient cohorts who received standard
treatment (appendix p 8). The selection of patients with
minimal residual disease (MRD) in all these trials after
completion of chemoradiation was based on the
assumption that MRD would minimise the tumour-
associated immuno suppression typical of glioblastoma.
ACT IV was designed as a pivotal, randomised, placebo-
controlled, phase 3 clinical trial to assess whether or not
Research in context
Evidence before this study
We searched PubMed for scientific literature published in
English before Aug 1, 2011, using the search terms
“glioblastoma” and publication type “randomized controlled
trial” or “clinical trial, phase III”. The standard of care for newly
diagnosed glioblastoma established in 2005—maximum
feasible surgical resection followed by radiotherapy and
temozolomide chemotherapy—is associated with median
overall survival of about 15 months. Despite the introduction of
several investigational approaches in the subsequent years, no
treatment has successfully shown further improvements in
survival. The addition of the search term “EGFRvIII” and
expansion of our search to any clinical trial did not identify any
other agents specifically targeting EGFRvIII. Finally, a search
including “glioblastoma”, “EGFRvIII”, and “survival” produced a
few retrospective studies showing similar or worse median and
long-term survival for patients whose tumour expressed
EGFRvIII. Three previous studies of rindopepimut have been
done in patients with newly diagnosed, EGFRvIII-expressing
glioblastoma and minimal residual disease (MRD). In these
studies, rindopepimut was associated with a strong
anti-EGFRvIII humoral immune response, a notable reduction in
EGFRvIII expression in available recurrent tumour samples, and a
median survival of 20–22 months, as compared with about
12 months for a small matched contemporary dataset and
15 months for the small subset of patients with newly
diagnosed EGFRvIII-expressing glioblastoma randomly assigned
to receive standard of care treatment in the ACT III study.
Added value of this study
To our knowledge, ACT IV is the first randomised trial to assess
the efficacy of an EGFRvIII-targeted treatment for patients with
newly diagnosed glioblastoma. Despite the strong anti-EGFRvIII
immune response generated in patients, the primary study
analysis did not show a survival benefit for patients with MRD
who received rindopepimut with temozolomide versus those
who received temozolomide alone. We recorded a potential
long-term survival benefit in exploratory analyses of a subset of
patients with significant residual disease (SRD), which might
challenge the view that minimal tumour burden is required for
immunotherapy to be effective. Also notable is that patients in
the control group fared markedly better than matched control
datasets available at the time of study design, suggesting that
glioblastoma outcomes have improved since the study was
originally designed.
Implications of all the available evidence
Our results question the utility of immunotherapy targeting a
single tumour antigen with heterogeneous tumour expression,
as well as the optimal setting for evaluation of immunotherapy.
Patients with more substantial residual disease expressing the
target antigen might experience greater benefit from generation
of targeted immunity than those with completely resected
disease. Recent data from a randomised, double-blind, phase 2
study in recurrent EGFRvIII-positive glioblastoma (the ReACT
study) suggest a prominent treatment effect (overall survival
HR 0·53, 95% CI 0·32–0·88; p=0·013) for rindopepimut when
combined with standard bevacizumab versus bevacizumab
alone. Its combination with temozolomide might compromise
an immunological effect, by contrast with bevacizumab. The
results of ACT IV also question the predictive value of both
historical control datasets (matched patients from non-study
databases) and small randomised phase 2 trial datasets (such as
ACT III) as a basis for the design of phase 3 studies. These data
lend support to further clinical trials that use combination
strategies such as immunotherapy with angiogenesis inhibition.
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the addition of rindopepimut to standard temozolomide
chemotherapy increased overall survival compared with
that for temozolomide alone in patients with newly
diagnosed EGFRvIII-expressing glioblastoma.
Methods
Study design and participants
ACT IV was a randomised, double-blind, phase 3 study
done at 165 hospitals in 22 countries (appendix p 12). The
study was open to men and women aged 18 years and
older with newly diagnosed EGFRvIII-expressing glio-
blastoma. Confirmation of glioblastoma histology and
EGFRvIII expression analysis from resected tissue by real-
time (RT) PCR were done centrally (LabCorp, Research
Triangle Park, NC, USA). Patients must have undergone
maximal surgical resection and have completed standard
radiotherapy (up to 60 Gy) with concomitant temozolomide
(75 mg/m² per day).
2
To be eligible, at least 90% of the
planned radiotherapy dose had to be delivered. Patients
had to have tumour tissue specimens (paran-embedded)
from surgical resection available for central pathology
review, MGMT status determination, and analysis of
EGFRvIII status. Exclusion criteria were disease
progression during chemoradiation, any additional
tumour-specific treatment for glioblastoma, inability to
taper corticosteroids to 2 mg of dexamethasone or lower
(or equivalent) per day for at least 3 days before
randomisation, Eastern Cooperative Oncology Group
(ECOG) performance status of 3 or higher in the week
before randomisation, diuse leptomeningeal disease,
gliomatosis cerebri, infratentorial disease, active infection,
metastatic disease, and immunosuppressive disease.
An independent imaging review committee (BioClinica,
Princeton, NJ, USA) assessed post-operative and post-
chemoradiation brain MRIs, and retrospectively classified
patients as having either MRD (<2 cm² of residual
enhancing tumour on post-chemoradiation imaging) or
significant residual disease (SRD; ≥2 cm² of residual
enhancing tumour on post-chemoradiation imaging).
The study was compliant with the Declaration of
Helsinki and Good Clinical Practice guidelines. Ethics
approval was obtained at all participating centres and all
patients provided written informed consent. The full trial
protocol can be found in the appendix.
Randomisation and masking
Eligible patients were stratified by MGMT promoter
methylation status (methylated vs unmethylated vs
unknown), European Organisation for Research and
Treatment of Cancer (EORTC) recursive partitioning
analysis class (III vs IV vs V),
10,11
and geographical region
(North America and western Europe vs all other regions),
and were randomly assigned (1:1) to the treatment groups
with a prespecified randomisation sequence with a block
size of four. Unblinded pharmacists who were otherwise
uninvolved in study conduct obtained randomly assigned
treatment assignments and managed study treatment via
interactive response technology. Study treatments were
prepared in the pharmacy and given to study sta in
blinded (label included patient ID and expiry information),
pre-loaded syringes. Keyhole limpet haemocyanin was
given as a control injection to produce a local reaction
similar to that expected with rindopepimut to maintain
the treatment blind. Pharmacovigilance sta at the study
funder and contract research organisation received
treatment assignments for individual patients when
necessary to comply with international safety reporting.
Pharmacy records were audited by an independent team
of contract research organisation sta. The study data
monitoring committee and the supportive independent
statistical group at the contract research organisation
viewed unblinded data. All other study sta, patients, and
investigators remained masked to treatment assignments.
Procedures
All patients received standard maintenance temozolomide
administered orally at a dose of 150–200 mg/m² on
days 1–5 of each 28-day cycle, for 6–12 cycles,
2
or longer if
consistent with the local standard of care. Patients
randomly assigned to the rindopepimut group also
received 500 µg of rindopepimut admixed with 150 µg
GM-CSF (Leukine, Sanofi Aventis, Bridgewater, NJ, USA),
while the control group received 100 µg keyhole limpet
haemocyanin (Biosyn, Carlsbad, CA, USA). Each 0·8 mL
dose was given as two to eight separate intradermal
injections into the skin of the thigh below the groin. The
allowance for between two and eight injections allowed
for a smaller volume of individual intradermal injections,
potentially reducing patient discomfort and risk of
leakage. Experimental treatment was started 7–14 days
after completion of standard chemoradiation, and was
given as two initial priming doses (on study days 1 and 15),
then monthly on day 22 of each temozolomide cycle and
continuing after the end of maintenance temozolomide
until disease progression or intolerance. Because all
toxicities related to rindopepimut vaccination were
expected to be immunologically mediated, no adjustment
to the dose of double-blind vaccine was allowed; however,
dose omission or delay was allowed for toxicity.
Brain MRI scans were done within 14 days after
completion of chemoradiation, every 8 weeks for
6 months, every 12 weeks from 6 months through year 2,
every 16 weeks from years 2–4, and every 26 weeks
thereafter, or until documented disease progression.
Tumour response and progression were assessed
according to the Response Assessment in Neuro-
Oncology (RANO) Working Group criteria,
12
with
minor modifications for the purpose of protocol standard-
isation (appendix p 9). Local investigator assessments
guided individual treatment decisions. The retrospective
imaging review committee assessment, masked to
treatment assignment and investigator assessments, was
used for the primary analyses of progression-free survival
and objective tumour response.
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Safety assessments included monthly physical
examination, vital signs, routine laboratory monitoring
(haematology on days 1 and 22 of each cycle, and blood
chemistry and urinalysis on day 1 of each cycle), and
evaluation of adverse events using National Cancer
Institute Common Terminology Criteria for Adverse
Events (CTCAE; version 4.0). The MD Anderson
Symptom Inventory Brain Tumor (MDASI-BT) and
EORTC Core Quality of Life Questionnaire (QLQ-C30)
and Brain Cancer Module (BN20) were completed every
month throughout treatment by patients who were fluent
in a language in which the questionnaires were validated.
To assess EGFRvIII expression, formalin-fixed paran-
embedded tumour tissue was analysed centrally (LabCorp,
Research Triangle Park, NC, USA). EGFRvIII variant and
EGFR wild-type status were ascertained with a Taqman-
based RT-PCR assay done on an ABI Prism (Applied
Biosystems Corporation, Foster City, CA, USA) 7900HT
instrument. The fluorescence detected was directly
proportional to the amount of RNA present and expressed
as cycle threshold. We used a predefined cuto expressed
as delta cycle threshold (cycle threshold of EGFRvIII
minus that of EGFR wild type) of 11·0 or lower to define a
sample as positive for EGFRvIII. The threshold, which
was selected as a conservative cuto to minimise the
possibility of including EGFRvIII-negative patients, was
defined by the delta cycle threshold values of samples
from the ACT III study that showed unambiguous calls of
positive (n=9) or negative (n=10) by corroboration of
immunohistochemistry and PCR results, confirmed by
reproducibility testing and accuracy verification.
To assess MGMT promoter methylation status,
formalin-fixed paran-embedded tumour samples were
analysed centrally at LabCorp under licence from MDx
Health (Irvine, CA, USA) by methylation-specific PCR,
based on previously published methods.
13
To assess humoral responses to the vaccine, antibody
titres were measured by ELISA with microtitre plates
directly coated with a 14-aminoacid peptide, which spans
the exons 1–8 junction of EGFR and is specific for the
EGFRvIII mutant.
14
Dilutions of patient plasma were
incubated in the plates, and the anti-EGFRvIII antibodies
were detected with an Fc-γ-specific goat anti-human
F(abʹ)2 antibody conjugated to horseradish peroxidase
(Jackson ImmunoResearch Labs, West Grove, PA, USA)
followed by tetra-methylbenzidine substrate. Absorbance
was measured at wavelength of 450 nm. Patient samples
were screened and positive samples titred against a plate-
specific floating cuto point. We calculated the antibody
titre for patient samples as the highest dilution with an
optical density value greater than the mean plus three
times the standard deviation (SD) of replicate-negative
control samples run on the same plate. Because the
starting dilution was 1:100, we reported samples that
screened negative with titres lower than 1:100. For post-
hoc exploratory analyses of survival, patients were
retrospectively classified according to the trajectory at
which anti-EGFRvIII titres developed with rindopepimut
treatment (slow, moderate, or rapid).
Typing of HLA class I alleles (A and B loci)
and HLA class II alleles (with a –DR locus) by serology
or DNA-PCR was done by an American Society for
Histocompatibility and Immunogenetics-accredited
laboratory (ClinImmune Labs, Aurora, CO, USA) using
buccal swab samples.
Outcomes
The primary endpoint was overall survival (defined as the
time from randomisation to death) in patients with newly
diagnosed, EGFRvIII-positive glioblastoma and MRD.
Patients with SRD formed a second exploratory cohort
that had not been included in previous studies; overall
survival was assessed in these patients and in the entire
patient cohort (all randomised patients) as supportive
secondary analyses. Secondary endpoints were
progression-free survival (defined as the time from
randomisation to disease progression or death, whichever
occurred first), the proportion of patients achieving an
objective tumour response (a confirmed complete or
partial response according to the RANO criteria), health-
related quality of life (assessed with the MDASI-BT,
QLQ-C30, and BN20), and to further characterise the
safety profile and overall immunogenicity of rindopepimut
in patients with both MRD and SRD. Correlative endpoints
were the specific humoral responses to EGFRvIII and
post-treatment EGFRvIII expression status.
Statistical analysis
Patients classified with MRD by the imaging
review committee were included in the modified
intention-to-treat population for the primary analysis of
overall survival. 283 deaths in the MRD population at the
time of the final analysis were calculated to provide
80% power to detect a target hazard ratio (HR) of 0·714,
which corresponded to a 6-month improvement in
median overall survival (from 15 months for the control
group to 21 months for the rindopepimut group). The
target number of deaths was based on a one-sided log-
rank test, overall type I error rate of 0·025, and
two planned interim analyses of overall survival for
superiority using an O’Brien-Fleming group sequential
monitoring plan. Allowing for a 48-month accrual period
and 10% attrition rate, a sample size of 374 patients with
MRD was expected to result in 283 deaths within
72 months of the first randomly assigned patient.
Supportive secondary analyses of overall survival were
done for all randomly assigned patients (intention-to-
treat analysis). To control the family-wise error rate (the
probability of making one or more false discoveries when
performing multiple hypotheses tests), study analyses
were to proceed according to a fixed sequence procedure
in which the primary analysis was completed for the
MRD population (modified intention to treat) and
all enrolled patients (intention to treat) sequentially,
