Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT02237638 |
Other study ID # |
NL45279.000.13 |
Secondary ID |
|
Status |
Completed |
Phase |
Phase 1
|
First received |
|
Last updated |
|
Start date |
April 2014 |
Est. completion date |
January 1, 2020 |
Study information
Verified date |
April 2021 |
Source |
VU University Medical Center |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The primary objectives of this study are to investigate the safety and tolerability profile
of the therapeutic vaccine hVEGF26-104/RFASE and to determine the effective dose of
hVEGF26-104/RFASE required to neutralize VEGF in serum, defined as a VEGF level below 9,0
pg/mL.
Description:
Angiogenesis (the formation of new blood vessels from pre-existing blood vessels) plays an
important role in the growth and spread of tumors. Angiogenesis is regulated by a balance of
activators and inhibitors. One of the angiogenic activators is the vascular endothelial
growth factor (VEGF, also referred to as VEGF-A). Over the past decade, several angiogenesis
inhibitors have been discovered and implemented in the therapy of cancer patients.
Bevacizumab (a humanized monoclonal antibody that inhibits VEGF-A) has been shown to improve
survival in different tumor types in first and second line therapy when given in various
chemotherapy combinations. Furthermore, research has shown a survival benefit of continued
VEGF suppression with bevacizumab beyond first progression in metastatic colorectal cancer.
So although repeated use of bevacizumab as a chronic therapy is much desired, currently this
is not feasible because of substantial disadvantages of bevacizumab therapy. First, since
bevacizumab only offers temporary VEGF neutralization, it needs frequent repeated
administration. Secondly, bevacizumab is an intravenous therapy, which requires
hospitalization on each administration. Third, bevacizumab has very high production costs.
These specific drawbacks of longer term monoclonal antibody therapy could be circumvented by
the use of a therapeutic cancer vaccine targeting VEGF. A vaccine is able to induce sustained
VEGF suppression and can be administered via an intramuscular (IM) injection. In addition, a
vaccine will likely inhibit VEGF more effectively as compared to bevacizumab, because a
vaccine induces a polyclonal antibody response, resulting in higher avidity binding.
Furthermore, it is believed that endogenous antibodies have a better tumor penetrating
capacity, as compared to exogenously administered antibodies. The vaccine hVEGF26-104 is a
truncated synthetic peptide mimic of the VEGF protein and consists of 79 amino acids (residue
26-104). The vaccine contains an antigen that directs the body's own polyclonal antibody
response towards the active site of the endogenous VEGF molecule. After binding of the
antibodies to endogenous VEGF this hormone will no longer be able to bind to its receptors
(VEGFR1 and VEGFR2) and consequently will no longer exert its pro-angiogenic effect. To
enhance the immune response, RFASE, which belongs to the adjuvant group of
sulpholipopolysaccharides, will be used as an adjuvant.
Primary objectives - To investigate the safety and tolerability profile of hVEGF26-104/RFASE.
- To determine the effective dose of hVEGF26-104/RFASE required to neutralize VEGF in serum,
defined as a VEGF level below 9,0 pg/mL.
Secondary objectives - To determine the anti-VEGF antibody titer, induced by
hVEGF26-104/RFASE administration. - To determine the effective dose of hVEGF26-104/RFASE
required to neutralize VEGF in plasma and in a platelet sample. - To assess the effect of
VEGF neutralization in a functional Ba/F3-R2 cell proliferation assay.
Exploratory objectives - To assess the cellular anti-tumor immune response induced by
hVEGF26-104/RFASE administration. - To assess immunomodulatory effects upon hVEGF26-104/RFASE
administration. - To make a preliminary assessment of hVEGF26-104/RFASE to suppress
angiogenesis within the tumor. - To assess the immune infiltration and the regulation of
endothelial cell adhesion molecules within the tumor.
This is an open label single center phase I study. A "3 + 3 " dose escalation design will be
used. The study will investigate sequential cohorts consisting of 3 patients to be enrolled
and treated at the applicable dose level. The study medication consists of 1.0 mL hVEGF26-104
(in escalating doses of 62.5, 125, 250 and 500 µg/mL) combined with 1.0 mL RFASE (fixed dose
of 20 mg/mL). Eligible subjects will receive three IM injections with hVEGF26-104/RFASE on
days 0 (primer), 14 and 28 (boosters). To assess potential toxicity of the adjuvant RFASE,
the 3 patients enrolled in the first cohort of the study (62.5 μg/mL) will receive a single
injection with 1.0 mL RFASE (fixed dose of 20 mg/mL) as a single agent 14 days prior to the
first immunization with hVEGF26-104/RFASE. If none out of 3 patients experiences dose
limiting toxicity (DLT) at a certain dose level, one can proceed to the next dose level. If
one patient experiences a DLT at a certain dose level, another 3 patients will be assigned at
the same dose level. In the highest dose escalation cohort, at least 6 patients will be
enrolled. If VEGF is no longer neutralized, but there is no sign of progression either; the
patient will receive another booster of hVEGF26-104/RFASE in order to achieve VEGF
neutralization again. This booster can be repeated until progressive disease, death or other
reasons for withdrawal from the study.
Eligible subjects will receive three intramuscular injections with hVEGF26-104/RFASE in
dose-escalation on days 0 (primer), 14 and 28 (boosters), followed by an observation period
of 6 weeks. Blood will be drawn at given timepoints to assess safety, immunogenicity and
angiogenesis parameters. At screening, a tumor biopsy will be performed for a baseline
assessment of angiogenesis and immune infiltration. In the case that VEGF is neutralized 8
weeks after first hVEGF26-104 administration, the patient will be asked to undergo another
biopsy at week 10 to assess any possible change in angiogenesis and immune infiltration in
the tumor. If VEGF is no longer neutralized, but there is no sign of progression either; the
patient will receive another booster of hVEGF26-104/RFASE in order to achieve VEGF
neutralization again.