Clinical investigators will assess the safety and efficacy of Immunovaccine's DPX-Survivac cancer vaccine candidate in combination with Merck's checkpoint inhibitor Pembrolizumab in patients with recurrent, platinum-resistant ovarian cancer. Study participants will also receive metronomic cyclophosphamide, which is a low-dose regimen with immuno-modulating effects.
PM listed the trial on www.clinicaltrials.gov and expects to initiate active enrollment following completion of the contract between Immunovaccine and UHN, and pending regulatory clearance from Health Canada.
Immunovaccine CEO Frederic Ors said: "Ovarian cancer is a main focus for Immunovaccine as we continue to develop DPX-Survivac.
"Combination therapies – particularly those with anti-PD-1 activity – are emerging as increasingly promising approaches for hard-to-treat cancers. We believe that the robust immunogenic and safety clinical profile for DPX-Survivac, along with its unique complementary activity to anti-PD-1 agents, which may boost their response rates, position our immuno-oncology candidate as an optimal co-therapy in this disease area."
The non-randomized, open-label trial is designed to evaluate the potential anti-tumor activity of the combination of Pembrolizumab, DPX-Survivac, and low-dose cyclophosphamide. It is expected to enroll 42 subjects with advanced epithelial ovarian, fallopian tube or primary peritoneal cancer.
The study's primary objective is to assess overall response rate (ORR). Secondary study objectives include progression free survival (PFS) rate, overall survival (OS) rate, and potential side effects, over a five-year period.
Amit M. Oza, Bsc (Hons), MBBS (Lon), MD (Lon), FRCPC, FRCP, Senior Staff Physician and Associate Professor of Medicine at PM is the lead investigator. Merck is funding this study and contributing materials. Immunovaccine is also contributing its product candidate as well as a related portion of analytical assays.
Dr. Oza said: "Ovarian cancer is among the most challenging cancers to treat, as it is associated with poor response rates to currently available medical interventions.
"To support the tens of thousands of women battling this disease, we need to develop new and novel approaches. With this trial, we have the opportunity to explore a novel combination of promising immunotherapies."
DPX-Survivac is Immunovaccine's lead immuno-oncology candidate, generated by its novel proprietary DepoVax adjuvanting technology platform. The DPX-Survivac target, survivin, is present in more than 20 types of solid tumor and hematologic cancers. It is involved in multiple critical pathways of cancer cell growth and survival.
Prior results from a Phase 1/1b study indicated that DPX-Survivac combined with a low dose of cyclophosphamide was highly immunogenic in individuals with high-risk ovarian cancer, inducing survivin- specific T cell immune responses in most trial participants.
The company has shown in other studies that a combination immunotherapy using a DepoVax-based vaccine could enhance the anti-tumor effects of a PD-1 blockade. Even tumors previously non-responsive to treatment with anti-PD-1 agents alone exhibited controlled cancer growth when combined with Immunovaccine's DepoVax-based compound.
In addition to this Phase 2 trial, Immunovaccine is conducting a Phase 1b trial with Incyte Corporation to evaluate the triple combination of DPX-Survivac with Incyte's investigational oral indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor, Epacadostat (INCB24360), and low-dose oral cyclophosphamide in patients with platinum sensitive or resistant ovarian cancer.
Immunovaccine expects to announce top-line interim results for this Phase 1b trial by the end of March 2017.