Immunovaccine Inc, a clinical stage immuno-oncology company, announced positive top-line clinical data from its ongoing Phase 1b trial evaluating the safety and efficacy of Immunovaccine’s lead immuno-oncology candidate, DPX-Survivac, in combination with Incyte’s IDO1 enzyme inhibitor epacadostat, and low-dose cyclophosphamide in patients with advanced ovarian cancer. Immunovaccine is conducting the trial in a collaboration with Incyte Corporation.
Initial results from ten evaluable patients in the DPX-Survivac plus 100 mg epacadostat dosing cohort demonstrate a disease control rate of 70%, including partial responses (PR, defined as ≥30% decrease in tumor lesion size) in 30% of the patients (three out of ten). To date, the combination also exhibited a well-tolerated safety profile, with the majority of adverse events (AEs) reported as Grade 1 and Grade 2, and only one potential treatment-related AE.
“Individuals with recurrent ovarian cancer, in particular, have not yet benefited from immunotherapy treatment breakthroughs in the way that those with other hard-to-treat cancers have,” said Frederic Ors, Chief Executive Officer of Immunovaccine. “We believe that these clinical results reported thus far for this combination immunotherapy in this patient population are promising. We are excited by the potential of DPX-Survivac to increase the number of individuals who may benefit from novel combination immunotherapies, and look forward to our continued work with Incyte and our other partners to increase the treatment options for such patients.”
Blood tests indicated that the majority of treated patients exhibited targeted T cell activation. Tumor biopsies and analyses thus far have supported the reported mechanism of action (MOA) of this immunotherapy combination, with DPX-Survivac triggering T cell infiltration into the tumor. This T cell activation was also correlated with tumor regression.
“These first data from this trial are consistent with our prior clinical findings, which indicated that DPX-Survivac could deliver best-in-class T cell activation,” continued Mr. Ors. “We believe that these results support the theory that our T cell activation can lead to tumor regressions, which is critical for advancing immunotherapy treatments for many types of cancer.”
About the Phase 1b Trial
The Phase 1b trial is a single-arm, non-randomized, open label, uncontrolled, safety and efficacy study for patients with advanced, platinum-sensitive and resistant ovarian cancer. Investigators completed enrollment of ten evaluable patients for the study’s first dosing cohort, which consists of 100 mg epacadostat twice daily (BID), DPX-Survivac, and low-dose cyclophosphamide.
In the first dosing cohort, investigators observed:
- A 30% overall response rate, with three out of ten PRs
- Two of the patients exhibiting PRs have completed one year of treatment with responses ongoing at 12 and 14 months, respectively
- Four patients (40%) had stable disease
- Two of the patients exhibiting stable disease are still enrolled in the trial, with one of those patients showing a 21% tumor reduction
- A 70% disease control rate (defined as the total number of patients achieving complete response, partial response, and stable disease)
At the time of data cut-off, there were also preliminary data on the first three evaluable patients in the second dosing cohort evaluating the combination of 300 mg BID epacadostat, DPX-Survivac, and low-dose cyclophosphamide. From the first three evaluable patients, two showed stable disease, with one patient showing tumor regression of approximately 25%. The second dosing cohort is ongoing and is expected to enroll 16 to 40 patients in total. Immunovaccine expects to provide a clinical update on the second dosing cohort in the first half of 2018 and investigators are also planning to submit the study findings for scientific publication.
“The activation of T cells is the hallmark of DPX-Survivac’s mechanism of action, and, we believe, this initial data shows, for the first time, a significant number of tumor regressions in a combination therapy clinical trial centered on T cell activation technology,” said Mr. Ors. “We are of the opinion that these data provide clinical proof-of-concept that significantly de-risks our development strategy for both our partners and shareholders, while potentially bringing future benefits to patients in need. We are looking forward to building on this solid foundation to accelerate the Company’s growth.”
Filed Under: Drug Discovery