DPX-Survivac Shows Durable Responses in Advanced Ovarian Cancers, Trial Data Show

DPX-Survivac Shows Durable Responses in Advanced Ovarian Cancers, Trial Data Show

A combination of IMV‘s immunotherapy DPX-Survivac plus intermittent low-dose cyclophosphamide leads to sustained responses in women with heavily-treated advanced ovarian cancer, with some responses lasting more than 10 months, updated findings from a Phase 1/2 clinical trial show.

“We believe these results highlight DPX-Survivac’s potential to alter the treatment landscape in advanced ovarian cancer and support its continued development,” Joanne Schindler, MD, chief medical officer at IMV, said in a press release.

The results were presented recently by Oliver Dorigo, MD, PhD, the trial’s principal investigator, at the American Society of Clinical Oncology 2020 (ASCO20) Virtual Scientific Program. The poster is titled “Infiltration of of tumor by T cells following treatment with DPX-Survivac and intermittent low dose cyclophosphamide (CPA) leads to clinical responses in advanced recurrent ovarian cancer (OvCa).

DPX-Survivac is a new class of T-cell immunotherapy designed to stimulate the immune system to target and destroy cancer cells, specifically those that have at their surface a protein called survivin, known to promote tumor growth.

The therapy consists of small fractions of the survivin protein, which are delivered as an under-the-skin injection to induce a durable activation of T-cells (immune cells with the ability to fight cancers) against survivin-positive cancers.

The DECIDE1 trial (NCT02785250) is evaluating a combination of DPX-Survivac and low-dose cyclophosphamide for ovarian cancer patients whose cancer came back after surgery and at least one chemotherapy regimen.

At the time of the analysis, 19 of the 22 enrolled patients were evaluated for effectiveness, four of whom were still undergoing treatment. All patients had been heavily treated, with a median number of three prior therapies.

The results showed that five patients (26%) attained a partial response — defined as at least 30% tumor regression — and 10 others had stable disease (53%), including five with tumor regression that was not enough to be called a response. In total, this amounted to a disease control rate of 79%.

Clinical benefits lasting more than six months were seen in seven (37%) patients, and five of them (71%) went on to show benefits for more than 10 months. Among these, three had a partial response and two achieved stable disease for almost one year.

Researchers also reported that one patient with stable disease on a prior analysis had converted to partial response, supporting “the potential for responses to deepen over time with ongoing therapy,” said Schindler.

The presence of survivin-specific T-cells within tumors had been reported to correlate with tumor regression in these patients. About 87% of patients generated these cells, and some had these immune cells within their tumors as early as day 56 after treatment.

“IMV’s targeted T-cell therapy continues to elicit a rapid and robust immune response with survivin-specific T cells infiltrating tumors as soon as 56 days post-treatment,” said Dorigo, who also is an associate professor and director of gynecologic oncology at Stanford University in California.

“These results validate DPX-Survivac’s unique mechanism of action and support the hypothesis that survivin-specific T cells can translate into clinical benefits when sustained over an extended period of time,” he added.

Treatment, in general, was well-tolerated, with most treatment-related adverse events (side effects) being mild-to-moderate reactions at the injection site.

“With these results, DPX-Survivac continues to exhibit significant and durable anti-tumor activity, paving the way for targeted T cell therapies in advanced recurrent ovarian cancer and other solid tumors,” said Schindler.

“Additionally, DPX-Survivac continues to be well tolerated, which is especially meaningful compared to single-agent chemotherapy and other approaches in development,” Schindler added.

DPX-Survivac has been granted fast track designation by the U.S. Food and Drug Administration as maintenance therapy for advanced ovarian cancer. It also has received orphan drug status from the FDA and the European Medicines Agency for ovarian cancer treatment.