Ovarian and Breast Cancer Vaccine Candidate Posts Positive Clinical Trial Results

A clinical-stage, immuno-oncology company announced positive results from an ongoing ovarian and breast cancer clinical trial.

A small, Phase 1 trial of TPIV200, is a multi-epitope T-cell vaccine targeting Folate Receptor Alpha (FRa) in patients with ovarian and breast cancer.

Patients were immunized over a six-month period following pretreatment with cyclophosphamide and then monitored for an additional twelve months.

This study showed that TPIV200 vaccination was well tolerated by all patients and over 90% developed robust and durable antigen-specific immune responses against FRa without regard for the human leukocyte antigen (HLA) type, which aligns with the intended mechanism of action of the vaccine.

The study "Folate Receptor Alpha Peptide Vaccine Generates Immunity in Breast and Ovarian Cancer Patients," will be published in the leading peer-reviewed oncology journal Clinical Cancer Research and will be available online today.

The Phase 1 study was not designed to show efficacy and involved a small number of patients.

TapImmune has published a white paper that further details this preliminary data and its potential implications for the company's ongoing Phase 2 clinical trial of TPIV200 in women with platinum-sensitive ovarian cancer.

Dr. Richard Kenney, Acting Chief Medical Officer for TapImmune, stated, "There remains a significant unmet need in ovarian cancer to delay or prevent disease recurrence following successful platinum-based therapy.”

“That is why TapImmune is focusing on TPIV200 immunotherapy at this earlier stage in the treatment paradigm where no approved therapies currently exist in the ongoing Phase 2 study.” 

"Women in first remission are likely to have healthier immune systems, having not gone through multiple rounds of chemotherapy and cancer recurrence, and may be better positioned to benefit from vaccination with TPIV200,” said Dr. Kenney.

The company said this study demonstrated that the TPIV200 vaccine generated robust immune responses and was well tolerated by all patients, with only one Grade 3 adverse event related to vaccination (a local ulceration that resolved).

Generation of T-cell immunity following immunization was robust and long-lasting. Analysis showed 91% of patients had an antigen-specific response, with 89% of those patients responding to multiple epitopes included in TPIV200 (median=3/5 FRa epitopes).

Additionally, T-cell responses developed slowly over the course of vaccination, with a median time to maximal immunity of five months. As is desired for a therapeutic vaccine, this T-cell immunity to FRa was durable, with antigen-specific T-cells remaining at high levels through the 12-month post-immunization monitoring period.

Finally, the company reported it was observed that ovarian cancer patients who entered the study in their first remission (n=10) had a median progression-free survival time of 528 days (95% confidence interval 110-548 days).

TapImmune Inc. is in the development of novel immunotherapies for cancer.