TapImmune is advancing two clinical-stage T-cell vaccine candidates in multiple Phase II and Phase Ib/IIa clinical trials, with ongoing clinical trials in ovarian and breast cancers. The U.S. market alone is very large for these cancers, with approx. 30,000 ovarian cancer patients, 40,000 triple negative breast cancer patients, and 220,000 Her2/neu breast cancer patients newly diagnosed with disease every year.

The current treatment options are surgery, radiation and chemotherapy, which can be effective initially, but the time to recurrence is relatively short for these cancers and survival prognosis is extremely poor following recurrence. New treatment options are urgently needed and an advanced immunotherapy approaches holds significant promise.

TapImmune’s clinical candidates have been validated in Phase I studies and fully vetted by industry and clinical leaders. The company is developing its programs in strategic collaboration with Mayo Clinic, Memorial Sloan Kettering Cancer Center, and AstraZeneca, and with significant non-dilutive funding from the U.S. Department of Defense. TapImmune’s novel vaccine candidate, TPIV200, has been granted both Orphan Drug and FDA Fast Track Designation for treating ovarian cancer and is also eligible for Fast Track Designation for triple-negative breast cancer.

TPIV200 – Phase II T-cell Vaccine Candidate Targeting Folate Receptor Alpha

TPIV200 is TapImmune’s lead immunotherapeutic candidate currently in Phase II clinical development for treating ovarian and breast cancers. It is a T-cell vaccine consisting of five naturally processed peptide antigens derived from the highly prevalent tumor cell surface molecule, Folate Receptor Alpha (FRa). FRa is overexpressed by ~90% of ovarian cancer cells and 80% of triple-negative breast cancer cells, making it an ideal target for comprehensive immunotherapy. Higher levels of FRa expression are also associated with cancer recurrence.

A completed Phase I study of TPIV200 that included stage II-III ovarian, peritoneal, and Fallopian tube cancer patients showed that 95% of evaluable patients generated robust immune responses to TPIV200 and 100% of patients demonstrated T-cell responses lasting six months or longer. These results were published in the Journal of Clinical Oncology and led to significant partnerships for Phase II development.

TapImmune and its collaborators are currently recruiting patients for 2 ongoing Phase II studies of TPIV200, including a fully funded 280 patient Triple Negative Breast Cancer study sponsored by Mayo Clinic.

TPIV110 – Phase I/II T-cell Vaccine Candidate Targeting HER2/neu

HER2/neu receptor-related cancer is a very aggressive form of breast cancer that affects a subset of patients. This molecule is overexpressed by ~30% of breast cancer cells and it is a well characterized molecular target for anti-cancer treatments, with approved drugs like Herceptin (an antibody-based HER2/neu inhibitor) generating annual sales in excess of $6 billion.

TapImmune’s novel T-cell vaccine targeting HER2/neu, TPIV110, consists of five carefully selected HER2/neu antigens. Similar to TPIV200, the mix of antigens that comprise TPIV110 were selected for binding to both MHC class I and class II. This mix of epitopes is expected to cover a significantly larger HER2/neu patient population than Herceptin (up to 90% vs. Herceptin’s 15-20%) and remain effective for significantly longer. In addition, published data show that TPIV110 is five-fold more effective at killing HER2/neu cancer cells compared to Neuvax*, a HER2/neu-targeted peptide immunotherapy currently in development.

In a completed Phase I study of TPIV100 (a predecessor to the current candidate TPIV110 that contains only four class II HER2/neu antigens), the vaccine was safe and well-tolerated by HER2/neu+ breast cancer patients. In this study, 95% of patients showing robust T-cell responses to two antigens and 75% of patients responded to all four antigens. An additional MHC class I antigen was added to create the current TPIV110 formulation, for which a Phase Ib/II trials are scheduled to begin in 2017 following submission of an updated IND. The first study, sponsored by TapImmune, will be in HER2/neu+ breast cancer and the other is expected to enroll patients with DCIS (ductal carcinoma in situ) breast cancer, which will be conducted in collaboration with the Mayo Clinic.

* Compared to E-75 (Neuvax). J. Immunol. (2013) 190, 479-488