RXi Pharmaceuticals Corporation (NASDAQ: RXII), a biotechnology company focused on discovering, developing and commercializing innovative therapies addressing major unmet medical needs using targeted biotherapeutics, presented Phase 2 efficacy results for NeuVax™ in combination with trastuzumab (Herceptin®; Genentech/Roche) at the American Society of Clinical Oncology (ASCO) annual meeting. The poster entitled, “Sequential administration of trastuzumab and a CD8 T cell-eliciting HER-2/ neu peptide vaccine in breast cancer patients compared to trastuzumab alone,” was presented during the “Breast Cancer HER2/ER” poster session on Monday, June 6, 2011. RXi is developing NeuVax, a CD8 T-cell eliciting immunotherapy, for the adjuvant treatment of low to intermediate HER2 expressing breast cancer.
Data from the E75 Phase 2 breast cancer trial and another CD8 T cell eliciting peptide were analyzed, and the control arms of each trial were combined for this analysis. Of 187 patients enrolled in the E75 trial, 108 received vaccine and 79 were in the control arm. Of the vaccine treated patients 15 received Tz. A total of 32 patients in the combined control arms received Tz (trastuzumab). The recurrance rate for the control arm was 12.5% (4/32), comparable with reported rates of similarly staged and treated patients. The recurrance rate for the NeuVax +Tz arm was 0% – no patients receiving vaccine after adjuvant Tz relapsed. A total of 30 patients were treated with Tz followed by vaccine, with zero patients recurring (0/30, p=0.06).
“These preliminary results indicate the potential for immunotherapy combined with Tz therapy for the improved treatment HER2 3+ breast cancer patients. The results of this trial clearly warrant a randomized Phase 2 study with NeuVax in combination with trastuzumab to confirm efficacy and safety in a larger population,” stated COL George E Peoples, MD, FACS, Director, Cancer Vaccine Development Program; Deputy Director, United States Military Cancer Institute; Professor (adjunct), Surgical Oncology, MD Anderson Cancer Center; Professor, Surgery, Uniformed Services University; Chief, Surgical Oncology, Brooke Army Medical Center (BAMC).