Veliparib: Phase II data

Researchers at the University of California, San Francisco and colleagues said a veliparib-containing regimen "graduated" from the open-label Phase II I-SPY 2 trial based on having a high probability of success in patients with triple-negative breast cancer (TNBC) in a Phase III trial. The trial is designed to rapidly and inexpensively develop data to support small Phase III trials of new neoadjuvant therapies for locally advanced breast cancer or to help companies quickly kill ineffective candidates. I-SPY 2 involves an adaptive trial design based on Bayesian predictive probability that a regimen will be statistically superior to standard therapy in an equally randomized 300-patient confirmatory trial.

In patients with TNBC, veliparib plus carboplatin and paclitaxel followed by anthracycline-based chemotherapy prior to surgery led to an estimated pCR rate of 52% vs. 26% for paclitaxel followed by anthracycline-based chemotherapy prior to surgery. Additionally, the Bayesian predictive probability of showing statistical superiority for the veliparib-containing regimen compared to standard therapy in a 300-patient Phase III trial to treat TNBC is 92%. In patients with HER2-negative breast cancer, the veliparib-containing regimen led to an estimated pCR rate of 33% vs. 22% for the control arm. The Bayesian predictive probability of showing statistical superiority for the veliparib-containing regimen compared to standard therapy in a 300-patient Phase III trial to treat HER2-negative breast cancer is 55%. The veliparib portion of the trial enrolled 134 patients - 72 in the veliparib arm and 62 in the control arm. Data were presented at the San Antonio Breast Cancer Symposium. AbbVie could not be reached for next steps for the veliparib-containing regimen. ...