Peregrine Pharmaceuticals has announced results from its randomized phase II trial, which is designed to determine overall response rate of carboplatin and paclitaxel with or without bavituximab in 86 patients with front-line, Stage IIIb and Stage IV non-small cell lung cancer. Patients treated with bavituximab plus carboplatin and paclitaxel demonstrated a current median PFS estimate of 5.8 months versus 4.6 months in patients treated with carboplatin and paclitaxel alone, a 26% improvement.
These results are consistent with a prior phase II single-arm study testing the same bavituximab combination in front-line NSCLC patients which showed a 6.1 month median PFS.
Patients demonstrated a current median PFS estimate of 6.7 months for the bavituximab-containing arm and 6.4 months for the chemotherapy-only arm. Peregrine clinical & regulatory affairs vice president Joseph Shan said while the data from the investigator assessments were in alignment with previous published reports for carboplatin and paclitaxel and suggested an encouraging difference between the treatment arms, the unexpected long PFS estimate for the control arm based on central reads confounds the company’s ability to fully interpret this secondary efficacy endpoint.
“We now await median OS data from this study which is the most clinically relevant endpoint from a drug development standpoint,” Shan said.
The company expects to report median overall survival (OS) from this trial in the second half of 2012. According to the study, patients treated with bavituximab plus carboplatin and paclitaxel demonstrated an ORR of 25%, versus 23% in patients treated with carboplatin and paclitaxel alone.
The study also showed that Investigator-determined response rates were 32% for bavituximab plus carboplatin and paclitaxel versus 31% for carboplatin and paclitaxel alone.
Peregrine president and chief executive officer Steven King said while the company had hoped the PFS results in this study would be more consistent, the company is encouraged by what it has seen so far in the trial and now look forward to the final and perhaps most important endpoint from the study, median OS. “In the coming months, we plan to unblind the second-line NSCLC Phase II trial and announce interim data from our Phase II trial in pancreatic cancer,” King said.