Peregrine Pharmaceuticals has announced top-line overall response rate (ORR) and current median progression free survival (PFS) estimates from its Phase II trial comparing bavituximab plus carboplatin and paclitaxel versus carboplatin and paclitaxel alone in patients with front-line Stage IIIb and Stage IV non-small cell lung cancer (NSCLC).
Bavituximab, a first-in-class phosphatidylserine (PS)-targeting monoclonal antibody, is being evaluated in seven clinical studies, including three randomised Phase II trials in front-line and second-line non-small cell lung cancer (NSCLC), front-line pancreatic cancer and four investigator-sponsored trials (ISTs) in additional oncology indications.
The randomised Phase II non-small cell lung cancer (NSCLC) trial enrolled 86 patients to compare the ORR of carboplatin and paclitaxel with or without bavituximab in patients with front-line, Stage IIIb/IV NSCLC.
Based on the study data, patients treated with bavituximab plus carboplatin and paclitaxel demonstrated a 26% improvement in current median PFS compared to patients treated with carboplatin and paclitaxel alone.
In the study, ORR was determined by both investigators and independent central imaging review using Response Evaluation Criteria in Solid Tumors (RECIST).
Based on independent central imaging reads, patients reported a current median PFS estimate of 6.7 months for the bavituximab-containing arm and 6.4 months for the chemotherapy-only arm.
The trial also showed that patients treated with bavituximab plus carboplatin and paclitaxel demonstrated an ORR of 25%, versus 23% in patients treated with carboplatin and paclitaxel alone.
Investigator-determined response rates were 32% for bavituximab plus carboplatin and paclitaxel versus 31% for carboplatin and paclitaxel alone.
Joseph Shan, vice president of clinical & regulatory affairs at Peregrine said: "We are pleased that the PFS results for the bavituximab-containing arm by both local and central image interpretation actually met or exceeded our expectations going into the study. 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 our ability to fully interpret this secondary efficacy endpoint."
Peregrine president and chief executive officer Steven King said in the coming months, the company plans to unblind the second-line NSCLC Phase II trial and announce interim data from the Phase II trial in pancreatic cancer.
The company expects to report median overall survival (OS) data from the trial in the second half of this year.