Peregrine drug reportedly doubles lung cancer survival in trial
UPDATE 9/24/2012: Peregrine reports discrepancies with regard to the result reported below, causing stock price to plunge and confidence in bavituximab program to falter. For more, see story here.
TUSTIN, Calif.—Peregrine Pharmaceuticals Inc. announced Sept. 10 that interim results were presented from its 121- patient randomized, double-blind, placebo-controlled Phase IIb trial of bavituximab in patients with refractory non-small cell lung cancer (NSCLC), with results that were strongly positive and the company felt warranted moving the compound toward Phase III trials.
The study evaluated two dose levels of bavituximab (the bavituximab-containing arms) given with docetaxel vs. docetaxel plus placebo (the control arm). The interim data showed a statistically significant improvement in overall survival (Hazard Ratio 0.524, p-value .0154) and a doubling of median overall survival in the bavituximab-containing arms compared to the control arm.
"This study was a rigorous trial designed to minimize bias, and we are encouraged that this trial yielded such positive results in the most important endpoint, overall survival. The positive overall response rates and progression free survival in both bavituximab-containing arms seen earlier in the study has now translated into a statistically significant extension in overall survival for patients, a result rarely achieved in phase II clinical trials." said Joseph Shan, vice president of clinical and regulatory affairs at Peregrine. "The quality of this data gives us a solid foundation for designing a phase III trial with an increased probability of success. We are planning for an end-of-phase II meeting with the FDA as we plan to initiate this trial by mid-2013."
The trial enrolled 121 patients (117 evaluable per the study protocol) with second-line non-squamous NSCLC following one prior chemotherapy regimen at over 40 clinical centers. Patients were equally randomized to one of the three treatment arms, docetaxel (75mg/m2) plus either placebo, 1 mg/kg bavituximab, or 3 mg/kg bavituximab until disease progression. Approximately 50 percent of the patients were enrolled in the United States and the rest were enrolled internationally, with equal distribution between all treatment groups.
"Robust data from this Phase II trial clearly demonstrate a significant benefit in overall survival with a good safety profile in patients receiving bavituximab plus docetaxel compared to those receiving docetaxel plus placebo," said Steven W. King, president and CEO of Peregrine. "We are currently in discussions with several potential pharmaceutical partners who have expressed great interest in our bavituximab oncology program. It is our goal to identify the optimal partner to assist with the design and logistics of a multinational Phase III pivotal trial. "
The interim results from the study showed no significant safety differences between the three treatment arms as determined by the trial's independent data monitoring committee. Baseline characteristics were well balanced across all three treatment arms of the study, including performance (ECOG) status, age, gender, and race. Tumor responses were determined in accordance with Response Evaluation Criteria In Solid Tumors (RECIST 1.1) based on blinded central radiology review.
"The median overall survival results from the proof-of-concept study are truly outstanding and great news for patients. Statistically significant overall survival results at this stage of development are rare and have put us in an excellent position for advancing the program. Our attention is now turned to an end of phase II meeting by year end which will help us define the most efficient path forward to potential regulatory approval," said Dr. Robert Garnick, head of regulatory affairs at Peregrine. "A global Phase III trial designed very similarly to the robust design of this Phase II trial greatly increases bavituximab's likelihood of success."