Text from Abstract:
Aims
The Vascular disrupting agent (VDA) fosbretabulin tromethamine selectively targets pre-existing tumor vasculature causing vascular shutdown leading to cell death and necrosis. Anti-angiogenesis agents like bevacizumab, a humanized anti-VEGF monoclonal antibody, might prevent revascularization after/during VDA treatment.
Methods
Patients with recurrent/persistent epithelial ovarian, tubal, or peritoneal carcinoma; measurable or detectable disease; and < 3 prior regimens were randomized to bevacizumab (15 mg/kg IV q 3weeks) or bevacizumab (15 mg/kg) + fosbretabulin (60 mg/m2) IV every 3 weeks until disease progression or toxicity. Randomization was stratified by disease status (measurable vs. non-measurable), prior bevacizumab, and platinum-free interval. The primary endpoint was progression-free survival (PFS). The study was designed with 80% power at a 10% level of significance to detect a hazard ratio (HR) reduction of 37.5%.
Results
The study enrolled 107 patients. Median PFS was 4.8 and 7.3 months for bevacizumab and bevacizumab+ fosbretabulin, respectively (HR = 0.685; 90% 2-sided CI=0.47 ~1.00). The proportion responding to bevacizumab was 28.2% (90% CI 16.7 ~ 42.3%) among 39 patients with measurable disease and 35.7% (90% CI 23.5 ~ 49.5%) among 42 patients treated with the combination. Adverse events (> grade 2) were more common in the combination particularly hypertension (35% versus 16%). There was one grade 3 thromboembolic event with the combination. One intestinal perforation in the bevacizumab arm was observed.
Conclusion
Based on the PFS and tolerability of these two anti-vascular therapies, further evaluation is warranted for this chemotherapy-free regimen. Fosbretabulin in combination with bevacizumab may double the risk of hypertension.
Company also indicated it would report on the additional data presented, so I expect we'll see a PR pre-market tomorrow.
GLTA,
Murocman