Due Diligence on the short case for VBLT and my response: Part two.
Concluding on ovarian, some skeptics felt the survival benefit between low and high cohorts for ovarian was not due to VB-111 but due to platinum. The low dose arm was 40mg weekly platinum versus 80 mg weekly platinum for the high dose arm. But I can't see how this is relevant since half of the patients were primary platinum resistant and all of the them were platinum refractory!
A final confounding point(my own)... from my reading of ovarian cancer, RECIST data is not the be and end all as many of the patients have metastatic disease that is more diffusely spread with ascites and microscopic seeding. This may make CA-125 reduction a more important surrogate marker for survival than RECIST in ovarian, despite what the shorts/skeptics argue. From my read on survival benefits, RECIST criteria is not the gold standard in examining or predicting overall survival(neither is CA-125 reduction although it is in terms of a clinical response to therapy). Both have their advocates and detractors. I found several articles on CA-125 response as being correlated with overall survival. In defense of the company here, this was a small scale run by Harvard(Harvard paid for the study to be run--not VBLT). Neither Harvard nor the company had/put up the needed funds to perform a randomized, double-blinded, adequately powered trial here. This was a phase I, turned into a phase II by definition. Ovarian was not initially on the companies radar.
