Sunitinib-Induced Hemoglobin Changes Are Related to the Dosing Schedule
"Does that mean COMET-2 was a unnecessary waste of money?"
Absolutely not. IMO Comet 2 will read out before Comet 1, perhaps up to a full year sooner. I firmly believe that the Comet 2 positive outcome on its primary endpoint is virtually a lock. We talked about the de Bono data. That 51 patient cohort was a trial run for Comet 2. It used the same patient reporting outcome tool used in Comet 2 with the phone response system. All patients were required to be docetaxel refractory and 2/3 were Abi/MDV refractory. It did not have the 2 week narcotic normalization period leading in to the treatment phase. Comet 2 will use a 60mg dose vs de Bono's 40mg. Here are the reported pain results: "A clinically significant reduction of pain, defined as a ≥30% decrease in BPI pain score, was observed in 18 patients (69%). Fifty-four percent of patients decreased their use of narcotics, including one patient who discontinued narcotics. The majority of patients in whom these improvements were observed had received both prior docetaxel and prior abiraterone or enzalutamide." Comet 2 will require patients to have successive periods of pain response to be considered " durable responders." Past history is that this requirement will knock that 69% rate down to the mid 50's. The primary endpoint for Comet 2 is a comparison of the number of durable responders on Cabo vs the number of durable responders on Mito. Mito's history suggests an approx 8% response rate. Compare that to Cabo's anticipated 55% rate. That is why I describe this trial as shooting fish in a barrel. In the SPA fiasco FDA did not reject a pain endpoint. FDA rejected an overly permissive protocol that would have anticipated an approval with a very low level of efficacy. EMA approval off Comet 2 is very likely and IMO FDA approval is probable.