The quote below is Dr Pazdur from OncLive today 5/15/13...
"The approval was based on the results of the ALSYMPCA trial, a phase III, double-blind, randomized, multinational study designed to compare radium-223 with a placebo and best standard care in patients with CRPC and at least two bone metastases. According to updated results presented at the 2012 American Society of Clinical Oncology (ASCO) Annual Meeting, radium-223 significantly improved overall survival (OS), with patients in the radium-223 arm of the study experiencing a median OS of 14.9 months compared with 11.3 months in the placebo arm (hazard ratio [HR] = 0.695; 95% CI, 0.581-0.832; P = .00007). Additionally, the time to the first skeletal-related event was a median of 15.6 months in the radium-223 arm of the study, a significant prolongation over the 9.8 months in the placebo arm (HR = 0.658; 95% CI, 0.522-0.830; P = .00037)."
If I understand the way the FDA works, I believe this approval raises the bar for Cabo. I know it's a bit like comparing apples to oranges, but the approval stats quoted above will become a major play in the numbers to beat for future approvals...at least wrt bone mets management. Time'll tell...
I agree; the AE profile from trials seems superior to placebo, though reading blogs seems to indicate that anemia occurs in many patients. On the other hand, there seems to be supply issues with Alpharadin for the short term, and its mechanism is also quite different from Cabo's; it's entirely possible that their effects stack and Alpharadin is far from a cure. Tivozanib in contrast wasn't especially novel in its mechanism.
The NRE data set from ASCO 2012 was pretty complete. The major addition tonight will be survival data. Let me warn you all in advance. There will be problems projecting the NRE data onto Comet 1&2. First is dose. The NRE was at 100mg and the Comets are at 60mg. Next is population. All NRE patients are docetaxel refractory, but Comet 1&2 are Docetaxel plus Abi/MDV refractory. Only 33 of the 93 NRE patients reported on matched this profile. EXEL looked at the Abiraterone COU-AA-301 phase three trial and concluded that a likely survival duration for the control arms for both Comet 1&2 was 7 months. That was the average survival period for patients who discontinued Abi. There is no guarantee that this number from the Abi trial will be recapitulated in the Comet trials. The NRE could be skewed by selection bias as physicians and patients were more willing to try another experimental drug for only the more mobile and active prospects with a better prognosis.
All of those limitations aside, tonight's number will be closely watched.