Dasatinib combo fails to improve outcomes in mCRPC
OncLive today 2/15/13
"The only positive finding for dasatinib was an increase in median time to first skeletal-related event; it was not yet reached in the dasatinib arm versus 31.1 months in the placebo arm (HR = 0.81; 95% confidence interval [CI], 0.64-1.02].
“Dasatinib targets bone. The modest decrease in time to first skeletal related event will be analyzed further,” Araujo said"
Wait'll these guys see P3 mCRPC results on Cabo-resolved SRE's...
There doesn't seem to be much benefit at all to Dasatinib, no PFS or pain palliation effects. It is causing a delay in the first SRE in patients, but it looks like this isn't sufficient for improving OS; there also doesn't seem to be any reports of effects on soft tissues. Looks like SRC is more of an intermediary in the cascade of signals in Prostate cancer, and blocking AR \ c-Met expression seems to be more of an earlier stopper for the complex cascade of signals. I'd be interested in seeing the extent of Dasatinib's bone effects as compared to Cabo.
Here's what published in the P1-2 study of dasatinib plus docetaxel in CRPC, Logothetis, et al March 2011. BSR appears minimal, but bone scan was not considered important the trial.
"Among all 46 patients, bone scan response was improved (disappearance of at least 1 lesion) in 14 patients (30%) and stable (no new bone lesions at ≥18 weeks) in 19 patients (41%). Nine patients (20%) had no new bone lesions at 6 and/or 12 weeks but were not scanned further because of discontinuation from the study. Three patients (7%) showed bone scan progression. One patient was not evaluable. As described in the Materials and Methods section, results on bone scan were not required to be confirmed."