Shares of Dendreon Corp. (DNDN) jumped 38 percent last Friday and another 13% in early morning trading today. However, we don't see any clear rationale for the rally at this point of time. We believe investors are looking ahead to long-awaited data on the company's experimental Provenge vaccine to treat advanced prostate cancer, but we are cautious about the final results anticipated by the end of April. As a reminder, Dendreon's lead drug candidate Provenge is under phase III IMPACT confirmatory study for prostate cancer under a special protocol assessment (SPA) with the FDA. Provenge is a therapeutic vaccine.Previous two phase III studies generated mixed results. Study D9901 showed that Provenge approached, but did not meet its primary end point of showing a significant delay in time to disease progression (p=0.052, HR=1.4). However, Provenge showed a statistically significant median survival benefit (secondary endpoint) in ...