Mirati update at ASCO raises tolerability concerns, says Piper Jaffray
Piper Jaffray analyst Steven Breazzano says Mirati Therapeutics ' top-line results for lead drug glesatinib at ASCO this weekend had a response rate of 27%, which is a slippage from the prior update of 50%. Tolerability, particularly diarrhea, appeared to have significantly affected efficacy with multiple dose reductions/discontinuations leading to suboptimal responses below the partial responses threshold, Breazzano tells investors in a research note. While the update may be disappointing to some investors, Mirati is evaluating a new formulation to improve bioavailability which appears promising, the analyst points out. He lowered his price target for the shares to $14 from $17 and keeps a Neutral rating on the shares.