Investors ding Tesaro despite responses for combo in NSCLC

Tesaro Inc. (NASDAQ:TSRO) reported data Friday from the Phase I AMBER trial showing that a combination of TSR-022 and TSR-042 led to four confirmed partial responses and 11 cases of stable disease among 31 evaluable non-small cell lung cancer patients who progressed following anti-PD-1 treatment. The company said all four of the responses occurred in PD-L1-positive patients.

Despite showing the possibility that the combination could rescue patients who failed previous PD-1 inhibitors, the company's stock took a hit and lost $5.81 (19%) to $25.10 on Friday. The move translated to a loss of about $320 million in the company's market cap...