Regeneron Revives NGF Inhibitor With Phase II/III Data; Safety Issue Remains

Tarrytown, New York-based Regeneron's stock initially increased, fell, then rose again on May 2 after it said pain scores were essentially cut in half for patients treated with the NGF-targeting monoclonal antibody, but the rate of neuro-musculoskeletal adverse events was nearly three times as high as in the placebo group – 17% versus 6%. Severe joint risks shut down clinical trials for NGF inhibitors in the past, including fasinumab, so the higher rate of those side effects wasn't unexpected, but analysts noted that longer term confirmatory trials are needed to confirm that safety risks don't outweigh efficacy.

Regeneron's share price increased by about $3 when the stock market opened, but fell almost $7 below the company's $376.71 per share closing price on April 29 before closing almost...