- Alnylam (NASDAQ:ALNY) craters 43% after hours on robust volume in response to its announcement that it has decided to terminate development of revusiran, an RNAi therapeutic for the potential treatment of hereditary ATTR amyloidosis (hATTR) with cardiomyopathy, an Orphan Drug designation. The company made its decision yesterday and communicated it to investigators, study sites and regulatory authorities.
- The problem appeared to be an unacceptable safety profile in the Phase 3 ENDEAVOR study following reports of new onset or worsening peripheral neuropathy (nerve damage) in revusiran-treated patients in the Phase 2 OLE trial. At the company's request, the Data Monitoring Committee met to review the reports and unblinded data from ENDEAVOR. Although, it did not find conclusive evidence of revusiran-related neuropathy it concluded that continued dosing was inappropriate due to an unfavorable benefit-risk profile, specifically an "imbalance" in mortality in the revusiran arm compared to placebo.
- The company says its decision does not affect Phase 3-stage patisiran, a candidate for the treatment of hATTR with polyneuropathy, or any other RNAi therapeutic program. It adds that an assessment of safety data across its other programs, including the ALN-PCSsc program with The Medicines Company (MDCO), revealed no evidence of a drug-related neuropathy signal in over 800 patients with exposures up to 34 months. Investors appear unconvinced. MDCO is down 12% after hours on robust volume.