Oct 05 2026 09:09 PM EST

Alnylam Shares Slide After Q2 Earnings Miss and FDA Label Setback

Alnylam Pharmaceuticals (NASDAQ: ALNY) posted a five‑day loss of 14.2%, wiping roughly $4.8 billion from its market value, as investors reassessed the company’s near‑term growth outlook following a Q2 earnings miss and a regulatory setback.

Q2 Earnings Miss and Guidance Cut

The July 30 8‑K reported revenue of $1.29 billion, but earnings per share of $1.84 fell short of the consensus estimate of $2.00. In the same filing, Alnylam trimmed its 2026 TTR product revenue guidance to a range of $4.4 billion–$4.7 billion, down from the prior $4.9 billion–$5.3 billion outlook.

Regulatory Setback on Onpattro

The company also received a FDA Complete Response Letter for a supplemental NDA seeking an expanded ATTR‑CM label for patisiran (Onpattro). The FDA cited insufficient evidence of clinical meaningfulness, overturning an earlier advisory committee vote. The CRL removed a near‑term catalyst that had been priced into the stock.

Macro Headwinds and Valuation Pressure

Rising U.S. Treasury yields—10‑year rates near 4.96%—have depressed valuation multiples for growth‑oriented biotech stocks. Alnylam trades at a forward P/E of roughly 73.8×, far above the sector average of 30.1×, leaving limited upside unless earnings accelerate or multiples compress. The broader biotech ETFs (XBI, IBB) have fallen 8%‑9% over the past month, reinforcing sector‑wide pressure.

Pipeline Outlook and Competitive Landscape

Alnylam’s long‑term growth hinges on diversification beyond its TTR franchise. Phase 3 data for vutrisiran (AMVUTTRA) presented at recent cardiology meetings confirmed durable knockdown but did not materially shift near‑term revenue expectations. Early‑stage programs—including nucresiran (expected launch 2030), ALN‑6400, and mivelsiran—remain years away from commercialization. Competitor Wainua (AZN/IONS) missed its late‑stage ATTR‑CM endpoint in July 2026, temporarily easing competitive pressure, while Pfizer’s Vyndamax remains protected from generic entry until mid‑2031.

Risks and Uncertainties

Key risks include further erosion of the TTR franchise if net pricing or payer reimbursement tightens, and the possibility that the FDA CRL on Onpattro may delay or block the intended label expansion. Insider selling—CEO Yvonne Greenstreet and director David E I Pyott sold several thousand shares in recent months—adds a perception of reduced confidence, though the transactions were disclosed as tax‑related. Finally, the upcoming Q3 earnings release on 29 October 2026 will test whether the company can restore guidance credibility and revive market sentiment.