Securities fraud scrutiny clouds Alnylam's premium valuation

Alnylam Pharmaceuticals (ALNY) faces securities fraud scrutiny linked to a sharp reduction in sales expectations for its TTR franchise, raising fresh questions about how reliably the portfolio can underpin future profits. The legal uncertainty arrives as the stock still trades at a premium price-to-earnings multiple to many biotech peers, a valuation built on its RNAi platform and ATTR portfolio.

The greatest operational risk sits in the TTR franchise itself. The cut to 2026 guidance and the fraud investigation both focus attention on how much of Alnylam's profit comes from ATTR and how predictable that stream is. Deeper payer pressure or further net pricing headwinds would test the premium multiple.

Views diverge sharply. The most bearish analysts, who focus on TTR execution risk, had projected 2029 revenue of about $7.4bn and earnings of roughly $1.3bn before the latest news, well below the consensus path. Among the fair value estimates, the lowest puts the shares at just $256.