Alnylam Pharmaceuticals (NASDAQ: ALNY) Shares Extend a Roughly 30% Selloff Since Thursday July 30 Q2 2026 Earnings, Losing Approximately $12 Billion in Market Capitalization; The Selloff Reflects the July 30 Amvuttra (Vutrisiran) TTR Guidance Cut to $4.2-4.5 Billion Full-Year From Higher Prior Expectations on Normalized Second-Line Volume, Plus the July AstraZeneca-Ionis Eplontersen (Wainua) Phase 3 CARDIO-TTRansform Setback That Complicates the Broader ATTR-CM Competitive Landscape Where Amvuttra Has Been Positioned as the Primary siRNA Alternative; Alnylam Presents Full Eplontersen Study Data at a Late-August Medical Meeting
Alnylam Pharmaceuticals (NASDAQ: ALNY) shares extended a roughly 30% selloff since the Thursday July 30, 2026 Q2 2026 earnings report, losing approximately $12 billion in market capitalization over the intervening days. The selloff reflects two consecutive negative signals for the RNAi therapeutics leader: the July 30 Amvuttra (vutrisiran, the TTR-directed siRNA that crossed $1 billion in quarterly revenue for the first time at $1.012 billion) full-year 2026 TTR product sales guidance cut to $4.2-4.5 billion (down from prior higher expectations) to reflect normalized second-line volume after the initial pent-up demand from patients waiting for a new therapy, combined with the July AstraZeneca-Ionis eplontersen (Wainua, antisense oligonucleotide) Phase 3 CARDIO-TTRansform study setback that complicates the broader ATTR-CM competitive landscape. The Amvuttra franchise has been positioned as the primary siRNA alternative to Pfizer's Vyndaqel/Vyndamax (tafamidis, small-molecule TTR stabilizer) and BridgeBio's Attruby (acoramidis, next-generation TTR stabilizer). Alnylam presents full eplontersen study data at a late-August medical meeting; analysts flagged the timing as a continued overhang until the presentation clarifies the ATTR-CM segment dynamics. Analyst commentary described the combination as a 'one-two punch' for the company.