What should I watch for in the ATTR-CM market?
Three themes: Wainua's July 2026 failure reinforces stabilisers as frontline; FDA scrutiny of promotional claims is intensifying; and real-world data showing 34% lower worsening risk with Attruby is accelerating a market-share shift away from Pfizer.
Three themes stand out. First, the stabiliser-versus-silencer debate. AstraZeneca and Ionis's silencer Wainua missed its primary endpoint in July 2026 and showed no added benefit in patients already on stabilisers, who made up most of the trial. This reinforces stabilizers as frontline therapy, which favours both BridgeBio and Pfizer. Second, scrutiny of promotional claims looks set to increase. The FDA has already challenged Alnylam's survival claims, and Pfizer has continued to be accused of misleading marketing claims. Third, market share. New data, including a recent study showing a 34% lower risk of clinical worsening versus tafamidis, make Attruby the leading stabiliser. With Attruby revenue growing fast and a $4 billion peak-sales model, BridgeBio expects its share to keep rising.