Alnylam is responding to new competitive pressure after AstraZeneca’s Wainua trial results for ATTR-CM did not meet expectations. In the reporting, some analysts interpreted the miss as evidence that RNAi silencers may not outperform when patients are already on a stabilizer regimen. Alnylam’s defense centers on the rationale for its approach, with implications for both its marketed Amvuttra and its next-generation nucresiran program. The debate highlights how clinical trial design—especially background therapies—can shape comparative interpretations across mechanism-of-action classes. For companies in RNA therapeutics, the key risk is not only efficacy but also positioning across lines of therapy and evolving standards of care.