AstraZeneca's Wainua misses primary endpoint in Phase IIIATTR-CM trial

AstraZeneca and Ionis announced that their investigational medication Wainua (eplontersen) did not meet the primary efficacy endpoint in the Phase III CARDIO-TTRansform clinical trial evaluating treatment for transthyretin-mediated amyloid cardiomyopathy (ATTR-CM) in adults.

The trial's primary composite endpoint of cardiovascular (CV) mortality and recurrent CV clinical events up to 140 weeks did not show a statistically significant benefit compared to placebo. The drug was generally well tolerated, with a safety profile consistent with previous findings.

While adding Wainua to the current standard of care, which included a majority of patients on a stabilizer, did not provide a statistically significant benefit for the composite outcome, a prespecified subgroup analysis showed a nominally significant reduction in primary composite events for patients receiving Wainua monotherapy compared to placebo. No treatment effect was observed in patients who were on stabilizer therapy at baseline.

ATTR-CM is a progressive and often fatal disease affecting the heart, estimated to affect 300,000 to 500,000 people worldwide. AstraZeneca and Ionis will analyze the full dataset to further understand the results, which will be shared at the European Society of Cardiology (ESC) Congress in August 2026.