AstraZeneca and Ionis report failure of eplontersen in ATTR-CM trial

AstraZeneca and Ionis said their nucleic‑acid drug eplontersen did not meet the primary goal in a large study of patients with transthyretin‑mediated amyloid cardiomyopathy (ATTR‑CM). Over a 140‑week period the therapy failed to show a statistically significant reduction in overall death or recurrent cardiovascular events compared with placebo.

The trial also showed no benefit for participants already receiving a standard stabilizer drug, while a modest 29% risk reduction was observed in patients not on that background therapy.

The companies noted that eplontersen was well tolerated and that several secondary endpoints showed positive signals, with full data to be presented at an upcoming medical meeting in August.

The unexpected setback surprised Wall Street analysts and led to a decline in the share prices of both AstraZeneca and Ionis.