AstraZeneca and Ionis report Wainua misses primary endpoint in CARDIO-TTRansform Phase III
The trial in transthyretin-mediated amyloid cardiomyopathy did not show a statistically significant benefit over placebo, though a monotherapy subgroup showed a nominally significant effect.
AstraZeneca disclosed on 9 July 2026 that the Phase III CARDIO-TTRansform trial for Wainua (eplontersen) in patients with transthyretin-mediated amyloid cardiomyopathy (ATTR-CM) failed to meet its primary efficacy endpoint, a composite of cardiovascular mortality and recurrent cardiovascular clinical events measured through 140 weeks compared with placebo.1
The company said among this contemporary patient population on standard of care, most of whom were also taking a stabiliser drug, the addition of Wainua did not produce a statistically significant improvement in the combined measure of cardiovascular death and recurrent cardiovascular events.1 A prespecified subgroup analysis of patients on Wainua alone, without a stabiliser, showed fewer primary composite events than placebo, a result the company called nominally significant.1 Patients who were already on stabiliser therapy at the start of the trial showed no treatment effect.1
Wainua's safety profile was described as generally consistent with prior data.1
Sharon Barr, an AstraZeneca R&D executive, said the trial was designed to test whether the gene-silencing therapy could reduce cardiovascular events and death on top of current standard treatments, and that despite missing its main goal, the company believes the findings add to scientific understanding of the disease, according to the release.
The study enrolled patients with 57% in each treatment arm receiving a stabiliser at baseline and another 24% starting one during the trial.1 AstraZeneca and its partner Ionis Pharmaceuticals said they plan to further examine the complete dataset and present findings at the European Society of Cardiology Congress scheduled for August 2026.
CARDIO-TTRansform enrolled 1,432 participants at 130 sites across 20 countries, randomizing them 1:1 to receive 45 mg of eplontersen or placebo by subcutaneous injection every four weeks, making it the largest ATTR-CM trial conducted to date.1
Written by readthrough’s AI from the linked primary sources and fact-checked against them automatically before publishing. Not investment advice.