AstraZeneca and Ionis Pharmaceuticals reported that their antisense heart disease candidate, Wainua, missed its primary endpoint in a pivotal late-stage trial in transthyretin-mediated amyloid cardiomyopathy (ATTR-CM). The therapy did not outperform placebo in reducing cardiovascular death and clinical events. The setback arrives as antisense and precision cardiology programs face increasing competition for ATTR-CM and related amyloidosis-driven cardiovascular endpoints. AstraZeneca said the result impacts its cardiovascular aspirations and is expected to reverberate through partner plans tied to Wainua. In markets, the trial failure triggered sharp premarket declines for both AstraZeneca and Ionis, underscoring investor sensitivity to late-stage cardiology readouts. For biotech investors and pipeline planners, the outcome highlights how crowded ATTR-CM development has become—where even pivotal wins can swing quickly to failures without a statistically meaningful effect on hard clinical endpoints.