AstraZeneca shares fell about 8.4% and Ionis dropped 23% after the Phase 3 CARDIO-TTRansform study of eplontersen, also known as Wainua, failed in ATTR cardiomyopathy.
AstraZeneca plc and Ionis Pharmaceuticals, Inc. are facing separate shareholder-law-firm investigations after disclosing on July 9, 2026 that the Phase 3 CARDIO-TTRansform trial in transthyretin amyloidosis cardiomyopathy, or ATTR-CM, failed to meet its primary efficacy endpoint. AstraZeneca shares fell about 8.4% in premarket trading, while Ionis shares fell $20.19, or 23%, erasing more than $3.3 billion in market value, according to Hagens Berman. Levi & Korsinsky is investigating whether AstraZeneca made materially false or misleading statements before the disclosure, while Hagens Berman is examining whether Ionis adequately disclosed trial data and design issues, including the extent of stabilizer use among participants. The companies said that in a contemporary patient population receiving standard of care, including a majority on a stabilizer, adding eplontersen did not provide a statistically significant benefit.