Ionis Pharmaceuticals, Inc. (IONS) Faces Investor Scrutiny After Surprise Trial Failure Drives Stock Down 23% – HBSS

Ionis Pharmaceuticals, Inc. (IONS) Faces Investor Scrutiny After Surprise Trial Failure Drives Stock Down 23%

Investors in Ionis Pharmaceuticals, Inc. ( NASDAQ: IONS ) saw the price of their shares plunge $20.19 (-23%) on July 9, 2026 after the commercial stage biotech company and its partner (AstraZeneca) announced that a late-stage trial for an experimental heart disease therapy did not meet its target. The surprise result and severe market reaction have prompted national shareholders’ rights firm Hagens Berman to open an investigation into whether Ionis was sufficiently transparent about the trial’s data and design and, if not, whether the company may have violated the federal securities laws. The firm encourages Ionis investors who suffered substantial losses to submit your losses now . Visit: www.hbsslaw.com/investor-fraud/ions Contact the Firm Now: IONS@hbsslaw.com 844-916-0895

The investigation is focused on Ionis’ statements regarding the development of eplontersen, a medicine intended to treat patients with transthyretin amyloidosis cardiomyopathy, or ATTR-CM. The company completed enrollment in the Phase 3 CARDIO-TTRansform study in July 2023. Just last month, Ionis touted the Phase 3 study as “the largest study ever conducted by far” in ATTR-CM , setting the company up “for the richest dataset for not only the primary endpoint, but the secondary endpoints[.]” Ionis also assured investors that “everything is going very well in the conduct of the study and execution.” Investors’ expectations were dashed on July 9, 2026 when Ionis announced that the Phase 3 CARDIO-TTRansform trial did not meet the primary efficacy endpoint.