Roche moved to shut down two Huntington’s disease antisense programs developed with Ionis Pharmaceuticals after disappointing efficacy signals. In a letter to the Huntington’s community, Roche said it will end the Phase 2 GENERATION HD2 study for tominersen after the therapy failed to meet a key efficacy objective. A separate trial of RG6496 was also stopped following new data from a parallel animal study. Both drugs target huntingtin biology, but with different approaches: tominersen lowers total huntingtin expression, while RG6496 is designed to bind a specific mutated huntingtin RNA variant. The term “Phase 2” refers to studies that typically assess efficacy signals and dosing before larger pivotal trials. The news lands amid additional Ionis pressure, including reports that the AstraZeneca-partnered Wainua (eplontersen) missed in the Phase 3 CARDIO-TTRansform trial in transthyretin amyloidosis cardiomyopathy. For Roche and Ionis, the cancellations concentrate remaining resources on other ongoing Huntington’s collaborations while investor focus shifts to alternatives such as gene therapies.