RARE Daily

Genentech Halting Late-Stage Huntington’s Disease Study

March 23, 2021

Rare Daily Staff

Genentech said it is discontinuing dosing in the phase 3 GENERATION HD1 study of tominersen in manifest Huntington’s disease after a pre-planned review of the data by an unblinded independent data monitoring committee.

The independent data monitoring committee made its recommendation based on the investigational therapy’s potential benefit/risk profile for study participants. No new or emerging safety signals were identified for tominersen in the review of the data from this study.

Huntington’s disease (HD) is a rare genetic, progressive condition in which the nerve cells in the brain break down, causing problems with a person’s ability to think, move and function, leading to increasing disability and loss of independence. It has a devastating impact on people living with the disease, and the hereditary nature of HD means it profoundly affects entire families for generations. Survival ranges from approximately 10-20 years following motor onset of the disease. There is no known cure for HD and no approved therapies that treat the underlying cause.

Genentech, at the end of 2017, licensed tominersen, previously IONIS-HTTRx, from Ionis Pharmaceuticals. Tominersen is an investigational antisense therapy designed to reduce the production of all forms of the huntingtin protein (HTT), including its mutated variant, mHTT.

Genentech said it intends to continue following participants for safety and clinical outcomes, without the dosing of the investigational medicine or placebo. Once full data from the phase 3 study are available and analyzed, Genentech will share learnings and future plans with the HD community.

Dosing will be paused in the open-label extension study (GEN-EXTEND) of tominersen while data are carefully analyzed to inform next steps on this study.

“This is very unfortunate news to deliver on the tominersen phase 3 study and we know it will be especially difficult for people with Huntington’s disease to hear. The HD community currently has no treatments to stop or slow the progression of this rare neurodegenerative disease that impacts families across generations,” said Levi Garraway, chief medical officer and head of global product development. “GENERATION HD1 is the largest clinical trial in Huntington’s disease to date and we do know that the data generated will significantly advance our understanding of huntingtin-lowering as a potential treatment approach.”

The phase I study (GEN-PEAK) of tominersen and the observational Genentech and Roche HD Natural History Study will continue.

Photo: Levi Garraway, chief medical officer and head of Global Product Development

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