Ionis Pharmaceuticals, Inc. (IONS) announced today that Roche has exercised its option to license IONIS-HTTRx following the completion of a Phase 1/2a randomized, placebo-controlled, dose escalation study of IONIS-HTTRx in people with Huntington's disease (HD). Roche will now be responsible for all development and commercial activities. IONIS-HTTRx is the first therapy in clinical development designed to target the underlying cause of HD by reducing the production of the toxic mutant huntingtin protein (mHTT). In conjunction with the decision to license IONIS-HTTRx, Ionis earned a $45 million license fee from Roche.

In the Phase 1/2a study, dose-dependent reductions of mHTT were observed in participants treated with IONIS-HTTRx. In addition, the safety and tolerability profile of IONIS-HTTRx observed in the Phase 1/2a study supports continued development. Ionis and Roche plan to present results from this study at medical conferences in the first half of 2018 and plan to submit the study results for publication in a peer-reviewed medical journal. Ionis and Roche have also recently initiated an open-label extension (OLE) study for patients who completed the Phase 1/2a study.

"We are encouraged by the performance of IONIS-HTTRx in the Phase 1/2a clinical study. The dose-dependent reductions of mHTT we observed in the study substantially exceeded our expectations and we were equally encouraged by the safety profile of the drug," said Dr. C. Frank Bennett, senior vice president of research at Ionis Pharmaceuticals. "We are grateful to the patients and investigators participating in this study. We could not have reached this important milestone without their commitment and that of the broader HD community."

"We are extremely pleased that to have reached this important milestone in our collaboration with Roche to discover and develop a therapy for people with Huntington's disease," said B. Lynne Parshall, chief operating officer at Ionis Pharmaceuticals. "This is our second antisense drug targeting a neurodegenerative disease to demonstrate a positive impact on a disease target in the CNS."

"The results of this trial are of ground-breaking importance for Huntington's disease patients and families. For the first time, a drug has lowered the level of the toxic disease-causing protein in the nervous system, and the drug was safe and well tolerated. The key now is to move quickly to a larger trial to test whether IONIS-HTTRx slows disease progression," said Dr. Sarah Tabrizi, professor of clinical neurology, director of the University College London's Huntington Centre and the global lead investigator on the Phase 1/2a study.

Roche is now responsible for all IONIS-HTTRx development, regulatory and commercialization activities and costs. The two companies will work together to transition the ongoing OLE to Roche which will be responsible for managing this study and all future studies.

This transaction is subject to clearances under the Hart-Scott-Rodino Antitrust Improvements Act.

ABOUT IONIS-HTTRx and HUNTINGTON'S DISEASE (HD)

IONIS-HTTRx is an antisense drug in development for the treatment of HD. IONIS-HTTRx is designed to reduce the production of all forms of the huntingtin (HTT) protein, which in its mutated variant (mHTT) is responsible for HD. As such, IONIS-HTTRx offers a unique approach to treat all patients with HD, irrespective of their individual HTT mutation. IONIS-HTTRx has been granted orphan drug designation by the U.S. Food and Drug Administration (FDA) and by the European Medicines Agency (EMA) for the treatment of patients with HD.