Ionis Pharmaceuticals Inc.'s license agreement with Roche Holding AG to develop and commercialize IONIS-HTTRx for treating Huntington's disease was cleared under U.S. antitrust laws.

Roche is taking over all development and commercial activities of the drug. Roche paid a $45 million license fee to Ionis for exercising the option.

IONIS-HTTRx is the first therapy in clinical development to target the underlying cause of Huntington's by reducing the production of the toxic mutant huntingtin protein.

Huntington's disease is a rare genetic neurodegenerative disease resulting in deterioration in mental abilities and physical control. About 30,000 individuals in the U.S. have symptomatic Huntington's disease.