Closely watched Parkinson's drug from Biogen, Denali comes up short

Big setback for Denali.

> In the study, 648 adults with Parkinson’s were randomized to receive either a placebo or a pill targeting a protein called LRRK2. In 2004, researchers discovered that mutations in the LRRK2 gene can cause a rare, inherited form of Parkinson’s. And in 2018, another group of scientists showed that blocking the protein might actually benefit all patients with the disease.

> The pill, called BIIB122, indeed knocked down LRRK2 in the blood and to a degree in the brain, as measured by spinal fluid. Yet trial participants who received BIIB122 did not decline any slower, as measured by multiple scales, than those on the placebo.