Merck Halts Development of Parkinson’s Drug on Lack of Benefit

Merck & Co. said it will end development of the experimental drug preladenant for Parkinson’s disease because a preliminary review of the data from late-stage clinical trials suggests it doesn’t work.

The drugmaker said it will stop the extension portions of the trials and no longer plans to file for marketing approval of the medicine. There were two studies that added preladenant to levodopa, the standard treatment for Parkinson’s disease, and one that tested it as stand-alone care, Whitehouse Station, New Jersey-based Merck said in a statement.

“While these results are disappointing, this program is an important example of Merck’s continued commitment to pursue promising science with the goal of bringing forward medicines that address important unmet medical needs,” said David Michelson, vice president of clinical research in neuroscience at Merck Research Laboratories.

The company is committed to working on complex diseases and neuroscience research, he said in a statement. The company will conduct additional analyses of the results and present them at a future medical meeting, he said.

Preladenant was forecast to generate $211 million in 2016 and $271 million in 2017, according to the average of three analysts’ estimates compiled by Bloomberg.

Parkinson’s is a progressive neurological disorder that causes body tremors, the loss of muscle control and impaired movement, according to the National Institutes of Health. There is no cure. A variety of medicines provide relief from symptoms for the estimated 10 million people worldwide with the disease.

Patients gradually lose neurons that make the brain chemical dopamine. The lack of dopamine leads to increasing activity in a part of the brain called the subthalamic nucleus, which influences movement. Treatment typically includes drugs designed to boost dopamine levels in the brain, though the benefits may wane and side effects become intolerable over time.

The clinical trials halted by Merck were part of the third and final stage of testing usually required for U.S. regulatory approval of a new therapy.

Before it's here, it's on the Bloomberg Terminal.