The U.S. Food and Drug Administration (FDA) has declined to approve Amneal Pharmaceuticals’ drug for Parkinson’s disease due to inadequate safety data on the treatment to help control symptoms in patients for a longer duration, the company said on Monday.
Shares of Amneal Pharmaceuticals fell 13.1% to $2.7 in choppy after-market trading.
The FDA in a complete response letter said while the company established the safety of one ingredient, levodopa, based on some studies, it was not able to adequately establish safety for the other ingredient, carbidopa.
The health regulator has requested additional information on the safety of the drug, while it did not identify any efficacy or manufacturing issues with the drug.
Amneal’s drug is a new formulation of carbidopa-levodopa, the standard of care for Parkinson’s, and is designed in a way that allows it to remain in a certain area of the small intestine for a longer period, helping in its consistent absorption.
The company said it will work closely with the health regulator to address the issues and plans to meet with the agency.
The health regulator’s decision is a potential hurdle to the company, which has been looking to grow its portfolio of branded drugs, expecting over $500 million in revenues from its specialty business by 2027.
The drugmaker said the decision does not impact its 2023 financial forecast as it did not include the revenue from the drug.
Amneal currently has another Parkinson’s drug, Rytary, which was approved in 2015 in the market but had been struggling to gain a foothold in the treatment space, with only 4% of patients using it.
Parkinson’s is a brain disorder that causes unintended or uncontrollable movements and is the second most-deadly neurodegenerative disease after Alzheimer’s. There is no cure for Parkinson’s currently, but medicines and other therapies can help relieve symptoms.