FDA Approves First Drug to Target Genetic Cause of ALS

The Food and Drug Administration on Tuesday granted accelerated approval to Biogen's drug Tofersen for the treatment of a rare and aggressive form of amyotrophic lateral sclerosis. ALS, also known as Lou Gehrig's disease, is a progressive neurodegenerative disease that affects nerve cells in the brain and spinal cord. Tofersen can be used to slow the progression of the disease. The FDA accelerates approval for drugs that meet an unmet need for serious conditions. Tofersen will need to be studied further in a confirmatory trial to be granted full approval by the FDA. Shares of the biotech company declined by 4 percent in Wednesday's premarket trading.