Biogen is an American biotechnology company founded in 1978 and headquartered in Cambridge, Massachusetts. It focuses on developing therapies for neurological and neurodegenerative conditions such as multiple sclerosis, Alzheimer's disease, and spinal muscular atrophy. The company is known for pioneering research in neuroscience and has brought several groundbreaking drugs to market, making it a key player in the biopharmaceutical industry.