Scientists Steven Gillis and Christopher Henney, along with businessman Stephen Duzan, founded Immunex in July 1981. They envisioned the company's mission as developing, producing, and licensing diagnostic and therapeutic immunological products. Its successful drugs included LEUKINE (sargramostim) for patients undergoing bone marrow transplants, NOVANTRONE for multiple sclerosis, and ENBREL (etanercept), an anti-inflammatory used to treat arthritis. By 2001, Immunex was the largest biotechnology company in Washington State. Amgen acquisitioned Immunex in 2002 and was a leading biotech company located on the shore of Lake Union until it closed its operations in 2015.