Progenics Pharmaceuticals is a biopharmaceutical company focusing on the development and commercialization of innovative products for the treatment and prevention of cancer, viral and other life-threatening diseases. The Company applies its immunology expertise to develop biopharmaceuticals that induce an immune response or that mimic natural immunity in order to fight cancers, such as malignant melanoma, and viral diseases, such as human immunodeficiency virus (HIV) infection. The Company's product candidates include GMK, a therapeutic vaccine for the treatment of melanoma; MGV, a vaccine for the treatment of various cancers; and PRO-542 and PRO-367, which are therapeutic products designed to block HIV. Drug candidate PRO 140 is designed to prevent HIV from infecting healthy immune systems cells. The biotech's lead drug candidate, however, targets pain: Methylnatrexone (MNTX) could block the side effects of opioids without lessening their pain-killing power. Progenics is developing the drug in collaboration with Wyeth Pharmaceuticals. Also in the firm's pipeline is a vaccine that may prevent melanoma. Through subsidiary PSMA Development Company, Progenics is developing monoclonal antibodies and immuno-vaccines for prostate cancer.