Nektar Therapeutics, a clinical-stage biopharmaceutical company, develops drug candidates that utilize its PEGylation and polymer conjugate technology platforms in the United States. Its product pipeline comprises drug candidates in therapeutic areas, including oncology, pain, anti-infectives, and immunology. The company?s drug candidates in clinical development stage comprise naloxegol, an opioid antagonist, which has completed Phase III clinical trial for treating opioid-induced constipation; BAY41-6551 that is in Phase III clinical trial to treat gram-negative pneumonias; NKTR-181, which has completed Phase II clinical trial for chronic pain; and NKTR-171 that is in Phase I clinical trial to treat neuropathic pain. Its other product candidates comprise etirinotecan pegol, a topoisomerase I inhibitor, which is in Phase III clinical trial for metastatic breast cancer and in Phase II clinical trial for second-line metastatic colorectal cancer; and in combination with 5-fluorouracil/leucovorin to treat metastatic colorectal cancer that has completed Phase I clinical trial. In addition, the company offers preclinical drug candidates comprising opioid/NKTR-118 to treat chronic pain; NKTR-192 to treat acute pain; and NKTR-214, a cytokine immunostimulatory therapy to treat oncology. Nektar Therapeutics has collaboration with Bayer Healthcare LLC to develop BAY41-6551, which is an inhaled solution of amikacin, an aminoglycoside antibiotic; and a license agreement with AstraZeneca AB to develop and commercialize naloxegol and naloxegol fixed-dose combination program. Further, it has license, manufacturing, and supply agreements with Amgen Inc.; MAP Pharmaceuticals, Inc.; Merck & Co., Inc.; Ophthotech Corporation; Pfizer, Inc.; F. Hoffmann-La Roche Ltd (Roche), Regado Biosciences, Inc.; and UCB Pharma. The company was founded in 1990 and is headquartered in San Francisco, California.