Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. Nextar Therapeutics -  Nektar Therapeutics (Nektar)(NASDAQ: NKTR) is a stage-clinical biopharmaceutical company. The company was founded in 1990 and is based in San Francisco California. The company develops new drug candidates by appliying its proprietary PEGylation and advanced polymer conjugate technologies to modify chemical structure of substances. It is a technology supplier to a number of pharmaceutical companies including Affymax Amegen Merck Pfizer and UCB Pharma etc.
Company