AcelRx Pharmaceuticals, Inc., a specialty pharmaceutical company, develops and commercializes therapies for the treatment of acute pain in the United States. The companys lead product candidates include ARX-04, a sufentanil sublingual tablet that is in Phase III clinical trials for the treatment of moderate-to-severe acute pain to be administered by a healthcare professional to a patient in medically supervised settings; and Zalviso, a sufentanil sublingual tablet system, which is in Phase III clinical trials for the treatment of moderate-to-severe acute pain in hospitalized adult patients. It is also developing ARX-03, a fixed-dose sufentanil/triazolam sublingual tablet, which has been completed Phase II clinical trial for mild sedation and pain relief during painful procedures. The company was formerly known as SuRx, Inc. and changed its name to AcelRx Pharmaceuticals, Inc. in August 2006. AcelRx Pharmaceuticals, Inc. was founded in 2005 and is headquartered in Redwood City, California.