In December 2011, Adolor was acquired by Cubist in an all cash deal. Cubist was itself an SBIR awardee that subsequently engaged with several other younger firms in the program. Adolor Corporation is a development stage biopharmaceutical corporation that discovers, develops and plans to commercialize proprietary pharmaceutical products for the treatment of pain and the side effects that are caused by pain treatments. The Company's lead product candidate, alvimopan, is designed to selectively block the unwanted effects of opioid analgesics on the gastrointestinal tract. The Company's other product candidates are being designed as analgesics to treat moderate-to-severe pain and itch. Additionally, the Company is exploring the development of an analgesic product candidate that would be a combination of alvimopan and an opioid that would be intended to produce the pain relief of an opioid while reducing side effects, such as constipation, nausea and vomiting. In keeping with the movement toward improved pain management (including the increased use of opioids like hydrocodone), the company is developing drugs that alleviate the side effects of some pain treatments. Adolor's lead drug candidate Entereg may reduce opioid-induced side effects such as bowel dysfunction. The company has partnered with GlaxoSmithKline for development and of Entereg as a treatment for opioid-related side effects and for postoperative ileus (or intestinal obstruction). The two companies halted development of Entereg for opioid-induced bowel dysfunction in 2007.