Opioids, such as morphine, are highly effective in the treatment of moderate to severe pain, which could include pain associated with or as a result of back pain, arthritis, cancer and other pain conditions.

When taken daily, particularly over a long period of time, opioids can cause a range of gastrointestinal (GI) side effects, known collectively as opioid bowel dysfunction (OBD).  OBD is characterized by a range of symptoms including constipation - infrequent, difficult or incomplete bowel movements, abdominal pain and discomfort, bloating, acid reflux and loss of appetite.   These effects tend to persist while patients take their opioids.

In patients affected by OBD, constipation is the most common, persistent and often debilitating symptom.  OBD can be distressing for patients, causing a significant burden of illness and reduced quality of life.  Constipation is ranked by most cancer patients as an even more common source of distress than the pain they are suffering.  Some patients receiving long-term opioid treatment for pain would rather endure their pain than the constipation that opioids may cause.

To treat OBD, Adolor is developing ADL7445, a proprietary, small molecule, peripherally-acting mu opioid receptor antagonist and ADL5945, a novel, potent mu opioid receptor antagonist to block the adverse effects of opioid analgesics on the GI tract without affecting analgesia.

Clinical Status

ADL5945
Both a Phase 1 single and multiple, escalating dose placebo-controlled safety study have been conducted with ADL5945.  Adolor initiated Phase 1 exploratory efficacy clinical studies in early 2010.

ADL7445
Preclinical safety and efficacy studies with ADL7445 have been conducted.  Adolor initiated Phase 1 clinical studies in November, 2009.