AstraZeneca commences NKTR-118 Phase III clinical programme for opioid-induced constipation

AstraZeneca today announced enrolment of the first patient in the Phase III clinical programme for NKTR-118, an oral peripherally-acting opioid antagonist being investigated for the treatment of opioid-induced constipation (OIC). The Phase III clinical programme is designed to investigate the safety and efficacy of NKTR-118 as a medicine to relieve opioid induced constipation, a common side effect of prescription opioids when used for chronic pain management.  NKTR-118 is part of the exclusive worldwide license agreement announced on September 21, 2009, between AstraZeneca and Nektar Therapeutics (NASDAQ: NKTR).

The Phase III clinical programme will consist of two 12-week, randomized, placebo-controlled efficacy studies (with approximately 630 randomized patients each) and an open-label, randomized, long-term safety study with a "usual care" comparator arm.  The 12 week efficacy studies will compare response rate among placebo and two different doses of NKTR 118 with primary endpoint at 4 weeks. There is a three month safety extension following one of the two 12 week studies.

The long-term safety study will include patients from the 12-week efficacy studies, as well as new patients not previously enrolled. All patients will be randomly assigned to open-label treatment of either NKTR-118 or physician's choice (usual care) laxative regimen.  Safety assessments will also be collected throughout the trials.

"This is a key milestone for NKTR-118," said Anders Ekblom, Executive Vice President of Global Medicines Development, AstraZeneca. "We will put our knowledge and our effort into studying NKTR-118 as a potential effective new treatment option for Opioid Induced Constipation, which continues to be an area of unmet need in patients needing effective pain treatment."

The first regulatory filings based on the programme are planned for 2013.