Nektar initiates Phase II opioid-induced constipation study

The Phase II trial for NKTR-118 is a multi-center, placebo-controlled, dose-escalation trial (5mg, 25mg, 50mg or 100mg) that will evaluate the efficacy, safety and tolerability of NKTR-118 in patients experiencing constipation while receiving opioid therapy. Patients experiencing opioid-induced constipation (OIC) will be randomized 1:1 to NKTR-118 or placebo in addition to their opioid treatment. Therapy will be administered orally once-daily over a five-week treatment period. The primary efficacy endpoint of the trial will be the increase from baseline in spontaneous bowel movements per week. The trial will be conducted in approximately 50 centers in North America and Europe.

NKTR-118 is being evaluated as an oral therapy to treat opioid-induced bowel dysfunction (OBD) and OIC, which are serious and debilitating conditions resulting from the use of opioids for pain management. NKTR-118, which is a PEGylated form of naloxol, was designed to selectively target peripheral opioid receptors to alleviate constipation associated with opioid therapy, while reducing the drug’s penetration across the blood-brain barrier (BBB) and into the central nervous system in order to preserve opioid analgesia.

Hoyoung Huh, COO and head of the PEGylation Business Unit at Nektar, said: “NKTR-118 represents an innovative application of our small molecule PEGylation technology to prevent drugs from entering the central nervous system.”