Nektar reports positive results from Phase II constipation trial

Nektar Therapeutics, a biopharmaceutical company, has reported positive topline results from a Phase II double-blind, randomized, placebo-controlled study of NKTR-118 in patients with opioid-induced constipation.

The Phase II study of NKTR-118 is terminating early on the basis of overwhelming evidence of efficacy at two different dose levels of 25mg once daily and 50mg once daily. The study achieved a clinically meaningful and highly statistically significant, dose-dependent increase in spontaneous bowel movements (SBMs) from baseline after the first week of NKTR-118 treatment with the 25mg dose and the 50mg dose versus placebo (p < 0.01 for all comparisons).

According to the company, patients receiving the 25mg dose of NKTR-118 had an average of 5.1 SBMs during the first week of treatment as compared to 1.5 SBMs per week during the baseline period. Patients receiving the 50mg dose of NKTR-118 had an average of 5.7 SBMs during the first week of treatment versus 1.6 SBMs per week during the baseline period.

The increase in SBMs versus placebo was maintained over the 28-day treatment period (p <0.01). More importantly, in the 25mg and 50mg dose cohorts, there was no reversal of analgesia as measured by a change in pain numerical rating scale and no increase in opiate use, the company said.

Final results from the Phase II study are expected to be reported in 2009. The results of the Phase II study will enable Nektar to evaluate the drug in Phase III pivotal trials in order to submit a new drug application to the FDA.

Howard Robin, president and CEO of Nektar, said: NKTR-118 demonstrates that our advanced polymer conjugate technology can potentially create new small molecule drugs with optimal physicochemical and pharmacological properties. This validation of our platform with small molecules is a major achievement for Nektar and sets the stage for the future growth of our pipeline.