OPKO Health said today that the long-acting human growth hormone candidate hGH-CTP, which is being developed in adults with growth hormone deficiency (GHD) under a collaboration with Pfizer, has failed a Phase III trial.
hGH-CTP missed its primary endpoint in the late-stage study of change in trunk fat mass from baseline to 26 weeks, after results showed no statistical difference between hGH-CTP and placebo. But OPKO Health quickly added that the primary outcome in adult GHD may have been swayed by “one or more outliers,” without disclosing specifics.
“As a result, OPKO is undertaking further review of the study population as promptly as possible,” the company said in a statement.
The company said the safety profile of hGH-CTP seen in the study was consistent with that known for growth hormone treatments, with a greater percentage of patients taking hGH-CTP normalizing serum concentrations of insulin-like growth factor 1 compared to placebo patients.
The Phase III trial was a multinational, multicenter study that used a 2:1 randomization between hGH-CTP and placebo. A total 203 patients were enrolled, all but five of which received at least one dose of study treatment administered through a weekly injection.
OPKO also said that it has begun another multiregional Phase III study this month focused on hGH-CTP. The new study is designed to assess the candidate in prepubertal growth hormone-deficient children, by evaluating weekly treatment with hGH-CTP versus daily injections of Genotropin®. The hGH-CTP will be delivered in a pen device.
OPKO and Pfizer inked an up-to-$570 million global collaboration and license agreement in December 2014. Under that agreement, OPKO is responsible for conducting the clinical program, while the pharma giant has responsibility for registering and commercializing hGH-CTP.
Shares of OPKO this morning fell 14% from yesterday’s closing price of $11.46, down to $9.85 as of 9:36 a.m.