Pfizer and Opko end 2016 downbeat as hGH-CTP fails phase 3 trial

Pfizer and drug partner Opko said this morning that their candidate for patients with a rare growth hormone deficiency missed its endpoint in a late-stage test, sending the biotech’s shares down more than 17% on the news.

Miami-based Opko said in a brief statement that the drug, hGH-CTP, flopped in a placebo-controlled phase 3 study of around 200 patients after not hitting its primary endpoint of change in trunk fat mass from baseline, over half a year, when compared to a dummy treatment.

But Opko has done some data mining and said: “After unblinding the study, Opko identified one or more outliers that may have affected the primary outcome. As a result, Opko is undertaking further review of the study population as promptly as possible.”

It did not go into details about the outliers but did say that “a greater percentage of subjects on hGH-CTP normalized serum concentrations of insulin-like growth factor-I compared to placebo.”

More data analyses from the study will be released in the future, the biotech said. The deal with Pfizer sees Opko do all the research work, while its Big Pharma partner will take over for registration and sales.

Outside of this disease area, Opko noted that it started its pivotal phase 3 study this month in prepubertal growth hormone-deficient children to evaluate weekly treatment with hGH-CTP versus daily injections of Pfizer’s Genotropin (somatropin).