FDA rejects Pfizer growth hormone deficiency drug

by Yudi Sherman

The FDA has rejected a new drug by Pfizer to combat growth hormone deficiency in children, Pfizer disclosed late Friday. Somatrogon, developed by Pfizer in conjunction with Opko Health, aims to compete with the treatment marketed by Ascendis Pharma, Skytrofa, which already received FDA approval in August.

Growth hormone deficiency is said to affect 4,000 – 10,000 children globally. Children who suffer from GHD have pituitary glands which do not produce enough growth hormone, leading to developmental disorders such as abnormally short height.

While Pfizer already markets a growth hormone treatment for children named Genotropin, which generated $427 million in 2020, it is a treatment that must be administered daily, while somatrogon would only need to be administered once a week. Children who receive daily injections of Genotropin grow at a velocity of around 10 cm per year. In its Phase 3 clinial trials, somatrogon was shown to have achieved non-inferiority when compared with Genotropin.

Pfizer did not disclose the reason for the FDA’s rejection of somatrogon.

"We will work closely with the FDA to determine the best path forward to bring this important once-weekly treatment option to pediatric growth hormone deficiency patients and their families," said Brenda Cooperstone, chief development officer of Rare Disease, Pfizer Global Product Development.

Somatrogon is already approved for use in Australia, Canada and in Japan under the brand name Ngenla.

Pfizer acquired the drug from Opko Health in 2014 for $295 million in exchange for the global rights to the drug. 

The FDA’s rejection of the Pfizer drug comes as concerns regarding Pfizer’s COVID-19 vaccine are arising globally, with many questioning the efficacy of the drug given that it neither blocks infection of COVID-19 nor blocks transmission of the virus.

Following news of the FDA’s decision, Opko Health shares tanked nearly 10% in after-hours trading on Friday in the US markets.