What happened

Shares of Opko Health (OPK 4.83%) were up more than 11% around 2:30 p.m. ET on Thursday. The healthcare company announced after the markets closed on Wednesday that a treatment for pediatric growth hormone deficiency that it was developing with Pfizer has been approved by the Food and Drug Administration (FDA). Opko's shares are up more than 53% so far this year.

So what

The FDA approved Ngenla (somatrogon-ghla), a once-weekly treatment for pediatric growth hormone deficiency (GHD), following a positive phase 3 study for the therapy. In the study, the drug was compared to once-daily somatropin and met its primary endpoint compared to Pfizer therapy Genotropin (somatropin), as measured by the subjects' height increase at a year. The drug also was generally well tolerated, Opko said, and had a similar safety profile to somatropin. The drug is expected to be launched by this August, Opko said.

GHD is a rare genetic condition that occurs when the pituitary gland doesn't make enough growth hormone. It affects only 1 in approximately 4,000 to 10,000 children. 

The key for the therapy is it's longer acting and means fewer injections than the current standard of therapy, which requires daily injections. 

Now what

Ngenla had a long road to approval in the U.S. First developed by Opko, the company came to a global agreement with Pfizer in 2014 that meant Opko was responsible for conducting the therapy's clinical program and Pfizer was responsible for commercializing it. The FDA denied the company's New Drug Application in January, but after the data from the phase 3 study was analyzed, the FDA approved the drug.

Opko was already receiving revenue via Pfizer on Ngenla because the therapy has already been approved in 41 countries, but adding the U.S. should help Opko's bottom line. In the first quarter, the company had an earnings per share (EPS) loss of $0.02.