By Stephen Nakrosis

The Janssen Pharmaceutical Companies of Johnson & Johnson on Thursday said the U.S. Food and Drug Administration approved its Stelara to treat pediatric patients with severe plaque psoriasis.

The company said Stelara, or ustekinumab, "is the first and only biologic to target interleukin (IL)-12 and IL-23 approved for pediatric psoriasis use."

The company said the FDA's approval was based on results from the Cadmus Junior study, a phase 3 clinical trial of 44 patients that saw 77% achieve clear or almost clear skin at week 12 after two doses.

Stelara had previously been approved to treat adult patients.

--Write to Stephen Nakrosis at stephen.nakrosis@wsj.com