US regulators have expanded the reach of Johnson & Johnson group Janssen Biologics' psoriasis blockbuster Stelara to include the treatment of patients with Crohn's disease.

The US Food and Drug Administration has cleared the drug's use in moderately to severely active forms of the condition in adults who have failed or were intolerant to treatment with immunomodulators or corticosteroids, but have never failed treatment with a tumour necrosis factor (TNF) blocker, or who failed/were intolerant to one or more TNF blockers.

Stelara (ustekinumab) is now the first biologic therapy for Crohn's disease targeting interleukin (IL)-12 and IL-23 cytokines, which play a key role in inflammatory and immune responses, the firm noted.

The approval "represents an important advancement" in treating patients with Crohn's disease, as it "offers an alternate mechanism of action to induce and maintain clinical remission over time," said study investigator William Sandborn, chief, Division of Gastroenterology, and Professor of Medicine, UC San Diego School of Medicine, and study investigator.

"Based on the results of the clinical development program, Stelara has the potential to benefit many adults living with Crohn's disease," he added.

In clinical studies, between 34 percent (UNITI-1 study) and 56 percent (UNITI-2 study) of patients experienced relief from their Crohn's disease symptoms in just six weeks after receiving the one-time intravenous infusion of the drug.

"Noticeable improvement" was observed as early as three weeks, according to the firm, while the majority of those responding to induction dosing and continued treatment maintenance doses every eight weeks were in remission at the end of 44 weeks.

Stelara is also currently being reviewed for Crohn's disease in Europe, where regulatory advisors have already recommended marketing approval.