The US Food and Drug Administration has given the green light to Novartis' Ilaris as a treatment for a serious form of childhood arthritis.

The agency has approved Ilaris (canakinumab) for the treatment of active systemic juvenile idiopathic arthritis (SJIA) in patients aged two and older. It is the first interleukin-1 beta inhibitor approved for SJIA and the only treatment approved specifically for the disease that is given as a once-monthly subcutaneous injection.

SJIA is a rare form of childhood arthritis characterised by spiking fever, rash and arthritis that can affect children as young as two and can continue into adulthood. It affects five-15 children per 100,000 in the USA and Novartis says that presently treatment options are limited; corticosteroids are often used despite their association with potentially serious adverse effects, including Cushing syndrome, growth suppression and osteoporosis.

The approval is based on two Phase III trials in SJIA patients, aged 2–19. In the first one, 84% of patients treated with one subcutaneous dose of Ilaris achieved the primary endpoint of the adapted paediatric American College of Rheumatology 30 scale, compared to 10%  for the placebo arm at day 15. In the second study, out of 92 patients, 62% were able to substantially reduce their use of corticosteroids, and 46% completely discontinued treatment with the latter.

This is the second approval for Ilaris in the USA, as it is already available for the rare diseases that form cryopyrin-associated periodic syndrome (CAPS). However, the FDA rejected the drug as a treatment for gout in August 2011, demanding further clinical data, though European regulators  gave the green light for that indication in March this year.

Timothy Wright, head of development at Novartis Pharmaceuticals, said that "we are committed to studying Ilaris in other IL-1 beta mediated inflammatory diseases, including several rare diseases for which treatment options do not currently exist".