AbbVie’s JAK1 Inhibitor Aces Ulcerative Colitis Trial, Prospers Amid Tough Regulatory Climate

On June 29th, AbbVie announced Rinvoq (Upadacitinib), an oral JAK1 inhibitor significantly increased clinical remission and all other predetermined parameters in patients with ulcerative colitis. The report comes days after the FDA announced it would not give a decision on supplemental New Drug Application for Rinvoq for other two indications due to its ongoing review of a different JAK inhibitor.

Rinvoq is an orally available, once-daily selective, and reversible JAK1 inhibitor. It functions by reducing inflammatory signals in immune cells. It is currently approved in the US for the treatment of rheumatoid arthritis, and it is currently seeking FDA approval for psoriatic arthritis and ankylosing spondylitis. However, the approval was delayed due to mounting scrutiny over the safety issues of JAK inhibitors.

Regardless of the FDA approval, Rinvoq continues to deliver topline results and several Phase 3 trials continue to investigate its efficacy in inflammatory diseases. 

Rinvoq and Ulcerative Colitis

Ulcerative colitis is a chronic, immune-mediated inflammatory bowel disease. Inflammation in the large intestine leads to bleeding, pain, bloody diarrhea, and increased stool frequency. In two previous Phase 3 clinical trials, Rivoq significantly improved symptoms and increased the number of patients reaching clinical remission.

The long-term drug safety and efficacy was tested in a multicenter, randomized, double-blind, placebo-controlled Phase 3 maintenance study where patients were randomized into three groups: Placebo, 15 mg, and 30 mg of Rinvoq  for 52 weeks.

Results showed that 42% of patients in the 15 mg, and 52% in patients in the 30 mg groups achieved clinical remission, as defined as normal stool frequency and no rectal bleeding. In comparison, in the placebo group, only 12% of people accomplished remission. Additionally, Rinvoq met the secondary endpoints of endoscopic improvement, histologic-endoscopic mucosal improvement (HEMI), and corticosteroid-free clinical remission at week 52.

Crucially, no new safety risks were observed. The most common adverse events were nasopharyngitis, exacerbation of ulcerative colitis, and blood creatine phosphokinase increase.

“Ulcerative colitis is a disease with unpredictable symptoms and frequent flares, which can make daily life challenging,” said Michael Severino, M.D., vice chairman and president, AbbVie. “We are encouraged by these results that demonstrate upadacitinib’s potential as a treatment option for patients with moderate to severe ulcerative colitis.”

The full results from the maintenance study will be presented at a future medical meeting.

Growing Scrutiny and Delays for JAK Inhibitors

There is growing scrutiny by the FDA before approving JAK inhibitors for new indications. This is a response in part to the growing evidence of severe adverse effects of some candidates. In February, the FDA alerted that a safety trial found Pfizer’s Xeljanz (tofacitinib) to be associated with an increased risk of serious heart problems and cancer.

In 2021, Pfizer, Incyte, and Lilly had their review timeline extended for their respective JAK inhibitors. Incyte has been particularly hard hit by the delays, losing about 5.6% in stock value on June 11th after its review was postponed.

Related Article: Industry News Pfizer’s JAK1 Inhibitor Impresses in Phase 3 Atopic Dermatitis Trial

Author

Daniel Ojeda