Pfizer has unveiled further Phase III data showing that its JAK inhibitor tofacitinib met key primary and secondary endpoints in trials investigating the drug’s safety and efficacy in ulcerative colitis. 

After eights weeks’ treatment, a significantly greater proportion of patients receiving tofacitinib were found to be in remission compared to those taking a placebo - 18.5 percent versus 8.2 percent in the OCTAVE Induction 1 trial and 16.6 percent vs 3.6 percent in OCTAVE Induction 2. 

The two trials also showed that a significantly greater number of patients in the tofacitinib arm achieved the secondary endpoint of mucosal healing at week eight compared to placebo: 31.3 percent versus 15.6 percent and 28.4 percent compared to 11.6 percent, respectively. 

In another plus, the trials threw up no new safety signals for the drug. Across both studies, a similar proportion of patients in the tofacitinib groups and the placebo groups reported an adverse event (AE) or serious AE (SAE) through week 8: in OCTAVE 1, rates of AEs and SAEs were 56.5 percent and 3.4 percent in the tofacitinib arm versus 59.8 percent and 4.1 percent in the placebo group, respectively; and in OCTAVE 2, rates were 54.1 percent and 4.2 percent verus 52.7 percent and 8.0 percent, respectively. 

Tofacitinib was first cleared by the US Food and Drug Administration in 2012 for the treatment of patients with moderately to severely active rheumatoid arthritis under the name Xeljanz, but was later declined (in 2015) as a treatment for moderate-to-severe chronic plaque psoriasis.

Xeljanz is the first JAK inhibitor being assessed for UC, a chronic, often debilitating inflammatory bowel disease that affects millions of people worldwide. The drug is also the first and only JAK inhibitor approved in over 40 countries for the second-line treatment of moderate to severe rheumatoid arthritis.