In a nutshell
This study investigated the safety and effectiveness of different doses of peficitinib (Smyraf; PFC) in treating rheumatoid arthritis (RA). They found that PFC doses of 50 mg or higher were the most effective in these patients.
Some background
Rheumatoid arthritis (RA) is a chronic condition caused by inflammation. Inflammation in the joints causes pain and swelling. Over time, joint tissue will degenerate. Disease-modifying anti-rheumatic drugs (DMARDs) are used to treat RA. DMARDs target the immune system to reduce inflammation. Over time the effect of DMARDs can be reduced. Drugs that target specific inflammatory proteins may improve RA symptoms.
Peficitinib (PFC) is a Janus kinase (JAK) inhibitor. JAKs stimulate immune cells to produce proteins and chemicals. This leads to excessive inflammation. JAK signaling is overactive in patients with RA. PFC may be effective in treating RA. It is unclear what dose of PFC is safe and effective in RA patients.
Methods & findings
This study included 948 patients from 3 clinical trials. Patients were treated with either PFC or placebo (inactive tablet). The doses of PFC used were 25, 50, 100 and 150 mg daily. The American College of Rheumatology (ACR) response was used to measure RA symptoms. An ACR20 represented a 20% improvement in RA symptoms.
ACR20 rates were significantly higher in patients treated with 50 mg PFC or higher. This was compared to a placebo. The ACR20 response was 3.61 times higher in patients treated with 150 mg PFC compared to placebo. 150 mg PFC was the most likely to achieve the best ACR20. ACR50 and ACR70 responses were similar.
The ACR20 response was 2.33 times higher with 100 mg PFC than with placebo. The ACR20 response was 2 times higher with 15 mg PFC than with placebo. No significant difference was found between PFC 25 mg and placebo.
A probability analysis suggested that lower PFC doses are safer. However, the number of serious AEs was similar across all doses.
The bottom line
The authors concluded that PFC doses of 50 mg or higher were effective in the treatment of RA symptoms.
The fine print
The treatment period in these studies was 12 weeks. The long-term safety and effectiveness is unclear. More studies are needed.
What’s next?
If you have any concerns regarding RA please consult with your physician.
Published By :
Clinical drug investigation
Date :
Oct 10, 2019
