Janus kinase inhibitors effective for pain reduction among Rheumatoid Arthritis patients: Study

A recent cohort study revealed that Janus kinase inhibitors (JAKis) are better at providing pain relief than TNF inhibitors (TNFis) at both 3 and 12 months, in rheumatoid arthritis (RA) patients previously treated with multiple biologic disease-modifying anti-rheumatic drugs (bDMARDs). The study findings were published in the journal Arthritis & Rheumatology.

Pain is the key patient-centered concern in Rheumatoid arthritis. Assessment tools for pain include pain measures without any significant emphasis on the pain thus underscoring the gap in the direct pain assessment without any impact on the quality of life. Hence, researchers conducted a study to compare the effectiveness of Janus kinase inhibitors (JAKis) and biologic disease-modifying anti-rheumatic drugs (bDMARDs) in reducing pain among patients with rheumatoid arthritis (RA).

A retrospective analysis was carried out by obtaining data from several Swedish national registers enabling a comprehensive review of treatment outcomes. The analysis included RA patients who were under treatment with various drugs like either a JAKi (n=1,827), TNF inhibitor (TNFi, n=6,422), IL-6 inhibitor (n=887), abatacept (n=1,102), or rituximab (n=1,149) between 2017 and 2019. A visual analogue scale (VAS) was used to measure pain level from 0 to 100 mm, with lower values indicating less pain. Pain was also assessed at baseline, 3 months, and at the end of the treatment. 

The two outcomes of measurement are change in pain from baseline to 3 months and the proportion of patients who achieved and maintained low pain (VAS pain score <20 mm) at 12 months while continuing on their initial treatment. To account for patient characteristics, such as demographics, comorbidities, concurrent medications, and prior treatments, multivariable linear regression models were employed for a more accurate comparison of pain relief between JAKis and various bDMARDs, including TNFis and non-TNFi agents.

Results:

• A greater reduction in pain at the 3-month mark was experienced by JAKi treated patients than TNFi therapy.
• Specifically, the adjusted mean decrease in pain for JAKi users was 4.0 mm greater than for TNFi users (95% confidence interval [CI]: 1.6–6.3).
• Similar trends were seen when comparing JAKis to non-TNFi bDMARDs, suggesting that JAKis may offer superior short-term pain relief across a broad range of biologic therapies.
• A higher proportion of patients treated with JAKis maintained low pain levels compared to those on TNFis at 12 months.
• This difference was particularly significant in patients who had previously been treated with two or more bDMARDs, a subgroup often more challenging to treat due to their history of inadequate response to multiple therapies.
• In this group, JAKi treatment was associated with an adjusted increase of 5.3 percentage points in the likelihood of achieving low pain (95% CI: 1.0–9.6), highlighting the potential advantage of JAKis in more refractory cases of RA.
• When comparing JAKis to non-TNFi bDMARDs (such as IL-6 inhibitors, abatacept, and rituximab), the pain reduction outcomes at 12 months were similar.
• This suggests that while JAKis may be slightly more effective in reducing pain in the short term compared to TNFis, their long-term effectiveness in controlling pain is at least comparable to that of non-TNFi bDMARDs.

Thus, the study concluded that JAK inhibitors provide slightly better pain relief at both 3 and 12 months compared to TNF inhibitors, especially in patients who have previously been treated with multiple bDMARDs. Additionally, JAKis were found to be at least as effective as non-TNFi bDMARDs in terms of long-term pain reduction. These findings suggest that JAK inhibitors may be a valuable option for RA patients, particularly those who have experienced suboptimal responses to other bDMARDs.

Further reading: Eberhard, Anna et al. “Effectiveness of janus kinase inhibitors compared with biologic disease modifying anti-rheumatic drugs on pain reduction in rheumatoid arthritis: Results from a nationwide Swedish cohort study.” Arthritis & rheumatology (Hoboken, N.J.), 10.1002/art.43014. 22 Sep. 2024, doi:10.1002/art.43014