medwireNews: Findings from two real-world studies presented at the EULAR 2021 Virtual Congress suggest that Janus kinase (JAK) inhibitors and biologics are similarly effective for the treatment of inflammatory arthritis.
In the first study, Andrei Barbulescu (Karolinska Institute, Stockholm, Sweden) and colleagues used Swedish registry data to evaluate treatment response rates among rheumatoid arthritis (RA) patients initiating JAK inhibitors or a biologic DMARD in 2017–2018.
Barbulescu reported that after adjustment for a range of baseline factors, including demographics, disease activity, other medications, and comorbidities, there were no significant differences in treatment response rates among patients taking JAK inhibitors (n=905) compared with those on tumor necrosis factor (TNF) inhibitors (n=3497), rituximab (n=692), abatacept (n=694), or interleukin (IL)-6 inhibitors (n=534).
These findings remained consistent regardless of which definition of treatment response was used: proportion of patients with a “good” EULAR response; DAS28 remission (<2.6 points); HAQ-DI improvement of more than 0.2 points; zero swollen or tender joints; or CDAI remission (≤2.8 points).
In the adjusted analysis, the proportion of patients remaining on treatment was significantly higher among those taking JAK inhibitors versus TNF inhibitors or IL-6 inhibitors, at approximately 70% versus 65% and 61%, respectively. Treatment retention rates were significantly lower in the JAK inhibitor group than the rituximab group, however, at approximately 70% versus 80%.
Together, these findings suggest “comparable overall effectiveness” with JAK inhibitors compared with biologic DMARDs, concluded Barbulescu.
The second study, presented by Isabel Castrejón (Hospital Universitario Gregorio Marañón, Madrid, Spain), involved 4532 patients with RA, psoriatic arthritis, ankylosing spondylitis, or other spondyloarthropathies from the Spanish BIOBADASER registry who initiated treatment with a JAK inhibitor or a TNF inhibitor between 2000 and 2020.
The presenter said that overall drug retention rates during up to 3 years of follow-up were “pretty similar” among patients taking JAK inhibitors and those on TNF inhibitors. In RA patients, 86.6% of those in the JAK inhibitors group and 81.2% of those taking TNF inhibitors remained on treatment at the 3-year follow-up.
Among people with spondyloarthritis, drug retention was “slightly lower” with JAK inhibitors than TNF inhibitors, said Castrejón. Retention rates were 75.7% versus 90.3% at 2 years (no data available for JAK inhibitors at 3 years).
Noting that retention rates are “an indirect indicator of effectiveness,” Castrejón said these findings suggest that JAK inhibitors are “an effective therapeutic option for patients who fail to respond to anti-TNF.”
The researchers also compared the safety profiles of JAK inhibitors versus TNF inhibitors, finding that rates of any infection and herpes zoster “tend to be more frequent in patients on JAK inhibitors.”
Castrejón noted, however, that people on JAK inhibitors were older, had more comorbidities, and a longer disease duration than those on TNF inhibitors, and there was no significant overall increase in the risk for adverse events with JAK inhibitors versus TNF inhibitors after adjustment for these factors in addition to sex and previous treatments.
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EULAR 2021 Virtual Congress; 2–5 June (abstract OP0122)
EULAR 2021 Virtual Congress; 2–5 June (abstract OP0123)