Sex-based differences in remission rates were noted among patients with early rheumatoid arthritis (RA), with higher remission rates observed in men vs women receiving treatment with biologic or conventional therapy, according to results of an analysis published in The Lancet Rheumatology.

To determine the sex differences in remission rates among patients with RA receiving biologic vs conventional therapy, a post-hoc analysis of the phase 4, multicenter, investigator-initiated, assessor-blinded, randomized, controlled NORD-STAR trial (ClinicalTrials.gov Identifier: NCT01491815) was conducted.

In the NORD-STAR trial, patients with newly diagnosed RA from Denmark, Finland, Iceland, Norway, Sweden, and The Netherlands who were naive to disease-modifying antirheumatic drugs (DMARDs) were randomly assigned 1:1:1:1 to receive active conventional therapy, certolizumab-pegol, abatacept, or tocilizumab.


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The co-primary outcomes of the current post-hoc analysis included differences in Clinical Disease Activity Index (CDAI) remission (score ≤2.8) between the sexes over time and at week 24; CDAI remission was evaluated with interaction terms (ie, men vs women within each treatment comparison) and using active conventional treatment as a reference.

Between December 2012 and 2018, a total of 812 patients (69% women) were enrolled in the study and received active conventional treatment (n=217); certolizumab-pegol (n=203); abatacept (n=204); or tocilizumab (n=188).

At 24 weeks, CDAI remission rates were numerically higher among men than women, regardless of comparable disease activity reported at baseline (55% vs 50%, respectively, with active conventional treatment; 57% vs 52%, respectively, with certolizumab-pegol; 65% vs 51%, respectively, with abatacept; 61% vs 40%, respectively, with tocilizumab).

In the adjusted analysis, with the active conventional treatment as the reference, the only significant difference reported between men and women was in the tocilizumab group (Pinteraction =.015). Results of the study showed that, on average, over time, men in the tocilizumab vs active conventional group had a significantly higher probability of CDAI remission (risk difference, 0.12; 95% CI, 0.00-0.23; P =.04). However, women in the tocilizumab vs active conventional group had a significantly lower probability of CDAI remission (risk difference, -0.05; 95% CI, -0.13 to 0.02; P =.17).

One of the limitations of the current analysis was that data available were of those participants who were more likely to have better responses or tolerance to the treatments compared with those who discontinued treatment early. Further, the sex differences in response to the conventional treatment might have influenced the study results as well, with prior research revealing that sex differences are present in patients with early, but not in those with established, RA.

The researchers concluded, “The underlying mechanisms responsible for the sex differences [between men and women with early RA] remain unknown.” The findings from the current analysis “could provide guidance about the optimal treatment choice for men and women with newly diagnosed [RA].”

Disclosure: Some of the study authors have declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures. 

Reference

Lend K, van Vollenhoven RF, Lampa J, et al. Sex differences in remission rates over
24 weeks among three different biological treatments compared to conventional therapy in patients with early rheumatoid arthritis (NORD-STAR): a post-hoc analysis of a randomised controlled trial
. Lancet Rheumatol. Published online August 23, 2022. doi:10.1016/S2665-9913(22)00186-2