Arundathi Jayatilleke, MD
Interleukin (IL)–6 is known to be of great importance in the pathogenesis of rheumatoid arthritis (RA) owing to its role in the inflammatory response. Current IL-6-directed therapies in RA, namely sarilumab and tocilizumab, target the receptor. In a double-blind randomized controlled trial with both placebo and active comparators, Smolen and colleagues evaluated the efficacy of olokizumab, which directly binds and inhibits the activity of IL-6, in combination with methotrexate, in the treatment of people with RA. Patients were treated with methotrexate alone or in combination with adalimumab or olokizumab, and clinical outcomes were evaluated after 12 weeks, a relatively short time frame. Olokizumab was noninferior to adalimumab in terms of the proportion of patients achieving an American College of Rheumatology 20 response, with similar rates of serious adverse events, the most common of which was infection. Though this study included patients from across the globe, the percentage of Black and Asian patients was relatively low and thus may affect the generalizability of this study to a US population; the numbers of patients in each group was also relatively small. These results certainly warrant larger-scale and longer studies to evaluate olokizumab's efficacy.
For those patients with RA who achieve sustained disease remission, the question of medication tapering has been raised as a possible strategy for minimizing risks for therapy. Using insurance database information, Birkner and colleagues performed a prospective cohort study of over 400 patients in Germany. Using shared decision-making between patients and their rheumatologists, two groups of patients were followed: 237 people who elected to remain on therapy and 200 who decided to taper medication. Of note, similar proportions of patients in both groups were taking conventional and biologic disease-modifying antirheumatic drug (DMARD) monotherapy, but more patients in the tapering group were taking a combination therapy with both. Flares and loss of remission were more common in the continuation group, a difference that did not persist after adjusting for patient risk characteristics. Overall, results from this "real-world" study were consistent with prior studies and support the possibility of tapering with flare in a subset of patients. Although the authors address the potential for selection bias in terms of patients "assigned" to each group, this can also be viewed as part of the shared decision-making in determining the appropriateness of tapering therapy in individual patients.
Because people receiving rituximab have experienced more severe COVID-19, studies aimed at enhancing the protection of these patients are of current interest. Of note, in a follow-up to a prior observational study by van der Togt and colleagues on the response to COVID-19 vaccines in people with RA being treated with rituximab, they looked at responses to the third (booster) dose of the COVID-19 vaccine. Only about 20% of patients treated with rituximab developed a humoral response to a third vaccine dose, as defined by immunoglobulins (Ig; total, IgG, and IgM) against SARS-CoV-2. Patients treated with 200 mg rituximab had a higher response rate than did those treated with 500 mg or 1000 mg, though this difference was not statistically significant. The study lacked a control arm of people being treated with other DMARD and also did not measure B-cell counts, COVID-19, or outcomes. Reassuringly, those patients who did have a positive humoral response to the first two vaccine doses tended to maintain a humoral response to the third, regardless of rituximab dose or timing.