Compared with control participants who did not receive rituximab, patients with inflammatory rheumatic and musculoskeletal diseases (RMDs) who were treated with rituximab developed more severe COVID-19 and had longer hospital stays, according to study results published in Lancet Rheumatology.
Although limited data exist, clinical observations have suggested a possible association between rituximab and severe COVID-19. The current study was conducted to assess this association in a cohort of patients with inflammatory RMDs.
In this multicenter, retrospective cohort study, researchers analyzed data from the French RMD cohort (ClinicalTrials.gov Identifier: NCT04353609). Data were collected between April 15 and November 20, 2020. The severity of COVID-19 disease (mild, moderate, or severe) was determined by the level of care needed for each patient (ambulatory care, nonintensive care, or admission to an intensive care unit or death, respectively). Outcomes were compared between patients with inflammatory RMDs receiving treatment with rituximab vs those who were not receiving rituximab.
A total of 1090 patients with inflammatory RMDs and suspected or confirmed COVID-19 (mean age, 55.2 years; 67% women) were included in the analysis. Of these, 63 received rituximab and 1027 were included in the control group (no rituximab). Severe disease was observed in 137 (13%) of patients. After adjusting for potential confounding factors, patients treated with rituximab were more likely to develop severe disease than the control group (effect size, 3.26; 95% CI, 1.66-6.40; P =.0006).
Length of hospital stay was also longer in the rituximab vs the control group (effect size, 0.62; 95% CI, 0.46-0.85; P =.0024). In the rituximab vs control group, a greater percentage of patients died (13 [21%] vs 76 [7%], respectively); however, the adjusted risk for death was not significantly increased (effect size, 1.32; 95% CI, 0.55-3.19; P =.53).
Study limitations included the observational study design, the small sample size, and the lack of information about disease activity, ethnicity, previous medications, rituximab dose/duration, and the presence of associated hypogammaglobulinaemia.
Researchers concluded, “Rituximab will have to be prescribed with particular caution for patients with inflammatory [RMDs], especially if they have other comorbidities that render them at risk [for] severe COVID-19 outcomes. Future research is now required to confirm this result in independent cohorts from other countries.”
Avouac J, Drumez E, Hachulla E, et al; on behalf of the FAI2R/SFR/SNFMI/SOFREMIP/CRI/IMIDIATE consortium and contributors. COVID-19 outcomes in patients with inflammatory rheumatic and musculoskeletal diseases treated with rituximab: a cohort study. Lancet Rheumatol. Published online March 25, 2021. doi:10.1016/ S2665-9913(21)00059-X