Tocilizumab Effectiveness Not Impacted by Obesity in Patients with RA

Obesity does not diminish the effectiveness of tocilizumab to treat patients with rheumatoid arthritis (RA), according to a study.

“Tocilizumab (TCZ) is a humanized monoclonal antibody against the interleukin 6 receptor approved for patients with moderate to severe RA. Although caution should be used in patients with diverticulitis, chronic or recurrent infections, neutropenia, or thrombocytopenia, the existence of prior comorbidities does not contraindicate its use,” the researchers explained. However, there are limited real-world data regarding the effect of comorbidity burden or obesity on tocilizumab’s effectiveness.

The present study included patients in the Corrona RA registry who were classified by comorbidity status per a modified Charlson Comorbidity Index (mCCI) (low [mCCI <2] or high [mCCI ≥2]) and obesity status based on their body mass index (BMI) (obese, BMI ≥30; nonobese, BMI <30). At six and 12 months following tocilizumab initiation, patients were compared for improved disease activity and functionality.

Final analysis included 575 low mCCI, 195 high mCCI, 356 obese, and 449 nonobese patients treated with tocilizumab.

The high mCCI group, compared to the low mCCI group, had older mean age (61.5 years vs. 56.9 years) and a higher proportion of patients with obesity (52.8% vs. 41.7%).

The nonobese group, compared to the obese group, had slightly longer mean disease duration (12.6 years vs. 11.4 years). The obese cohort had a greater history of diabetes (16.3% vs. 5.6%).

When classified by BMI, 3.9% of patients were underweight, 23.0% were normal weight, 28.9% were overweight, 22.4% were obese class I, and 21.9% were obese class II & III.

More than 95% of patients were biologic experienced, and about a third of patients received tocilizumab alone; no significant differences were observed by comorbidity burden or obesity status. At six and 12 month follow-up, none of the groups presented significant differences in improvements in disease activity and functionality.

The study was published in The Journal of Rheumatology.