Arthritis Attributed to Immunotherapy May Persist Even After Therapy

Cancer patients who develop immune checkpoint inhibitor (ICI)-induced inflammatory arthritis (IA) may sustain long-term consequences even after cessation of ICI, a new study suggests.

The goals of the prospective observational study, in addition to determining what long-term side effects ICI-induced IA patients may sustain, were also “to define factors associated with IA persistence after treatment cessation, the need for immunosuppressants and the impact of these medications on underlying malignancies,” per the authors, whose research appeared in Annals of the Rheumatic Diseases.

Patients with ICI-related IA were recruited between June 2015 and December 2018. Baseline data were collected and patients attended follow-up visits at varying intervals for up to two years after terminating ICI. IA persistence was established using Kaplan-Meier curves, factors associated with IA persistence were found using Cox proportional hazards models, and the effects of IA treatment on tumor response were evaluated using logistic regression.

Final analysis included 60 patients, who were followed for a median of nine months after ICI cessation. At their final follow-up, more than half (53.3%) of patients had active IA. Patients who used ICI for a longer period of time were more likely to have persistent IA, as were patients receiving combination ICI therapy and with more than one additional immune-related adverse events. Immunosuppression did not affect tumor response. There was a not statistically significant association between persistent IA and better tumor complete or partial response.

“Conclusion ICI-induced IA can become a long-term disease necessitating management by rheumatology for immunomodulatory treatment. Importantly, the use of immunomodulatory treatment has not been shown to impact cancer outcomes in this study,” the authors wrote in sum.