according to a new study of long-term outcomes of immune-related adverse events published in Annals of the Rheumatic Diseases.
“This study is one of the largest longitudinal reports to date of patients with ICI-induced IA and the first to evaluate persistence of ICI-induced IA and identify influential factors on outcome,” wrote Tawnie J. Braaten, MD, and coauthors. “Continued clinical and translational investigation on larger longitudinal cohorts will allow for increased understanding of pathophysiology and determination of the best clinical care for patients with ICI-induced IA.”
Dr. Braaten conducted the study at Johns Hopkins University, Baltimore, when she was a postdoctoral fellow there, and she is now in the division of rheumatology at the University of Utah, Salt Lake City.
To determine how long IA can persist after patients cease ICI therapy, along with factors associated with its persistence, the researchers studied 60 patients who were referred to the Johns Hopkins Arthritis Center for IA caused by ICIs. The patients – 32 females and 28 males – had a median follow-up of 9 months after ICI cessation.
Of the 51 patients with 3-month follow-up data, 70.6% had active IA. Of the 41 patients with 6-month follow-up data, 48.8% had active IA. All told, 53.3% of patients had active IA at their last follow-up visit, which occurred anywhere from 1 to 24 months after stopping ICI therapy.
According to univariable analysis, arthritis was less likely to improve in patients with a longer duration of ICI exposure (hazard ratio, 0.93; 95% confidence interval, 0.87-0.99; P = .02), in patients receiving combination ICI therapy (HR, 0.29; 95% CI, 0.12-0.72; P = .008) and in patients with a history of other immune-related adverse events (HR, 0.61; 95% CI, 0.39-0.95; P = .03).
The authors acknowledged their study’s limitations, including a potential selection bias for symptomatic individuals and the possibility that persistent IA sufferers may have pursued follow-up for longer periods of time. In addition, they noted that some patients were omitted from analysis if they were on a blinded clinical trial or had been receiving an investigational immunotherapy agent.
The study was funded via a grant from Bristol-Myers Squibb, an arthritis fellowship award from AbbVie, and additional financial support from the Camille Julia Morgan Arthritis Research and Education Fund, the Jerome L. Greene Foundation, and the National Institutes of Health. The authors reported various conflicts of interest, including receiving honoraria, grants, and research funding from numerous pharmaceutical companies.
SOURCE: Braaten TJ et al. Ann Rheum Dis. 2019 Sep 20. doi: 10.1136/annrheumdis-2019-216109.