Sjogren's syndrome due to immune checkpoint inhibitors (ICIs): Insights from a single-institution series and systematic review of the literature.

IntroductionCareful adverse event assessment and management are important when prescribing immune checkpoint inhibitors (ICIs) to cancer patients. Iatrogenic Sjogren's syndrome is a relatively rare immune-related adverse event (irAEs) that affects the moisture-producing glands.MethodsWe describe a series of four patients who developed Sjogren's syndrome while being treated with ICIs at a community cancer center in Southern California, USA (1/1/2017-12/31/2023). Patient, drug and disease-related data were collected by retrospective chart review. A systematic search of the PubMed database was performed to identify similar cases in the literature (1/1/2016-12/31//2023).ResultsOf 224 cancer patients at our center treated with ICIs, four (1.8%) developed iatrogenic Sjogren's syndrome. All of our patients were male; three received PD-1 inhibitors (nivolumab, pembrolizumab) and one received the PD-L1 inhibitor atezolizumab. The median time to development of Sjogren's syndrome was 24 weeks (range, 8-36 weeks); dry mouth symptoms were more prominent than dry eye symptoms. None of the patients had elevated SS-A, SS-B or antinuclear antibodies. One patient developed multiple tooth cavities and had several extractions, due to severe xerostomia. Management of all patients was primarily symptomatic. Two cases were irreversible; one was reversible and the 4^th case is undermined as he is still on ICI therapy. Our systematic review of the literature identified 80 cases in five articles. Incidence of xerostomia was twice of that of xerophthalmia. The male/female ratio was 1.5:1. SS-A, SS-B, or antinuclear antibodies were found in only 9% of patients. Steroids were reported to have had only a limited role in management.ConclusionsThe incidence of Sjogren's syndrome due to ICIs in our center was 1.8%. Details of clinical course and management in these patients are presented. Caring for patients with ICI-related Sjogren's syndrome is facilitated by a multidisciplinary effort including oncologists, otolaryngologists, dentists, ophthalmologists and rheumatologists. Expanding the knowledge base pertaining to iatrogenic Sjogren's syndrome in patients on ICIs will be helpful in promoting early detection and treatment, and improving outcomes.