Braaten, Tawnie

Objective Our objective was to identify and describe the clinical characteristics and outcomes in patients with pre‐existing idiopathic inflammatory myopathies (IIMs) in the Veterans Health Administration (VHA) treated with immune checkpoint inhibitors (ICIs). Methods All veterans receiving ICI infusions were identified. Patients with at least two International Classification of Disease codes for IIM before first ICI infusion underwent chart review to identify patients with confirmed IIM by American College of Rheumatology/EULAR criteria. The demographics, cancer diagnoses, laboratory findings, clinical course, and mortality rates were reported. IIM cases were also reviewed to determine if patients developed IIM flare following ICI treatment. Results We identified 29,539 veterans who received at least one ICI infusion in the VHA between June 6, 2011, and February 14, 2023. The eight patients with confirmed IIM before ICI treatment were mostly White men with an average age of 71.7 years at first ICI infusion. The IIM diagnoses were dermatomyositis in three patients, polymyositis in two, antisynthetase syndrome in two, and one rheumatoid arthritis (RA)/myositis overlap. Cancer diagnoses were lung (two), melanoma (two), head and neck (two), kidney/other urinary (one), and mesothelioma (one). Diagnosis of IIM was made on average 3.1 years before ICI treatment. One patient had an IIM flare after ICI. No IIM flares were identified in other patients. Conclusion Our findings show that an IIM flare after ICI therapy can occur, but most patients did not develop a flare. These observations suggest ICIs can be considered as an option in patients with cancer with IIM with shared decision‐making and close monitoring.

Objective Immune checkpoint inhibitor (ICI) myositis is a rare but a highly morbid condition, particularly with the ICI myositis triad syndrome of myositis, myocarditis, and myasthenia gravis. We report the clinical characteristics of ICI myositis and all‐cause mortality in these patients. Methods We performed a national retrospective cohort study of US veterans treated with an ICI between June 2011 and February 2022. Cases were identified by elevated creatinine kinase (CK) following ICI therapy and/or “myositis” in notes. Chart review determined if candidates had ICI‐associated myositis and were subsequently classified as isolated ICI myositis or ICI triad syndrome. Results Of 29,296 veterans treated with ICIs, 68 (0.2%) ICI‐induced myositis cases were identified, including 23 patients with ICI triad syndrome and 45 patients with isolated ICI myositis. Median survival duration for ICI triad syndrome was 2.5 (95% confidence interval [CI] 1.7–18.5) months in comparison to 20.4 (95% CI 6.2–60) months for isolated ICI myositis and 12.6 (95% CI 12.3–12.8) months median survival for patients treated with ICI without myositis. Patients with ICI triad syndrome had 60.0% mortality during the six months following initiation of ICI treatment, in comparison to 30.2% mortality in isolated ICI myositis and 31.5% mortality in patients without myositis. Six months after the first ICI treatment, subsequent mortality trends were similar in the three groups. Conclusion ICI triad syndrome is associated with higher overall mortality and shortened median survival times during the first six months after initial ICI therapy, whereas isolated ICI myositis is associated with similar mortality outcomes compared to patients treated with ICI who did not develop myositis. image

The NCCN Guidelines for the Management of Immunotherapy-Related Toxicities are intended to provide oncology practitioners with guidance on how to manage the wide-ranging and potentially fatal toxicities that may occur with cancer immunotherapy. The guidelines address immune-related adverse events related to immune checkpoint inhibitors, CAR T-cell therapies, and lymphocyte engagers (which include T-cell–engaging bispecific antibodies). These NCCN Guidelines Insights highlight recent guideline updates pertaining to the management of emerging toxicities related to cancer immunotherapy.