Impact of Selective Immunosuppressive Therapy on Subsequent Immune-Related Adverse Events After Immune Checkpoint Inhibitor-Induced Colitis Treatment.

OBJECTIVES: Immune checkpoint inhibitors (ICI) can cause immune-related adverse events (irAEs) such as colitis. irAEs can be managed by selective immunosuppressive therapy (SIT) agents such as infliximab and vedolizumab. We aimed to elucidate the incidence of subsequent new irAEs after exposure to SIT by describing patients' clinical course. METHODS: We conducted a retrospective chart review of adult patients at a tertiary cancer center diagnosed with ICI-mediated colitis (IMC) treated with SIT from February 2013 through October 2021. Patients' clinical courses, treatments, and outcomes of new irAEs after SIT were collected and analyzed. RESULTS: The study included 156 patients. Most were male (67.3%), 44.8% had melanoma, and 43.5% received anti-PD1/L1 ICIs. For IMC treatment, 51.9% received infliximab and 37.8% received vedolizumab. Twenty-six patients (16.6%) resumed ICI treatment after their colitis event. Twenty-five patients (16%) developed a new irAE after receiving SIT. The most common new irAE involved skin (44%), and most (60%) were treated with steroids. Higher diarrhea grade and ≥2 doses of SIT were associated with lower incidence of post-SIT irAEs ( P =0.038, P =0.050). However, the type of SIT or individual dosage of infliximab did not affect the occurrence of subsequent irAEs. CONCLUSIONS: New irAEs usually occur more than 6 months after SIT completion for initial colitis event. Severe diarrhea grade and higher number of SIT infusions appeared to have protective effect to lower the occurrence of new irAEs. Otherwise, the type of SIT or individual dosage of infliximab did not affect the occurrence of subsequent irAEs.

Immune-related adverse events after immune checkpoint inhibitor exposure in adult cancer patients with pre-existing autoimmune diseases.

PURPOSE: Immune checkpoint inhibitor (ICI) therapy can predispose patients to immune-related adverse events (irAEs) and autoimmune disease (AD) flare-ups, but the characteristics of irAEs among patients with pre-existing ADs are largely unknown. We conducted this study to determine the clinical courses, irAEs, AD flares, treatment, and outcomes of patients with AD on ICIs. METHODS: This was a retrospective study of adult cancer patients at a large cancer center who were diagnosed with ADs before undergoing ICI therapy. Patients' clinical courses, complications, treatments, and outcomes related to both ADs flares and irAEs were collected and analyzed. RESULTS: The study included 197 patients. Most (55.4%) were women. Melanoma comprised the highest proportion (28.4%) of malignancies, and most (83.8%) patients received PD-1/PD-L1 inhibitors. Fifty (25.3%) patients developed a new irAE after starting ICI therapy, while 29 (14.7%) patients had an AD flare-up. Patients with inflammatory bowel disease had the highest incidence of AD flare-ups (31.7%), while patients with Hashimoto hypothyroidism had the highest incidence of new irAEs (39.2%). Patients with inflammatory bowel disease had more severe adverse events. In our cohort, patients with a new diagnosis of irAE were treated with immunosuppressive therapy. AD flares were managed similarly. With regard to irAE manifestations, the most common presentations were colitis (24 [12.1%] patients), hepatic transaminase elevations (8 [4%] patients), and pneumonitis (7 [3.5%] patients). CONCLUSION: Our findings suggest that patients with gastrointestinal and rheumatologic ADs had a higher incidence of AD flare-ups, while patients with Hashimoto hypothyroidism and neurologic ADs had a higher incidence of new irAEs. Patients with prior ADs experiencing flare-ups or new irAEs after ICI therapy tend to require aggressive immunosuppressive treatment. Thorough evaluation of baseline disease status, appropriate medical management before ICI therapy, and early recognition of inflammatory exacerbation may help ensure long-term success in treating and improving outcomes in these patients.

Characteristics, treatment, and outcome of patients with bowel perforation after immune checkpoint inhibitor exposure.

PURPOSE: Exposure to immune checkpoint inhibitors (ICIs) can predispose to immune-related adverse events (irAEs) involving the gastrointestinal tract. The association between ICIs and bowel perforation has not been well studied. We aimed to describe the clinical course, complications, treatment, and outcomes of patients experiencing bowel perforation during or after ICI treatment. METHODS: This retrospective, single-center study included adult cancer patients with bowel perforation that occurred between the first dose of ICI treatment and up to 1 year thereafter between 1/1/2010 and 4/30/2021. Patients' clinical course, imaging, treatment, and outcomes related to bowel perforation were collected and analyzed. RESULTS: Of the 13,991 patients who received ICIs during the study period, 90 (0.6%) met the inclusion criteria. A majority were male (54.4%), the most common cancer type was melanoma (23.3%), and most patients had received PD-1/L1 inhibitor treatment (58.8%). Onset of perforation occurred after a median of four ICI treatment cycles. The most common symptom was abdominal pain (95.5%). The colon was the most common location for the perforation (37.7%). Evidence of diverticulitis, enterocolitis, or appendicitis was seen in 32 (35.6%) patients, and 6 (6.6%) patients had luminal cancer involvement at the time of perforation. The overall hospitalization rate related to perforation was 95.5%, with mortality of 15.5% during the same admission. Antibiotics were given in 95% of our sample; 37.8% of patients also required surgical/interventional radiology intervention. Forty-six patients (51.1%) had perforation-related complications (e.g., sepsis, fistula, abscess), which were associated with a higher mortality rate (30%). CONCLUSION: Our findings suggest a low incidence of bowel perforation after ICI treatment (0.6%), with 40% of patients having coexisting bowel inflammation as a potential contributing factor. Patients with bowel perforation had an aggressive disease course and high rates of hospitalization, complications, and mortality. Early recognition and prompt intervention is critical to improve patient outcomes. Future studies are warranted to further investigate the cause, predictive markers, and optimal treatment for this patient population.