Cytomegalovirus Infections in Patients Treated With Immune Checkpoint Inhibitors for Solid Malignancies.

Cytomegalovirus (CMV) infection/disease has been repeatedly reported in patients treated with immune-checkpoint inhibitors (ICIs) and most commonly involves patients with relapsed/refractory (R/R) immune-related adverse events (irAEs). In the current study, we present a patient with melanoma who developed CMV gastritis during treatment with pembrolizumab in the absence of irAEs and without previous or current immunosuppression. Moreover, we review the literature regarding CMV infection/disease in patients treated with ICIs for solid malignancies. We present the currently available data on the pathogenesis, clinical characteristics, endoscopic findings, and histologic features and highlight the potential differences among cases complicating R/R irAEs versus those occurring in patients who are immunosuppression naive. Finally, we discuss the currently available data regarding potential useful diagnostic tools as well as the management of these patients.

Immune-Related Colitis Induced by Camrelizumab: A Case Report.

In recent years, immunotherapy has become a major research focus in the field of cancer treatment. Because of its good efficacy and lasting immune response, immune checkpoint inhibitors have benefited the long-term survival of many types of cancer patients. However, overactivation of the immune system may attack normal organs and cause a series of immune related adverse reactions. Among them, due to the high incidence of immune-related colitis, it deserves special attention. Camrelizumab is a programmed cell death 1 (PD-1) inhibitor that was developed by Jiangsu Hengrui Medicine Company. We reported the clinical data of a case of hepatocellular carcinoma with immune-related colitis after treatment with camrelizumab. A 63-year-old man with hepatocellular carcinoma developed diarrhea and hematochezia after receiving 4 cycles of camrelizumab. Endoscopy showed multiple flake congestion and edema in the terminal ileum and total colon mucosa with bright red surface. Pathological evaluation showed chronic inflammation of colonic mucosa. After giving 0.25g bid of enteric-coated sulfasalazine tablets orally for 6 weeks, his colitis improved. Camrelizumab can induce immune-related colitis. Sulfasalazine could be used to reduce adverse reactions of glucocorticoids.

Gut microbiota composition in patients with advanced malignancies experiencing immune-related adverse events.

Introduction: The gut microbiota is implicated in the occurrence and severity of immune-related adverse events (irAEs), but the role it plays as well as its causal relationship with irAEs has yet to be established. Methods: From May 2020 to August 2021, 93 fecal samples were prospectively collected from 37 patients with advanced thoracic cancers treated with anti-PD-1 therapy, and 61 samples were collected from 33 patients with various cancers developing different irAEs. 16S rDNA amplicon sequencing was performed. Antibiotic-treated mice underwent fecal microbiota transplantation (FMT) with samples from patients with and without colitic irAEs. Results: Microbiota composition was significantly different in patients with and without irAEs (P=0.001) and with and without colitic-type irAEs (P=0.003). Bifidobacterium, Faecalibacterium, and Agathobacter were less abundant and Erysipelatoclostridium more abundant in irAE patients, while Bacteroides and Bifidobacterium were less abundant and Enterococcus more abundant in colitis-type irAE patients. Major butyrate-producing bacteria were also less abundant in patients with irAEs than those without (P=0.007) and in colitic vs. non-colitic irAE patients (P=0.018). An irAE prediction model had an AUC of 86.4% in training and 91.7% in testing. Immune-related colitis was more common in colitic-irAE-FMT (3/9) than non-irAE-FMT mice (0/9). Conclusions: The gut microbiota is important in dictating irAE occurrence and type, especially for immune-related colitis, possibly by modulating metabolic pathways.

Immune-related colitis and pancreatitis treated with infliximab.

Patients with various cancers benefit from immune checkpoint inhibitors. However, immune checkpoint inhibitor-induced adverse events have also been reported, such as colitis. Prednisolone is the first-line treatment for immune-related adverse events, but second-line therapy for patients refractory to steroids has not been established. Furthermore, the inflammatory cytokine expression pattern in the intestinal mucosa of patients with steroid-refractory immune-related colitis remains unclear. We present the case of a 48-year-old man diagnosed with immune-related colitis and pancreatitis induced by pembrolizumab for advanced lung cancer. First, we administered 50 mg/day of prednisolone, and the patient's abdominal symptoms improved. However, the pancreatic enzyme levels did not return to normal. Furthermore, the patient's diarrhea worsened and hematochezia appeared at a 40 mg/day prednisolone dose. A mucosal cytokine analysis identified a low interleukin-10 messenger RNA level, which has been associated with a poor response to prednisolone. Thus, we administered 5 mg/kg of infliximab; the patient's diarrhea and hematochezia immediately improved, and the pancreatic enzyme levels returned to normal. Infliximab was administered three times every 2 weeks. After, the patient's colitis and pancreatitis did not recur. To our knowledge, this is the first report demonstrating the effectiveness of infliximab for immune-related colitis and pancreatitis.

Moderate Colitis Not Requiring Intravenous Steroids Is Associated with Improved Survival in Stage IV Melanoma after Anti-CTLA4 Monotherapy, But Not Combination Therapy.

BACKGROUND: For patients with melanoma, gastrointestinal immune-related adverse events are common after receipt of anti-CTLA4 therapy. These present difficult decision points regarding whether to discontinue therapy. Detailing the situations in which colitis might predict for improved survival and how this is affected by discontinuation or resumption of therapy can help guide clinical decision-making. MATERIALS AND METHODS: Patients with stage IV melanoma receiving anti-CTLA4 therapy from 2008 to 2019 were analyzed. Immune-related colitis treated with ≥50 mg prednisone or equivalent daily or secondary immunosuppression was included. Moderate colitis was defined as receipt of oral glucocorticoids only; severe colitis was defined as requiring intravenous glucocorticoids or secondary immunosuppression. The primary outcome was overall survival (OS). RESULTS: In total, 171 patients received monotherapy, and 91 received dual checkpoint therapy. In the monotherapy group, 25 patients developed colitis and a nonsignificant trend toward improved OS was observed in this group. Notably, when colitis was categorized as none, moderate or severe, OS was significantly improved for moderate colitis only. This survival difference was not present after dual checkpoint therapy. There were no differences in known prognostic variables between groups, and on multivariable analysis neither completion of all ipilimumab cycles nor resumption of immunotherapy correlated with OS, while the development of moderate colitis did significantly affect OS. CONCLUSION: This single-institution retrospective series suggests moderate colitis correlates with improved OS for patients with stage IV melanoma treated with single-agent anti-CTLA4, but not dual agent, and that this is true regardless of whether the immune-checkpoint blockade is permanently discontinued.

Differential risks of immune-related colitis among various immune checkpoint inhibitor regimens.

BACKGROUND: Colitis is a life-threatening and common immune-related adverse event in patients receiving immune checkpoint inhibitors (ICIs). Therefore, we performed a meta-analysis to assess the risk of immune-related colitis among various ICI treatment regimens. METHODS: We used PubMed, EMBASE, and the Cochrane Library to retrieve phase II or III randomized controlled trials (RCTs) of ICIs that specified the number of all-grade (grade 1-5) colitis and high-grade (grade 3-5) colitis events through January 2020. The pooled relative risk (RR) and 95% confidence intervals (CIs) were calculated to compare the risk of colitis among various therapeutic regimens. RESULTS: The search strategy identified 40 RCTs involving 26,893 patients. The risk of all-grade and high-grade colitis after PD-1/PD-L1 inhibitor was significantly lower than that of CTLA-4 inhibitor (0.18 and 0.14 relative risk respectively). The risk of all-grade and high-grade colitis was dose-dependent for CTLA-4 inhibitor therapy, but not for PD-1/PD-L1 inhibitor therapy. The relative risk of all-grade and high-grade colitis after combination therapy with PD-1/PD-L1 inhibitor and CTLA-4 inhibitor compared to PD-1/PD-L1 inhibitor alone was 9.25 and 12.00 respectively. No significant difference was found between PD-1/PD-L1 inhibitor combined with chemotherapy or targeted therapy and PD-1/PD-L1 inhibitor alone for either all-grade or high-grade colitis. CONCLUSIONS: Our meta-analysis indicates that CTLA-4 inhibitor is associated with a higher risk of colitis compared with PD-1/PD-L1 inhibitor, whether used as a monotherapy or combination immunotherapy. Importantly, the combination of PD-1/PD-L1 inhibitor with chemotherapy or targeted therapy may not increase the risk of colitis significantly compared to PD-1/PD-L1 inhibitor alone.

Immune checkpoint inhibitor-associated gastrointestinal and hepatic adverse events and their management.

BACKGROUND: Drug-induced colitis is a known complication of therapies that alter the immune balance, damage the intestinal barrier or disturb intestinal microbiota. Immune checkpoint inhibitors (ICI) directed against cancer cells may result in activated T lymphocyte-induced immune-related adverse events (AEs), including immune-related colitis and hepatitis. The aim of this review article is to summarize the incidence of gastrointestinal (GI) and hepatic AEs related to ICI therapy. We have also looked at the pathogenesis of immune-mediated AEs and propose management strategies based on current available evidence. METHODS: A literature search using PubMed and Medline databases was undertaken using relevant search terms pertaining to names of individual drugs, mechanism of action, related AEs and their management. RESULTS: ICI-related GI AEs are common, and colitis appears to be the most common side effect, with some studies reporting incidence as high as 30%. The incidence of both all-grade colitis and hepatitis were highest with combination therapy with anti-CTLA-4/PD-1; severity of colitis was dose-dependent (anti-CTLA-4). Early intervention is associated with better outcomes. CONCLUSION: ICI-related GI and hepatic AEs are common and clinicians need to be aware. Patients with GI AEs benefit from early diagnosis using endoscopy and computed tomography. Early intervention with oral steroids is effective in the majority of patients, and in steroid-refractory colitis infliximab and vedolizumab have been reported to be useful; mycophenolate has been used for steroid-refractory hepatitis.

The incidence and relative risk of PD-1/PD-L1 inhibitors-related colitis in non-small cell lung cancer: A meta-analysis of randomized controlled trials.

BACKGROUND: The programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) inhibitors have shown encouraging merits in non-small cell lung cancer (NSCLC) patients, however, they are often related to potentially fatal immune-related adverse events (irAEs) including colitis. Considering the incidence and characteristics of immune-related colitis may have significant implications for the appropriate utilization of PD-1/PD-L1 inhibitors in clinical practice, we conduct this meta to systematically analyze the correlation between PD-1/PD-L1 inhibitors for the treatment of NSCLC and the incidence of immune-associated colitis. METHODS: Electronic databases including PubMed, Embase, Cochrane Library and ClinicalTrials.gov (http://clinicaltrials.gov/) were searched up to May 2019, clinical trials reporting all grade (1-5), higher grade (3-5) colitis and grade 3-5 diarrhea were included, data were expressed as relative risk (RR), incidence, corresponding p value and 95% confidence intervals (CIs). RESULTS: 9 randomized controlled trials (RCTs) were identified (7 with PD-1 inhibitors [n = 4526]) and 2 with PD-L1 inhibitors [n = 1464]). The overall incidence of PD-1/PD-L1 target agents was 1.40% for all grade colitis, 0.89% for severe colitis, 11.62% for all grade diarrhea and 1.36% for severe diarrhea. Compared with chemotherapy group, the PD-1/PD-L1 inhibitors had a significantly higher risk of all grade (RR: 3.68, p < 0.001) and high-grade (RR: 2.97, p = 0.01) colitis. Additional analysis of relative risk of diarrhea revealed that PD-1/PD-L1 treatment moderately reduce the risk of all grade diarrhea (RR: 0.64, p = 0.03), while the difference was not statistically significant in the risk of grade 3-5 diarrhea (RR: 0.83, p = 0.64). Subgroup analyses showed that the RR of all grade and higher grade colitis in PD-1 inhibitors was more significant (RR: 3.56, p = 0.001 vs RR: 2.98, p = 0.02 respectively). However, there was no appreciable difference in PD-L1 inhibitors (RR: 4.75, p = 0.15 vs RR: 2.85, p = 0.52 respectively). When compared with first-line therapy, second-line therapy associated with a higher risk of all grade colitis than first-line therapy (RR: 3.29, p = 0.006; RR: 4.69, p = 0.026). CONCLUSION: Our meta-analysis indicates when compared with control group, the PD-1/PD-L1 inhibitors may lead to a higher risk of all grade and high grade immune-mediated colitis, but may result in a reduction in all grade diarrhea. PD-1 inhibitors in NSCLC patients, but not PD-L1 inhibitors, increase the risk of all- and high grade colitis. These results suggest that clinicians shall pay more attention to this rare but life-threatening toxic effect.

Risk of immune-related colitis with PD-1/PD-L1 inhibitors vs chemotherapy in solid tumors: systems assessment.

Background: We performed a meta-analysis to evaluate the risk of immune-related colitis associated with PD1/PD-L1 inhibitors as compared to chemotherapy in solid tumor patients. Methods: Eligible studies were identified through a comprehensive search of multiple databases and included solid tumor patients in randomized controlled trials (RCTs) with PD-1/PD-L1 inhibitors. The data was analyzed by Stata version 12.0 software. Results: After exclusion of ineligible studies, 11 clinical trials were considered eligible for the meta-analysis, including 5751 patients. Compared with chemotherapy, the risk ratios (RRs) of all-grade colitis were significant for the PD-1 inhibitor subgroup (RR 2.69, 95% confidence interval (CI): 1.15-6.29, p=0.023), and for pembrolizumab subgroup (RR 3.17, 95% CI: 1.08-9.37, p=0.037), but not for nivolumab treatment and PD-L1 inhibitor (atezolizumab) treatment (RR 2.05, 95% CI: 0.52-8.13, p=0.305; RR 4.75,95% CI: 0.56-40.50, p=0.154, respectively). The RR of all-grade colitis was significant for PD-1/PD-L1 inhibitor in NSCLC (RR 4.34, 95% CI: 1.37-13.82, p=0.013), and not significant in melanoma (RR 2.11, 95% CI: 0.54-8.34, p=0.285). Moreover, the RRs of all-grade diarrhea were significant for the PD-1 inhibitor subgroup (RR 0.61, 95% CI: 0.44-0.83, p=0.002), for the nivolumab subgroup (RR 0.54, 95% CI: 0.34-0.87, p=0.012), and for atezolizumab subgroup (RR 0.48, 95% CI: 0.25-0.89, p=0.021). The RR of high-grade diarrhea was significant for atezolizumab subgroup (RR 0.34, 95% CI: 0.12-0.94, p=0.037). Conclusions: Our meta-analysis demonstrates that compared with chemotherapy, pembrolizumab may result in a higher risk of all-grade immune-mediated colitis. PD-1/PD-L1 inhibitor treatment in NSCLC patients, but not in melanoma patients, increases the risk of all-grade colitis incidence.

Isolated immune-related pancreatic exocrine insufficiency associated with pembrolizumab therapy.

We report a case of isolated immune-related pancreatic exocrine insufficiency in a patient treated with pembrolizumab for metastatic melanoma. This patient presented with explosive diarrhea and was treated with high dose corticosteroids for possible immune-related colitis. However, biopsies from colon and duodenum did not show any histological evidence of colitis/enteritis. Serum amylase and lipase were not elevated. There was no evidence of pancreatitis or pancreatic metastases on imaging. Significantly lower fecal elastase test on two occasions confirmed the diagnosis of pancreatic exocrine insufficiency. He was treated with pancreatic enzyme supplementation with complete resolution of diarrhea. This case reinforces the importance of awareness and anticipation of unusual immune-related adverse events related to checkpoint inhibitors.

Incidence of immune checkpoint inhibitor-related colitis in solid tumor patients: A systematic review and meta-analysis.

Background: With the rising use of immune checkpoint inhibitors (ICI) across varying tumors types, immune-related colitis is an increasingly encountered, serious adverse event requiring appropriate management. The incidence across ICI treatment regimens and tumor types is unclear. Objective: To characterize the incidence of immune-related colitis among various ICI regimens and tumor types. Methods: Thirty-four original studies of prospective ICI trials were identified based on a PubMed search completed on November 1st, 2016. Seventeen studies compared incidences across tumor types. The incidences of all-grade, grade 3-4 (severe) colitis, and grade 3-4 (severe) diarrhea were collected. Results: Thirty-four studies containing 8863 patients were included in the meta-analysis. The overall incidence during ipilimumab monotherapy was 9.1% for all-grade colitis, 6.8% for severe colitis, and 7.9% for severe diarrhea. The incidence was lowest during PD-1/PD-L1 inhibitor monotherapy with 1.3% for all-grade colitis, 0.9% for severe colitis and 1.2% for severe diarrhea, while combination ipilimumab and nivolumab resulted in the highest incidences of all-grade colitis (13.6%), severe colitis (9.4%) and severe diarrhea (9.2%) among ICIs. Among melanoma, NSCLC, RCC patients, incidences of colitis and diarrhea with PD-1/PD-L1 inhibitor monotherapy did not significantly differ. Severe colitis incidence was similar with ipilimumab monotherapy at 3 mg/kg and 10 mg/kg (7.1% vs 5.1%, respectively), but significantly higher for severe diarrhea with 10mg/kg (11.5% vs 5.2%). Conclusions: The incidence of immune-related colitis and severe diarrhea was higher with ipilimumab-containing regimens compared with PD-1/PD-L1 inhibitors. There was no significant difference in immune-related colitis between different tumor types with PD-1/L1 inhibitors.

Osimertinib reactivated immune-related colitis after treatment with anti-PD1 antibody for non-small cell lung cancer.

We reported a case of relapsing immune-related colitis (initially caused by nivolumab) following osimertinib therapy for lung adenocarcinoma. A 45-year-old female who had never smoked was diagnosed with adenocarcinoma of the lung and underwent surgical resection. Four years after surgical resection, she was diagnosed with recurrent disease and was eventually treated with nivolumab as third-line therapy. One month after the completion of nivolumab therapy, the patient reported abdominal pain and frequent diarrhea. We diagnosed immune-related colitis and started oral prednisolone. However, the steroid therapy was ineffective, so the patient was administered infliximab and an increased dose of prednisolone. Her symptoms subsequently resolved, and her mucosal lesions improved. Six months after the last administration of nivolumab, osimertinib was initiated as fourth-line therapy, but 3 days later, the patient developed blood in the stool and frequent diarrhea. Osimertinib treatment was discontinued, given the possibility that it had reactivated the patient's immune-related colitis. We subsequently re-administered oral prednisolone (2 mg/kg/day), and the colitis resolved within a few weeks.