Practice Changes in Checkpoint Inhibitor-Induced Immune-Related Adverse Event Management at a Tertiary Care Center.

Understanding of immune-related adverse events (irAEs) has evolved rapidly, and management guidelines are continually updated. We explored temporal changes in checkpoint inhibitor-induced irAE management at a tertiary cancer care center to identify areas for improvement. We conducted a single-center retrospective study of patients who developed a gastrointestinal, pulmonary, renal, or cardiac irAE between July and 1 October in 2019 or 2021. We collected patient demographic and clinical information up to 1 year after toxicity. Endoscopic evaluation and specialty follow-up after discharge for patients with gastrointestinal irAEs declined between the 2019 and 2021 periods. Symptom duration and steroid taper attempts also declined. For pulmonary irAEs, rates of specialty consultation, hospital admission and readmission, and mortality improved in 2021 compared with 2019. Follow-up rates after hospital discharge were consistently low (<50%) in both periods. For cardiac irAEs, consultation with a cardiologist was frequent and prompt in both periods. Outpatient treatment and earlier specialty consultation improved outcomes with gastrointestinal irAEs. Our study exploring irAE practice changes over time identified areas to improve management; specifically, timely specialty consultation was associated with better outcomes for gastrointestinal irAEs. These findings can help improve the quality of management algorithms at our institution and may inform policies in other institutions.

Pneumatosis intestinalis in cancer patients who received immune checkpoint inhibitors.

PURPOSE: Immune checkpoint inhibitor (ICI) therapy may give rise to immune-related adverse events (irAEs). Pneumatosis intestinalis (PI), or gas within the bowel wall, has very rarely been observed following ICI therapy, and its clinical significance is unclear. We described the clinical characteristics and outcomes of PI as a possible irAE in cancer patients. METHODS: We retrospectively identified 12 adult cancer patients with radiologic evidence of PI within 1 year after ICI exposure during January 2010-January 2023. Clinical characteristics, treatment, and outcomes were evaluated. RESULTS: The median age of our sample was 64 years. The most common cancer types were thoracic/head & neck and gastrointestinal. Eleven patients (92%) received anti-PD-1/L1 monotherapy, while 1 patient (8%) received a combination of anti-PD-1/L1 and anti-CTLA-4. PI occurred a median of 7 months after the first ICI dose. Half the patients (50%) were asymptomatic on diagnosis, and the most common presenting symptom was abdominal pain (42%). Six patients experienced complications, namely pneumoperitoneum (n = 6, 50%) and microperforation (n = 1, 8%), identified on imaging. Nine patients were treated with antibiotics and 3 patients were monitored conservatively. Nine patients (75%) resumed cancer treatment after PI. CONCLUSION: PI may develop as an irAE. While half of cases were incidental radiologic findings, management with antibiotics as well as hospitalization for observation may still be appropriate. The decision to restart cancer therapy and possibly resume ICI therapy remains to be elucidated. Further large-scale studies may be warranted to clarify the association between PI and ICI therapy.

Colon Adenoma After Diagnosis of Immune Checkpoint Inhibitor-mediated Colitis.

Purpose: While the occurrence of colitis during immune checkpoint inhibitor (ICI) treatment is recognized as a sign of robust immune activation and correlates with better oncological outcomes, the long-term impact of ICI-mediated colitis on the colonic mucosa has not been studied. We thus aim to describe the colonoscopy and histology findings in patients at a follow-up time of ≥ 6 months post initial colitis event. Methods: This retrospective analysis included adult cancer patients diagnosed with ICI colitis at a tertiary cancer center between October 2013 and June 2020. The study group included patients diagnosed with immune mediated colitis who had also undergone a follow up colonoscopy or flex sigmoidoscopy. The control group was patients exposed to ICI without immune mediated colitis. We reported patients' colitis clinical course, treatment, outcomes, and endoscopic and histologic features at diagnosis and at follow-up time of ≥ 6 months. Results: Total 39 patients met the study criteria, with 82% being male, and 35.8% having melanoma. Most patients received a combination of CTLA-4 and PD-1/L1 inhibitors (82%). On initial endoscopic evaluation, inflammation without ulceration was reported in 76.9% of patients and active inflammation on histologic examination in 79.3% of patients. Most patients (79.4%) received corticosteroids, and 56.4% received add-on selective immunosuppressive therapy. Four patients received fecal microbiota transplantation. On follow-up, new incidence of colonic polyps was reported in 51.2% of patients, including adenomas in 33.3% among the colitis patients with median follow up duration of 12 months. The incidence of adenoma polyps 12 months after the colitis event was significantly higher compared to the control group without colitis based on the time-to-event analysis (p=0.041). Conclusion: At a median follow up of 12 months after their initial colitis diagnosis, 51.2% of the patients had new incidence of colonic polyps, including a third with adenoma, at a significantly higher incidence than the control group without colitis. Studies with larger sample sizes are needed to further define the long-term impact of colitis and its treatments on colon health and to refine recommendations for surveillance of colonic adenomas and colorectal cancer.

The Safety of Immunosuppressants Used in the Treatment of Immune-Related Adverse Events due to Immune Checkpoint Inhibitors: a Systematic Review.

Purpose: Immune checkpoint inhibitor (ICI) use can lead to immune-related adverse events (irAEs) that require treatment with immunosuppressive medications in moderate to severe cases. Oncology society guidelines recommend systemic steroids and immunosuppressants such as infliximab and vedolizumab for the treatment of refractory cases. Limited information is available about the safety profile and potential adverse effects of these immunosuppressants. We have investigated the safety profile of multiple immunosuppressants which are used in the treatment of ICI-related irAEs. Methods: We performed a systematic review of studies reporting irAEs, from ICI use, and their medical management with immunosuppressants in adult cancer patients. We searched MEDLINE, EMBASE, Cochrane Library, and ClinicalTrials.gov from inception through September 1, 2022, using the following keywords or their equivalents: ICI, immunosuppressant, and irAE. We extracted observational studies and clinical trials that matched our criteria. A random effects model was used to estimate the overall incidence of infections associated with the treatment of irAEs. Results: Among the 11 studies included in this review (1036 total patients), melanoma (548 patients, 52.9%) was the most common primary cancer, followed by lung cancer (139 patients, 13.4%) and genitourinary cancers (131 patients, 12.6%). PD-1/PD-L1 monotherapy (460 patients, 44.4%) was used most, followed by a combination of PD-1/PD-L1 and CTLA-4 therapy (350 patients, 33.8%) and CTLA-4 monotherapy (226 patients, 22%). A total of 1024 (98.8%) patients had their irAEs treated with systemic steroids with majority having colitis and hepatobiliary irAEs; 335 patients (32.3%) were also treated with infliximab (mainly for colitis). Our review found 22.3% of patients treated for irAEs developed infectious adverse events (95% CI: 15.6%-29.1%, p<0.001). Among the 3 studies reporting the types of infections (41 total patients), bacterial (80.5%), followed by fungal (36.6%), infections were most common. Conclusions: Adverse events from irAE treatment occurred in about one-third of patients that received either steroids or a combination of steroids and other immunosuppressants. Clinicians should be aware of these immunosuppressant-related adverse effects, which can negatively impact cancer treatment and patient outcomes, when treating irAEs and consider shortening treatment duration or using alternative strategies when possible to mitigate these complications, future prospective studies should further investigate the safety of immunosuppressants in treating irAEs.

Role of C-Reactive Protein in Predicting the Severity and Response of Immune-Mediated Diarrhea and Colitis in Patients with Cancer.

Background: Immune-mediated diarrhea and colitis (IMDC) frequently develop after treatment with immune checkpoint inhibitors. C-reactive protein (CRP) is a serum inflammatory biomarker used to stratify and monitor disease severity in many inflammatory conditions. However, CRP level is not specific and is widely influenced by various factors non-specific to bowel inflammation. We aimed to study the utility of CRP as a predictor of disease severity and therapy response in IMDC. Methods: We performed a retrospective analysis of patients diagnosed with IMDC who had CRP measured at IMDC onset and after treatment with selective immunosuppressive therapy (SIT: infliximab and vedolizumab), between 01/2016 and 02/2022 at MD Anderson Cancer Center. Patient demographics, clinical characteristics, and IMDC data were collected and analyzed. Results: Our sample of 128 patients had a median age of 67 years; most were white (89.8%); and male (65.6%). Prior to development of IMDC, 15 (11.7%) were initially treated with anti-CTLA-4, 42 (32.8%) with anti-PD-1 or PD-L1, and 71 (55.5%) with a combination of both. We found higher CRP level was associated with higher CTCAE grade of clinical symptoms such as diarrhea (p=0.015), colitis (p=0.013), and endoscopic findings (p=0.016). While CRP levels decreased after IMDC treatment, there was no significant association between CRP levels with clinical remission, endoscopic remission or histologic remission. There also was no significant correlation between CRP level and recurrence of IMDC, or with fecal calprotectin levels. Conclusion: CRP level may be useful to assess initial severity of IMDC, including grade of diarrhea and colitis and degree of endoscopic inflammation. However, CRP is not a robust surrogate biomarker for assessing treatment response or disease recurrence. Despite the reduction of CRP levels observed following IMDC treatment, this finding might be nonspecific and potentially confounded by concurrent clinical factors, such as underlying malignancy, other inflammatory processes, and systemic anti-cancer therapy. Further studies of the role of CRP are warranted in patients with cancer and IMDC.

Microbiome alteration via fecal microbiota transplantation is effective for refractory immune checkpoint inhibitor-induced colitis.

Immune checkpoint inhibitors (ICIs) target advanced malignancies with high efficacy but also predispose patients to immune-related adverse events like immune-mediated colitis (IMC). Given the association between gut bacteria with response to ICI therapy and subsequent IMC, fecal microbiota transplantation (FMT) represents a feasible way to manipulate microbial composition in patients, with a potential benefit for IMC. Here, we present a large case series of 12 patients with refractory IMC who underwent FMT from healthy donors as salvage therapy. All 12 patients had grade 3 or 4 ICI-related diarrhea or colitis that failed to respond to standard first-line (corticosteroids) and second-line immunosuppression (infliximab or vedolizumab). Ten patients (83%) achieved symptom improvement after FMT, and three patients (25%) required repeat FMT, two of whom had no subsequent response. At the end of the study, 92% achieved IMC clinical remission. 16S rRNA sequencing of patient stool samples revealed that compositional differences between FMT donors and patients with IMC before FMT were associated with a complete response after FMT. Comparison of pre- and post-FMT stool samples in patients with complete responses showed significant increases in alpha diversity and increases in the abundances of Collinsella and Bifidobacterium, which were depleted in FMT responders before FMT. Histologically evaluable complete response patients also had decreases in select immune cells , including CD8+ T cells, in the colon after FMT when compared with non-complete response patients (n = 4). This study validates FMT as an effective treatment strategy for IMC and gives insights into the microbial signatures that may play a critical role in FMT response.

Clinical Features and Management of Acute and Chronic Radiation-Induced Colitis and Proctopathy.

BACKGROUND: RICAP is a recognized adverse effect of radiation therapy (RT) that can adversely affect cancer patients' quality of life. Data on the clinical characteristics and outcomes of RICAP are scarce. We aimed to analyze the clinical and endoscopic characteristics of acute or chronic radiation-induced colitis and proctopathy (ARICAP and CRICAP) based on symptom onset after RT (≤ or >45 days, respectively). METHODS: This is a retrospective observational study of a single tertiary cancer center, from January 2010 and December 2018, of cancer patients with endoscopically confirmed ARICAP and CRICAP. We conducted univariate and multivariate logistic regression analyses to associate clinical variables with endoscopic and medical outcomes. RESULTS: One hundred and twelve patients were included (84% Caucasian; 55% female; median age of 59 years); 46% had ARICAP with non-bloody diarrhea as the predominant symptom, whereas 55% had CRICAP with mostly bloody diarrhea. Neovascularization was the most frequent finding on endoscopy, followed by bleeding. ARICAP patients more often received medical management (p < 0.001), whereas CRICAP patients with bleeding more often received argon plasma coagulation (APC) (p = 0.002). Female sex and undergoing less-intense RT treatments were more associated with medical treatment; bleeding clinically and during the endoscopy was more associated with APC treatment. However, APC treatment did not significantly reduce bleeding recurrence or RICAP symptoms. CONCLUSION: Patients with ARICAP and CRICAP experience different symptoms. Medical management should be considered before endoscopic therapy. APC may be useful in patients with endoscopically apparent bleeding.

Concurrent immune checkpoint inhibition and selective immunosuppressive therapy in patients with immune-related enterocolitis.

PURPOSE: Immune checkpoint inhibitor (ICI) therapy is often suspended because of immune-related enterocolitis (irEC). We examined the effect of resumption of ICIs with or without concurrent selective immunosuppressive therapy (SIT) on rates of symptom recurrence and survival outcomes. METHODS: This retrospective, multicenter study examined patients who were treated with ICI and developed irEC requiring SIT (infliximab or vedolizumab) for initial symptom control or to facilitate steroid tapering between May 2015 and June 2020. After symptom resolution, patients were restarted either on ICI alone or on concurrent ICI and SIT at the discretion of the treating physicians. The associations between irEC recurrence and treatment group were assessed via univariate analyses and multivariate logistic regression. Cox proportional hazards model was used for survival analysis. RESULTS: Of the 138 included patients who required SIT for initial irEC symptom control, 61 (44.2%) patients resumed ICI without concurrent SIT (control group) and 77 (55.8%) patients resumed ICI therapy with concurrent SIT: 33 with infliximab and 44 with vedolizumab. After symptom resolution, patients in the control group were more commonly restarted on a different ICI regimen (65.6%) compared with those receiving SIT (31.2%) (p<0.001). The total number of ICI doses administered after irEC resolution and ICI resumption was similar in both groups (four to five doses). Recurrence of severe colitis or diarrhea after ICI resumption was seen in 34.4% of controls compared with 20.8% of patients receiving concurrent SIT. Concurrent SIT was associated with reduced risk of severe irEC recurrence after ICI resumption in a multivariate logistic regression model (OR 0.34; 95% CI 0.13 to 0.92; p=0.034). There was no difference in survival outcomes between patients in the control group and patients concurrently treated with SIT. CONCLUSION: After resolution of irEC symptoms, reinitiation of ICI with concurrent SIT is safe, reduces severe irEC recurrence, and has no negative impact on survival outcomes.

Obesity Measured via Body Mass Index May Be Associated with Increased Incidence but Not Worse Outcomes of Immune-Mediated Diarrhea and Colitis.

Obesity defined by high body mass index (BMI) has traditionally been associated with gastrointestinal inflammatory processes but has recently been correlated with better survival in patients receiving immune checkpoint inhibitors (ICI). We sought to investigate the association between BMI and immune-mediated diarrhea and colitis (IMDC) outcomes and whether BMI reflects body fat content on abdominal imaging. This retrospective, single-center study included cancer patients with ICI exposure who developed IMDC and had BMI and abdominal computed tomography (CT) obtained within 30 days before initiating ICI from April 2011 to December 2019. BMI was categorized as <25, ≥25 but <30, and ≥30. Visceral fat area (VFA), subcutaneous fat area (SFA), total fat area (TFA: VFA+SFA), and visceral to subcutaneous fat (V/S) ratio were obtained from CT at the umbilical level. Our sample comprised 202 patients; 127 patients (62.9%) received CTLA-4 monotherapy or a combination, and 75 (37.1%) received PD-1/PD-L1 monotherapy. Higher BMIs ≥ 30 were associated with a higher incidence of IMDC than BMIs ≤ 25 (11.4% vs. 7.9%, respectively; p = 0.029). Higher grades of colitis (grade 3-4) correlated with lower BMI (p = 0.03). BMI level was not associated with other IMDC characteristics or did not influence overall survival (p = 0.83). BMI is strongly correlated with VFA, SFA, and TFA (p < 0.0001). Higher BMI at ICI initiation was linked to a higher incidence of IMDC but did not appear to affect outcomes. BMI strongly correlated with body fat parameters measured by abdominal imaging, suggesting its reliability as an obesity index.

Sclerosing mesenteritis following immune checkpoint inhibitor therapy.

PURPOSE: Sclerosing mesenteritis (SM), a fibroinflammatory process of the mesentery, can rarely occur after immune checkpoint inhibitor (ICI) therapy; however, its clinical significance and optimal management are unclear. We aimed to assess the characteristics and disease course of patients who developed SM following ICI therapy at a single tertiary cancer center. METHODS: We retrospectively identified 12 eligible adult cancer patients between 05/2011 and 05/2022. Patients' clinical data were evaluated and summarized. RESULTS: The median patient age was 71.5 years. The most common cancer types were gastrointestinal, hematologic, and skin. Eight patients (67%) received anti-PD-1/L1 monotherapy, 2 (17%) received anti-CTLA-4 monotherapy, and 2 (17%) received combination therapy. SM occurred after a median duration of 8.6 months from the first ICI dose. Most patients (75%) were asymptomatic on diagnosis. Three patients (25%) reported abdominal pain, nausea, and fever and received inpatient care and corticosteroid treatment with symptom resolution. No patients experienced SM recurrence after the completion of corticosteroids. Seven patients (58%) experienced resolution of SM on imaging. Seven patients (58%) resumed ICI therapy after the diagnosis of SM. CONCLUSIONS: SM represents an immune-related adverse event that may occur after initiation of ICI therapy. The clinical significance and optimal management of SM following ICI therapy remains uncertain. While most cases were asymptomatic and did not require active management or ICI termination, medical intervention was needed in select symptomatic cases. Further large-scale studies are needed to clarify the association of SM with ICI therapy.

Diarrhea and colitis related to immune checkpoint inhibitor and BRAF/MEK inhibitor therapy.

Background: Immune checkpoint inhibitor (ICI) therapy can be complicated by gastrointestinal adverse events (AEs). Similarly, gastrointestinal AEs have been reported with the use of serine/threonine-protein kinase B-Raf (BRAF) and mitogen-activated protein kinase kinase (MEK) inhibitor therapy. We investigated the characteristics and management of gastrointestinal AEs related to sequential ICI and BRAF/MEK inhibitor therapy. Methods: We identified 255 adult cancer patients who received both BRAF/MEK inhibitor therapy and ICI therapy between 2014 and 2021. Thirty-two eligible patients had gastrointestinal AEs after receiving both therapies and were categorized based on the order of their administration. Their clinical characteristics, evaluation, treatment and outcomes were compared. Results: Of the 32 eligible patients, 18 (56.3%) received ICI therapy followed by BRAF/MEK inhibitors (early ICI group), and 14 (44.8%) received BRAF/MEK inhibitor therapy followed by ICI (early BRAF/MEK inhibitor group). Compared with the early BRAF/MEK inhibitor group, the early ICI group had higher rates of grade 3-4 diarrhea (50.0% vs. 14.3%, P=0.047) and grade 3-4 colitis (38.9% vs. 0%, P=0.010). The early ICI group had a later onset of colitis (347.5 vs. 84.5 days, P=0.011) and a higher rate of hospitalization at initial colitis presentation (100% vs. 71.4%, P=0.028). Patients in the early ICI group were more likely to have diarrhea or colitis recurrence (69.2% vs. 9.1%, P=0.019) and re-hospitalization for colitis (38.9% vs. 0%, P=0.010). Conclusion: The sequential exposure of BRAF/MEK therapy after ICI may contribute to a more aggressive clinical profile of gastrointestinal toxicities that may warrant a more aggressive management strategy.

Characteristics, treatment, and outcome of diverticulitis after immune checkpoint inhibitor treatment in patients with malignancies.

PURPOSE: Immune checkpoint inhibitors (ICIs) are efficacious for treating various malignancies. In addition to immune-related adverse events (irAEs), growing evidence suggests that ICIs might also be associated with diverticulitis. We aim to assess the clinical presentations and management of colonic diverticulitis among cancer patients after ICI treatment. METHODS: A retrospective study was conducted on ICI-treated adult cancer patients between 01/2010 and 06/2020. Patients were grouped based on when diverticulitis developed relative to ICI treatment, either before (controls) or after (cases). Patient clinical characters, treatment, and outcomes were compared between both groups. RESULTS: 77 eligible patients were included: 63 patients developed diverticulitis after ICI exposure (46 had initial episode after ICI exposure, 17 had a history of diverticulitis prior then recurred after ICI exposure), and 14 had diverticulitis before ICI exposure. Diverticulitis occurred after a median of 129 days after ICI initiation. Clinical characteristics overlapped with traditional diverticulitis. 93% of patients had symptom resolution after treatment, while 23.8% experienced complications. These patients exhibited higher rates of hospitalization (87% vs 48%, P = 0.015) and surgery/interventional radiology procedures (27% vs 0, P = 0.002), and worse overall survival (P = 0.022). History of diverticulitis was not associated with a more severe disease course. Immunosuppressants (e.g., corticosteroids) were rarely required unless for concurrent ICI-mediated colitis. CONCLUSION: Colonic diverticulitis can occur after ICI therapy at very low incidence (0.5%). Its clinical presentation, evaluation, and management are similar to traditional diverticulitis, but associated with higher complication rates requiring surgical intervention and has lower overall survival.

Characteristics and outcomes of cancer patients with pre-existing microscopic colitis after exposure to PD-1 and PD-L1 inhibitors.

PURPOSE: Immune checkpoint inhibitors (ICIs) are frequently associated with adverse events, often affecting the gastrointestinal tract. We conducted this study to determine the characteristics and outcomes of cancer patients with pre-existing microscopic colitis (MC) who underwent ICI treatment. METHODS: In this retrospective study, we identified 10 patients with pre-existing MC who received ICIs at our center 01/2010-06/2020. Clinical characteristics and disease outcomes were recorded. RESULTS: Of 124 screened patients with MC before ICI exposure, 10 had sufficient data to be included in the study. Melanoma (40%) and lung cancer (30%) were the most prevalent cancer types, with 70% of stage IV cancer. Patients received either anti-programmed death 1 regimen (8, 80%) or anti-programmed death ligand 1 agent (2, 20%). Six patients (60%) had collagenous colitis, and 4 (40%) had lymphocytic colitis. The median time from MC diagnosis to ICI initiation was 4 years, with 1 patient on budesonide within 2 months of ICI initiation. Eight patients (80%) developed colitis exacerbations after ICI  and required selective immunosuppression. One patient received a compassionate-use fecal transplantation. The median time from ICI to colitis exacerbation was 14 days, with 40% and 50% of patients experiencing grade 3 diarrhea and grade 2 colitis, respectively, leading to hospitalization in 3 patients. Six patients received steroids and vedolizumab with no colitis recurrence. Of 8 patients who had colitis exacerbation, 6 resumed ICI therapy afterward; with 5 receiving concomitant vedolizumab for secondary prophylaxis. CONCLUSION: Our findings suggest that ICI exposure increases the risk of exacerbation of underlying colitis necessitating and responding to potent immunosuppression therapy.

Clinical characteristics and outcomes of tyrosine kinase inhibitor-related lower GI adverse effects.

PURPOSE: A variety of tyrosine kinase inhibitors (TKIs) are currently approved for the treatment of solid tumors and hematological cancers. However, TKIs are often associated with gastrointestinal (GI) adverse effects (AEs), especially diarrhea. Therefore, in the present study, we aimed to describe the clinical features and outcomes of TKI-associated lower GI AEs. METHODS: This was a retrospective single-center cohort study of patients with cancer treated with TKIs from March 2016 to September 2020 who experienced diarrhea without other identifiable causes. Basic and GI AE-related characteristics and outcomes were compared using χ2 and Mann-Whitney U tests. RESULTS: Of 2172 patients who received TKIs over the study period, we included 228 in the final analysis. Of these, 166 (72.8%) had hematological cancers. Besides diarrhea, GI symptoms included nausea (36.4%), vomiting (21.9%), abdominal pain (15.4%), and bleeding (3.1%). Symptoms were typically mild, with 209 patients (91.7%) presenting with Common Terminology Criteria for Adverse Events grade 1-2 diarrhea. Only 5 patients (2.2%) received immunosuppressants for diarrhea treatment, 83 (36.4%) received no treatment, 29 (12.7%) received antibiotics, 101 (44.3%) received supportive antidiarrheal medications, and 17 patients (7.5%) needed TKI dose reduction or cessation of TKI use. When compared with patients with hematological cancers, those with solid tumors had a higher rate of hospitalization (29.0% vs. 7.2%; p < 0.001) and mortality (75.8% vs. 43.4%; p < 0.001) but a lower rate of recurrence of GI AEs (21.0% vs. 42.8%; p = 0.003. Only 15 patients (6.6%) underwent colonoscopy, with normal endoscopic findings in 8 patients (53.3%) and nonulcerative inflammation in 5 patients (33.3%). The inflammation universally involved the left colon. Twelve of the 15 patients who underwent colonoscopy had active colitis. In the hematological cancer group, patients with acute myeloid leukemia had a lower GI AE recurrence rate than did patients with other hematological cancers (7.2% vs. 30.1%; p = 0.001). CONCLUSION: Ten percent of cancer patients receiving TKIs experienced lower GI AEs, which were usually mild. Symptoms TKI-related GI adverse effects were nonspecific, often overlapping those of other cancer therapy-related GI AEs. Treatment of GI AEs was largely supportive, with limited roles for antibiotics and immunosuppressants.

Mesalamine and cholestyramine for immune checkpoint inhibitor-mediated diarrhea and colitis.

PURPOSE: Immune checkpoint inhibitors (ICI) are effective against various malignancies. However, adverse events including diarrhea and colitis can lead to significant morbidity and mortality. Recommendations for the management of ICI mediated diarrhea and colitis include steroids and biologics. Given their associated risks, this study evaluated the role of the non-immunosuppressive agents, mesalamine and or cholestyramine. METHODS: This is a retrospective, descriptive, single-center study of adults who developed ICI diarrhea and colitis between 2010 and 2020 at MD Anderson Cancer Center. Clinical data and outcomes were compared between those treated with the non-immunosuppressive therapies mesalamine and/or cholestyramine alone versus those who received additional immunosuppression with steroids and biologics. RESULTS: Our sample comprised 66 patients wherein, the mean age was 63 years, 71% were males, and 97% had stage III/IV cancers. Fourteen patients were treated successfully with non-immunosuppressive therapy. They had grade 1-3 diarrhea and 1-2 colitis with no difference in the rate of histologic colitis compared to those who received immunosuppressive therapy. They had less CTLA-4 inhibitor-based therapy (36% vs. 73%, p = 0.034), delayed onset of symptoms (159 vs. 64 days, p = 0.011), lower fecal calprotectin levels (56 vs. 234, p = 0.012) and were more likely to resume ICI therapy (64% vs. 25%, p = 0.006). CONCLUSION: Mesalamine and/or cholestyramine may be effective for mild ICI diarrhea and colitis among patients with delayed symptom onset with lower colonic inflammatory burden. Prospective studies randomizing patients with mild colitis between mesalamine/cholestyramine and immunosuppressive treatment are warranted to assess their efficacy and safety.

Cytomegalovirus infection among patients with cancer receiving immune checkpoint inhibitors.

Background: Immune checkpoint inhibitors (ICIs), used for the treatment of solid and hematologic malignancies, come with the risk of immune-related adverse events (irAEs). Opportunistic infections (e.g., cytomegalovirus [CMV]) mimic irAE symptoms and are understudied in this population. We aimed to describe the incidence, characteristics, treatment and outcomes of CMV infection in ICI-treated patients. Methods: We conducted a single-center retrospective review of all adult patients who were CMV-positive after ICI therapy between 06/2011 and 05/2020. A CMV-positive non-ICI cohort was matched to the ICI group based on age, sex and cancer type. Variables of interest were collected through electronic medical records. Results: The study population comprised 192 patients overall. CMV infection incidence was 7.7% in ICI patients and 12.9% in non-ICI patients (P<0.001). Rates of infection clearance (83% vs. 50%, P=0.002) and recurrence (20% vs. 3%, P=0.037) were higher in ICI patients with hematologic vs. solid tumors, despite similar treatments. All-cause mortality was higher in solid rather than hematologic malignancies in ICI patients (83% vs. 54%, P=0.009); CMV-related mortality was low (3-4%) in both groups. Conclusions: CMV infection occurred in about 7.7% of the ICI-treated cancer population. The infection can be disseminated in multiple organs and has a wide spectrum of clinical symptoms. ICI-treated patients with a hematologic malignancy had higher viral clearance and recurrence than those with solid tumors. In this study, CMV itself did not lead to high mortality in cancer patients. Further study is needed to investigate the role of CMV infection in patients' irAEs and cancer outcome.

Immune checkpoint inhibitor-related gastrointestinal toxicity in patients with malignancy involving the luminal gastrointestinal tract and its impact on cancer outcomes.

Background: Immune checkpoint inhibitors (ICI) are known to cause immune-related adverse events (irAE) with the gastrointestinal (GI) tract among the most affected. Our knowledge of GI irAE in patients with luminal GI malignancies is poor. We aimed to characterize the incidence, clinical features, treatment, and outcomes of these GI irAEs. Methods: This was a retrospective study of patients with malignancies involving the luminal GI tract and GI irAEs at MD Anderson Cancer Center from January 2010 to June 2020. Clinical data were collected and analyzed. Results: Eighteen patients with luminal GI tract malignancies treated with ICIs had evidence of GI irAEs based on clinical symptoms and/or histology. The predominant GI irAE symptom was diarrhea (78%). Ten had non-ulcerative inflammation (56%) and 5 had ulcerative inflammation (28%) on endoscopy. Histologically, 3 patients (17%) had evidence of acute inflammation, 4 (22%) had chronic inflammation, and 9 (50%) had both. Ten patients (56%) received immunosuppressant treatment, which included steroids alone (n=2, 20%), steroids with biologics (infliximab or vedolizumab) (n=7, 70%), or biologics alone (n=1, 10%), with clinical remission in all cases. Of the 6 patients who previously had stable or ICI-responsive cancer and received immunosuppressants, none developed progression of GI luminal malignancy during the study period. Conclusions: GI irAEs occurred in 2.4% of patients treated with ICI for cancer involving the luminal GI tract. Immunosuppressant therapies (e.g., vedolizumab) appear to be effective for GI irAEs, showing no association with further GI luminal cancer progression, recurrence, or a subsequent poor response to ICI therapy.

Clostridioides difficile infection in cancer patients receiving immune checkpoint inhibitors.

Background: Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment, but are associated with immune-mediated diarrhea and colitis (IMDC). Clostridioides difficile infection (CDI) can cause infectious diarrhea with overlapping symptoms. Thus, we sought to elucidate the characteristics of CDI in patients treated with ICI, in the context of IMDC. Methods: We conducted a retrospective, single-center study of adult cancer patients (N=421) with ICI exposure from 2015-2020 and a positive stool nucleic acid amplification test and/or enzyme immunoassay for CDI. Baseline characteristics, treatments, and outcomes were compared between patients with and without concurrent IMDC. Results: Forty-one eligible patients were included, 27 with concurrent IMDC and 14 without. Twenty-seven patients were taking programmed death-1 or its ligand inhibitors and 14 were taking cytotoxic T-lymphocyte-associated antigen 4 inhibitors. Patients with concurrent CDI and IMDC had a longer symptom duration (20 vs. 5 days, P=0.003) and a higher rate of grade 3-4 diarrhea (41% vs. 7%, P=0.033). Among patients with concurrent IMDC, preceding antibiotics (P=0.050) and proton pump inhibitors (PPI) (P=0.038) were used more frequently among individuals who developed CDI after immunosuppressant exposure. Thirty-eight patients received antibiotics for CDI, while 5 required fecal microbiota transplantation for concurrent CDI & IMDC. Conclusions: CDI is common in ICI-treated cancer patients, especially those with IMDC requiring immunosuppressants. Antibiotics did not alter the need for immunosuppressants in those with concurrent IMDC. Use of PPI and antibiotics while receiving immunosuppressants for IMDC was associated with a greater risk of CDI. Further large-scale studies are warranted to clarify the role of CDI, antibiotics and immunosuppression treatment in IMDC patients.

Safety and efficacy of fecal microbiota transplantation to treat and prevent recurrent Clostridioides difficile in cancer patients.

Background: Cancer patients are at increased risk of recurrent Clostridioides difficile infection (rCDI) due to malignancy itself, cancer therapy, and frequent antibiotic use and have a lower response rate to standard oral antibiotics. There are limited data on the safety and efficacy of fecal microbiota transplantation (FMT) for treating rCDI in cancer patients. We aim to describe our experience of using FMT to treat rCDI at a tertiary cancer center. Methods: We conducted a retrospective study of cancer patients who underwent FMT for rCDI at The University of Texas MD Anderson Cancer Center from June 2017 through January 2020. Baseline clinical data and risk factors related to rCDI and FMT were evaluated and compared between cancer types and between cases with remission and recurrence. Results: A total of 19 patients were studied: 12 with solid malignancies and 7 with hematologic malignancies. Most patients had stage IV cancer, and 21% of patients were in cancer remission. On average, patients had 2 episodes of CDI and received 3 courses of antibiotics within 1 year before FMT. 84% of patients with rCDI responded to FMT. Compared with patients who had CDI remission following FMT, non-remission cases were more likely to have received antibiotics following FMT. There were no serious adverse events or mortality within 30 days associated with FMT. Conclusions: FMT is safe, well-tolerated, and efficacious in treating rCDI in selected cancer patients. However, additional antibiotic use for complications from chemotherapy or immunosuppression negatively affected the efficacy of FMT in this population with advanced cancer.

Clinical Characteristics and Outcomes of Oral Mucositis Associated With Immune Checkpoint Inhibitors in Patients With Cancer.

BACKGROUND: Immune checkpoint inhibitor (ICI) therapy predisposes patients to immune-related adverse events (irAEs). Data are limited regarding the incidence, management, and outcomes of one such irAE: mucositis. In this study, we evaluated the clinical characteristics, disease course, treatment, and outcomes of ICI-mediated mucositis. METHODS: This was a retrospective, single-center study of patients who received ICI therapy and developed oral mucositis at The University of Texas MD Anderson Cancer Center from January 2009 to September 2019. Inclusion criteria included age ≥18 years, a diagnosis of oral mucositis and/or stomatitis based on ICD-9 and ICD-10 codes, and therapy using CTLA-4 or PD-1/L1 inhibitors alone or combined with other agents. RESULTS: We identified 152 patients with a mean age of 60 years, 51% of whom were men. Of the sample patients, 73% had stage IV cancer, with melanoma the most common (28%). Median time from ICI initiation to mucositis was 91 days. The most common clinical presentation of mucositis was odynophagia and/or oral pain (89%), 91% developed CTCAE grade 1-2 mucositis, and 78% received anti-PD-1/L1 monotherapy. Compared with anti-PD-1/L1-based therapy, anti-CTLA-4-based therapy was more frequently associated with earlier onset of mucositis (73 vs 96 days; P=.077) and a lower rate of symptom resolution (76% vs 92%; P=.029); 24% of patients required immunosuppressive therapy, which was associated with longer symptom duration (84 vs 34 days; P=.002) and higher mucositis recurrence rate (61% vs 32%; P=.006). ICI interruption was associated with worse survival (P=.037). Mucositis recurrence, immunosuppressant use, and presence of other irAEs did not affect survival. CONCLUSIONS: For ICI-mediated mucositis, a diagnosis of exclusion has not been well recognized and is understudied. Although the clinical symptoms of mucositis are mostly mild, approximately 25% of patients require immunosuppression. Mucositis recurrence can occur in approximately 39% patients. Our results showed that ICI interruption compromises overall survival.