Gastrointestinal toxicities of proteasome inhibitor therapy.

PURPOSE: Proteasome inhibitors (PIs), which cause cell death via tumor suppressor and pro-apoptotic proteins, are integral to treatment of many hematologic malignancies but are limited by their gastrointestinal adverse effects. Evidence regarding these PI-related adverse effects is scant. In this study, we evaluated gastrointestinal adverse events caused by PIs and compared gastrointestinal toxicities between bortezomib, carfilzomib, and ixazomib. METHODS: We conducted a retrospective study of cancer patients treated with PIs at a tertiary care cancer center to investigate the clinical characteristics of PI-related gastrointestinal adverse events. RESULTS: Our sample comprised 973 patients with PI exposure and stool studies ordered between January 2017 and December 2022. Of these, 193 patients (20%) had PI-related gastrointestinal toxicity based on clinical symptoms and stool study results. The most common symptom was diarrhea, present in 169 (88% of those with gastrointestinal toxicity). Twenty-two (11%) required hospitalization, and 71 (37%) developed recurrence of symptoms. Compared to bortezomib or carfilzomib, ixazomib had a longer interval from PI initiation to the onset of gastrointestinal symptoms (313 days vs 58 days vs 89 days, p = 0.002) and a significantly lower percentage of diarrhea-predominant presentation of gastrointestinal toxicity (71% vs 96% vs 91%, p = 0.048). CONCLUSION: While PI-related gastrointestinal toxicities have various presentations and courses based on different regimens, the vast majority of patients presented with milder disease behavior. Despite a considerably high rate of hospitalization and recurrence after treatment necessitating optimization of clinical management, our cohort demonstrates favorable outcomes without long-term consequences.

Outcomes of Budesonide as a Treatment Option for Immune Checkpoint Inhibitor-Related Colitis in Patients with Cancer.

BACKGROUND: Current treatment guidelines for moderate to severe colitis (IMC) secondary to immune checkpoint inhibitors (ICI) recommend systemic corticosteroids as the primary therapy in conjunction with biologics, namely infliximab and/or vedolizumab. We aimed to explore the efficacy and safety of oral budesonide in the treatment of IMC. METHODS: We performed a retrospective analysis at MD Anderson Cancer Center of adult cancer patients with a confirmed (based on clinical, radiographic and laboratory assessment) diagnosis of IMC between 1 January 2015 and 31 November 2022, treated with budesonide. Data collection included demographics, oncologic history, IMC-related information and outcomes up to 6 months after the last dose of ICI. RESULTS: Our sample (n = 69) comprised primarily of Caucasian (76.8%) females (55.1%). The majority of patients received combination therapy with anti-PD-1/L1 and anti-CTLA-4 (49.3%), and the most common malignancy treated was melanoma (37.6%). The median grade of diarrhea was 3 and of colitis was 2. Of the 50 patients who underwent endoscopic evaluation, a majority had non-ulcerative inflammation (64%) and active colitis on histology (78%). Budesonide was used as primary treatment at onset of IMC in 56.5% patients, as well as a bridging therapy from systemic corticosteroids in 33.3%. Less than half of the patients (44.9%) required additional therapies such as biologics or fecal microbiota transplant. Additionally, 75.3% of patients achieved full remission of IMC and 24.6% had a recurrence of IMC. ICI was resumed in 31.9% of patients and 17.4% received other forms of cancer therapies. CONCLUSIONS: Budesonide may be an effective strategy to treat and prevent the recurrence of IMC. The remission rates observed in our analysis with budesonide alone are comparable to systemic corticosteroids. Patients that require an extended duration of steroid exposure and those with moderate to severe colitis may benefit from budesonide given its lower risk of infection and complications. Furthermore, we observe that budesonide may serve as a successful bridge from systemic corticosteroids with subsequent biologic treatment. Larger prospective studies are necessary to determine the role of budesonide as well as its safety profile.

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.

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.

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.