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

Exploring potential biomarkers and therapeutic targets in inflammatory bowel disease: insights from a mega-analysis approach

Background

Understanding the molecular pathogenesis of inflammatory bowel disease (IBD) has led to the discovery of new therapeutic targets that are more specific and effective. Our aim was to explore the molecular pathways and genes involved in IBD pathogenesis and to identify new therapeutic targets and novel biomarkers that can aid in the diagnosis of the disease.

Methods

To obtain the largest possible number of samples and analyze them comprehensively, we used a mega-analysis approach. This involved reprocessing raw data from multiple studies and analyzing them using bioinformatic and machine learning techniques.

Results

We analyzed a total of 697 intestinal biopsies of Ulcerative Colitis (n = 386), Crohn's disease (n = 183) and non-IBD controls (n = 128). A machine learning analysis detected 34 genes whose collective expression effectively distinguishes inflamed biopsies of IBD patients from non-IBD control samples. Most of these genes were upregulated in IBD. Notably, among these genes, three novel lncRNAs have emerged as potential contributors to IBD development: ENSG00000285744, ENSG00000287626, and MIR4435-2HG. Furthermore, by examining the expression of 29 genes, among the 34, in blood samples from IBD patients, we detected a significant upregulation of 12 genes (p-value < 0.01), underscoring their potential utility as non-invasive diagnostic biomarkers. Finally, by utilizing the CMap library, we discovered potential compounds that should be explored in future studies for their therapeutic efficacy in IBD treatment.

Conclusion

Our findings contribute to the understanding of IBD pathogenesis, suggest novel biomarkers for IBD diagnosis and offer new prospects for therapeutic intervention.

Severe Colitis in 2 Patients with Melanoma Treated with BRAF/MEK Inhibitors: Case Report and Literature Review

Introduction

Encorafenib and binimetinib, a combination of BRAF and MEK inhibitors, is a standard of care for patients with advanced BRAFV600-mutant melanoma. This combination is known to have gastrointestinal side effects, most of which are mild and managed symptomatically. However, very few studies have reported severe colitis.

Case Presentation

We report here 2 patients with advanced melanoma who developed severe ulcerated right colitis manifested by diarrhea and hematochezia while being treated with encorafenib and binimetinib after immune checkpoint therapy.

Conclusion

This rare but serious adverse event was not described in early phase 3 trials but has emerged in recent years, particularly with the sequential use of immune checkpoint inhibitors followed by BRAF/MEK inhibitors. In a comprehensive review of the existing literature, we identified 20 cases of severe colitis due to BRAF/MEK inhibitors. Clinical, endoscopic, and histological features are described to provide insight into the current understanding of this poorly understood clinical entity.