Severe colitis in patients with melanoma treated with BRAF/MEK inhibitors

Optimizing targeted therapy for metastatic melanoma: a combination of encorafenib and trametinib beyond standard protocols

Only three combinations of BRAF inhibitor (BRAFi) and MEK inhibitor (MEKi) targeted therapies are marketed for the treatment of BRAF-mutated metastatic melanoma. The use of these combinations can be limited by the occurrence of severe adverse events (AEs) that may lead to discontinuation of treatment or contraindication. We present the case of a 45-year-old male diagnosed with stage III melanoma of the left thigh, as classified by the 8th edition of the American Joint Committee on Cancer (AJCC), exhibiting rapid recurrence of inguinal lymph node metastasis following complete surgical resection. Molecular biology revealed a mutated BRAFV600E status, indicating treatment associated with BRAFi/MEKi. First-line treatments were introduced successively with dabrafenib-trametinib and then encorafenib-binimetinib, both stopped for fever and severe digestive AEs. After the failure of a third line with an immune checkpoint inhibitor, a new rechallenge of targeted therapy (TT) was introduced with encorafenib-trametinib to increase tolerance. This unusual and innovative combination allowed a spectacular tolerance and complete oncological response for 39 months after the failure of the usual combinations. This is the first case in the literature to show the potential efficacy of a non-standard combination of encorafenib and trametinib, which are commercialized in two different market combinations. A pharmacological evidence-based analysis was performed to understand these good clinical results.

Midline Low-Grade Gliomas of Early Childhood: Focus on Targeted Therapies

PURPOSE

Midline low-grade gliomas (mLGGs) of early childhood have a poorer prognosis compared with tumors of other localizations and in older patients. LGGs are associated with aberrant activation of RAS-RAF-MEK pathway, and pharmacological inhibition of the pathway has therapeutic promise. The aim of this study was clinical and molecular characterization of infantile mLGGs, with emphasis on the efficacy of targeted kinase inhibition.

PATIENTS AND METHODS

This study enrolled 40 patients with mLGG age <3 years. The majority of the patients (30/40) received first-line chemotherapy (CT) as per International Society of Paediatric Oncology LGG 2004 guidelines. In all patients, molecular genetic investigation of tumor tissue by polymerase chain reaction and RNA sequencing was performed. The median follow-up was 3.5 years.

RESULTS

First-line CT failed in 24 of 30 recipients. The identified molecular profiles included KIAA1549::BRAF fusions in 26 patients, BRAF V600E in six patients, FGFR1::TACC1 fusions in two patients, and rare fusion transcripts in four patients. At disease progression, targeted therapy (TT) was initiated in 27 patients (22 patients received trametinib) on the basis of molecular findings. TT was administered for a median of 16 months, with partial response achieved in 12 of 26 (46%) patients in which response was evaluated. Severe adverse events were detected only on trametinib monotherapy: acute damage of GI or urinary mucosa complicated by hemorrhage and development of transfusion-dependent anemia in four patients and grade 3 skin toxicity in three patients.

CONCLUSION

mLGGs of early childhood are often aggressive tumors, resistant to CT, and frequently require alternative treatment. The majority of patients harbor druggable molecular targets and respond to molecular TT.

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.