# A Complete Response in a Metastatic Melanoma Patient After a Single Dose of Dual Checkpoint Inhibitors Blockade Could Be Predictable: A Case Report

## TL;DR

A melanoma patient achieved a complete response after a single dose of dual checkpoint inhibitors, with the response lasting four years despite treatment discontinuation due to toxicity.

## Contribution

This case report highlights a rare and durable complete response to dual checkpoint inhibitors in metastatic melanoma.

## Key findings

- A 57-year-old patient achieved complete response after first-line treatment with nivolumab and ipilimumab.
- The favorable response has been maintained for four years despite treatment discontinuation due to toxicity.
- The case underscores the potential for durable responses with dual checkpoint inhibitors in metastatic melanoma.

## Abstract

Cutaneous malignant melanoma is one of the most aggressive forms of skin cancer and thus, a high mortality has been reported over decades. The prognosis for melanoma varies widely based on several factors, including the stage at which it is diagnosed, the location and thickness of the tumor, the patient's age and overall health, and specific genetic factors associated with melanoma. Therapeutic options include checkpoint inhibitors, regardless of V-Raf Murine Sarcoma Viral Oncogene Homolog B status (BRAF), and targeted therapy (anti-BRAF) in the adjuvant or metastatic setting. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment but predicting which patients will benefit from these therapies remains challenging. Biomarkers like leukocytes, neutrophils, eosinophils, basophils, platelets, and other peripheral blood biomarkers have been investigated for their potential to predict responses to ICIs. Tumor mutational burden (TMB), circulating tumor DNA (ctDNA), and soluble PD-L1 (sPD-L1) have emerged as potential biomarkers for predicting responses to ICIs. Elevated baseline levels of ctDNA and elevated sPD-L1 levels have been associated with worse prognosis in melanoma patients. High TMB is often associated with better responses to ICIs in melanoma. Here we present a case from our department, of a 57-year-old patient, diagnosed in 2019 with stage IV - pT4cNx cM1 (lymph nodes metastases) and suspicion of lung metastases, BRAF wild-type right hallux malignant melanoma. Due to impressive results, first-line treatment with ICIs nivolumab and ipilimumab was the preferred treatment of choice, which showed a favorable response, with regression of oncological disease after the first cycle, and achieving complete response afterward. Unfortunately, the treatment was discontinued due to severe hepatic and pancreatic toxicity, but the favorable response to immunotherapy has been maintained for four years and is ongoing. Identifying predictive biomarkers is important to achieve the best response for the patient, with minimal adverse events, especially if long-term clinical benefit can be reached.