Outcomes after retreatment with MAPK inhibitors and immune checkpoint inhibitors in melanoma patients

Background: When patients with advanced melanoma progress after MAPK inhibitor (MAPKI) and immune checkpoint inhibitor (ICI) treatment, they can either undergo chemotherapy or rechallenge with previously used treatments. Methods: The outcomes of 48 patients retreated with MAPKIs and 50 patients retreated with ICIs following progression were retrospectively analyzed. Results: Upon retreatment with MAPKIs, the disease control rate was 60%. Univariate analysis of possible risk factors associated with short progression-free survival upon MAPKI treatment showed elevated lactate dehydrogenase to be associated with decreased progression-free survival. Disease control rate after ICI retreatment was 24%. Melanoma of unknown primary was associated with prolonged progression-free survival upon ICI retreatment. Conclusion: Retreatment with MAPKIs or ICIs is a feasible option for patients with advanced melanoma. Lay abstract Targeted therapy and immunotherapy are standard treatments for advanced melanoma. Although this treatment often helps patients, at some point melanoma cells often find a way to continue growing despite treatment, which means that patients progress even with treatment. Once patients progress after both targeted therapy and immunotherapy, the physician is faced with the decision to restart a treatment to which melanoma cells may have become resistant or to switch the patient to chemotherapy. The aim of this study was to analyze outcomes after retreatment with targeted therapy and immunotherapy. The disease was controlled in 60% of 48 patients retreated with targeted therapy and in 24% of 50 patients retreated with immunotherapy, indicating that both are feasible options for melanoma retreatment