Impact of systemic therapies in metastatic melanoma of unknown primary: A study from MELBASE, a French multicentric prospective cohort.

Background: Clinical outcomes of advanced melanoma of unknown primary (MUP) in the era of novel therapies have been scarcely studied.
Objective: To investigate the efficacy and safety of systemic treatments in patients with advanced MUP compared to patients with stage-matched melanoma of known cutaneous primary (cMKP).
Methods: Based on the nationwide MelBase prospective database, this study included advanced melanoma patients treated from March 2013 to June 2021 with first-line immunotherapies, targeted therapies, or chemotherapy. Co-primary outcomes were progression-free survival and overall survival. Secondary outcome was treatment-related toxicities. Multivariate and propensity score analyses were performed.
Results: Of 1882 patients, 265 (14.1%) had advanced MUP. Patients with advanced MUP displayed more often unfavorable initial prognostic factors than those with cMKP. Progression-free and overall survival did not differ significantly between the groups (P = .73 and P = .93, respectively), as well as treatment-related toxicity rate and severity, regardless of treatment type.
Limitations: No record of standard diagnostic criteria of MUP used in the participating centers.
Conclusions: Although patients with MUP had less favorable baseline prognostic factors, they benefited from the novel therapies as much as those with cMKP. They should be managed according to similar strategies.
Competing Interests: Conflicts of interest Dr Dalle received research grants by BMS and MSD, travel costs covered by BMS, spouse working for Sanofi; Dr Dereure reported a Consulting or Advisory Role with Bristol-Myers Squibb, Genevrier, Kiowa Kirin, Leo Pharma, MSD, Novartis, Pierre Fabre, and Recordati, and reports travel, accommodations, and expenses from Bristol-Myers Squibb, Novartis, Pierre Fabre, and Recordati; Dr Saiag has received outside of this study personal fees from Bristol-Myers Squibb, MSD, Merck-Serono, Pfizer, Roche-Genentech, Pierre Fabre, and Novartis; Dr Arnault consulting for NOVARTIS, Dr Lebbé reported honoraria from Amgen, Bristol-Myers Squibb, Incyte, MSD, Novartis, Pfizer, Pierre Fabre, and Roche, reports a Consulting or Advisory Role with Amgen, Bristol-Myers Squibb, Merck Serono, MSD, Novartis, Roche, and Sanofi, is on the Speakers' Bureau for Amgen, Bristol-Myers Squibb, MSD, Novartis, and Roche, received Research Funding from Bristol-Myers Squibb, and Roche, reports travel, accommodations, and expenses from Bristol-Myers Squibb and MSD, and reports other relationship with Avantis Medical Systems; and Dr Montaudié reported a Consulting or Advisory Role with Bristol-Myers Squibb, MSD, Novartis, and Pierre Fabre, received Research Funding from Leo Pharma and Novartis, and reports travel, accommodations, and expenses from Bristol-Myers Squibb, Novartis, and Pierre Fabre.
(Copyright © 2022 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)