MELCHRONO: A Prospective Randomized Study Investigating Chrono-immunotherapy for Advanced Melanoma.

The introduction of ICIs a decade ago revolutionized the treatment of various malignancies, particularly melanoma. Yet treatment responses are heterogenous and depend on patient characteristics such as sex and age, and tumor characteristics. The relationship between sex and ICI response in melanoma is complex and may be influenced by various factors, including the type of ICI, tumor mutation burden, presence of infiltrating immune cells, microbiome, and concomitant medications affect the immune system's ability to mount antitumor responses. While some retrospective data indicate poorer outcomes for female patients, in other real-world reports female sex is associated with better outcomes. Prospective, sex-stratified clinical studies are necessary to provide a definitive answer and to integrate sex as a critical variable in personalizing melanoma treatment strategies. Temporal variations in antibody responses and anticancer immunity after vaccination have been reported in both humans and mice. Circadian rhythms also remain an important regulator of immune cell activities. The optimal time for inducing adaptive immune responses consistently appears to be situated around or just before behavioral activity; for nocturnal mice this optimal window appears to be the afternoon, while in diurnal humans this may be the early morning. However, the optimal time of day for ICI administration is currently unknown. A retrospective single-center analysis of advanced melanoma patients showed that receiving less than 20% of the ICI infusions after 16h30 was associated with enhanced overall survival. In subgroup analyses, female patients had a significantly longer OS when less than 20% of the treatment was administered after 16h30. Optimizing the timing of ICI therapy to target the immune system at the time of its highest sensitivity could significantly improve patient outcomes, particularly for female patients, without exposing patients to additional drugs and generating additional toxicity and costs. Given the limitations of retrospective analyses, a prospective randomized trial is essential to obtain results that could potentially change clinical practice.