MMAP-03 A NEW ERA IN LEPTOMENINGEAL DISEASE (LMD): RECENT ADVANCEMENTS IN IMMUNE THERAPIES AND RADIOTHERAPY IN MELANOMA LMD, WHAT HAS BEEN DONE AND FUTURE DIRECTIONS

Abstract Leptomeningeal disease (LMD) arises as a metastatic complication from tumor cells invading the leptomeninges and cerebrospinal fluid. Advances in targeted and immune therapies in the last decade have not translated to this disease and the prognosis for patients is dismal, with most surviving only weeks to months after the diagnosis is made. Melanoma is one of the most common etiologies of LMD, however specific developments for this complication still represent a huge gap in research. Recent clinical trials have been covering different delivery methods (systemic, intrathecal), different types of drugs (immune checkpoint inhibitors, small molecule inhibitors) and different radiation therapy modalities (IFRT, WBRT, pCSI) with varied results. With this review we aimed to summarize recent advances in LMD therapies, current efforts and active clinical trials, focusing on melanoma LMD. We found challenges that need to be overcome to improve research including the limited amount of melanoma LMD patients accrued in trials and limited access to specialized therapies such as pCSI. We also found research gaps that could be further explored, such as tumor characterization with scRNAseq. This could potentially open additional research avenues in the future as we better understand the intricacies of LMD ultimately providing patients with better odds of survival.