Despite the dramatic improvement in both overall survival (OS) and progression-free survival (PFS) in patients with metastatic
melanoma treated with
immune checkpoint inhibitors, up to 60% will develop treatment resistance and 50% will die from their disease. Therefore, although
dacarbazine is no longer a mainstay of modern
melanoma management, we examined the extent to, and in which context, it may still play a role. A retrospective analysis of electronic medical records of patients who had received
dacarbazine treatment between October 2014 and October 2021, following innate or acquired resistance to
immune checkpoint inhibitors, was performed to determine PFS and OS and examine tolerability. Nine patients with locally advanced ( n = 1) or metastatic
melanoma ( n = 8) were identified (average age: 74 years, 4 males and 5 females). The number of cycles of
dacarbazine ranged from 2 to 45 (mean = 12). One-third of patients developed a complete ( n = 2) or partial ( n = 1) response, two-thirds did not respond to treatment. The median PFS time was 90 days. Common adverse events included blood dyscrasias; one patient developed a grade 3
hepatitis, although it was unclear if this was due to the
chemotherapy or the preceding combined
immunotherapy.
Dacarbazine may still be a valid option in the setting of treatment for refractory, relapsed, or progressive disease. Future studies should focus on the immunomodulatory effects of
dacarbazine on the tumor microenvironment, which could be harnessed to potentially restore sensitivity to immune checkpoint-based
therapy.