Comparative real-world outcomes of stage III melanoma patients treated with talimogene laherparepvec or interleukin 2.

Background: Talimogene laherparepvec (T-VEC) and interleukin-2 (IL-2) are both used in the intralesional treatment of melanoma skin metastases. T-VEC received regulatory approval from the European Medicines Agency and the U.S. Food and Drug Administration in 2015, while IL-2 has been used off-label for this purpose for many years. Despite their use in clinical practice, there is a lack of comparative data on the efficacy and safety of these treatments.

Objectives: This retrospective study aimed to compare the efficacy and safety of intralesional T-VEC and IL-2 in non-resectable stage III patients with melanoma treated at a single center between January 2016 and September 2024.

Methods: We identified eligible patients using the Central Malignant Melanoma Registry and the local University Hospital Pharmacy database. Overall survival (OS) and progression-free survival (PFS) were calculated. Furthermore, best response rates and occurrence of adverse events (AEs) were compared between the T-VEC and the IL-2 group. Concomitant systemic treatment was allowed.

Results: A total of 62 patients were included, with 37 receiving T-VEC and 25 receiving IL-2 as first-line therapy. Ten patients received both therapies subsequently. The median PFS for the cohort was 5.0 months, and the median OS was 34.0 months. No significant differences in PFS (p = 0.790), OS (p = 0.894), or best response rates (p = 0.468) were found between groups. Common AEs included local injection site reactions and fever, with no severe events leading to discontinuation by a physician.

Conclusion: No significant differences in PFS, OS, or best response rates were observed between IL-2 and T-VEC treatments. The choice of therapy may be influenced by factors such as availability, physician preference, and patient-specific considerations.