Immuno-oncology approaches in uveal melanoma: tebentafusp and beyond

Uveal melanoma (UM) is the most common ocular malignancy in adults, associated with the poorest prognosis, with metastatic disease occurring in up to 50% of patients. In contrast to metastatic cutaneous melanoma, the use of immune checkpoint inhibitors is associated with poor outcomes in metastatic uveal melanoma (mUM). Tebentafusp, a bispecific molecule, has recently become the first treatment in decades to improve overall survival for mUM. This review summarises the existing and emerging immuno-oncology approaches for the treatment of mUM, and biomarkers of response and resistance to the same. Finally, we propose future research directions that could maximise treatment benefit to a wider pool of patients with UM.

Successful treatment of metastatic uveal melanoma with ipilimumab and nivolumab after severe progression under tebentafusp: a case report

Metastatic uveal melanoma (UM) is a rare form of melanoma differing from cutaneous melanoma by etiology, prognosis, driver mutations, pattern of metastases and poor response rate to immune checkpoint inhibitors (ICI). Recently, a bispecific gp100 peptide-HLA-directed CD3 T cell engager, tebentafusp, has been approved for the treatment of HLA-A*02:01 metastatic or unresectable UM. While the treatment regime is complex with weekly administrations and close monitoring, the response rate is limited. Only a few data exist on combined ICI in UM after previous progression on tebentafusp. In this case report, we present a patient with metastatic UM who first suffered extensive progression under treatment with tebentafusp but in the following had an excellent response to combined ICI. We discuss possible interactions that could explain responsiveness to ICI after pretreatment with tebentafusp in advanced UM.

Review of bi-specific therapies in uveal melanoma

Uveal melanoma is a rare subtype of melanoma that once metastatic portends a poor prognosis. Likely due to the distinct differences in biology, metastatic potential, and immunologic profile as compared to cutaneous melanoma, uveal melanoma's response to immune checkpoint inhibition has been disappointing. Bi-specific fusion protein therapies (T cell engagers) are a novel strategy to forcibly bridge the immune system with a target on a cancer cell. This approach has been explored in a number of cancer types and has recently demonstrated success in uveal melanoma. Tebentafusp, a first in class ImmTAC (Immune-mobilizing monoclonal TCRs against cancer), has now shown an overall survival benefit when compared to investigator's choice. This review aims to summarize the experience with this first in class bi-specific T cell engager as well as highlight bi-specifics as a novel treatment strategy in uveal melanoma.

Tebentafusp for the treatment of metastatic uveal melanoma

Uveal melanoma is a rare disease; nevertheless, it is the most common primary intraocular malignancy among adults. Approximately half of affected patients will suffer from metastatic disease, mostly to the liver. No standard-of-care treatment exists for these patients. Median progression-free survival and overall survival for all types of treatment, including checkpoint inhibitors, have remained poor. However, the most recent phase III study results for tebentafusp, a member of a new-in-class molecule, are raising hopes for stage IV uveal melanoma patients. In this review, we examine the current literature, focusing on the most recent trial results for this new reagent. We evaluate the latest clinical results for tebentafusp and aim to shed light on its immunological strategy.