A phase II study on the efficacy of regorafenib in treating patients with c-KIT-mutated metastatic malignant melanoma that progressed after previous treatment (KCSG-UN-14-13)

European consensus-based interdisciplinary guideline for melanoma. Part 1: Diagnostics - Update 2024

This guideline was developed in close collaboration with multidisciplinary experts from the European Association of Dermato-Oncology (EADO), the European Dermatology Forum (EDF) and the European Organization for Research and Treatment of Cancer (EORTC). Recommendations for the diagnosis and treatment of melanoma were developed on the basis of systematic literature research and consensus conferences. Cutaneous melanoma (CM) is the most dangerous form of skin tumor and accounts for 90 % of skin cancer mortality. The diagnosis of melanoma can be made clinically and must always be confirmed by dermoscopy. If melanoma is suspected, a histopathological examination is always required. Sequential digital dermoscopy and whole-body photography can be used in high-risk patients to improve the detection of early-stage melanoma. If available, confocal reflectance microscopy can also improve the clinical diagnosis in special cases. Melanoma is classified according to the 8th version of the American Joint Committee on Cancer classification. For thin melanomas up to a tumor thickness of 0.8 mm, no further diagnostic imaging is required. From stage IB, lymph node sonography is recommended, but no further imaging examinations. From stage IIB/C, whole-body examinations with computed tomography or positron emission tomography CT in combination with magnetic resonance imaging of the brain are recommended. From stage IIB/C and higher, a mutation test is recommended, especially for the BRAF V600 mutation. It is important to perform a structured follow-up to detect relapses and secondary primary melanomas as early as possible. A stage-based follow-up regimen is proposed, which in the experience of the guideline group covers the optimal requirements, although further studies may be considered. This guideline is valid until the end of 2026.

Regorafenib promotes antitumor progression in melanoma by reducing RRM2

Melanoma is a malignant tumor with a terrible prognosis. Although so many therapies are used for melanoma, the overall survival rate is still poor globally. Novel therapies are still required. In our study, the role and potential mechanism of regorafenib in melanoma are explored. Regorafenib has the ability to limit the growth, invasion, and metastasis of melanoma cells but to upregulate apoptosis-prompting markers (cleaved-PARP and Bax). RRM2 is identified to be the downstream target of regorafenib by RNA sequencing. In addition, we discovered that RRM2 inhibition and regorafenib have comparable effects on melanoma cells. Rescue experiments showed that RRM2 is crucial in regulating regorafenib's anti-melanoma progression. Moreover, ERK/E2F3 signaling influences regorafenib's ability to suppress melanoma cell growth. Ultimately, regorafenib significantly inhibits tumor growth in vivo. In conclusion, our finding demonstrated that regorafenib promotes antitumor progression in melanoma by reducing RRM2.

Regorafenib in patients with pretreated advanced melanoma: a single-center case series

Melanoma patients failing all approved treatment options have a poor prognosis. The antimelanoma activity of regorafenib (REGO), a multitargeted kinase inhibitor, has not been investigated in this patient population. The objective response rate and safety of REGO treatment in advanced melanoma patients was investigated retrospectively. Twenty-seven patients received REGO treatment. All patients had progressed on anti-programmed cell death protein 1 (PD-1) and anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) checkpoint inhibition and BRAF/MEK inhibitors (in case of a BRAF V600 mutation). REGO was administered in continuous dosing and combined (upfront or sequentially) with nivolumab ( n  = 5), trametinib ( n  = 8), binimetinib ( n  = 2), encorafenib ( n  = 1), dabrafenib/trametinib ( n  = 9), or encorafenib/binimetinib ( n  = 7). The best overall response was partial response (PR) in five patients (18.5%) and stable disease in three patients (11.1%). Three of seven (42.8%) BRAF  V600mut patients treated with REGO in combination with BRAF/MEK inhibitors obtained a PR (including regression of brain metastases in all three patients). In addition, PR was documented in a BRAF V600mut patient treated with REGO plus anti-PD-1, and a NRASQ61mut patient treated with REGO plus a MEK inhibitor. Common grade 3-4 treatment-related adverse events included arterial hypertension ( n  = 7), elevated transaminase levels ( n  = 5), abdominal pain ( n  = 3), colitis ( n  = 2), anorexia ( n  = 1), diarrhea ( n  = 1), fever ( n  = 1), duodenal perforation ( n  = 1), and colonic bleeding ( n  = 1). Median progression-free survival was 11.0 weeks (95% confidence interval, 7.1-14.9); median overall survival was 23.1 weeks (95% confidence interval, 13.0-33.3). REGO has a manageable safety profile in advanced melanoma patients, in monotherapy as well as combined with BRAF/MEK inhibitors or PD-1 blocking monoclonal antibodies. The triplet combination of REGO with BRAF/MEK inhibitors appears most active, particularly in the BRAF V600mut patients.

Recent advances in tyrosine kinase inhibitors VEGFR 1-3 for the treatment of advanced metastatic melanoma

INTRODUCTION

Increasing evidence from preclinical and clinical studies suggests the role of vascular endothelial growth factor (VEGF) signaling in melanoma progression, response to therapy, and overall survival. Moreover, the discovery of the potential involvement of the VEGF pathway in resistance to immunotherapy has led to new clinical trials with VEGFR inhibitors.

AREAS COVERED

We have reviewed recent literature, mainly published within the last 5 years, on VEGFR-targeted treatments for advanced melanoma, including mucosal, acral, and uveal melanoma. The VEGFR inhibitors were used as a single therapy or combined with either immunotherapy or chemotherapy, and they were employed in treatment for KIT-mutated cutaneous melanoma and for patients with brain metastases.

EXPERT OPINION

Trials involving monotherapy have been unsuccessful in demonstrating meaningful efficacy. Despite some activity, the combination of VEGFR-targeting tyrosine kinase inhibitors (TKIs) with immune checkpoint inhibitors (ICI) in patients with ICI-resistant melanoma, the combination did not significantly improve outcomes compared to anti-PD-1 monotherapy in the first-line settings. On the contrary, some patients with mucosal, acral or KIT-mutant melanoma may benefit from TKI-based therapies. Further studies focused on biomarker discovery and randomized trials are necessary to better understand the role of VEGFR1-3 as a therapeutic target in melanoma.