Anti-PD-(L)1 plus BRAF/MEK inhibitors (triplet therapy) after failure of immune checkpoint inhibition and targeted therapy in patients with advanced melanoma

Advancements in Melanoma Treatment: A Review of PD-1 Inhibitors, T-VEC, mRNA Vaccines, and Tumor-Infiltrating Lymphocyte Therapy in an Evolving Landscape of Immunotherapy

Melanoma, an aggressive skin cancer, presents significant therapeutic challenges. Consequently, innovative treatment strategies beyond conventional chemotherapy, radiation, and surgery are actively explored. This review discusses the evolution of immunotherapy in advanced melanoma, highlighting PD-1/PD-L1 inhibitors, mRNA vaccines, Talimogene Laherparepvec (T-VEC), and tumor-infiltrating lymphocyte (TIL) therapies. PD-1/PD-L1 inhibitors such as pembrolizumab and nivolumab block immune checkpoints, promoting T-cell cytotoxic activity and improving overall survival in patients with advanced melanoma. T-VEC, a modified oncolytic herpes virus, promotes a systemic anti-tumor response while simultaneously lysing malignant cells. mRNA vaccines, such as Moderna's mRNA-4157/V940, take advantage of malignant-cell-specific neoantigens to amplify the adaptive immune response while protecting healthy tissue. TIL therapy is a form of therapy involving ex vivo expansion and reinfusion of the patient's tumor-specific lymphocytes and has been shown to provide durable tumor control. While these therapies have demonstrated promising clinical outcomes, challenges such as tumor resistance, high financial burden, and limited accessibility pose challenges to their widespread use. This review explores combination therapies such as PD-L1 inhibitors with mRNA vaccines, or TIL therapy, which aim to enhance treatment through synergistic approaches. Further research is required to optimize these combinations, address barriers preventing their use, and control adverse events.

Safety and Efficacy Analysis of Targeted and Immune Combination Therapy in Advanced Melanoma-A Systematic Review and Network Meta-Analysis

The combinations of BRAF inhibitor-based targeted therapies with immune checkpoint inhibitors currently represent less common therapeutic approaches in advanced melanoma. The aim of this study was to assess the safety and efficacy of currently available melanoma treatments by conducting a systematic review and network meta-analysis. Four databases were systematically searched for randomized clinical studies that included patients with advanced/metastatic melanoma receiving chemotherapy, immune checkpoint inhibitors, BRAF/MEK inhibitor therapy, or combinations thereof. The primary endpoints were treatment-related adverse events (TRAE), serious adverse events (SAE) of grade ≥ 3 adverse events, therapy discontinuation, progression-free survival (PFS), as well as objective response rate (ORR) and complete response rate (CRR). A total of 63 articles were eligible for our systematic review; 59 of them were included in the statistical analysis. A separate subgroup analysis was conducted to evaluate the efficacy outcomes, specifically in BRAF-positive patients. Triple combination therapy or triple therapy (inhibiting BRAF, MEK and PD1/PDL1 axis) showed significantly longer progression-free survival compared to BRAF + MEK combination therapies (HR = 0.76; 95% CI 0.64-0.9), but similar objective and complete response rates in BRAF-mutated melanoma. This safety analysis suggests that triple therapy is not inferior to combined immune checkpoint inhibitors (ICI) and BRAF/MEK therapies in terms of serious adverse events and therapy discontinuation rates. However, monotherapies and BRAF/MEK combinations showed notable advantage over triple therapy in terms of treatment-related adverse events. Combination strategies including BRAF/MEK-targeted therapies with ICI therapies are effective first-line options for advanced, BRAF-mutant melanoma; however, they are associated with more frequent side effects. Therefore, future RCTs are required to evaluate and identify high-risk subpopulations where triple therapy therapies should be considered.

Agnostic Administration of Targeted Anticancer Drugs: Looking for a Balance between Hype and Caution

Many tumors have well-defined vulnerabilities, thus potentially allowing highly specific and effective treatment. There is a spectrum of actionable genetic alterations which are shared across various tumor types and, therefore, can be targeted by a given drug irrespective of tumor histology. Several agnostic drug-target matches have already been approved for clinical use, e.g., immune therapy for tumors with microsatellite instability (MSI) and/or high tumor mutation burden (TMB), NTRK1-3 and RET inhibitors for cancers carrying rearrangements in these kinases, and dabrafenib plus trametinib for BRAF V600E mutated malignancies. Multiple lines of evidence suggest that this histology-independent approach is also reasonable for tumors carrying ALK and ROS1 translocations, biallelic BRCA1/2 inactivation and/or homologous recombination deficiency (HRD), strong HER2 amplification/overexpression coupled with the absence of other MAPK pathway-activating mutations, etc. On the other hand, some well-known targets are not agnostic: for example, PD-L1 expression is predictive for the efficacy of PD-L1/PD1 inhibitors only in some but not all cancer types. Unfortunately, the individual probability of finding a druggable target in a given tumor is relatively low, even with the use of comprehensive next-generation sequencing (NGS) assays. Nevertheless, the rapidly growing utilization of NGS will significantly increase the number of patients with highly unusual or exceptionally rare tumor-target combinations. Clinical trials may provide only a framework for treatment attitudes, while the decisions for individual patients usually require case-by-case consideration of the probability of deriving benefit from agnostic versus standard therapy, drug availability, associated costs, and other circumstances. The existing format of data dissemination may not be optimal for agnostic cancer medicine, as conventional scientific journals are understandably biased towards the publication of positive findings and usually discourage the submission of case reports. Despite all the limitations and concerns, histology-independent drug-target matching is certainly feasible and, therefore, will be increasingly utilized in the future.