A phase I study of the safety and efficacy of talimogene laherparepvec in Japanese patients with advanced melanoma

Recent advances in immunotherapy and its combination therapies for advanced melanoma: a review

The incidence of melanoma is increasing year by year and is highly malignant, with a poor prognosis. Its treatment has always attracted much attention. Among the more clinically applied immunotherapies are immune checkpoint inhibitors, bispecific antibodies, cancer vaccines, adoptive cell transfer therapy, and oncolytic virotherapy. With the continuous development of technology and trials, in addition to immune monotherapy, combinations of immunotherapy and radiotherapy have shown surprising efficacy. In this article, we review the research progress of immune monotherapy and combination therapy for advanced melanoma, with the aim of providing new ideas for the treatment strategy for advanced melanoma.

Where Are We Now with Oncolytic Viruses in Melanoma and Nonmelanoma Skin Malignancies?

Skin cancer prognosis has greatly improved recently due to the introduction of immune checkpoint inhibitors (ICIs). However, many patients with advanced skin cancer still experience immunotherapy resistance and disease progression during ICI treatment, thus calling for novel therapeutics which address this treatment gap. Talimogene laherparepvec (T-VEC) has gained popularity in recent years as a viable treatment option for patients with skin cancer. In preclinical studies, T-VEC demonstrated both a direct anti-tumor effect in injected lesions as well as a systemic immune-mediated effect in non-injected lesions, which could pose additional benefits when combined with ICI therapy. Following promising results from the OPTiM trial, the Food and Drug Administration (FDA) approved the usage of T-VEC as a single agent in advanced melanoma. However, the MASTERKEY-265 trial demonstrated that adding T-VEC to pembrolizumab did not offer additional clinical benefit in patients with melanoma. Nevertheless, the promising efficacy of T-VEC and its approval by the FDA helped oncolytic viruses (OVs) gain wide attention in cancer therapy, and extensive research has been undertaken to evaluate the usage of OVs in other tumors such as sarcomas and breast cancers. Here, we provide a review of clinical results from 2022 to 2024 that investigate the efficacy and safety of OVs as a monotherapy or in combination with other therapies in skin malignancies. Furthermore, we delineate the current limitations in OV utilization and outline future directions to enhance clinical outcomes for patients with skin malignancies receiving OV-based therapies.

TIGIT, a novel immune checkpoint therapy for melanoma

Melanoma is the most aggressive and deadliest type of skin cancer. In the last 10 years, immune checkpoint blockades (ICBs) including PD-1/PD-L1 and CTLA-4 inhibitor has been shown to be effective against melanoma. PD-1/PD-L1 and CTLA-4 inhibitors have shown varying degrees of drug resistance in the treatment of melanoma patients. Furthermore, the clinical benefits of ICBs are also accompanied by severe immune toxicity. Therefore, there is an urgent need to develop new immune checkpoint inhibitors to optimize melanoma therapy and reduce cytotoxicity. T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) is thought to activate inhibitory receptors in T cells, natural killer (NK) cells, and regulatory T cells (Tregs), and has become a promising target for immunotherapy. Studies have found that TIGIT can be detected in different stages of melanoma, which is closely related to the occurrence, development, and prognosis of melanoma. This review mainly describes the immunosuppressive mechanism of TIGIT and its role in antitumor immunity of melanoma, so as to provide new ideas and schemes for the clinical treatment of melanoma with targeted TIGIT.

Oncolytic virotherapy: basic principles, recent advances and future directions

Oncolytic viruses (OVs) have attracted growing awareness in the twenty-first century, as they are generally considered to have direct oncolysis and cancer immune effects. With the progress in genetic engineering technology, OVs have been adopted as versatile platforms for developing novel antitumor strategies, used alone or in combination with other therapies. Recent studies have yielded eye-catching results that delineate the promising clinical outcomes that OVs would bring about in the future. In this review, we summarized the basic principles of OVs in terms of their classifications, as well as the recent advances in OV-modification strategies based on their characteristics, biofunctions, and cancer hallmarks. Candidate OVs are expected to be designed as "qualified soldiers" first by improving target fidelity and safety, and then equipped with "cold weapons" for a proper cytocidal effect, "hot weapons" capable of activating cancer immunotherapy, or "auxiliary weapons" by harnessing tactics such as anti-angiogenesis, reversed metabolic reprogramming and decomposing extracellular matrix around tumors. Combinations with other cancer therapeutic agents have also been elaborated to show encouraging antitumor effects. Robust results from clinical trials using OV as a treatment congruously suggested its significance in future application directions and challenges in developing OVs as novel weapons for tactical decisions in cancer treatment.