Society for Immunotherapy of Cancer (SITC) clinical practice guideline on immunotherapy for the treatment of melanoma, version 3.0

Since the first approval for immune checkpoint inhibitors (ICIs) for the treatment of cutaneous melanoma more than a decade ago, immunotherapy has completely transformed the treatment landscape of this chemotherapy-resistant disease. Combination regimens including ICIs directed against programmed cell death protein 1 (PD-1) with anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) agents or, more recently, anti-lymphocyte-activation gene 3 (LAG-3) agents, have gained regulatory approvals for the treatment of metastatic cutaneous melanoma, with long-term follow-up data suggesting the possibility of cure for some patients with advanced disease. In the resectable setting, adjuvant ICIs prolong recurrence-free survival, and neoadjuvant strategies are an active area of investigation. Other immunotherapy strategies, such as oncolytic virotherapy for injectable cutaneous melanoma and bispecific T-cell engager therapy for HLA-A*02:01 genotype-positive uveal melanoma, are also available to patients. Despite the remarkable efficacy of these regimens for many patients with cutaneous melanoma, traditional immunotherapy biomarkers (ie, programmed death-ligand 1 expression, tumor mutational burden, T-cell infiltrate and/or microsatellite stability) have failed to reliably predict response. Furthermore, ICIs are associated with unique toxicity profiles, particularly for the highly active combination of anti-PD-1 plus anti-CTLA-4 agents. The Society for Immunotherapy of Cancer (SITC) convened a panel of experts to develop this clinical practice guideline on immunotherapy for the treatment of melanoma, including rare subtypes of the disease (eg, uveal, mucosal), with the goal of improving patient care by providing guidance to the oncology community. Drawing from published data and clinical experience, the Expert Panel developed evidence- and consensus-based recommendations for healthcare professionals using immunotherapy to treat melanoma, with topics including therapy selection in the advanced and perioperative settings, intratumoral immunotherapy, when to use immunotherapy for patients with BRAFV600-mutated disease, management of patients with brain metastases, evaluation of treatment response, special patient populations, patient education, quality of life, and survivorship, among others.

Immune Checkpoint Inhibitors for Solid Tumors in the Adjuvant Setting: Current Progress, Future Directions, and Role in Transplant Oncology

The rationale for administering immune checkpoint inhibitors (ICIs) in the adjuvant setting is to eradicate micro-metastases and, ultimately, prolong survival. Thus far, clinical trials have demonstrated that 1-year adjuvant courses of ICIs reduce the risk of recurrence in melanoma, urothelial cancer, renal cell carcinoma, non-small cell lung cancer, and esophageal and gastroesophageal junction cancers. Overall survival benefit has been shown in melanoma while survival data are still not mature in other malignancies. Emerging data also show the feasibility of utilizing ICIs in the peri-transplant setting for hepatobiliary malignancies. While ICIs are generally well-tolerated, the development of chronic immune-related adverse events, typically endocrinopathies or neurotoxicities, as well as delayed immune-related adverse events, warrants further scrutiny regarding the optimal duration of adjuvant therapy and requires a thorough risk-benefit determination. The advent of blood-based, dynamic biomarkers such as circulating tumor DNA (ctDNA) can help detect minimal residual disease and identify the subset of patients who would likely benefit from adjuvant treatment. In addition, the characterization of tumor-infiltrating lymphocytes, neutrophil-to-lymphocyte ratio, and ctDNA-adjusted blood tumor mutation burden (bTMB) has also shown promise in predicting response to immunotherapy. Until additional, prospective studies delineate the magnitude of overall survival benefit and validate the use of predictive biomarkers, a tailored, patient-centered approach to adjuvant ICIs that includes extensive patient counseling on potentially irreversible adverse effects should be routinely incorporated into clinical practice.

Clinical Trials in Melanoma: Margins, Lymph Nodes, Targeted and Immunotherapy

Multiple randomized controlled trials have influenced the current standard of care for patients with cutaneous melanoma. Since the development of targeted and immune therapy, studies of adjuvant therapy for patients with resected stage III/IV melanoma have led to the approval of combined B-raf proto-oncogene (BRAF) and mitogen-activated protein kinase kinase inhibitors for patients with a BRAF mutation, and cytotoxic T-lymphocyte associated protein-4 or antiprogrammed cell death-1 therapy for patients without a BRAF mutation. This article discusses the details of the trials that have influenced these treatment decisions, in addition to discussing ongoing trials and possible future directions.

Adjuvant Anti-PD-1 Immunotherapy versus Conventional Therapy for Stage III Melanoma: A Real-World Retrospective Cohort Study

The use of adjuvant therapy has provided survival benefits in patients with advanced melanoma. This study aimed to explore the recurrence and prognosis of the PD-1 inhibitor, conventional interferon (IFN), or observation (OBS) on resected stage III acral and cutaneous melanoma patients through a retrospective analysis. Patients with resected stage III melanoma at Fudan University Shanghai Cancer Center from 2017 to 2021 were enrolled with all of their clinicopathologic characteristics collected. They were divided into three groups: PD-1 inhibitor, IFN, and OBS. Survival analyses were performed to indicate the significance of different adjuvant therapies. A total of 199 patients were enrolled (PD-1 n = 126; IFN n = 31; and OBS n = 42), with their median follow-up times being 21 months, 24 months, and 49 months, respectively. The PD-1 inhibitor significantly improved relapse-free survival (p = 0.027) and overall survival (p = 0.033) compared with conventional treatment (IFN+OBS). The superiority of the PD-1 inhibitor was witnessed in stage IIIC/D (p = 0.000) acral (p = 0.05) melanoma patients with ulceration (p = 0.011) or lymph node macrometastasis (p = 0.010). The PD-1 inhibitor significantly reduced local recurrence and systemic metastasis compared with conventional therapy (p = 0.002). In conclusion, adjuvant anti-PD-1 immunotherapy can achieve better survival outcomes in acral and cutaneous melanoma patients compared with conventional treatment, without considering adverse events. More clinical benefits were seen in later-stage acral melanoma patients with ulceration or lymph node macrometastasis.

Progression/Recurrence-Free Survival 2 in Adjuvant Melanoma

The long-term outcome of patients with stage III melanoma - that is, melanoma that has spread to nearby lymph nodes, lymphatics, or skin - who have received treatment with immune checkpoint inhibitors is of substantial interest. The article by Eggermont et al.1 published in this issue of NEJM Evidence reports 5-year outcomes from the stage III melanoma trial, KEYNOTE-054, which compared pembrolizumab (anti-programmed cell death protein 1 [PD-1]) with placebo. The data show durable recurrence-free survival (RFS) and distant metastasis-free survival (DMFS).

Systemic adjuvant therapy for high-risk cutaneous melanoma

Cutaneous melanoma continues to increase in incidence and poses a significant mortality risk. Surgical excision of melanoma in its early stages is often curative. However, patients with resected stages IIB-IV are considered at high risk for relapse and death from melanoma where systemic adjuvant therapy is indicated. The long-studied high-dose interferon-α was shown to improve relapse-free survival (RFS) and overall survival (OS) but is no longer in use. Adjuvant therapy with ipilimumab at 10 mg/kg (ipi10) demonstrated significant RFS and OS improvements but at a high cost in terms of toxicity, while adjuvant ipilimumab 3 mg/kg was shown to be equally effective and less toxic. More recently, the adjuvant therapy for resected stages III-IV melanoma in clinical practice has changed in favor of nivolumab, pembrolizumab, and BRAF-MEK inhibitors dabrafenib plus trametinib (for BRAF mutant melanoma) based on significant improvements in RFS as compared to ipi10 (nivolumab and pembrolizumab) and placebo (dabrafenib plus trametinib). For resected stages IIB-IIC melanoma, pembrolizumab achieved regulatory approval in the United States based on significant RFS benefits. In this article, we review completed and ongoing phase III adjuvant therapy trials. We also briefly discuss neoadjuvant therapy for locoregionally advanced melanoma. Finally, we explore recent studies on predictive and prognostic melanoma biomarkers in the adjuvant setting.

Management of In-Transit Metastases

PURPOSE OF REVIEW

The purpose of this study is to discuss the current knowledge and future perspectives regarding the treatment options for in-transit metastases (ITM), along with the optimal algorithms for patients presenting with this adverse manifestation of melanoma.

RECENT FINDINGS

In addition to procedures historically accepted for the management of ITM, encompassing surgery and regional techniques, novel medications in the form of immune checkpoint inhibitors (ICI) and targeted therapies now represent standard options, allowing for the possibility of combined approaches, with an expanding role of systemic therapies. Melanoma in-transit metastases consist of intralymphatic neoplastic implants distributed between the primary site and the regional nodal basin, within the subepidermal and dermal lymphatics. Distinct risk factors may influence the development of ITM, and the clinical presentation can be highly heterogeneous, enhancing the complexity of the management of ITM. Surgical resection, when feasible, continues to represent a standard approach for patients with curative intent. Patients with extensive or unresectable disease may also benefit from regional approaches that include isolated limb perfusion or infusion, electrochemotherapy, and a wide variety of intralesional therapies. Over the past decade, regimens with ICI and BRAF/MEK inhibitors dramatically expanded the benefit of systemic treatments for patients with melanoma, both in the adjuvant setting and for those with advanced disease, and the combination of these modalities with regional treatments, as well as neoadjuvant approaches, may represent the future for the treatment of patients with ITM.

Low-Dose Nivolumab with or without Ipilimumab as Adjuvant Therapy Following the Resection of Melanoma Metastases: A Sequential Dual Cohort Phase II Clinical Trial

Simple Summary

Optimal dosing and duration of adjuvant treatment with PD-1 immune checkpoint inhibitors in melanoma patients have not been established. The investigated low-dose regimen of nivolumab with or without ipilimumab (in a sequential dual-cohort phase II trial), resulted in a 12-months relapse-free survival (RFS) rate and tolerability that was comparable to what has been served with standard dosing of nivolumab or pembrolizumab when patients were matched for stage. The incidence of immune-related adverse events was similar to what has been reported from registration trials in this indication. Immunohistochemical quantification of intra- and peritumoral immune cells, but not PD-1/PD-L1 staining, correlated significantly with RFS. Therefore, low-dose regimes of PD-1 blocking monoclonal antibodies deserve further study as cost-effective alternatives for currently approved standard dosing regimens, with baseline immunohistochemical tumor profiling to be further explored as a promising biomarker.

Abstract

Background: Optimal dosing and duration of adjuvant treatment with PD-1 and CTLA-4 immune checkpoint inhibitors have not been established. Prior to their regulatory approval we investigated a low-dose regimen of nivolumab with or without ipilimumab in a sequential dual-cohort phase II clinical trial. Methods: Following the complete resection of melanoma metastases, patients were treated with a single fixed dose of ipilimumab (50 mg) plus 4 bi-weekly fixed doses of nivolumab (10 mg) (cohort-1), or nivolumab for 1 year (10 mg fixed dose, Q2w x9, followed by Q8w x4) (cohort-2). Twelve-months relapse-free survival (RFS) served as the primary endpoint. Results: After a median follow-up of 235 weeks for cohort-1 (34 patients), and 190 weeks for cohort-2 (21 patients), the 12-months RFS-rate was, respectively, 55.9% (95% CI, 39–72), and 85.7% (95% CI, 70–100). Treatment-related adverse events occurred in 27 (79%), and 18 (86%) patients, with 3 (9%), and 1 (5%) grade 3 adverse events in cohort-1 and -2, respectively. Immunohistochemical quantification of intra- and peritumoral CD3⁺ T cells and CD20⁺ B cells, but not PD-1/PD-L1 staining, correlated significantly with RFS. Conclusions: One year of adjuvant low-dose nivolumab could be an effective and economically advantageous alternative for standard dosing, at the condition of further confirmation in a larger patient cohort. A shorter low-dose nivolumab plus ipilimumab regimen seems inferior and less tolerable.

Clinical Significance of Distant Metastasis-Free Survival (DMFS) in Melanoma: A Narrative Review from Adjuvant Clinical Trials

Cutaneous melanoma is the most dangerous skin cancer, with high death rates in advanced stages. To assess the impact of each treatment on patient outcomes, most studies use relapse-free survival (RFS) as a primary endpoint and distant metastasis-free survival (DMFS) as a secondary endpoint. The aim of this narrative review of the main adjuvant studies for resected stage III/IV melanoma, with a specific focus on DMFS, is to evaluate DMFS trends and their potential association with RFS, identify which treatments are possibly associated with better outcomes in terms of DMFS and their potential predictive factors, and discuss DMFS trends in terms of patient management in daily practice. We outline the impact of each available treatment option on DMFS and RFS according to the years of follow-up and compare data from different studies. Overall, the trends of DMFS closely follow those of RFS, with most patients relapsing at visceral rather than regional sites. As it captures the burden of patients who develop distant relapse, DMFS could be considered a primary endpoint, in addition to RFS, in adjuvant trials, identifying patients whose relapse is associated with a worse prognosis and who may need further systemic treatment.

Multicenter, double-blind, placebo-controlled trial of seviprotimut-L polyvalent melanoma vaccine in patients with post-resection melanoma at high risk of recurrence

BACKGROUND

Most patients with advanced melanomas relapse after checkpoint blockade therapy. Thus, immunotherapies are needed that can be applied safely early, in the adjuvant setting. Seviprotimut-L is a vaccine containing human melanoma antigens, plus alum. To assess the efficacy of seviprotimut-L, the Melanoma Antigen Vaccine Immunotherapy Study (MAVIS) was initiated as a three-part multicenter, double-blind, placebo-controlled phase III trial. Results from part B1 are reported here.

METHODS

Patients with AJCC V.7 stage IIB-III cutaneous melanoma after resection were randomized 2:1, with stage stratification (IIB/C, IIIA, IIIB/C), to seviprotimut-L 40 mcg or placebo. Recurrence-free survival (RFS) was the primary endpoint. For an hypothesized HR of 0.625, one-sided alpha of 0.10, and power 80%, target enrollment was 325 patients.

RESULTS

For randomized patients (n=347), arms were well-balanced, and treatment-emergent adverse events were similar for seviprotimut-L and placebo. For the primary intent-to-treat endpoint of RFS, the estimated HR was 0.881 (95% CI: 0.629 to 1.233), with stratified logrank p=0.46. However, estimated HRs were not uniform over the stage randomized strata, with HRs (95% CIs) for stages IIB/IIC, IIIA, IIIB/IIIC of 0.67 (95% CI: 0.37 to 1.19), 0.72 (95% CI: 0.35 to 1.50), and 1.19 (95% CI: 0.72 to 1.97), respectively. In the stage IIB/IIC stratum, the effect on RFS was greatest for patients <60 years old (HR=0.324 (95% CI: 0.121 to 0.864)) and those with ulcerated primary melanomas (HR=0.493 (95% CI: 0.255 to 0.952)).

CONCLUSIONS

Seviprotimut-L is very well tolerated. Exploratory efficacy model estimation supports further study in stage IIB/IIC patients, especially younger patients and those with ulcerated melanomas.

TRIAL REGISTRATION NUMBER

NCT01546571.