Adjuvant Systemic Therapies for Resected Stages III and IV Melanoma: A Multi-Center Retrospective Clinical Study

BACKGROUND

Adjuvant therapies have been approved for resected melanoma based on improved recurrence-free survival. We present early findings from a real-world study on adjuvant treatments for melanoma.

METHODS

A comprehensive chart review was conducted for patients receiving adjuvant systemic therapy for resected high-risk stages III and IV melanoma. Statistical analysis was performed to assess recurrence-free survival and subgroup differences.

RESULTS

A total of 149 patients (median age = 58.0 years, 61.1% men, 49.7% with BRAF V600E/K genotypes) were included, with 94.6% having resected stage III melanoma. Anti-PD-1 immunotherapy was received by 86.5% of patients, while 13.4% received BRAF-targeted therapy. At a median follow-up of 22.4 months, the recurrence rate was 31.5%, with 1-year and 2-year recurrence-free survival rates of 79% and 62%, respectively. Similar recurrence rates were observed between anti-PD-1 immunotherapy and BRAF-targeted therapy. Long-term toxicity affected 27.4% of patients, with endocrinopathies and late-emergent immune-related adverse events being common.

CONCLUSIONS

Real-world adjuvant systemic therapy aligns with clinical trial practice. Recurrence rates remain high despite treatment, and long-term toxicities, including endocrinopathies and chronic inflammatory conditions, are not uncommon.

Survival of patients with stage IIIC and IIID melanomas with nodal metastases in the light of new therapies

Introduction

Within stage III melanoma prognosis and outcomes significantly vary. Advances in systemic therapy improved prognosis in metastatic melanoma. Adjuvant therapy in stage III significantly lowered relapses, although the effect on survival is less evident. Analysis of treatment results in stage IIIC and IIID before introduction of the modern adjuvant therapy, but after introduction of the effective systemic therapy in metastatic relapse, is needed.

Aim

To analyse the clinical outcomes in patients with stage IIIC and IIID melanoma before the introduction of the novel adjuvant therapy.

Material and methods

Consecutive stage IIIC and IIID melanoma patients treated in 2015-2018 in 4 reference centres in Poland were enrolled in the analysis of RFS and OS (in-transit metastases excluded). Median follow-up was 26.6 months (1.7-67.2).

Results

There were 224 stage IIIC and 49 stage IIID patients. Recurrence was observed in 170 (62.2%); 102 (45.5%) deaths in stage IIIC and 28 (57.1%) in stage IIID were reported. RFS and OS were better in stage IIIC compared to stage IIID. RFS and OS in the IIIC group were 19.7 and 36.2 months, respectively, and in IIID - 8.9 and 27.8 months, respectively.

Conclusions

The survival of patients with high-risk melanomas has improved in recent years, however, it is still unsatisfactory. The major changes in melanoma management related to the introduction of the adjuvant therapy require further careful observation.

Current Landscape and Open Questions on Adjuvant Therapies in Melanoma

Melanoma is a form of skin cancer that is frequently diagnosed at early stages. In most cases, surgical resection is curative. In case of thicker melanomas (> pT1b) without clinical or instrumental evidence of metastasis, a sentinel lymph node biopsy is recommended for staging purposes. If the lymph nodes are the only site of disease (macroscopic or microscopic> 1mm), configuring stage III, the international guidelines recommend the use of adjuvant therapy with checkpoint inhibitors (nivolumab or pembrolizumab) or targeted therapies (dabrafenib plus trametinib). These drugs have shown a significant increase in recurrence-free survival, although some doubts and open questions remain. Specifically, none of the available treatments has shown a clear benefit in the overall survival rates, the advantages they give in stage IIIA are not well known, and finally there are still no prospective clinical studies identifying the best approach to continue the therapeutic process in case of relapse. Furthermore, there are new opportunities opening up with the upcoming results of the neoadjuvant trials that could revolutionize the treatment of clinically evident stage III melanoma.

Adjuvant therapy versus watch-and-wait post surgery for stage III melanoma: a multicountry retrospective chart review

AIM

To describe treatment patterns among patients with stage III melanoma who underwent surgical excision in years 2011-2016, and assess outcomes among patients who subsequently received systemic adjuvant therapy versus watch-and-wait.

METHODS

Chart review of 380 patients from 17 melanoma centers in North America, South America and Europe.

RESULTS

Of 129 (34%) patients treated with adjuvant therapy, 85% received interferon α-2b and 56% discontinued treatment (mostly due to adverse events). Relapse-free survival was significantly longer for patients treated with adjuvant therapy versus watch-and-wait (hazard ratio = 0.63; p < 0.05). There was considerable heterogeneity in adjuvant treatment schedules and doses. Similar results were found in patients who received interferon-based adjuvant therapy.

CONCLUSION

Adjuvant therapies with better safety/efficacy profiles will improve clinical outcomes in patients with stage III melanoma.

Current management of regional lymph nodes in patients with melanoma

The publication of recent randomized trials has prompted a significant shift in both our understanding and the management of patients with melanoma. Here, the current management of the regional lymph nodes in patients with melanoma is discussed. This review focuses on selection for sentinel lymph node biopsy, management of the positive sentinel node, management of the clinically positive node, and the controversy over the therapeutic value of early nodal intervention.

Xenogeneic cell-based vaccine therapy for stage III melanoma: safety, immune-mediated responses and survival benefits

New therapies for melanoma have yielded promising results, but their application is limited because of serious side-effects and only moderate impact on patient survival. Vaccine therapies may offer some hope by targeting tumor-specific responses, considering the immunogenic nature of melanomas. To investigate the safety profile and efficiency of a xenogeneic cell-based vaccine therapy in stage III melanoma patients and evaluate the survival rate in treated patients. Twenty-seven stage III melanoma patients were immunized with a lyophilized xenogeneic polyantigenic vaccine (XPV) prepared from murine melanoma B16 and carcinoma LLC cells. Neither grade III/IV toxicities, nor clinically significant changes in blood and biochemical parameters were noted after an induction course of 10 XPV subcutaneous immunizations. No laboratory or clinical signs of systemic autoimmunity were documented. Following 10 vaccinations, a relative increase in the numbers of circulating memory CD4+CD45RO+ T cells (but not CD8+ CD45RO+ T cells) was observed. Peripheral blood mononuclear cells obtained from XPV-treated patients demonstrated increased proliferative responses to human BRO melanoma-associated antigens and marked increases in serum levels of IFN-γ and IL-8. Serum levels of TNF-α, IL-4 and IL-6 were not affected. The overall five-year survival rate in the treated patients was significantly higher than that in 27 control patients with matched clinical and prognostic characteristics (55% vs 18%). XPV-based immunotherapy could be maximally effective when started as early as possible before or after surgical excision of the primary tumor and local metastases, i.e. when tumor-mediated suppressive effects on immunity are minimal.

Sentinel node metastasis mitotic rate (SN-MMR) as a prognostic indicator of rapidly progressing disease in patients with sentinel node-positive melanomas

Risk stratification of sentinel lymph node biopsy (SNB)-positive patients with malignant melanoma differs among current classification systems. To improve classification of patients with rapidly progressive disease who may profit from adjuvant therapy with novel immune or targeted treatment modalities, a single-center retrospective analysis was performed including all melanoma patients diagnosed with a positive SN at a university-based skin cancer center over a 10-year period (2002-2012) (96 of 419 patients). Sentinel node metastasis mitotic rate (SN-MMR) and further histologic parameters were determined by blinded histological re-evaluation and correlated with clinical follow-up (overall [OS], melanoma-specific [MSS], and disease-free survival [DFS]). Median follow-up was 53 months. In univariate analyses, SN tumor penetrative depth (TPD), maximum tumor diameter (MTD), number of positive SN, SN-MMR and the S-, Rotterdam, RDC, Hannover I and II classification systems correlated with OS, MSS and DFS. Multivariate Cox regression analyses showed that a binary classification system based only on the SN-MMR (<1 vs. ≥1 mitoses/mm2 ) was the strongest independent prognostic indicator for all endpoints analyzed. Kaplan-Meier analyses confirmed binary SN-MMR to be superior to stratify patients into high- and low-risk groups (45.45% vs. 87.92% 5-yr MSS). The general prognostic validity of the published SN classification systems was confirmed. The novel SN-MMR classification system may improve discrimination of patients with slowly and rapidly progressive disease. We therefore propose its implementation into clinical practice as the SN-MMR can be easily and reliably determined in routine pathology reports. Its prognostic value for the selection of patients amenable to adjuvant therapies should be studied in clinical trials.

Adjuvant dendritic cell vaccination induces tumor-specific immune responses in the majority of stage III melanoma patients

Purpose: To determine the effectiveness of adjuvant dendritic cell (DC) vaccination to induce tumor-specific immunological responses in stage III melanoma patients.

Experimental design: Retrospective analysis of stage III melanoma patients, vaccinated with autologous monocyte-derived DC loaded with tumor-associated antigens (TAA) gp100 and tyrosinase after radical lymph node dissection. Skin-test infiltrating lymphocytes (SKILs) obtained from delayed-type hypersensitivity skin-test biopsies were analyzed for the presence of TAA-specific CD8⁺ T cells by tetrameric MHC-peptide complexes and by functional TAA-specific T cell assays, defined by peptide-recognition (T2 cells) and/or tumor-recognition (BLM and/or MEL624) with specific production of Th1 cytokines and no Th2 cytokines.

Results: Ninety-seven patients were analyzed: 21 with stage IIIA, 34 with stage IIIB, and 42 had stage IIIC disease. Tetramer-positive CD8⁺ T cells were present in 68 patients (70%), and 24 of them showed a response against all 3 epitopes tested (gp100:154–162, gp100:280–288, and tyrosinase:369–377) at any point during vaccinations. A functional T cell response was found in 62 patients (64%). Rates of peptide-recognition of gp100:154–162, gp100:280–288, and tyrosinase:369–377 were 40%, 29%, and 45%, respectively. Median recurrence-free survival and distant metastasis-free survival of the whole study population were 23.0 mo and 36.8 mo, respectively.

Conclusions: DC vaccination induces a functional TAA-specific T cell response in the majority of stage III melanoma patients, indicating it is more effective in stage III than in stage IV melanoma patients. Furthermore, performing multiple cycles of vaccinations enhances the chance of a broader immune response.