Gastman, Brian

Neoadjuvant immune checkpoint inhibition (Neo-ICI) in melanoma is an emerging therapeutic strategy that induces pathologic responses with significant prognostic implications for survival. Tumor burden in nonresectable melanoma has a major impact on immunotherapy efficacy, yet little is known on its impact in the Neo-ICI setting. We evaluated the association between tumor burden, measured by the sum of diameters (SoD), and pathological response in melanoma patients treated with Neo-ICI. A meta-analysis of published trials in resectable stage III/IV melanoma was conducted, extracting data on patient characteristics, treatment regimens, pathological response, and survival outcomes. A total of 451 patients were included in the meta-analysis. The pooled pathological complete response (pCR) rate was 47% (95% confidence interval: 35–58%; P < 0.001). Meta-regression demonstrated a significant association between SoD and pCR (moderator = −0.36; P = 0.032), with greater tumor burden associated with lower pCR rates. No significant association was observed between SoD and recurrence-free survival (RFS). This study identifies higher tumor burden as a potential risk factor for lower pathologic response rates to neoadjuvant therapy, underscoring the need to incorporate tumor burden into future clinical research and potentially clinical decision-making.

9557 Background: Lymphaticovenous anastomosis (LVA) is a physiologic surgery indicated for secondary lymphedema of the extremities, particularly for disease refractory to conservative management. Immediate lymphatic reconstruction (ILR) is prophylactic LVA concurrently performed with CLND. After the transected lymphatics are mapped through a dye injection, they are anastomosed to a nearby venous outflow tract. Though prophylactic LVA is increasingly being performed, its risk on cancer recurrence and distant metastasis is currently unknown. The purpose of this study was to compare the distant-metastasis free survival (DMFS) and relapse-free survival (RFS) times in melanoma patients who underwent prophylactic LVA during CLND versus those who underwent conventional CLND for grossly metastatic disease. Our study is the first prospective evaluation of the impact of prophylactic LVA on DMFS in patients undergoing CLND. Methods: This was a prospective study of patients with cutaneous melanoma who underwent CLND with concurrent LVA (LVA group) or CLND alone (comparison group) between 2012 and 2021. Patients were excluded if they had non-melanoma skin cancers, stage IV cancers before CLND, microscopic lymphatic disease only or follow-up time of less than 12 months who did not die from melanoma-related causes. The comparison group consisted of all consecutive patients that underwent CLND alone and met inclusion criteria. To reduce surgical technique variability, all cases were performed by a single, high-volume surgeon at a tertiary care center. Results: A total of 46 melanoma patients underwent prophylactic LVA during this time period. Twenty-three of these patients met all inclusion criteria and were included in the LVA group. Twenty-two consecutive patients that underwent CLND alone were included in the comparison group. All patients underwent either axillary or inguinal CLND. Average number of lymph nodes removed during CLND were 18.20 ± 9.61 and 17.04 ± 9.97 for the LVA and comparison groups, respectively (p = 0.69). Size of largest metastatic tumor in lymph nodes was 45.91 ± 35.03 mm and 44.54 ± 23.32 mm, respectively (p = 0.99). Average time to first recurrence diagnoses was 6.75 ± 3.54 months vs 8.28 ± 5.66 months. For distant metastases only, the average time to first recurrence diagnoses was 6.16 ± 3.79 months and 9.39 ± 6.19 months, respectively (p = 0.25). There was no significant difference in recurrence type between the two groups (p = 0.66). There were no differences in DMFS and RFS times between the LVA and comparison groups. Conclusions: Prophylactic LVA performed for grossly metastatic melanoma does not negatively impact DMFS nor RFS. Considering the extremely aggressive nature of melanoma, our finding is potentially applicable to other cancers that are amenable to CLND and LVA.

Over the past few years, the NCCN Guidelines for Melanoma: Cutaneous have been expanded to include pathways for treatment of microscopic satellitosis (added in v2.2020), and the following Principles sections: Molecular Testing (added in v2.2019), Systemic Therapy Considerations (added in v2.2020), and Brain Metastases Management (added in v3.2020). The v1.2021 update included additional modifications of these sections and notable revisions to Principles of: Pathology, Surgical Margins for Wide Excision of Primary Melanoma, Sentinel Lymph Node Biopsy, Completion/Therapeutic Lymph Node Dissection, and Radiation Therapy. These NCCN Guidelines Insights discuss the important changes to pathology and surgery recommendations, as well as additions to systemic therapy options for patients with advanced disease.

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.

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Cutaneous melanoma have been significantly revised over the past few years in response to emerging data on immune checkpoint inhibitor therapies and BRAF-targeted therapy. This article summarizes the data and rationale supporting extensive changes to the recommendations for systemic therapy as adjuvant treatment of resected disease and as treatment of unresectable or distant metastatic disease.