SDPA Presents 20th Annual Fall Dermatology Conference–Abstracts and Posters
November 16-20, 2022, Miami, FL
5. Improving Patient Selection for Adjuvant Therapy: Considerations for the Role of the 31-gene Expression Profile
Kelli Ahmed, PhD1, Christine N. Bailey, MPH1, Brian Martin PhD1, Sarah J. Kurley, PhD1, Matthew S. Goldberg, MD1,2, Valentina I. Petkov, MD, MPH3, Kyle R. Covington, PhD1
1Castle Biosciences, Inc. Friendswood, TX, 2Icahn School of Medicine at Mount Sinai, New York, NY, 3National Cancer Institute, Surveillance Research Program, Bethesda, MD
Cutaneous melanoma guidelines suggest patients with stage I-IIA are low risk and stage IIB-III high risk for recurrence and death. Pembrolizumab was approved in late 2021 for stage IIB-IIC disease; however, a minimal survival difference at 12 months relative to placebo and an associated high adverse event (AE) rate (7%RFS benefit vs. 12% higher adverse events) suggests refinement in patient selection for therapy is needed. Identifying stage IIB-IIC patients who have high survival rates without adjuvant therapy can improve the benefit-risk ratio of adjuvant therapy. The 31-gene expression profile (31-GEP) test stratifies patients into low (Class 1A), intermediate (Class 1B/2A), and high (Class 2B) risk of recurrence, metastasis, and death. Patient data provided through collaboration with the National Cancer Institute’s Surveillance, Epidemiology, and End Results program (diagnosis 2016-2018) was linked to data for patients tested with the 31-GEP (stage I-III: n=4,687). Kaplan-Meier analysis with log-rank test was used to analyze melanoma-specific survival (MSS). In patients with stage I-IIA (n=4,038), those with a Class 1A result had higher 3-year MSS than those with a Class 1B/2A or Class 2B result (99.8% vs. 97.5% vs. 94.8%, p<0.001). Similar results were seen for patients with stage IIB-IIC (n=376; Class 1A: 100% vs. Class 1B/2A: 100% vs. Class 2B: 88.3%, p=0.04) and stage III (n=273; Class 1A: 96.1% vs. Class 1B/2A: 90.9% vs. Class 2B: 79.6%, p=0.03). Using the 31-GEP test to improve risk-stratification with traditional staging allows physicians and patients to make risk-aligned management decisions, particularly by identifying low-risk patients with good survival profiles who may consider avoidance of the AE risks from therapy, and high-risk patients with higher likelihood of developing metastasis who may consider additional intervention.