Jun 06, 2019

Analysis of Newly Expanded Cumulative Cohort Demonstrates that DecisionDx-Melanoma Improves Risk Prediction for Patients with Cutaneous Melanoma

Poster presentation at 2019 Fall Clinical Dermatology Conference for PAs & NPs

Friendswood, TX – June 6, 2019 – Castle Biosciences, Inc., a skin cancer diagnostics company providing personalized genomic information to improve cancer treatment decisions, today announced the presentation of newly expanded performance results for DecisionDx®-Melanoma at the 2019 Fall Clinical Dermatology Conference for PAs & NPs held in Scottsdale, Arizona. The poster, titled “The prognostic 31-gene expression profile (31-GEP) test improves risk prediction in cutaneous melanoma (CM) patients within current AJCC stages,” demonstrated the utility of DecisionDx-Melanoma in identifying risk for patients with cutaneous melanoma beyond traditional staging.

Using a newly expanded performance cohort of 901 archival cutaneous melanoma samples (211 of which were not previously reported) from 22 centers, the analysis was designed to examine whether incorporating the DecisionDx-Melanoma test result in treatment decisions improves upon traditional melanoma staging methods. Patients assessed in the expanded cohort had a median age of 60 years and a median Breslow thickness of 1.4 mm. Forty-four percent of melanomas were American Joint Committee on Cancer (AJCC) Stage I, 24% were Stage II and 32% were Stage III.

Key Study Findings

  • DecisionDx-Melanoma was a significant and independent predictor of recurrence-free survival, distant metastasis-free survival and melanoma-specific survival (MSS) in the cumulative cohort of 901 cutaneous melanoma patients.
  • Within each AJCC stage, DecisionDx-Melanoma further stratified risk of melanoma-specific mortality. Using AJCC staging alone, patients with Stage I melanoma have an estimated 5-year MSS rate of 98%. Within that group, those with a Class 1A (lowest risk) DecisionDx-Melanoma test result had an estimated 5-year MSS rate of 99.7%, a risk equivalent to AJCC Stage IA. Stage I, Class 2B (highest risk) patients had a 92.8% 5-year MSS rate, lower than patients with Stage IIIA disease.
  • Patients with Stage II cutaneous melanoma have an estimated 5-year MSS rate of 90% using AJCC staging alone. Stage II patients who had a Class 1A DecisionDx-Melanoma test result had a 5-year MSS rate of 97%, equivalent to Stage IB. The MSS rate for Stage II patients with a Class 2B test result was 87.4%, aligned with risk estimates for AJCC Stage IIB.

“Accurate risk assessment in cutaneous melanoma is important because most treatment decisions are based on the patient’s expected risk of metastasis or recurrence,” commented study co-author Darrell S. Rigel, M.D., M.S., Clinical Professor at New York University School of Medicine. “These results show that DecisionDx-Melanoma provided a more comprehensive assessment of patient risk compared to AJCC staging alone, supporting its utility in developing individualized patient management plans.”

The poster can be found in the Publications section of the Castle Biosciences website.

About DecisionDx-Melanoma

DecisionDx-Melanoma is a gene expression profile test that uses an individual patient’s tumor biology to predict individual risk of cutaneous melanoma metastasis or recurrence, as well as sentinel lymph node positivity, independent of traditional staging factors, and has been studied in more than 3,100 patient samples. Using tissue from the primary melanoma, the test measures the expression of 31 genes. The test has been validated in four archival risk of recurrence studies of 901 patients and five prospective risk of recurrence studies including more than 780 patients. Prediction of the likelihood of sentinel lymph node positivity has also been validated in two prospective multicenter study cohorts that included more than 1,400 patients. Impact on patient management plans for one of every two patients tested has been demonstrated in four multicenter and single-center studies including more than 560 patients. The consistent performance and accuracy demonstrated in these studies provides confidence in disease management plans that incorporate DecisionDx-Melanoma test results.

More information about the test and disease can be found at www.SkinMelanoma.com.

About Castle Biosciences
Castle Biosciences is a skin cancer diagnostics company dedicated to helping patients and their physicians make more informed decisions about treatment and follow-up care based on the individual molecular signature of the patient’s tumor. The Company currently offers tests for patients with cutaneous melanoma (DecisionDx®-Melanoma, DecisionDx®-CMSeq; www.SkinMelanoma.com) and uveal melanoma (DecisionDx®-UM, DecisionDx®-PRAME and DecisionDx®-UMSeq; www.MyUvealMelanoma.com), with products in development for other underserved cancers, the most advanced of which is focused on patients with cutaneous squamous cell carcinoma. Castle Biosciences is based in Friendswood, Texas (Houston), and has laboratory operations in Phoenix, Arizona. More information can be found at www.CastleBiosciences.com.

DecisionDx-Melanoma, DecisionDx-CMSeq, DecisionDx-UM, DecisionDx-PRAME and DecisionDx-UMSeq are the trademarks of Castle Biosciences, Inc. Any other trademarks are the property of their respective owners.



Derek Maetzold, President and CEO