Castle Biosciences disclosed new clinical data on November 14 2025 that was presented at the 2nd European Congress on Dermato‑Oncology in Paris on November 17‑18. The data come from two oral presentations and demonstrate that the company’s 31‑gene expression profile can identify patients with a predicted sentinel lymph node (SLN) positivity risk below 5% with an actual positivity rate of 2.6%, and that the test can flag high‑risk patients even when SLN status is negative.
The first study was a prospective, multicenter analysis of 1,200 melanoma patients. Patients whose i31‑SLNB algorithm predicted a <5% risk of SLN positivity had a 2.6% actual positivity rate, compared with 12% in the higher‑risk cohort. The second study, an independent predictor analysis, showed that the test identified 30% of patients who would experience recurrence within five years despite a negative SLN, underscoring its value beyond traditional staging.
By accurately stratifying patients, DecisionDx‑Melanoma can reduce unnecessary SLN biopsies, which are performed in roughly 88% of cases but yield a positive node in only about 12% of patients. Avoiding these procedures can lower surgical costs and complications, while still ensuring that high‑risk patients receive appropriate adjuvant therapy.
Castle’s management highlighted the commercial implications of the data. CEO Derek Maetzold noted that the company has surpassed 10,000 test reports for DecisionDx‑Melanoma in a single quarter, a milestone that reflects growing adoption. The new evidence supports the company’s guidance that full‑year 2025 revenue will be $327–$335 million, up from the prior $320–$330 million range, driven by increased test volume and higher reimbursement rates.
The data also reinforce Castle’s competitive positioning against other risk‑assessment tools such as the Melanoma Institute Australia nomogram. By providing a molecular signature that correlates with both SLN status and recurrence risk, DecisionDx‑Melanoma offers clinicians a more comprehensive decision aid, potentially expanding its market share in the precision‑diagnostics space.
Analysts have noted that the continued release of robust clinical data is a key driver of investor confidence, and Castle’s recent earnings have shown a 51% revenue increase year‑over‑year in 2024, with gross margins at 75% in Q3 2025. The company’s focus on cost control and strategic investments in high‑margin segments underpins its ability to maintain profitability while scaling test volume.
The content on BeyondSPX is for informational purposes only and should not be construed as financial or investment advice. We are not financial advisors. Consult with a qualified professional before making any investment decisions. Any actions you take based on information from this site are solely at your own risk.