CSTL Castle Biosciences, Inc.
Price Chart
Executive Summary
Castle Biosciences announced publication of data from a large prospective study showing its DecisionDx-Melanoma i31-SLNB test accurately identifies melanoma patients with less than 5% risk of sentinel lymph node (SLN) positivity, enabling clinicians to safely forgo SLNB in low-risk cases. The study demonstrated a 2.6% observed SLN positivity rate in patients predicted to be low-risk and a 97.8% three-year recurrence-free survival rate, outperforming traditional staging and other gene expression tests.
Actionable Insight
Traders should monitor uptake of the DecisionDx-Melanoma test in clinical practice following this high-quality prospective validation. The data support expanded use, especially in early-stage melanoma, which could drive volume and reimbursement momentum. The upcoming webcast on March 23 may provide further commercial insights.
Key Facts
- Prospective, multicenter study of 912 patients with T1–T4 cutaneous melanoma across 30 U.S. centers
- Patients predicted by i31-SLNB to have <5% risk of SLN positivity had a 2.6% observed positivity rate
- Patients with >10% predicted risk had a 21.4% observed positivity rate (8.2x higher)
- In T1b–T2a tumors, SLN positivity was only 1.4% in those predicted <5% risk
- Low-risk patients had 97.8% three-year recurrence-free survival (RFS)
- i31-SLNB showed TN:FN ratio of 55:1 in T1–T2a and 73:1 in T1b–T2a, exceeding NCCN’s 19:1 benchmark
- Outperformed other GEP tests like CP-GEP, which reported lower TN:FN ratios (15:1)
Financial Impact
Potential revenue growth from increased test adoption due to strong clinical validation; no direct financial figures disclosed
Risk Factors
- Forward-looking statements about reduced procedures and cost savings are not guaranteed
- Adoption depends on payer reimbursement and physician behavior, not just clinical data
- Recent insider selling ($303K in 30 days) may indicate caution despite positive data
Market Snapshot
Documents Analyzed
This report is based on 1 press release from GlobeNewswire.
| Document | Accession Number |
|---|---|
| PRESS-RELEASE Data (Synthetic) | press-3255641 |
Filters
| Type | Now | ||||
|---|---|---|---|---|---|
|
Jun 11, 2026
3d ago
|
Institutional Cluster
| $20.89 awaiting T+1 | awaiting T+1 | — | $20.70 (+0.91%) |
|
Jun 1, 2026
13d ago
|
144
| $19.71 $20.39 | ▲ +3.45% | ▲ +4.17% | $20.70 (+5.02%) |
|
May 7, 2026
5w ago
|
144
| $19.83 $19.04 | ▼ −3.98% | ▼ −4.22% | $20.70 (+4.39%) |
|
Apr 8, 2026
9w ago
|
DEFA14A
| $25.19 $23.43 | ▼ −6.99% | ▼ −7.56% | $20.70 (−17.82%) |
|
Mar 13, 2026
13w ago
|
Press Release
| $25.56 $25.83 | ▲ +1.06% | ▲ +0.03% | $20.70 (−19.01%) |
|
Mar 12, 2026
13w ago
|
Insider Cluster
| $25.32 $25.56 | ▼ −0.95% | ▼ −1.55% | $20.70 (+18.25%) |
|
Mar 12, 2026
13w ago
|
Insider Cluster
| $25.32 $25.56 | ▼ −0.95% | ▼ −1.55% | $20.70 (+18.25%) |
|
Mar 9, 2026
13w ago
|
Press Release
| $27.02 $26.60 | ▼ −1.55% | ▼ −1.37% | $20.70 (−23.39%) |
|
Mar 5, 2026
14w ago
|
Insider Cluster
| $27.91 $27.12 | ▲ +2.83% | ▲ +1.52% | $20.70 (+25.83%) |
|
Mar 5, 2026
14w ago
|
Insider Cluster
| $27.91 $27.12 | ▲ +2.83% | ▲ +1.52% | $20.70 (+25.83%) |
US Market Status
Subscribe to SecBot
Get Real-Time SEC Filing Intelligence
Comprehensive SEC filing analysis delivered the moment filings hit EDGAR. Sentiment scoring, impact analysis, and actionable insights for every material event.
Try SecBot Free Coming soon: SecBot Pro with alerts, watchlists, and API access