On November 5, 2026 Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through innovative tests that guide patient care, reported its financial results for the third quarter and nine months ended September 30, 2026.

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"Our team delivered another strong quarter, reflecting consistent execution across our portfolio," said Derek Maetzold, president and chief executive officer of Castle Biosciences. "TissueCypher was a key contributor to our top-line performance, delivering 47% year-over-year growth in test report volume compared to the third quarter of 2025. We generated $19.7 million in net cash provided by operating activities, reflecting our disciplined approach to expense management and operational efficiency while continuing to invest in strategic growth opportunities.

"DecisionDx-Melanoma continues to serve as the foundation of our dermatologic testing franchise, with 5% year-over-year growth in test report volume through the first nine months of 2026 compared to the same period in 2025. Alongside DecisionDx-Melanoma, AdvanceAD-Tx and DecisionDx-SCC broaden the clinical value of our dermatologic portfolio and position us to support our medium- and long-term growth opportunities, and combined, our dermatology commercial team delivered 15,168 test reports in the third quarter.

"Overall, our third-quarter results reflect the strength of our portfolio, consistent execution and continued progress toward our long-term growth objectives. I want to thank the entire Castle team for their dedication, hard work and unwavering commitment to improving patient care."

Third Quarter Ended Sep. 30, 2026, Financial and Operational Highlights
•Revenues were $102.9 million, compared to $83.0 million in the third quarter of 2025.

Core revenue drivers:
•Third quarter 2026 total test reports for our core revenue drivers (DecisionDx-Melanoma, TissueCypher) increased 22% over the third quarter of 2025:
◦DecisionDx-Melanoma test reports delivered in the quarter were 10,177, compared to 10,459 in the third quarter of 2025.
◦TissueCypher Barrett’s Esophagus test reports delivered in the quarter were 15,574, compared to 10,609 in the third quarter of 2025.

Additional tests:
◦DecisionDx-SCC test reports delivered in the quarter were 3,882, compared to 4,186 in the third quarter of 2025.
◦MyPath Melanoma test reports delivered in the quarter were 798, compared to 1,151 in the third quarter of 2025.

◦DecisionDx-UM test reports delivered in the quarter were 422, compared to 436 in the third quarter of 2025.
◦AdvanceAD-Tx test reports delivered in the quarter were 1,109. The test was not offered during the third quarter of 2025.
◦Esopredict test reports delivered in the quarter were 469. The test was not offered during the third quarter of 2025.

•Gross margin was 75%, and Adjusted Gross Margin was 77%, compared to 75% and 77%, respectively, for the same periods in 2025.
•Net loss, which includes non-cash stock-based compensation expense of $11.2 million, was $4.1 million, compared to net loss of $0.5 million for the same period in 2025.
•Net loss per share and Adjusted Net Loss per Share, Basic and Diluted, was $0.13, compared to net loss per share and Adjusted Net Loss per Share, Basic and Diluted, of $0.02, for the same period in 2025.
•Adjusted EBITDA was $12.7 million, compared to $9.2 million for the same period in 2025.
•Net cash provided by operations was $19.7 million, compared to net cash provided by operations of $22.6 million for the same period in 2025.

Nine Months Ended Sep. 30, 2026, Financial and Operational Highlights
•Revenues were $290.1 million, compared to $257.2 million for the nine months ended September 30, 2025. Affecting comparison to 2025 includes the change in DecisionDx-SCC Medicare coverage effective April 24, 2025, the re-focus of our commercial efforts, as well as the discontinuation of IDgenetix in May 2025.

Core revenue drivers:
•Nine months ended September 30, 2026, total test reports for our core revenue drivers (DecisionDx-Melanoma, TissueCypher) increased 29% over the nine months ended September 30, 2025.
◦DecisionDx-Melanoma test reports delivered in the nine months ended September 30, 2026, were 30,478, compared to 29,061 for the same period in 2025.
◦TissueCypher Barrett’s Esophagus test reports delivered in the nine months ended September 30, 2026, were 42,307, compared to 27,211 for the same period in 2025.
Additional tests:
◦DecisionDx-SCC test reports delivered in the nine months ended September 30, 2026, were 11,595, compared to 13,323 for the same period in 2025.
◦MyPath Melanoma test reports delivered in the nine months ended September 30, 2026, were 2,832, compared to 3,243 for the same period in 2025.
◦DecisionDx-UM test reports delivered in the nine months ended September 30, 2026, were 1,396, compared to 1,374 for the same period in 2025.
◦AdvanceAD-Tx test reports delivered in the nine months ended September 30, 2026, were 2,548. The test was not offered during the nine months ended September 30, 2025.
◦Esopredict test reports delivered in the nine months ended September 30, 2026, were 986. The test was not offered during the nine months ended September 30, 2025.

•Gross margin for the nine months ended September 30, 2026, was 74%, and Adjusted Gross Margin was 77%, compared to 67% and 80%, respectively, for the same period in 2025.

•Net loss, which includes non-cash stock-based compensation expense of $32.6 million, was $20.7 million, compared to net loss of $21.8 million for the same period in 2025.
•Net loss per share and Adjusted Net Loss per Share, Basic and Diluted, was $0.69, compared to net loss per share and Adjusted Net Loss per Share, Basic and Diluted, of $0.76 and $0.06, respectively, for the same period in 2025.
•Adjusted EBITDA was $20.0 million, compared to $32.5 million for the same period in 2025.
•Net cash provided by operations was $12.8 million, compared to $37.4 million net cash provided by operations for the same period in 2025.
Cash, Cash Equivalents and Marketable Investment Securities
As of Sep. 30, 2026, the Company’s cash, cash equivalents and marketable investment securities totaled $277.7 million.
2026 Outlook
Castle Biosciences is raising its guidance for anticipated total revenue in 2026. The Company now anticipates generating between $385-395 million in total revenue in 2026, compared to the previously provided guidance of between $365-375 million. Further, the Company maintains its expectation to achieve positive Adjusted EBITDA for the fourth quarter 2026, the full year 2026 and the full year 2027.

Third Quarter 2026 Highlights

Dermatology – Skin Cancer
•In September, the Company presented new data on DecisionDx-Melanoma from the largest, prospective multi-center study of gene expression profiling (GEP) in cutaneous melanoma to date, involving 2,799 patients across 29 U.S. centers. This study, presented at the European Academy of Dermatology and Venereology (EADV) Congress 2026, supports the use of DecisionDx-Melanoma in sentinel lymph node biopsy (SLNB) and risk of recurrence decision-making management. Among 676 patients with low-risk i31-SLNB results who underwent SLNB had an observed SLN positivity of 4.4%, and 565 SLNB-eligible patients with low-risk results who did not undergo SLNB had five-year recurrence-free survival (RFS) of 99.6%. These findings support identifying low-risk patients who may safely forgo SLNB. A separate analysis of 687 patients with transected melanomas showed that patients with early-stage disease (stage I–IIA) and high-risk Class 2B results had recurrence risk similar to stage IIB disease, supporting closer surveillance when staging is uncertain. See the Company’s news release from September 30, 2026, for more information.
•The Company announced the publication of a multi-center study in the Journal of the American Academy of Dermatology (JAAD) validating the integrated DecisionDx-SCC test result (i40-GEP) for patients with high-risk cutaneous squamous cell carcinoma (SCC). DecisionDx-SCC analyzes 40 genes to provide results related to prognosis and response to adjuvant radiation therapy (ART) based on an individual patient’s tumor biology. The enhanced algorithm integrates the molecular data with five clinicopathologic risk factors (immunosuppression, tumor diameter, histological differentiation, perineural invasion and anatomic site) using optimized nested predictive models. This integrated approach provides a comprehensive assessment of metastatic risk, local recurrence risk and likelihood of benefit from ART. The study published in JAAD showed that the test results can shift or stratify patients across clinically actionable risk thresholds, supporting risk-aligned decisions regarding patient follow-up, surveillance imaging, multidisciplinary referral and ART. See the Company’s news release from September 9, 2026, for more information.

Dermatology – Atopic Dermatitis
•The Company announced the publication of a new study highlighting the challenges patients with atopic dermatitis (AD) experience in achieving their treatment goals and

strong patient interest in molecular testing to help guide systemic therapy selection. The findings support the clinical need for molecular guidance in AD care. Castle’s AdvanceAD-Tx test is designed to address this need by helping personalize systemic therapy decisions based on an individual patient’s underlying disease biology. This new paper complements an earlier prospective, multicenter clinical validation study in the Journal of the American Academy of Dermatology that demonstrated the ability of AdvanceAD-Tx to identify differences in systemic therapy class response in patients with moderate-to-severe AD. See the Company’s news release from September 24, 2026, for more information.

Gastroenterology
•The Company announced the publication of a study showing that its TissueCypher Barrett’s Esophagus test helped guide risk-aligned management decisions for patients with non-dysplastic Barrett’s esophagus (NDBE). In the study, clinicians changed their management recommendations 90% of the time after receiving TissueCypher results, including escalating management for all patients with intermediate- or high-risk results and de-escalating management for 84% of those with low-risk results. See the Company’s news release from September 28, 2026, for more information.
•The Company announced the publication of a new decision modeling study showing that the TissueCypher Barrett’s Esophagus test can help better align Barrett’s esophagus (BE) management with a patient’s individual risk of progression to high-grade dysplasia (HGD) or esophageal adenocarcinoma (EAC). In the study, simulated use of TissueCypher significantly increased appropriate management aligned with known progression outcomes across patients with NDBE, indefinite for dysplasia (IND) and low-grade dysplasia (LGD). See the Company’s news release from September 15, 2026, for more information.
Pipeline Initiatives
•In September, SciBase, the Company’s collaboration partner developing the use of electrical impedance spectroscopy technology to predict relapses in atopic dermatitis announced that Castle placed an additional order for acceleration of the Company’s current, ongoing clinical study and preparations for a second clinical study under the collaboration. The order consisted of both the portable pen device and electrodes to a value of approximately $0.6 million. Deliveries began early in the fourth quarter 2026.

Corporate
•The Company announced the opening of its new laboratory and office facility in Scottsdale, Arizona. The 55,000-square-foot facility, located within the 260-acre Perimeter Center business park, expands Castle’s operational footprint in the Phoenix metropolitan area. This investment gives our teams additional space, infrastructure and capacity to support our work on behalf of patients and clinicians today as well as our anticipated growth in the future. See the Company’s news release from September 22, 2026, for more information.

Conference Call and Webcast Details
Castle Biosciences will hold a conference call on Thursday, November 5, 2026, at 4:30 p.m. Eastern time to discuss its third quarter 2026 results and provide a corporate update.

A live webcast of the conference call can be accessed here: View Source or via the webcast link on the Investor Relations page of the Company’s website, View Source Please access the webcast at least 10 minutes before the conference call start time. An archive of the webcast will be available on the Company’s website until November 26, 2026.
There will be a brief Question & Answer session following management commentary.

(Press release, Castle Biosciences, NOV 5, 2026, View Source [SID1234674301])