Empowering people, informing care decisions First Quarter 2025 May 5, 2025 ©2025 Castle Biosciences 1 Disclaimers Forward-Looking Statements This presentation contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended, which are subject to the "safe harbor" created by those sections. These forward-looking statements include, but are not limited to, statements concerning: our positioning f ...

Castle Biosciences, Inc. (CSTL) came out with a quarterly loss of $0.20 per share versus the Zacks Consensus Estimate of a loss of $0.08. This compares to loss of $0.09 per share a year ago. These figures are adjusted for non-recurring items.This quarterly report represents an earnings surprise of -150%. A quarter ago, it was expected that this company would post earnings of $0.11 per share when it actually produced earnings of $0.32, delivering a surprise of 190.91%.Over the last four quarters, the company ...

Financial Data and Key Metrics Changes - Revenue grew by 21% to $88 million in Q1 2025 compared to Q1 2024, driven by strong test volume growth [7][25] - Adjusted revenue was $87.2 million, reflecting a 22% increase year-over-year [25] - Gross margin for Q1 2025 was 49.2%, down from 77.9% in Q1 2024, primarily due to a one-time amortization expense of approximately $20.1 million [25][26] - Adjusted gross margin was 81.2%, compared to 80.5% in the same period in 2024 [26] - Net loss for Q1 2025 was $25.8 million, compared to $2.5 million in Q1 2024 [30] - Adjusted EBITDA for Q1 was $13 million, up from $10.5 million in Q1 2024 [31] Business Line Data and Key Metrics Changes - DecisionDx Melanoma test reports increased by 3% to 8,621 in Q1 2025 compared to Q1 2024 [12] - DecisionDx SCC test reports delivered were 4,375 in Q1 2025, with ongoing studies supporting its clinical utility [16][18] - TissueCypher test reports grew by 117% year-over-year, with 7,432 reports delivered in Q1 2025 [21] Market Data and Key Metrics Changes - The company raised its total revenue guidance for 2025 to between $287 million and $297 million, up from a previous range of $280 million to $295 million [26] - The company anticipates high single-digit volume growth for DecisionDx Melanoma for the full year 2025 compared to 2024 [12] Company Strategy and Development Direction - The company signed an agreement to acquire ProVise, enhancing its position in the gastrointestinal space [7][23] - The acquisition aims to expand offerings within the GI vertical and address unmet clinical needs [23] - The company plans to discontinue the iGenx test effective May 2025 to focus resources on more profitable growth areas [24] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in maintaining financial discipline while executing growth initiatives [7] - The company expects to deliver positive net cash flow from operations for the full year of 2025 [31] - Management highlighted the importance of the DecisionDx tests in improving patient outcomes and reducing unnecessary healthcare costs [80] Other Important Information - The company is pursuing reconsideration requests for DecisionDx SCC reimbursement following a local coverage determination [18] - The company continues to assess opportunities for strategic acquisitions that align with its growth criteria [23] Q&A Session Summary Question: Clarification on gross margin guidance - The mid-seventy percent gross margin guidance is adjusted and includes the impact of DecisionDx SCC reimbursement [35][36] Question: Details on ProVise's technology - ProVise offers a tissue-based methylation technology and a non-endoscopic sponge-based technology, with expectations for future integration [37][38] Question: Impact of ID Genetics discontinuation - The discontinuation will have a modest impact on revenue but will positively benefit EBITDA performance [46][47] Question: Volume growth expectations for DecisionDx tests - High single-digit volume growth is expected for DecisionDx Melanoma, with consistent growth anticipated for TissueCypher [49][50] Question: Sales force distribution and hiring expectations - The company currently has around 65 sales territories and is assessing the need for further expansion based on market response [51][52] Question: Timing of reconsideration requests - Timing for the reconsideration requests is uncertain, and management will provide updates as more information becomes available [57][58] Question: Acquisition details and revenue impact - The acquisition of ProVise was cash-based, and its revenue contribution is not material to Castle [83][84]

Financial Data and Key Metrics Changes - Revenue grew by 21% to $88 million in Q1 2025 compared to Q1 2024, driven by a 33% increase in total test report volume for core revenue drivers [6][23] - Adjusted revenue was $87.2 million for Q1 2025, reflecting a 22% increase year-over-year [23] - Gross margin for Q1 2025 was 49.2%, down from 77.9% in Q1 2024, primarily due to a one-time amortization expense of approximately $20.1 million [24][25] - Adjusted gross margin was 81.2% for Q1 2025, compared to 80.5% in the same period in 2024 [24] - Net loss for Q1 2025 was $25.8 million, compared to $2.5 million in Q1 2024, with adjusted net loss per share at $0.20 [28][29] Business Line Data and Key Metrics Changes - DecisionDx Melanoma test reports increased by 3% to 8,621 in Q1 2025, with expectations of high single-digit volume growth for the full year [11][12] - DecisionDx SCC test reports totaled 4,375 in Q1 2025, with ongoing efforts to enhance risk stratification [15] - TissueCypher test reports grew by 117% year-over-year, reaching 7,432 in Q1 2025 [19][20] Market Data and Key Metrics Changes - The company raised its total revenue guidance for 2025 to a range of $287 million to $297 million, up from the previous range of $280 million to $295 million [24] - The gross margin for the remaining quarters of 2025 is expected to be in the mid-70s range [25] Company Strategy and Development Direction - The company signed an agreement to acquire ProVise, enhancing its position in the gastrointestinal space and expanding its offerings [6][21] - The focus remains on driving both near and long-term stockholder value through strategic growth initiatives [31] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in maintaining financial discipline while executing growth initiatives, supported by a strong balance sheet with $275 million in cash and equivalents [6] - The company anticipates continued adoption of its tests, bolstered by recent publications validating their clinical utility [12][14] Other Important Information - The company plans to discontinue the iGenx test effective May 2025 to reallocate resources to other areas with unmet clinical needs [22] - The reimbursement landscape for DecisionDx SCC is under review, with ongoing reconsideration requests submitted [17][53] Q&A Session Summary Question: Clarification on gross margin guidance - The mid-seventy percent gross margin guidance is adjusted and includes the impact of DecisionDx SCC reimbursement [32] Question: Details on ProVise's technology - ProVise offers tissue-based methylation technology and a non-endoscopic sponge-based technology, with expected downstream impacts on revenue [33][38] Question: Competition between EsoPredict and TissueCypher - EsoPredict is a methylation-based assay for Barrett's Esophagus, similar to TissueCypher, but the latter has a more robust dataset [41] Question: Discontinuation of ID Genetics and reinvestment plans - The discontinuation will have a modest impact on revenue but is expected to positively benefit EBITDA [42][44] Question: Volume growth expectations for DecisionDx Melanoma - High single-digit volume growth is expected for DecisionDx Melanoma, with continued improvement in average selling price [46][47] Question: Sales force distribution and hiring expectations - The company currently has around 65 sales territories and is assessing the need for further expansion based on market response [48] Question: Update on Medicare reimbursement for DecisionDx SCC - The timing for the reconsideration request is uncertain, and the company will provide updates as more information becomes available [53][75]

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _________ to _________ Commission File Number: 001-38984 CASTLE BIOSCIENCES, INC. (Exact name of registrant as specified in its charter) (St ...

Exhibit 99.1 Castle Biosciences Reports First Quarter 2025 Results Q1 2025 revenue increased 21% over Q1 2024 to $88 million ® ® Q1 2025 total test reports for our core revenue drivers (DecisionDx -Melanoma, DecisionDx -SCC, TissueCypher ) increased 33% over Q1 2024 ® Raising full-year 2025 revenue guidance to $287-297 million from $280-295 million Conference call and webcast today at 4:30 p.m. ET FRIENDSWOOD, Texas - May 5, 2025--Castle Biosciences, Inc. (Nasdaq: CSTL), a company improving health through i ...

Core Insights - Castle Biosciences, Inc. reported a 21% increase in Q1 2025 revenue to $88 million compared to Q1 2024 [1] - The company raised its full-year 2025 revenue guidance to $287-297 million from the previous range of $280-295 million [1][6] - The total test reports for core revenue drivers increased by 33% over Q1 2024 [1] Financial Performance - Revenues for Q1 2025 were $88 million, up from $73 million in Q1 2024, representing a 21% increase [4] - Adjusted revenues, excluding prior period adjustments, were $87.2 million, a 22% increase from $71.3 million in the same period last year [4] - The gross margin was 49%, while the adjusted gross margin remained at 81% [4] - The net loss for Q1 2025 was $25.8 million, compared to a net loss of $2.5 million in Q1 2024 [4][8] Operational Highlights - The company delivered 24,402 total test reports in Q1 2025, a 17% increase from 20,888 in Q1 2024 [4] - DecisionDx-Melanoma surpassed 200,000 test orders since its launch, indicating strong demand and clinical value [3][9] - The company decided to discontinue the IDgenetix test offering effective May 2025 [4][12] Cash Position - As of March 31, 2025, the company's cash, cash equivalents, and marketable investment securities totaled $275.2 million [5] Future Outlook - The company anticipates total revenue in 2025 to be between $287-297 million, reflecting confidence in continued growth [6] - Castle Biosciences is focused on expanding its proprietary test portfolio and enhancing patient outcomes [4][22]

Core Insights - Castle Biosciences has signed a definitive agreement to acquire Capsulomics, Inc., also known as Previse, which focuses on gastrointestinal health, particularly chronic acid reflux diseases and esophageal cancer [2][3] - The acquisition aims to enhance Castle's existing gastroenterology franchise by integrating Previse's methylation technology and other developmental technologies, thereby expanding its testing options [3][4] - The transaction is expected to close in the coming weeks, pending customary closing conditions [3] Company Overview - Castle Biosciences is a diagnostics company listed on Nasdaq (CSTL) that develops innovative tests to guide patient care and improve health outcomes [5] - The company's current portfolio includes tests for skin cancers, Barrett's esophagus, mental health conditions, and uveal melanoma, with ongoing research in other high clinical need areas [6] Previse Overview - Previse, established in 2018, specializes in gastrointestinal health and aims to improve patient outcomes through early detection and prevention of diseases like esophageal cancer [4] - The company utilizes advanced biomarker technology developed at Johns Hopkins University, which is exclusively licensed to Previse, to support its mission [4]

Core Insights - Castle Biosciences, Inc. is presenting new data on its TissueCypher Barrett's Esophagus test at the Digestive Disease Week® (DDW 2025) Annual Meeting, emphasizing its role in improving risk stratification and management of Barrett's esophagus patients [1][2][9] Company Overview - Castle Biosciences is a diagnostics company focused on innovative tests that guide patient care, with a portfolio that includes tests for skin cancers, Barrett's esophagus, and mental health conditions [10][11] - The TissueCypher Barrett's Esophagus test is designed to predict the future development of high-grade dysplasia and/or esophageal cancer in patients with Barrett's esophagus [9] Event Highlights - The company will showcase two posters at DDW 2025, including findings on the detection of missed neoplasia and risk stratification for Barrett's esophagus patients [3][2] - A product theater titled "The Time is Now: A Clinical Practice Model to Help Prevent Progression from Barrett's to EAC" will be hosted by an expert physician panel [1][6] Educational Collaborations - Castle is collaborating with the American Society for Gastrointestinal Endoscopy (ASGE) and other GI experts to conduct educational sessions on the use of TissueCypher [1][2]

Core Insights - Castle Biosciences, Inc. announced that its DecisionDx-Melanoma test significantly outperforms traditional methods in identifying low-risk melanoma patients who may avoid sentinel lymph node biopsy (SLNB) surgery, with a sentinel lymph node positivity rate of 2.8%, well below the NCCN's 5% threshold [1][2][3] Company Overview - Castle Biosciences is a diagnostics company focused on innovative tests that enhance patient care, with a portfolio that includes tests for skin cancers and other conditions [6][8] - The DecisionDx-Melanoma test has been ordered over 200,000 times for patients diagnosed with cutaneous melanoma, demonstrating its widespread adoption and clinical relevance [5] Study Findings - The study published in Cancer Diagnosis & Prognosis indicates that DecisionDx-Melanoma provides better risk stratification compared to the American Joint Committee on Cancer (AJCC) staging and the CP-GEP test, confirming its clinical utility [2][3] - Patients identified as low risk by CP-GEP had a sentinel lymph node positivity rate of 6.2%, while those identified by DecisionDx-Melanoma had a significantly lower rate of 2.8%, highlighting the latter's superior accuracy [3] Clinical Implications - The findings support the use of DecisionDx-Melanoma in clinical decision-making, allowing clinicians to confidently recommend forgoing SLNB for patients with low-risk results, thereby improving patient outcomes and reducing unnecessary procedures [4][5] - The test integrates tumor biology with clinical factors, providing personalized risk assessments for sentinel lymph node positivity and melanoma recurrence [5]