Core Insights - Castle Biosciences, Inc. is presenting research at the 2025 ASCO Annual Meeting that highlights the effectiveness of the DecisionDx-Melanoma test in reducing mortality risk for melanoma patients by 32% compared to untested patients [1][2][3] Group 1: DecisionDx-Melanoma Test - The DecisionDx-Melanoma test is a 31-gene expression profile that provides independent risk stratification for cutaneous melanoma patients, demonstrating significant mortality risk predictions [2][4] - In a study involving over 13,500 patients, the DecisionDx-Melanoma test showed a Class 2B hazard ratio of 4.59 and a Class 1B/2A hazard ratio of 3.42, indicating its strong predictive capability for melanoma-specific mortality [2][3] - The test has been ordered more than 200,000 times for patients diagnosed with cutaneous melanoma, supporting its clinical value through over 50 peer-reviewed studies [4][6] Group 2: DecisionDx-UM Test - The DecisionDx-UM test is a 15-gene expression profile that predicts the risk of metastasis in uveal melanoma patients and is widely used in ocular oncology practices in the U.S. [5] - The test is recognized in AJCC staging and NCCN guidelines as a prognostic factor, with nearly 80% of uveal melanoma patients in the U.S. receiving it as part of their diagnostic workup [5][6] Group 3: Research and Development - Castle Biosciences is actively engaged in research and development for tests addressing high clinical needs, including a test for guiding systemic therapy selection for atopic dermatitis [7] - The company aims to transform disease management through innovative tests that prioritize patient care [6][7]

Company Overview - Castle Biosciences, Inc. is a diagnostics company focused on improving health through innovative tests that guide patient care [3] - The company aims to transform disease management by prioritizing patients, clinicians, employees, and investors [3] Upcoming Presentation - The executive management of Castle Biosciences is scheduled to present a company overview at the 2025 Jefferies Global Healthcare Conference on June 4, 2025, at 7:35 a.m. Eastern time [1] - A live audio webcast of the presentation will be available on the company's website, with a replay accessible after the live broadcast [2] Product Portfolio - Castle's current portfolio includes tests for skin cancers, Barrett's esophagus, and uveal melanoma [4] - The company is engaged in research and development for tests addressing high clinical needs, including a test for guiding systemic therapy selection for patients with moderate-to-severe atopic dermatitis seeking biologic treatment [4]

Core Insights - Castle Biosciences announced new data from the independent validation of the Collaborative Ocular Oncology Group Study No. 2 (COOG2.1), highlighting the importance of adding PRAME gene expression information to the DecisionDx-UM test for predicting metastatic risk in uveal melanoma patients [1][2] Group 1: Company Overview - Castle Biosciences, Inc. is a diagnostics company focused on innovative tests that guide patient care, with a mission to transform disease management by prioritizing patients, clinicians, employees, and investors [4] - The company's current portfolio includes tests for skin cancers, Barrett's esophagus, and uveal melanoma, with ongoing research for additional tests in high clinical need areas [5] Group 2: DecisionDx-UM Test - DecisionDx-UM is a 15-gene expression profile test that predicts the risk of metastasis in uveal melanoma patients, recognized as the standard of care in the majority of ocular oncology practices in the U.S. [3] - The test has been validated in prospective, multi-center studies and is considered a superior predictor of metastasis compared to other factors like chromosome 3 status and AJCC stage [3] - Approximately 80% of uveal melanoma patients in the U.S. undergo the DecisionDx-UM test as part of their diagnostic process [3] Group 3: Research Findings - The recent study presented at the ARVO 2025 Annual Meeting involved a cohort of 1,297 uveal melanoma patients, confirming the long-term performance of the DecisionDx-UM test and the clinical value of PRAME as an adjunct biomarker [2][5] - The findings indicate that combining PRAME status with DecisionDx-UM results can further refine risk stratification, providing clinicians with better insights for treatment decisions [5]

At just 26 years old, Leah Adams heard the words no one wants to hear: malignant melanoma. In this powerful and emotional story, Leah shares how a routine skin check —prompted by her mother's intuition—led to a life-altering diagnosis. As a runner and only child, Leah's journey through surgery, recovery, and her father's parallel battle with stage 4 metastatic melanoma sheds light on how deeply this disease can impact families. Watch as Leah explains how the DecisionDx® Melanoma test helped guide her next s ...

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]

Revenue Generation - Castle Biosciences primarily generates revenue from its DecisionDx-Melanoma and DecisionDx-SCC tests, with additional contributions from TissueCypher and DecisionDx-UM tests[111]. - The reimbursement rate for DecisionDx-Melanoma is set at $7,193 per test for 2024 and 2025, based on median private payor rates[125]. - DecisionDx-SCC has a list price of $8,500 per test, effective from April 1, 2024, through December 31, 2025[128]. - The rate for TissueCypher is set at $4,950 per test for 2025, based on median private payor rates[130]. - MyPath Melanoma has a reimbursement rate of $1,950 per test for 2024 and 2025[132]. - IDgenetix will be discontinued effective May 2025, with a reimbursement rate of $1,336 per test for 2024[137]. Market Opportunity - The estimated total addressable market (TAM) for invasive cutaneous melanoma (CM) is approximately $540 million, with around 130,000 patients diagnosed annually in the U.S.[114]. - For cutaneous squamous cell carcinoma (SCC), 20% of cases are classified as high-risk, representing an estimated TAM of approximately $820 million[115]. - TissueCypher has an estimated U.S. TAM of approximately $1 billion, aimed at predicting the progression of Barrett's esophagus[117]. Performance Metrics - The number of test reports delivered is a key performance indicator for assessing business performance[139]. - Test report volume increased by 16.8% in Q1 2025 compared to Q1 2024, with dermatologic tests up by 7.4%[140]. - TissueCypher test reports surged by 117% in Q1 2025 compared to the same period in 2024[140]. - Approximately 52% of clinicians ordering DecisionDx-SCC also ordered DecisionDx-Melanoma in Q1 2025[141]. - Total test reports delivered in 2024 reached 96,071, with 36,008 from DecisionDx-Melanoma and 16,348 from DecisionDx-SCC[140]. Financial Performance - Net revenues for the three months ended March 31, 2025, increased by $15.0 million, or 20.6%, to $87.988 million compared to the same period in 2024[166]. - Revenue from non-dermatologic tests increased by $11.4 million, primarily due to a 117% increase in test report volumes for the TissueCypher Barrett's Esophagus test[167]. - Revenue from dermatologic tests increased by $3.6 million, with net revenue from these tests rising from 18.7% to 28.4% of total net revenue[168]. - Total operating expenses increased by $37.471 million, or 47.8%, to $115.916 million, driven by higher amortization of acquired intangible assets and increased personnel costs[169]. - Gross margin percentage decreased to 49.2% for the three months ended March 31, 2025, down from 77.9% in the same period in 2024[171]. Expenses and Investments - The company expects significant increases in expenses due to clinical studies, commercialization strategies, and new product development[146]. - The company anticipates increased research and development expenses as it invests in new product development[154]. - Research and development expenses decreased by $1.2 million, or 8.8%, reflecting lower personnel costs and clinical study expenses[172]. - Selling, general and administrative expenses increased by $10.125 million, or 20.9%, primarily due to higher personnel costs and business development activities[174]. - Stock-based compensation expense totaled $11.2 million for the three months ended March 31, 2025, down from $12.7 million in the same period in 2024[181]. Cash Flow and Debt - As of March 31, 2025, the company had cash and cash equivalents of $89.7 million and marketable investment securities of $185.5 million[182]. - Net cash used in operating activities was $6.0 million for the three months ended March 31, 2025, primarily due to a net loss of $25.8 million[202]. - Net cash used in investing activities was $22.4 million for the three months ended March 31, 2025, mainly from purchases of marketable investment securities totaling $48.4 million[205]. - As of March 31, 2025, the company had long-term debt of $8.9 million, with total long-term debt net of current portion at $10.0 million[189]. - The company has a $25.0 million line of credit available until March 31, 2025, with no draws made as of March 31, 2025[197]. Future Outlook - The company expects to incur additional expenses in the future as it invests in the commercialization of existing products and the development of new product candidates[187]. - The company expects total capital expenditures for the development of its future corporate headquarters to be approximately $43.1 million, with $5.1 million spent as of March 31, 2025[186]. - The 2024 Loan and Security Agreement includes a $10.0 million term loan and a $25.0 million credit line, secured by substantially all assets excluding intellectual property[191]. - A hypothetical 10% change in interest rates would not have a material impact on the company's financial statements[212]. - The company lost Medicare coverage for its DecisionDx-SCC test in April 2025, which is expected to decrease revenues and cash inflows from this test[187]. Economic Factors - Macroeconomic conditions, including geopolitical conflicts and inflation, may materially impact the company's financial condition and operational performance[145]. - Federal NOL carryforwards as of December 31, 2024, totaled $129.4 million, with $52.9 million expiring in 2031 and $76.5 million available indefinitely[162].

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 ...