Castle Biosciences, Inc. Q1 FY2026 earnings call

• CASEL delivered revenue of $83.7 million in Q1 2026, with test report volumes for core revenue drivers growing 36% year-over-year. Excluding certain revenues, Q1 2026 revenue growth was approximately 42% year-over-year. • Raised the 2026 revenue outlook to $345 million to $355 million from the previous $340 million to $350 million. • Presented new data at the 2026 American Academy of Dermatology Annual Meeting for DecisionDx melanoma showing it can significantly improve risk prediction within American Joint Committee on Cancer or AJCC stages for patients with cutaneous melanoma. • Two studies at the Digestive Disease Week by researchers at the Mayo Clinic demonstrated how molecular risk stratification with the tissue cipher test refined risk assessment and informed real-world management decisions for patients with Barrett's esophagus. • Advanced ADTX received approximately 650 orders in the first quarter under a limited-access program, with clinicians appreciating its integration into the atopic dermatitis care pathway. • Discussed M&A as part of the growth strategy, intending to evaluate candidates that fit within the strategic opportunities criteria

Core revenue drivers: DecisionDx Melanoma delivered 10,021 test reports in Q1 2026, representing 16% year-over-year growth, with March 2026 being an all-time high month for test reports. Gastroenterology franchise: Delivered 11,745 tissue cipher test reports in Q1 2026, a 58% increase from Q1 2025, and March 2026 was an all-time record month for tissue cipher. Advanced ADTX: Received approximately 650 orders in the first quarter under a limited-access program

• Raised the 2026 revenue outlook to $345 million to $355 million from $340 million to $350 million. • Anticipates mid to high single-digit volume growth for DecisionDx melanoma in 2026. • Expects to add a similar number of tests in 2026 as in 2025 for tissue cipher, indicating year-over-year growth approaching 50%. • Likely to provide more detail on reimbursement for the Advanced ADTX test by the end of the third quarter of 2026. • Moving forward with an FDA submission for the DecisionDx melanoma test in 2026

• Forward-looking statements involve inherent risks and uncertainties, and actual results may differ materially from those contemplated. • Factors and risks detailed in recent SEC filings could cause actual results to differ significantly from forward-looking statements. • Seasonality in test report volumes may impact performance. • Reimbursement challenges for the Advanced ADTX test could affect revenue. • Uncertainties exist in evaluating and acquiring suitable M&A candidates

Q: On the modest quarter-over-quarter decline in tissue cipher volumes, are there any unique dynamics?

A: Historically, the first quarter of the year has fewer GI procedures, but March and April were record months for tissue cipher, and they expect to add a similar number of tests in 2026 as in 2025.

Q: Update on the reimbursement progress for the Advanced ADTX test?

A: Likely to provide clarity on reimbursement by the end of the third quarter of 2026, with other avenues like partnerships possible.

Q: What is the impact of relocating the Phoenix lab on gross margins?

A: No significant impact on gross margins is expected as the move is towards staying ahead of demand in terms of capacity.

Q: Will the initial rollout of the Advanced ADTX be broadened?

A: Will look at volume and revenue cycle management assumptions and continue to release it over time.

Q: What are the factors considered in evaluating M&A candidates?

A: Look at candidates fitting the strategic opportunities criteria, not compelled to chase anything, and the Goldilocks approach is used in evaluation.

Q: Update on FDA submission for DecisionDx melanoma?

A: Moving forward with the submission in 2026.

Q: Timing of SEC reconsideration requests?

A: No official update, but expect the review cycle to be sufficient.

Q: Trends and impact on the cost of goods sold for the Advanced ADTX?

A: The ADTX test is efficient, and growth in volumes won't materially impact the company's blended adjusted cost of goods sold structure in the near term.

Q: Expense cadence and cash flow positivity?

A: Focus on growth, expect some growth in operating expenses, and intent is to leverage the cost structure to drive value.

Q: Revenue beat and tissue cipher details?

A: Most of the revenue beat was driven by the tissue cipher, and they expect to add a similar number of tests in 2026 as in 2025 with seasonality