Castle Bio (CSTL) Q3 2026 Earnings Call Transcript

DATE

Nov. 5, 2026

CALL PARTICIPANTS

• Founder, President and Chief Executive Officer - Derek Maetzold
• Chief Financial Officer - Frank Stokes
• Vice President, Investor Relations and Corporate Affairs - Camilla Zuckero

TAKEAWAYS

• Total Revenue -- $102.9 million, representing 24% growth driven primarily by TissueCypher test report volume.
• Full-Year Revenue Guidance -- $385 million to $395 million, increased from the previous range of $365 million to $375 million due to strength in TissueCypher volumes and improved average selling prices.
• TissueCypher Volume -- 15,574 test reports, a 47% increase reflecting continued commercial momentum and increased utilization among the existing clinician base.
• DecisionDx-Melanoma Volume -- 10,177 test reports, maintaining a consistent base as the fifth consecutive quarter exceeding 10,000 reports.
• Adjusted EBITDA -- $12.7 million, an increase from $9.2 million in the prior year period.
• Net Cash Provided by Operating Activities -- $19.7 million, reflecting disciplined expense management and operational efficiency.
• Cash and Marketable Securities -- $278 million, providing financial flexibility to invest in growth priorities.
• TissueCypher Growth Guidance -- 50% to 52%, with management reiterating expectations for full-year 2026 volume growth.
• AdvanceAD-Tx Volume -- 1,109 test reports, supporting the clinical need for molecular guidance in atopic dermatitis care.
• DecisionDx-SCC Volume -- 3,882 test reports, showing durability despite a lack of recent marketing support and current Medicare coverage status.
• Adjusted Gross Margin -- 77%, remaining consistent with the prior year period due to lab efficiencies and improved technology.
• Sales and Marketing Expense -- $37.7 million, up from $32.8 million primarily due to higher personnel costs and travel expenses.
• General and Administrative Expense -- $26.1 million, driven by higher information technology costs and personnel expansions.
• Research and Development Expense -- $15.8 million, increased from $13 million to support pipeline initiatives and ongoing research activities.
• Cost of Sales -- $23.9 million, reflecting higher test volumes and increased investment in lab supplies and services.
• Net Loss -- $4.1 million, or $0.13 per share, including $11.2 million in noncash stock-based compensation expense.
• Esopredict Volume -- 469 test reports, utilized as an alternative clinical answer when TissueCypher cannot be performed due to inadequate tissue.
• MyPath Melanoma Volume -- 798 test reports, contributing to the broader dermatologic testing franchise.
• DecisionDx-UM Volume -- 422 test reports, providing prognostic testing for uveal melanoma patients.
• Market Penetration -- 15% for TissueCypher, based on a run rate of eligible surveillance endoscopy procedures.

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RISKS

• Stokes stated, "the treatment of the holidays tends to disrupt part of the quarter a little bit," warning that fourth-quarter performance can be seasonally lighter due to medical practice schedules.
• Maetzold noted that while the company expects a draft LCD for DecisionDx-SCC in the next quarter or two, management has not assumed "recovering Medicare coverage in '27" within current revenue plans.

SUMMARY

Castle Biosciences, Inc. (NASDAQ:CSTL) reported total revenue growth of 24% for the third quarter, led by substantial volume expansion in its gastroenterology segment. Management raised its full-year revenue guidance by $20 million at the midpoint, citing sustained momentum in TissueCypher utilization and improvements in average selling prices. The company generated positive adjusted EBITDA and maintained a cash position of $278 million, which executives stated provides the flexibility to fund ongoing research and development and commercial expansion. While the dermatology segment remains anchored by DecisionDx-Melanoma, the company is continuing to navigate the recovery of Medicare coverage for its squamous cell carcinoma test and the early-stage commercialization of its atopic dermatitis offering.

• The company opened a new 55,000-square-foot facility in Scottsdale, Arizona, to expand infrastructure and capacity for anticipated future growth.
• A decision modeling study published in September showed that TissueCypher-guided management nearly doubled the proportion of patients receiving appropriate care escalation for non-dysplastic Barrett's esophagus, from approximately 30% to 57%.
• Management indicated that the dermatology sales force and gastroenterology sales force each consist of approximately 100 representatives, which they believe is sufficient for current growth needs.
• CEO Maetzold noted that personalized cancer vaccines could drive long-term growth for DecisionDx-Melanoma by helping clinicians identify high-risk patients who would benefit most from early adjuvant therapy.
• AdvanceAD-Tx clinical data showed that 98% of patients tested had their systemic treatment aligned with the test's molecular results.
• Management confirmed its expectation for positive adjusted EBITDA for the full year 2026 and the full year 2027.

INDUSTRY GLOSSARY

• AD: Atopic dermatitis, a chronic inflammatory skin condition.
• ART: Adjuvant radiation therapy, a treatment used after primary surgery to lower the risk of cancer recurrence.
• DecisionDx-Melanoma: A multi-gene expression profile assay for assessing metastasis risk in invasive cutaneous melanoma.
• DecisionDx-SCC: A 40-gene expression profile test for predicting squamous cell carcinoma metastasis risk.
• GEP: Gene expression profile, a measurement of the activity of thousands of genes at once to create a global picture of cellular function.
• HGD/EAC: High-grade dysplasia and esophageal adenocarcinoma, advanced stages of disease progression from Barrett's esophagus.
• LCD: Local Coverage Determination, a decision made by a Medicare Administrative Contractor regarding whether a service is reasonable and necessary.
• NGS: Next-generation sequencing, a technology for high-throughput DNA and RNA sequencing.
• TissueCypher: A diagnostic test designed to predict the risk of progression in patients with Barrett's esophagus.

Full Conference Call Transcript

Operator: Good afternoon, and welcome to Castle Biosciences Third Quarter 2026 Conference Call. As a reminder, today's call is being recorded. We will begin today's call with opening remarks and introductions, followed by a question-and-answer session. I would now like to turn the call over to Camilla Zuckero, Vice President, Investor Relations and Corporate Affairs. Thank you. You may begin.

Camilla Zuckero: Thank you, operator. Good afternoon, everyone. Welcome to Castle Biosciences Third Quarter 2026 Results Conference Call. Joining me today are Castle's Founder, President and Chief Executive Officer, Derek Maetzold; and Chief Financial Officer, Frank Stokes. Information recorded on this call speaks only as of today, November 5, 2026. Therefore, if you are listening to the replay or reading the transcript of this call, any time-sensitive information may no longer be accurate. A recording of today's call will be available on the Investor Relations page of the company's website for approximately 3 weeks following the conclusion of the call.

Before we begin, I would like to remind you that some of the statements made today will contain forward-looking statements, including statements about expected addressable markets, statements containing projections regarding future events or our future financial or operational results and performance, including our anticipated 2026 total revenue, test report volume growth guidance and positive adjusted EBITDA for the fourth quarter, full year 2026 and full year 2027, and the impact of our investments in growth initiatives, including our ability to achieve long-term growth and drive stockholder value. Forward-looking statements are based upon current expectations and involve inherent risks and uncertainties, and there can be no assurances that the results contemplated in these statements will be realized.

A number of factors and risks could cause actual results to differ materially from those contained in these forward-looking statements. Please refer to the risk factors in our most recent SEC filings for more information. These forward-looking statements speak only as of today, and we assume no obligation to update or revise these forward-looking statements as circumstances change. In addition, some of the information discussed today includes non-GAAP financial measures such as adjusted revenue, adjusted gross margin and adjusted EBITDA that have not been calculated in accordance with U.S. GAAP.

Reconciliations of these non-GAAP financial measures to the most directly comparable GAAP financial measures are presented in the tables at the end of our earnings release issued earlier today, which has been posted on the Investor Relations page of the company's website. I will now turn the call over to Derek.

Derek Maetzold: Thank you, Camilla, and good afternoon, everyone. Our team closed out a very successful third quarter, reflecting our focused execution and disciplined expense management, underscored by the clinical value our tests provide to clinicians and their patients. We delivered revenue of $102.9 million, 24% growth compared to the third quarter of 2025, primarily driven by TissueCypher test support volume, which grew by 47% compared to the third quarter of 2025. We generated $19.7 million in net cash provided by operating activities and ended the quarter with cash, cash equivalents and marketable investment securities totaling approximately $278 million.

We are increasing our full year 2026 total revenue guidance from our prior range of $365 million to $375 million to $385 million to $395 million. This represents a $20 million increase at the midpoint, reflecting our year-to-date performance and anticipated continued strength in TissueCypher test volume growth. Importantly, at the midpoint, our updated guidance represents a $45 million increase from where we entered the year. Now, I will walk you through the business highlights from the third quarter, and then Frank will provide additional financial highlights before we turn to your questions. But first, let me take a moment to thank the Castle team.

Without each person's dedication to serving our patients, we would not be in the strong financial position we are in today. So thank you, Team Castle. Now, let's start with our core revenue drivers for 2026, DecisionDx-Melanoma and TissueCypher. For DecisionDx-Melanoma, we delivered 10,177 test reports in the third quarter of 2026, making our fifth consecutive quarter exceeding 10,000 test reports and contributing to 5% year-over-year volume growth through the first 9 months of 2026 compared to the first 9 months of 2025. DecisionDx-Melanoma remains a central priority for our dermatology commercial organization. We've aligned commercial focus and incentive structures to reinforce that priority while leveraging our established customer relationships to increase use of our broader portfolio of dermatology tests.

Our objective is to drive continued adoption of DecisionDx-Melanoma while building future growth opportunities across our dermatology tests. With DecisionDx-Melanoma continuing to provide a durable foundation for our dermatology business and reflecting third quarter and year-to-date test report volume, we are refining our outlook for full year 2026 DecisionDx-Melanoma test volume growth and now expect mid-single-digit year-over-year growth compared with 2025. Now, turning to TissueCypher. During the third quarter, we delivered 15,574 test reports, representing strong growth of 47% compared to the third quarter of 2025. This performance reflects continued momentum in our commercial execution, driven by increased utilization among our existing clinician base and to a lesser degree, the addition of new ordering clinicians.

Based on our year-to-date performance, we are reiterating our expectation for full year 2026 TissueCypher test report volume growth of 50% to 52% compared to 2025. Alongside the strong commercial performance, we remain focused on expanding the body of clinical evidence supporting TissueCypher's utility and helping physicians make more informed risk-aligned management decisions for patients with Barrett's esophagus disease. In September, we announced the publication of a new decision modeling study in the Annals of Gastroenterology.

This study, which leveraged data from 699 patients across 5 previously published clinical validation studies, demonstrated that incorporating TissueCypher results into clinical decision-making could significantly improve the portion of patients receiving appropriate management, including in patients with non-dysplastic and short-segment Barrett's who are considered clinically to be at lower risk for neoplastic progression. In patients with non-dysplastic Barrett's disease, whose disease did progress, use of TissueCypher to guide management decisions increased appropriate management in the form of endoscopic eradication therapy or short interval surveillance from 30.4% to 56.9%.

Notably, among patients with non-dysplastic Barrett's who later progress to high-grade dysplasia or esophageal cancer, TissueCypher-guided management would have nearly doubled the proportion of patients receiving appropriate escalation of care from approximately 30% to 57%, while also reducing unnecessary procedures among those patients who did not progress. We believe these findings add to the growing body of evidence supporting TissueCypher's clinical value and further reinforce its role in helping physicians tailor patient management based on individualized risk of disease progression. Now let's move back to dermatology and focus on our AdvanceAD-Tx test. During the third quarter of 2026, we delivered 1,109 test reports, reinforcing the value of our AdvanceAD-Tx test.

We were particularly pleased with the recent publication of a new study in dermatology and therapy, highlighting, one, the challenges patients with moderate to severe atopic dermatitis experience in achieving their treatment goals; and two, strong patient interest in molecular testing to help guide systemic therapy selection. Among patients who have been treated with targeted systemic therapies, 55% modified their treatment due to lack of efficacy. Overall, 83% of respondents expressed interest in molecular testing to guide treatment selection, increasing to 94% among those open to initiating a new systemic therapy.

Further, in a real-world clinical use study that was presented in June at the Revolutionizing Atopic Dermatitis or RAD conference, found 98% of patients tested had their systemic treatment aligned with our advanced AdvanceAD-Tx results, meaning the 94% interest in patients new to systemic therapy who are interested in molecular testing aligns well with the 98% that Dr. Ames and colleagues reported at the RAD conference. We believe these findings support the clinical impact that our test is having on patient care. And with that, I will now turn the call over to Frank.

Frank Stokes: Thank you, Derek. Good afternoon. Reiterating Derek's sentiment, we're pleased with our strong financial results for the third quarter of 2026. Revenue was $102.9 million for the quarter, an increase of 24% over the third quarter of 2025, driven primarily by strong TissueCypher test volume growth. For total revenue for 2026, we are raising our revenue guidance to $385 million to $395 million, up from the previously provided range of $365 million to $375 million. This increase is primarily due to anticipated TissueCypher test volume growth and to a lesser extent, ASP improvement. Our gross margin during the third quarter of 2026 was 75% compared to 75% in the third quarter of 2025.

Our adjusted gross margin, which excludes the effects of intangible asset amortization related to our acquisitions and excludes the effects of revenue adjustments in the current period associated with test reports delivered in prior periods was 77% for the quarter compared to 77% for the same period in 2025. Turning to expenses. Our total operating expenses, including cost of sales for the third quarter of 2026 were $105.6 million compared to $89.8 million for the third quarter of 2025. Sales and marketing expenses for the quarter were $37.7 million compared to $32.8 million for the same period in 2025, primarily driven by higher personnel costs and higher expenses associated with travel.

Higher personnel costs reflect headcount additions in our commercial teams as well as merit and annual inflationary wage adjustment for existing employees. General and administrative expenses were $26.1 million for the quarter compared to $23.1 million for the same period in 2025, primarily attributable to higher information technology-related costs and higher personnel costs. Higher personnel costs reflect headcount expansions in our administrative functions as well as merit and annual inflationary wage adjustment for existing employees. Cost of sales expenses were $23.9 million in the third quarter of 2026 compared to $18.7 million in the third quarter of 2025, primarily due to higher personnel costs, higher expenses for lab supplies and higher lab services costs.

The increase in lab supplies and lab services costs reflect higher test report volumes. Increases in personnel costs reflect a higher headcount due to higher test volumes, investment additions made to support planned business growth in response to growing test report volumes as well as merit and annual inflationary wage adjustment for existing employees. R&D expenses were $15.8 million for the quarter compared to $13 million for the same period in 2025, primarily due to higher personnel costs driven by increased headcount to support ongoing research activities and continued business growth related to our pipeline initiatives.

Total noncash stock-based compensation expense, which is allocated among cost of sales, R&D and SG&A expense was $11.2 million for the third quarter of 2026 compared to $12.1 million in the third quarter of 2025. Interest income was $2.5 million for the third quarter of 2026 compared to $2.8 million in the third quarter of 2025. Our net loss for the third quarter of 2026 was $4.1 million compared to a net loss of $0.5 million for the third quarter of 2025. Diluted loss per share for the third quarter was $0.13 compared to diluted loss per share of $0.02 for the same period in 2025.

Adjusted EBITDA for the third quarter was $12.7 million compared to $9.2 million for the comparable period in 2025. We continue to expect positive adjusted EBITDA for the fourth quarter and full year 2026. Importantly, absent a change in strategic direction, we also expect adjusted EBITDA for the full year 2027 to be positive. Net cash provided by operating activities was $19.7 million for the third quarter of 2026. and net cash provided by operating activities was $12.8 million for the 9 months ended September 30, 2026. As of September 30, 2026, we had cash, cash equivalents and marketable investment securities of approximately $278 million.

Importantly, our strong balance sheet continues to provide financial flexibility to invest in our growth priorities. In closing, we delivered strong third quarter results, including strong top line growth, positive adjusted EBITDA and operating cash flow and an upward adjustment to our annual revenue guidance of $20 million at the midpoint. I'll now turn the call back over to Derek.

Derek Maetzold: Thank you, Frank. In summary, we remain focused on serving our patients and clinicians, driving operational excellence and advancing our growth initiatives, including advancing our pipeline to deliver long-term value for stockholders. I want to thank the entire Castle team. Our consistent execution is a direct reflection of their contribution, and I'm grateful for their effort and commitment. Thank you for your continued interest in Castle Biosciences. Now, we will be happy to take your questions. Operator?

Operator: [Operator Instructions] Our first question comes from Bradley Bowers with Mizuho.

Bradley Bowers: Just wanted to ask on TissueCypher here. Obviously, a nice step-up in what's typically, I guess, a procedurally, seasonally like a little bit slower 3Q versus 2Q. Just wanted to hear about what you're seeing in that business in terms of trend, how we should kind of think about fourth quarter, whether that's contemplated in the guidance? And then just kind of the pace of the penetration, what you think you need the guidelines to go deeper? Just any thoughts on that.

Derek Maetzold: Sure. Thanks for joining us here. Still real happy with TissueCypher. We're probably around 15% penetrated on a run rate basis in terms of the eligible procedures a year. The procedure there are surveillance endoscopy for Barrett's and it looks like we're about 15% penetrated on that. But yes, I think the trends will continue through the end of the year that we've seen. The guidance certainly contemplates that. We've got a nice early start in that test here in the early years and still plenty of room to go. But good solid quarter for the test. We see it continuing through the end of the year, and we like the business quite a bit.

Bradley Bowers: Got it. That's helpful. Just maybe one other one on profit. Gross margin actually held on a bit better than I think we were expecting. I know that there was some onetime pricing items in 1H, but that would imply that, I guess, most of this was organic? Or are we still kind of expecting a fall off? And what should we be thinking about kind of into the end of the year and next year?

Derek Maetzold: I think adjusted gross margins stayed pretty consistent through the year here. We've done some nice work in the lab, improving our efficiencies there. Some of it's with people, some with technology. But I think that number is probably pretty durable through the year. we -- importantly there, a big part of that is the number of unpaid. And so it looks like that's kind of staying consistent through the year as well.

Operator: Our next question comes from Max Masucci with ROTH Capital Partners.

Max Masucci: Just first one, even if you carry forward the Q3 beat, the implied Q4 guide is strong. So talk about were there any -- are there any sort of emerging drivers or areas of outperformance that are powering that Q4 implied strength? And is that coming from the core business or any sort of new incremental contributors?

Frank Stokes: Just core business. Max, good to talk to you. Just continuing to see the core business do well through the end of the year.

Max Masucci: Okay. Got it. And so moving to DecisionDx-Melanoma. I think previously you called out reps adjusting to selling multiple tests. Just curious, just looking for a little bit more detail on the growth trends for DecisionDx-Melanoma in the quarter. And if there's anything -- any impact coming from softer ordering or competitive pressures. So really just structural versus kind of transitory factors in the quarter.

Derek Maetzold: Yes. This is Derek, Max. Good to hear you. We -- certainly nothing structural. We remain on target to reach our volume guidance that we provided at the start of the year. So nothing has changed from that perspective, and we are quite pleased with the year-to-date growth and the expectation we have for the fourth quarter.

Max Masucci: Okay. Got it. Maybe I'll sneak one more quick one in. It's great to see the Esopredict volumes for, I believe, the first time. It looks like it implies a strong sequential ramp this quarter. So what are the headline takeaways for that launch, I guess, even year-to-date? And just more broadly, how should we think about the role of that test within your portfolio and commercial potential over the longer term?

Derek Maetzold: And Max, you broke just a minute there, which test were you asking about?

Max Masucci: Esopredict.

Derek Maetzold: Esopredict. Sure. So yes, when we acquired the test, we saw an opportunity there to potentially incorporate that into the patient flow for our broader Barrett's prognostic business. And so it's not a large number, but occasionally, we do have samples we get in that we can't get adequate tissue to run TissueCypher on, Esopredict is a different technology. So we're able to, in many cases, pivot that over and provide a test report using Esopredict. And that's really more about -- certainly, we want to be able to provide a clinical answer as many -- for as many patients as we can.

So by incorporating that into the flow, again, it's not a big piece of business, but if you're one of those patients and -- or their physician and you -- there's an issue with the tissue and you can't quite get the answer we need with TissueCypher, it's quite comforting and clinically beneficial to be able to pivot that over to Esopredict and provide a clinical answer. So I guess the summary there is it's doing exactly what we hoped it would do when we made that acquisition now just a bit over a year ago.

Operator: Our next question comes from Subbu Nambi with Guggenheim Securities.

Ethan Kriss: This is Ethan on for Subbu. Congrats on the quarter. Just on AdvanceAD-Tx, CMS proposed gap fill instead of the panel's recommendation of crosswalk. I was just wondering if you submitted a comment or seeking an alternative there. And if gap fill is the final decision, does that change anything about assumptions for Medicare revenue or commercial payer negotiations?

Derek Maetzold: Yes, Ethan, this is Derek. Good questions there. So we were surprised to go ahead and see CMS not only with our AdvanceAD-Tx test, but also other tests are being priced. I don't want to ignore or set aside the advisory panel's recommendations to go to gap fill. Yes, we did submit appropriate additional crosswalk test that actually had private payer data. I think schedule-wise, if you aren't aware of this, I think they anticipate probably taking a little bit longer to post this year for the final recommendations. It usually comes around Thanksgiving week, but I think we've been led to believe it could be early December.

And I think we have logic that would say they should be cross-walking to existing genome expression profile test run on NGS in which there is private payer data.

Operator: Our next question comes from Mason Carrico with Stephens.

Mason Carrico: So ASP has obviously been strong throughout this year. Could you just talk through some of maybe the coverage wins that have helped drive that and maybe your expectations around the durability of ASP moving forward or any maybe near-term incremental gains that you have visibility into today?

Derek Maetzold: Yes. Thanks for the question, Mason. As you know, we don't typically talk about coverage decisions, and it's probably -- we'll probably continue to take that stance. We're pleased with what we're seeing on the ASP front. It represents both -- I think it's a durable patient mix, Mason. I think that those -- that progress is probably durable. We don't necessarily model incremental upside going forward. And if we see it, we'll take it. But I think we're pleased with where we've gotten on both of our primary drivers here. And I think we expect that progress to be durable for the near to midterm here.

Mason Carrico: Got it. Okay. And maybe moving to dermatology here. Could you expand, I guess, or give us some color on what the split look like from a commercial standpoint across kind of your 3 core dermatology products and maybe how we should think about how much time the commercial team is spending on each as we move into 2027 and AdvanceAD-Tx kind of volumes open up?

Derek Maetzold: Yes. And by split, you mean sort of focus, time and focus on...

Mason Carrico: Exactly Yes.

Derek Maetzold: Yes, still very much focused on melanoma. We certainly haven't abandoned SCC. We -- as you can see from the volumes, it's still a very clinically relevant test. And we've not meaningfully supported that from a marketing perspective for several quarters here, but the volumes have stayed pretty impressive. And I think that speaks to, one, the value of that clinical information to physicians, and we've talked with you before about challenge and the decision they have with a high-risk SCC patient, particularly of a Medicare age who may be more fragile from a health perspective otherwise anyway and trying to make that really hard decision about whether to send that patient to adjuvant radiation therapy or not.

So I think that we're -- we don't have to say I think the volume says that, that's a clinically very, very important test. AD is -- we're just not really putting a lot of force behind it while we go through the process here of figuring out what the ASPs are going to look like. And we'll make that decision soon. And it's a really -- there's a lot of value in that test as well. There's a lot of economic benefit from the test. But for now, we're still really focused the derm team primarily on melanoma and that business and progress.

Operator: Our next question comes from Kyle Mikson with Canaccord Genuity.

Charlotte Maurer: This is Charlotte Maurer on for Kyle Mikson. Congrats on the great quarter. First, on DecisionDx-SCC, volume has remained under pressure following the loss of Medicare coverage. Where does that process stand today? And how -- what should we view as the next meaningful milestone? Is the [ CAC ] meeting in the first half of 2027, a reasonable expectation? Or how do you think we should think about the potential timing from there to a draft LCD and then ultimately coverage?

Derek Maetzold: That's an excellent question, Charlotte. This is Derek here. I think the sort of, I guess, our expectation or guidance we put out will be certainly we don't have in our 2027 revenue, any assumptions for recovering Medicare coverage in '27. So we put into our '28 plan right now. I think seeing a draft LCD come out with or without a TAC meeting is probably a reasonable expectation. There's nothing formal for us to be able to provide you at this time, but I think certainly something which go into the next couple of months, next quarter or 2 is not on a reasonable expectation.

Charlotte Maurer: Great. And then if I could ask another question. Total revenue during the quarter came in well ahead of expectations. Given the volume performance across DecisionDx-Melanoma and TissueCypher, could you help us bridge where that revenue upside maybe came from? And then what drove that guidance increase? Like how much is driven by stronger ASPs or prior period collections across your core products versus like volume or other factors?

Derek Maetzold: Yes, sure. Prior period wasn't really a big factor in there. The drivers were primarily ASPs on our 2 lead products. And we did have some ahead of expectation SCC revenue. We don't break it out, but it was certainly ahead of what we had -- this time last year, what we modeled it would be. So primarily ASP, a little bit of volume on SCC, but just good solid progress from the core drivers of revenue. And as it relates to the revised guidance, I think what you see is that's reflective of our confidence in the state of play for Q3 continuing into Q4 through the end of '26 here.

Operator: Our next question comes from Matthew Parisi with KeyBanc Capital Markets.

Matthew Parisi: This is Matthew Parisi on for Paul Knight at KeyBanc Capital Markets. Congrats on a great quarter. You called out the increase in lab headcount to handle the increase in test volumes that you're seeing. Should we expect to continue to see lab headcount and expenses rise with the rising test volumes? Or do you now have the infrastructure in place to be able to kind of handle them going forward?

Frank Stokes: So definitely, as volumes grow, headcount in our COGS area in the labs does grow along with it. It's not one for one. We get leverage and we get incremental efficiencies. But the technology in the lab is very good. The efficiency is very good, but it's just a matter of bandwidth. You have to have -- as the volumes grow, we will have to add people in both facilities, Pittsburgh and Scottsdale, and we would expect to see that going forward as well.

Matthew Parisi: Awesome. Appreciate the insight. And then if I can squeeze in one more. Would you expect any long-term impact for DecisionDx-Melanoma stemming from the Moderna personalized cancer vaccine readout? Just kind of what you're thinking about that long term?

Derek Maetzold: Uplift on the vaccine readout, you mean? Okay. Yes, I think that potentially could be a very interesting area of driving our DecisionDx-Melanoma growth over the long term. As you may recall, today, there are adjuvant therapies, PD-1 inhibitors, ipi approved for, I guess, Stage 2 BC and Stage 3 patients. Unfortunately, of course, the majority of patients who we test are really earlier, which is kind of Stage 1 to 2A. So there are no really adjuvant therapies available today. So most of our clinical use, as you know, is going to be either avoiding an unnecessary sentinel biopsy surgical procedure.

And also then if you happen to have a high-risk DecisionDx-Melanoma test result, we see many physicians pushing forward on either implementing routine imaging, some are adopting early use of ctDNA. The kind of look for early recurrences. So those are important actionable steps because we have seen that if you can initiate immunotherapy when a metastatic spread is detected when it's small, which is usually asymptomatic and picked up on imaging or ctDNA trends, then those patients have a higher likelihood of a more robust response.

I think the hope would be that as the vaccines progress and assuming that the developments are all successful that those could hopefully move into earlier-stage patient populations of the ones that we are more routinely testing. And I think then the thesis becomes now you have a dermatologist, a surgeon or medical oncologist saying, okay, I have a lower risk patient by staging, but a very high risk by the Castle DecisionDx-Melanoma test. This is a patient we should preferentially look to initiate that adjuvant therapy. So I think that's where we see it going, and that's where your question was heading. That's where I hope the marketplace gets to.

Operator: Our next question comes from Thomas Flaten with Lake Street Capital.

Thomas Flaten: Just a quick one on the pipeline. What cadence of news and activity should we anticipate over 2027, particularly with respect to the SciBase? collaboration?

Derek Maetzold: We haven't at least much time, I'll take. I thought we had talked about in the third quarter earnings. In the first half of next year, we'd expect to go ahead and have updates on pipeline progress. But I think beyond that, I can't -- we're not prepared to give you any more specific dates or months at this point in time, Thomas.

Thomas Flaten: No, no, no worries. And then, Frank, just if I'm doing my back of the envelope math correctly here, the midpoint of the guide implies a slightly down to flat fourth quarter over third quarter. Is that just conservatism baked in? Or are there other things we should be attended to? And I apologize if we're retreading ground here.

Frank Stokes: No, no. Just -- your math is good. Typically, Q4 can be a little bit seasonally lighter just as practices. There's a big range of how medical practices handle the December holidays. And so that treatment of the holidays tends to disrupt part of the quarter a little bit. So that's all you're seeing there.

Operator: Our next question comes from Puneet Souda with Leerink Partners.

Jin-Yep Penikis: This is Carlos on for Puneet. Congrats on the quarter. So one thing that we've seen emerge this year has been a bit more seasonality in TissueCypher. And if I'm doing my math right, I think sequentially, you're going to be up around 1,000 units in the fourth quarter compared to just shy of 600 this quarter, and we saw the seasonality between Q1 and Q2 as well.

So I'm not asking for a 2027 guide yet, but it would be helpful to think about how you folks are thinking about the seasonality in the context of future years for what is still a very rapidly growing test that's penetrating an underpenetrated market and how those factors balance with each other?

Derek Maetzold: Yes. There -- with all of our therapeutic areas, and all of our tests within those areas, there's definitely going to be seasonality. And sometimes you'll hear it called out, maybe there's a weather event or maybe there's a holiday or something like that. So quarter-to-quarter, the number of business days in a quarter may be close, but the number of those days that are actually operating days kind of varies from quarter-to-quarter. And we -- I would expect we've always seen that. But when you're in the earlier growth stages, you're kind of growing through it and the growth kind of camouflages that. We don't really have any particular strategy or tactic to try to manage that.

Our teams have quarterly expectations, and they don't change based on -- for better for worse, they're consistent regardless of where it falls in the calendar. But the other thing just to keep in mind through this year is we have had a couple of changes in the size of the sales force on TissueCypher. And so that causes -- the good news is you add sales reps, you've got a bigger megaphone. But short term, there are some dislocations in coverages and sometimes that can create a little bit of bumpiness as well. But I expect we'll see that with TissueCypher going forward. It doesn't really change our view on the opportunity or how we execute against it.

It just means that some quarters, you get more working days than others. And sometimes those working days are more fruitful than others. So no real change in just sort of a -- I think it's just the reality of the business.

Jin-Yep Penikis: All right. That's really helpful. I appreciate it. And staying on TissueCypher, we've talked a little bit about -- I think you're starting to see some wins with commercial payers for TissueCypher just based on the utility of the test and how it really is guiding therapy. So it would be great to get some color on how significant this ASP contribution is right now and how significant it could be as we look forward over the next few years?

Derek Maetzold: I would assume ASPs are steady from here. We hope to see upside. But as you noted, it's difficult to predict both scale and timing. I think that when you look at the ability to identify really high-risk patients that weren't being appropriately surveilled and the benefits of that, I think that resonates with certainly clinicians but also payers as well. And then you have the other side of the coin, you have the patient who might have been over surveilled and you can downgrade that and have a very beneficial impact on the patient's care as well as on the cost of that care.

So we'll -- we continue to work very hard to demonstrate the clinical utility and the economic benefit to payers, and we would hope and expect to continue to have successes through the next couple of years. But in terms of modeling and how we look at the business, we just sort of assume we're going to hold where we are, and we'll take the win when it comes.

Operator: Our next question comes from Mark Massaro with U.S. Bancorp.

Meaghan Rockey: This is Meaghan on for Mark. So we're just curious if you have an update on the size of the sales team since Q2, especially with regards to TissueCypher with volumes up and we're just looking to see if there's any new territories being opened or if the current headcount is sufficient to sustain the growth that we've been seeing?

Derek Maetzold: Sales force expansion on TissueCypher, Meaghan, did I hear that correctly?

Frank Stokes: Yes, you're just looking for sales force on both sides, right?

Meaghan Rockey: Yes.

Frank Stokes: Yes. We -- both are around 100 -- around or under 100, and we think both are sufficient for now. I don't think we had -- it's been a bit since we had an expansion on either side, I think.

Derek Maetzold: Second quarter was the TissueCypher for most recent expansion. So those -- if our historical norms in terms of when the new area managers or sales representatives are sort of fully operational, that's kind of what, 5 to 6 months in our model. So we should expect to see some impact here in the fourth quarter, but more so going into 2027. So I think we are set up well for continued growth in 2027 based upon our investments this year.

Operator: We have reached the end of the question-and-answer session. I'd now like to turn the call back over to Derek Maetzold for closing comments.

Derek Maetzold: Thank you. This concludes our third quarter 2026 earnings call. Thank you again for joining us today and for your continued interest in Castle Biosciences.

Frank Stokes: Thanks, everybody.

Operator: This concludes today's conference. You may disconnect your lines at this time, and we thank you for your participation.

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