Castle Biosciences (CSTL) Q2 2026 earnings call transcript

Thank you, Operator. Good afternoon, everyone. Welcome to CASTLE BIOSCIENCES' second quarter 2026 results conference call. Joining me today are CASTLE's founder, president, and chief executive officer, Derek Masold, and chief financial officer, Frank Stokes. Information recorded on this call speaks only as of today, July 30, 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 three 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 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.

Thank you, Camilla, and good afternoon, everyone. What a great quarter. Our team across all areas at CASTLE did a phenomenal job in executing on our growth plans and pulling it through the business, including revenue on the top line in evidence development and clinical research. Thanks to the efforts by our team and the clinical value that our clinicians see in the actionability of our tests, we delivered revenue of $103.5 million, 20% growth compared to the second quarter of 2025. Furthermore, if we exclude DecisionDX SCC and IDGX revenue for both 2026 and 2025, our revenue growth for the second quarter of 2026 was 40% compared to the second quarter of 2025.

Test report volume for our core revenue drivers grew 32% compared to the second quarter of 2025. Our strong second quarter results reflect the continued execution of our growth strategy, and that we remain focused on investing thoughtfully in the future growth of CASTLE. We continue to invest in commercial resources to drive adoption of our tests, generate the clinical evidence needed to support reimbursement and expand adoption, advance pipeline opportunities across our dermatology and gastroenterology offerings, and add the laboratory capacity, technology, and personnel needs to support future growth. Supported by our robust balance sheet, we believe these investments position us to capitalize on the opportunities across our current portfolio and pipeline while maintaining a disciplined approach to capital allocation.

We believe we will continue this positive momentum in the second half of 2026, and our strong second quarter performance gives us the confidence to raise our 2026 total revenue guidance to $365 to $375 million compared to the previously provided I will walk you through the business highlights in the second quarter, and then Frank will provide additional financial highlights before we turn to your questions. Let's start with our four revenue drivers for 2026, DecisionDX melanoma and TissueCypher. For DecisionDX melanoma, we delivered 10,280 test reports in the second quarter, representing 3% growth compared to the second quarter of 2025. We are on track to meet our expectations of mid to high single-digit volume growth for the full year 2026 over 2025.

The CISDX melanoma test volume also increased approximately 3% in the second quarter of 2026 compared with the first quarter of 2026, representing moderate sequential growth, though below the sequential increase we typically see based upon historical seasonality. We believe this moderate sequential growth was due in part to our commercial team adapting its customer engagement model to support three products within the same customer call. This is a deliberate investment in the growth of our business.

DecisionDX melanoma remains the established foundation of our dermatological commercial portfolio, While the additional products, DecisionDX SCC and Advanced ADTX, expand the value we can provide the same customer base and support growth over the medium and long term. Additionally, we continue to generate a substantial body of evidence to support the clinical performance and use of our DecisionDX melanoma test. In fact, during the second quarter, we were pleased to announce the publication of a prospective multicenter study demonstrating decision-DX melanoma outperforming the Melanoma Institute of Australia Nomogram, or MIA, in identifying patients at low and high risk of sentinel-lifted biopsy positivity. Importantly, patients predicted to be low-risk by CASTLE-DX melanoma, that is, they were predicted to have a sentinel-lifted positivity rate of less than 5% at an actual observed sentinel-lifted positivity rate of just 2.6%, well below the National Comprehensive Cancer Network, or NCCM, 5% threshold used to consider avoiding a sentinel-lifted biopsy surgical procedure.

These findings further demonstrate the value of integrating tumor biology with clinical pathologic factors to improve risk assessment, support more informed, risk-aligned care, and help identify patients who may safely forego the sentinel-lifted biopsy surgical procedure.

Now, let's turn to our tissue site for tests. During the quarter, we delivered 14,988 tissue cipher test reports, representing 63% growth compared to the second quarter of 2025. Based upon trends for the first half of the year, we believe our 2026 test report volume for tissue cipher will trend toward 50% to 52% growth compared to 2025.

Now, let's move on to our advanced ADTX test. During the second quarter, we delivered more than 1,000 orders. Given the testability to guide systemic treatment selection for patients ages 12 and up with moderate to severe atopic dermatitis, we were particularly pleased that the Advanced ADTX test was recently recognized with the Genomics Innovation Award in the 10th Annual MedTech Breakthrough Awards Program. In addition, we were encouraged by a new independent real-world clinical utility study for Advanced ADTX presented in June at the Revolutionizing Atopic Dermatitis meeting.

In this multicenter study, only 54.3%, or just over half, of patients receiving baseline systemic therapy were initially on pathway concordant treatment. However, following testing with our advanced AD test, 97.8% of patients were initiated on molecularly concordant systemic therapy.

The impact of advanced AD TX on assisting clinicians and patients with making molecularly aligned therapy decisions overlaps the market research we conducted in the summer and fall of 2025. That is, clinicians are searching for tools, in this case, our advanced ADTX test, to assist in making more informed, better therapy selections that align with an individual patient's underlying disease biology.

And with that, I will now turn the call over to Frank.

Thank you, Derek, and good afternoon, everyone. Reiterating Derek's sentiment, we're proud to report excellent financial results for the second quarter of 2026. Revenue was $103.5 million for the quarter, driven by continued strength in our core revenue drivers, primarily tissue-ciper test volume growth and some improvement in ASP, due in part to modifications in our accrual processes that were implemented earlier this year. For total revenue for 2026, we are raising our revenue guidance to $365 to $375 million, up from the previously provided range of $345 million to $355 million. Our gross margin during the second quarter of 2026 was 74.9% compared to 77.3% in the second 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 76.3% for the quarter compared to 79.5% for the same period in 2025.

For the full year 2026, we continue to expect our adjusted gross margin to be in the low to mid-70s range. Turning to expenses, our total operating expenses, including cost of sales for the second quarter of 2026, were $106.6 million compared to $90.4 million for the second quarter of 2025. Sales and marketing expenses for the quarter were $40.9 million compared to $35.1 million for the same period in 2025, primarily driven by higher personnel costs, higher expenses associated with travel, and higher business administration costs.

General and administrative expenses were $25.2 million for the quarter compared to $22.9 million for the same period in 2025, primarily attributable to higher personnel costs. Higher personnel costs reflect headcount expansions in our administrative functions, as well as merit and annual inflationary wage adjustments for existing employees. Cost of sales expenses were $23.7 million in the second quarter of 2026, compared to $17.6 million in the second quarter of 2025, primarily due to higher expenses for lab supplies, higher personnel costs, and higher lab services costs.

The increase in lab supplies and lab services costs reflects higher test report volumes. Increases in personnel costs reflect a higher headcount due to additions made to support business growth in response to growing test report volumes as well as merit and annual inflationary wage adjustments for existing employees R expenses were million for the quarter compared to million for the same period in 2025 primarily due to higher personnel costs driven by increased headcount to support continued business growth as well as increased advisory board clinical trial and travel costs related to our pipeline initiatives Total non-cash stock-based compensation expense, which is allocated among cost of sales, R&D, and SG&A expense, was $11.6 million for the second quarter of 2026, compared to $11.2 million in the second quarter of 2025.

Interest income was $2.4 million for the second quarter of 2026, compared to $2.9 million in the second quarter of 2025. Our net loss for the second quarter of 2026 was $2.1 million, compared to net income of $4.5 million for the second quarter of 2025. Diluted loss per share for the second quarter was $0.07, compared to diluted earnings per share of $0.15 for the same period in 2025.

Adjusted EBITDA for the second quarter was $12.4 million, compared to $10.4 million for the comparable period in 2025. We continue to support and invest in growth initiatives while focusing on thoughtful expense control. We expect to achieve positive adjusted EBITDA for the third quarter, the fourth quarter, and the full year 2026, and absent any strategic direction shift as well as for the full year 2027. Net cash provided by operating activities was $15.2 million for the second quarter of 2026, and net cash used in operating activities was $6.9 million for the sixth month ended June 30, 2026. Net cash used in investing activities was $41.8 million from the six months ended June 30, 2026, and consisted primarily of purchases of marketable investment securities of $109.6 million, purchases of property and equipment, partially offset by the maturities of marketable investment and debt securities, along with the sale of equity securities.

As of June 30, 2026, we had cash, cash equivalents, and marketable investment securities of $266.8 million. Our strong balance sheet continues to provide financial flexibility to invest in our growth priorities.

In closing, we delivered strong financial results through the first half of the year, continuing our longstanding history of consistent execution and performance excellence. I'll now turn the call back over to Derek.

Thank you, Frank. In summary, we continue to execute at a high level, and I'm encouraged by the momentum we're carrying into the remainder of the year. None of this would be possible without the dedication of the entire CASTLE team, and I'm proud of what they have accomplished through their unwavered commitment to improving patient care. Thank you for your continued interest in CASTLE. Now we will be happy to take your questions. Operator?

Yeah, good question, Max. Derek here. So, first of all, in our analysis before we submitted our request to be crosswalked to that code, we believe that CASTLE, that was the most appropriate code. The crosswalk code is for a test that predicts drug response to patients with psoriasis. The advanced AD test, as you know, predicts systemic drug response to people with atopic dermatitis, We thought that was appropriate to take care of that. Obviously, the panel did a 21-0 vote in favor of crosswalking. The rate of 36.75, I think, is a very, very strong rate for our test. We are quite pleased with the panel's recommendation or early voting outcome there. As you know, CMS will go ahead and take that input, and I think we see preliminary draft 2026 CLFS rate schedules in late September.

So we're looking forward to seeing that affirmed going forward. I think from an overall perspective, as that goes on with the clinical laboratory fee schedule effective January 1, 2026, that gives us a good benchmark in order to go ahead and set conversations with commercial payers as well regarding reimbursement rates, et cetera. So I think it's a very nice, consistent plotting launch going forward here, which lets us get in a better position to open up a full loss in the future.

Frank?

We did have a pickup in ASP, Max. We've been selling the test for long enough now that we've got a bit more experience in terms of expected rates and actual collected rates. And so we were able to increase the ASP a bit in the first half of this year. And having said that, I wouldn't expect to see the same stepwise increase in the back half. I think, you know, we all are evaluating our payer experience and comparing that to our expectations. But I would not expect to see it again. So most of the raise in our guide here is based on performance to date and continued performance of our two primary revenue drivers, DecisionX melanoma and tissue cycle.

We have continued to sort of expand as we see territories hitting a forward-looking, you know, $2.5 million in revenue, Thomas.

We don't necessarily give out specific numbers, but we're kind of floating around 100 sales, represented our sales territories for both our gas neurology division and our dermatology division. We think that's probably pretty close to where it needs to be from a tissue cipher standpoint and dermatology sample for that matter. So I think we're kind of there. That being said, we had expansions last year and had expansions late second quarter of this year here. So we aren't even seeing the full fruits, I guess, of those expansion opportunities. But we feel pretty comfortable with coming in from a volume year-over-year of 50-52 percent is what we believe we're on track for. So that's very quite positive.

I think that's to be determined, I think, maybe. Based upon our market research interactions with our investigators and also interactions with our medical dermatologists who are skin cancer doctors, but, of course, the majority of what they see in their practice is basically atopic dermatitis in terms of diseases like this. The commentary there is that, you know, we have high-dose steroids. We can start those up in a couple of days in advance. You've got a topical JAK inhibitor. That works pretty quick as well. So one could say you could go as short as a day and a half, two days in advance. We'd like to see if we can get earlier than that so it gives patients the time to maybe use less high-powered topical therapies to kind of keep control and keep their symptoms depressed or suppressed.

So I think we'll kind of look at that, see if the data unwinds this fall, put preliminarily, and get a good positive set for what it looks like. That being said, the patient research that we have done recently in the second quarter of this year, there is such an acute need to be able to say, so you're telling me I could use a disposable, I mean, not a disposable, a pen, And they'll be able to help me kind of understand my disease, control my disease as if I was a diabetic, wanting to really appreciate how do I stay dialed in to being as normal as possible. So that's a very, very positive feedback set there.

So I think we have a range of what we could detect in advance of an actual flare to be extremely clinically meaningful to both patients and their clinicians. The other end of the equation that we are getting commentary on, which I think is quite positive as well, So is that once my flare has resolved, if I can't get ahead of it, that is, how long do I stay on my sort of rescue medications before I can begin tapering those medications off? And, again, we should be able to predict the front end, and if they can't suppress their flare completely and it actually becomes symptomatic, hopefully it's much more mild than if they didn't know that.

And at the back end, rather than sort of having their rescue medication treatment plan be sort of, well, once the symptoms resolve themselves, stay on your high-dose steroids for, what, five days, four days, three days, we believe that one of the uses of this device will be able to go ahead and help patients taper off of their rescue medications quicker I will now turn the call over to management for the CASTLE BIOSCIENCES Or stay out longer if they still have this underlying heavy biological disease pattern going on And then the final thing which is quite exciting is that we also have seen broad trends in the marketplace where patients would desire to sort of lengthen out their injection rates lengthen out their use of oral therapies.

So rather than kind of following what's on the label is to say, well, I've got copay exposure potentially. I don't like the idea of taking injections every two weeks. Can I sort of take fewer injections and kind of lengthen out the frequency but also still be controlled? And right now we talk to our dermatological colleagues. They're telling us that's all, of course, basically empirical. You know, the last patient I had here, Derek, was able to go from sort of two-week injections of one drug to three and then to four. But when they got to five weeks, they all of a sudden had a, you know, a heavy flare, the knowledge up. So we said, well, go back to four.

This device should be able to help a patient who wants to take that as a pathway of choice and let them potentially sort of lengthen out therapy dosage once they're well controlled to go ahead and just be on less medication over time. I'm telling you, most people would appreciate it.

Yeah, Ben. I think that we, as tempting as it is to look sequentially in these tests, I think we really need to look on a trend line. And if you look at the trend on tissue cipher, it's pretty steady growth. We had, you know, a little bit lower Q1, a little higher Q2. If you kind of smooth that over four quarters, you get closer to a pretty consistent trend. And so I would say in the first place, I would look sort of at that multi-quarter pathway. But secondly, yeah, the seasonality we saw in Q1 did seem to be driven by fewer patient encounters. And just as we see on the DERM side, we will probably continue to see that on tissue cipher.

But, you know, we get to Q1, we'll look year over year and look at the multi-quarter trend rather than just sequentially quarter to quarter.

I don't have the raw data in front of me to answer that quantitatively, Ben, but my recollection the last time we reviewed that last month was that we are seeing both new ordering customers as we sort of release this to additional customers, get their staff trained up or the clinician trained up on how to do this non-invasive scraping technique, get kits in the offices, et cetera, that we are seeing the sort of new ordering adoption. We expect to see based upon the emphasis of putting it on from a Salesforce standpoint.

And we have, I think, very few clinicians who have sort of been one and done. So we do see heavy repeat users going on right now.

Frank? My question was… Good to talk to you. Thanks for the question. Yeah, I'm sorry. I tracked you. Yeah, I think we'll continue to see some increase in R&D as we continue to focus on newly internally developed programs. I think you've heard us say before we're very excited about the pipeline we have and the way the story at CASTLE has evolved from the IPO days when we really had one kind of primary product to now two therapeutic areas and multiple products in each opportunity. So we will see some increase. It's a deliberate investment, and we are running CASTLE for not only near-term quarter-to-quarter growth, but also mid- and long-term growth to ensure long-term value creation well past 2030, 2035.

So some increase, but I think in terms of priority, it will continue to be those programs within our existing therapeutic areas that line up so well in our commercial footprint.

I think the number one driver of SCC volumes is the clinical value, existing customers seeing the test and how they use it to manage their patients' high-risk MSL carcinomas.

We did what I think we talked about at first quarter earnings, allow, sounds like a funny word, encourage, I guess, our sales force to say, hey, Our predominant focus is and will remain on the short-term cutaneous melanoma, but you have this atopic dermatitis test. You have this squamous cell carcinoma test that's had great clinical value. We need to make sure that we are spending some time on those elements, a small amount of time, but some time. So I think it's a combination of existing users, more working days in the second quarter, certainly, and some return to some promotional time with our sales force.

Sure. So we have, as you know, when we acquired PROVISE, we had a portfolio of IP that came out of Hopkins, was licensed into PROVISE. They had a tissue-based assay, ESO PREDICT, that we made available in the first, I guess, early first quarter of this year as a reflexive test or backstop test in those few cases that we couldn't get a tissue cipher result to a physician under the expectation that, hey, the most well-documented, the most valuable test that predicts progression of Barrett's disease to high-grade dysplasia or cancer is the tissue cipher test. But if we're unable for features of the way the biopsy was taken, et cetera, not to get a spatial limits test to work, it would offer up EPSO-Predict as a backup in those few cases.

Regarding the cell collection device, it also worked out a sponge, which was fit into a capsule and attached to a string that went through the capsule. The expectation was that it would swallow that, let it go down into your lower esophagus, maybe upper stomach or lower esophagus. The capsule dissolves, the sponge pops out, and you pull the sponge back out with that string. We have protocols for cell collection devices that are in design and sort of ready to go here. So I would say probably the update on that probably maybe first half of next year is probably the right timing.

Yeah, just clarifying there, we think we exited 25 at about 10 to maybe 11 or 12 percent patient penetration on the addressable patient market. And if the numbers we provided earlier today, you know, would get us to, you know, maybe 15% middle teens, we are certainly going to begin to face the headlines of big numbers. And, you know, by definition, the easier positions to convert are the first ones, and the ones that come later are perhaps take a bit more work. So at some point we'll begin to see that. But I think importantly, at this juncture in the life of that test and the marketing of that test, we still have maybe way too many, you might think, physicians who haven't yet had the chance to be educated on the clinical benefit of using tissue cipher for their various esophagus patients.

And so lots of runway ahead as we convert those physicians that don't yet have the opportunity. So we will begin to get into those big numbers and begin to get into that more mature phase but that test has a long way to go yet Got it.

So we have no, I guess, public commentary about data discussions with either Medicare contractor. As you may know, there is no timeline for their response. We've heard nothing, by the way, negative, so don't take that commentary as negative. From a standpoint of a return to coverage, we did model out based upon a very, very limited database that maybe would take a year, year and a quarter to have those Medicare contractors work through the reconsideration requests.

That would be sort of in the second half of this year. So I think, you know, expecting to see daylight in the second half of 2026, I think, is a reasonable expectation. Once a draft was posted, we don't really have any sense right now as would they work quicker to go from draft to final, or would they follow the currently path, which has roughly taken the entire year to finalize a draft LCD to final. So I think guidance has been pretty consistent, which is to say if we see a positive draft coverage LCD coming out from either one of the Medicare contractors In the latter half of this year, or the second half of this year, I should say, then we should anticipate roughly a year later regaining coverage for Medicare beneficiaries, which would be a fantastic opportunity to really advance their care.

So that's how I would kind of view that, per se. We, of course, always are generating additional publications, additional evidence developed to support the correct decision to enable Medicare beneficiaries to benefit from this test on a broad basis. But that's being worked through right now.

So I would separate those two things here, Megan. So the breakthrough device designation enables us to sort of go to the front line, get other special features, I guess you would say, in terms of the review of that I don't know if we've talked publicly about our timing of that. I would think we might expect to have FDA clearance slash approval maybe later on this year, early next year.

Yeah, we had talked through, I guess, the first quarter earnings was a high year-over-year growth rate, and we hopefully tried to speak intuitively, which is to say we think at the end of the year we're going to come in with between kind of mid- to high single-digit growth, and I think we're right on track to achieve what our internal goals are. So we're seeing the promotional responsiveness, the value of our test in the marketplace hasn't really changed a whole lot.

Frank, you or me?

Yeah, sure. So we don't yet have the procedures data for the second quarter. And as we noted in our last call, first quarter was lower in terms of upper endoscopy procedures than we've seen in prior quarters. But again, I think that the important focus here is on that multi-quarter trend, maybe trailing four. You draw a nice trend line, and you see the tissue ciphers fairly steady, fairly in line with where it's been through those maybe trailing three or four quarters. So we believe we probably – I don't know yet. I don't know if we did. We probably saw more procedures in the quarter than we saw in Q1. But, you know, when you trim that out, it's just good, solid increased penetration on the volume side for tissue cipher through the last year.

So I don't think we have any visibility to be able to comment on that question, I guess I would say.

I don't think, I was trying to think about our test report data for second quarter. I don't recall our reimbursement team saying there was a change in the mix of insured patients commercially, Medicare patients commercially, Medicare managed patients commercially, or Medicaid. Medicaid, we've always had a very low exposure, a couple of points is all. So I guess you would say, well, if there are less people ordering tests or going to doctors because they chose to back out of their insurance, we're not, we have no way to see that, I guess you would say.

So, I guess confidence is we have an enterprise model, I guess, similar to you that you do on the outside, and we're on the inside. And based upon what we see in our model against actuals, we believe we're still tracking towards what we thought we would do, which is kind of mid to high single digits for the year.

In terms of third and fourth quarter, second half expectations, I guess that would sort of take our first half And get a range and see how you get to the second half from a full year-end volume growth is the way I would approach that.

So, we are still managing sort of, I guess, field-based expectations. So, maybe the best way to go ahead and say it is that our field force in dermatology, I believe, for the remainder of the year, at least certainly third quarter, is relatively, you know, 80, 85, or 85 percent focused on cutaneous melanoma from sort of a call-focused commission bonus perspective. With the remaining 15% being, I guess, more heavier weighted to atopic dermatitis, advanced AD tests, and some on SCC from a bonus standpoint, just to make sure that we're balancing out both near-term needs, mid-term needs, and long-term needs.

So that will certainly, I think, change a bit of the acceleration in a positive manner for advanced AD without having us hopefully see a sacrifice in melanoma focus. We are still trying to manage volume so we don't get too far ahead of ourselves. But as you would know, if you don't create demand, then there isn't much of a reason to have Medicare or commercial payers to really step up and pay attention.

And as we sort of create volume, we can also model collections against our internal collection model. And as we get more confident with that towards the end of this year or half of the third quarter, That will let us go ahead and say now we should plan on opening things up a bit more in 2027.

Thank you, Operator. This concludes our second quarter 2026 earnings call. We thank you again for joining us today and for your continued interest in CASEL BIOSCIENCES. This concludes today's conference. You may disconnect your lines at this time. Thank you for your participation.