Aclaris Therapeutics, Inc._December 31, 2025

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF

THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2025 Commission file number 001-37581

ACLARIS THERAPEUTICS, INC.

Incorporated under the Laws of the I.R.S. Employer Identification No.

701 Lee Road, Suite 103

Wayne, PA19087

(484) 324-7933

Securities registered pursuant to Section 12(b) of the Act:

Common Stock, $0.00001 par value ACRS The Nasdaq Stock Market, LLC

Securities registered pursuant to Section 12(g) of the Act:

None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ◻No⌧

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Exchange Act. Yes ◻No⌧

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes⌧ No ◻

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes⌧ No ◻

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or emerging growth company. See definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ◻

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ◻

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ◻

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ◻

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ◻ No ⌧

As of June 30, 2025, the last business day of the registrant’s last completed second quarter, the aggregate market value of the registrant’s common stock held by non-affiliates of the registrant was approximately $149.2 million based on the closing price of the registrant’s common stock, as reported by the Nasdaq Global Select Market, on such date.

As of January 30, 2026, 120,595,189shares of common stock, $0.00001 par value, were outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

None.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report on Form 10-K (this “Annual Report”) contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), that involve substantial risks and uncertainties. The forward-looking statements are contained principally in Part I, Item 1. “Business,” Part I, Item 1A. “Risk Factors,” and Part II, Item 7. “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” but are also contained elsewhere in this Annual Report. In some cases, you can identify forward-looking statements by the words “may,” “might,” “can,” “will,” “to be,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “objective,” “anticipate,” “believe,” “estimate,” “predict,” “project,” “potential,” “likely,” “continue” and “ongoing,” or the negative of these terms, or other comparable terminology intended to identify statements about the future. These statements involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. Although we believe that we have a reasonable basis for each forward-looking statement contained in this Annual Report, we caution you that these statements are based on a combination of facts and factors currently known by us and our expectations of the future, about which we cannot be certain. Forward-looking statements include statements about:

● our plans to develop our product candidates;

● our plans and expectations related to manufacturing capabilities and strategy;

● the timing of our regulatory filings and approvals for our product candidates;

● our intellectual property position;

● our expectations regarding competition;

● the size and growth potential of the markets for our product candidates;

● our expectations regarding our continued reliance on third parties;

● the impacts of macroeconomic conditions on our business;

● our expectations regarding our use of capital; and

You should refer to Part I, Item 1A. “Risk Factors” in this Annual Report for a discussion of important factors that may cause our actual results to differ materially from those expressed or implied by our forward-looking statements. As a result of these factors, we cannot assure you that the forward-looking statements in this Annual Report will prove to be accurate, and you should not place undue reliance on these forward-looking statements. Furthermore, if our forward-looking statements prove to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve our objectives and plans in any specified time frame, or at all. The forward-looking statements in this Annual Report represent our views as of the date of this Annual Report. We anticipate that subsequent events and developments may cause our views to change. However, while we may elect to update these forward-looking statements at some point in the future, we undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. You should, therefore, not rely on these forward-looking statements as representing our views as of any date subsequent to the date of this Annual Report.

All brand names or trademarks appearing in this Annual Report, including KINect and RHOFADE, are the property of their respective owners. Unless the context requires otherwise, references in this report to “Aclaris,” the “Company,” “we,” “us,” and “our” refer to Aclaris Therapeutics, Inc. and its subsidiaries.

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Page

PART I

Item 1. Business 4

Item 1A. Risk Factors 22

Item 1B. Unresolved Staff Comments 64

Item 1C. Cybersecurity 64

Item 2. Properties 65

Item 3. Legal Proceedings 66

Item 4. Mine Safety Disclosures 66

PART II

Item 6. [Reserved] 67

Item 7A. Quantitative and Qualitative Disclosures About Market Risk 81

Item 8. Financial Statements and Supplementary Data 82

Item 9A. Controls and Procedures 108

Item 9B. Other Information 109

Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections 109

PART III

Item 10. Directors, Executive Officers and Corporate Governance 110

Item 11. Executive Compensation 114

Item 14. Principal Accountant Fees and Services 128

PART IV

Item 15. Exhibits and Financial Statement Schedules 129

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PART I

Item 1. Business

Overview

We are a clinical-stage biopharmaceutical company focused on discovering and developing novel small and large molecule product candidates for immuno-inflammatory diseases. Our proprietary KINect drug discovery platform coupled with our integrated discovery approach to small and large molecules enables us to identify and advance product candidates designed to have superior target affinity, specificity and potency. We are seeking to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our novel product candidates.

Our Approach

We are dedicated to developing a pipeline of novel product candidates to address the needs of patients with immuno-inflammatory diseases who lack satisfactory treatment options. Our approach to achieving this goal includes the following key elements:

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Our Key Product Candidate Pipeline

Our pipeline of key product candidates is summarized in the table below.

Bosakitug, an Investigational, Novel Anti-TSLP Monoclonal Antibody

Bosakitug (ATI-045) is an investigational, novel, humanized anti-TSLP monoclonal antibody that specifically binds to human TSLP, blocking its interaction with the receptor complex and disrupting signal transduction. This mechanism prevents immune cells targeted by TSLP from releasing proinflammatory cytokines. Bosakitug has potential best-in-class properties, including a very high affinity to TSLP, very high potency, an extremely low dissociation rate from TSLP leading to long residence time and enhanced neutralization activity, and a half-life that can potentially support an extended dosing interval. The high affinity and low dissociation observed with bosakitug may be the result of unique biparatopic binding to both the N- and C-terminus of TSLP. Bosakitug has the potential to treat a variety of atopic, immunologic and respiratory diseases. We exclusively license global rights (excluding Mainland China, Macau, Hong Kong and Taiwan (“Greater China”)) to bosakitug from Biosion, Inc. (“Biosion”).

In a Phase 2a, single-arm, proof-of-concept trial in 22 U.S. patients with moderate to severe atopic dermatitis conducted by Biosion, 94% of patients receiving bosakitug achieved at least a 75% improvement in the Eczema Area and Severity Index (“EASI”), 65% of patients achieved EASI-90, and 88% of patients achieved an Investigator’s Global Assessment (“IGA”) score of 0 or 1 (clear or almost clear skin), at week 26 (n=17). Bosakitug demonstrated a strong pharmacodynamic profile and was generally well-tolerated with no serious adverse events reported. The most common treatment-emergent adverse event was headache (22.7% of patients). Grade 1 injection site reactions, primarily tenderness, occurred in 47.6% of patients.

In June 2025, we initiated a Phase 2 trial to investigate the efficacy, safety, tolerability, pharmacokinetics (“PK”) and pharmacodynamics (“PD”) of bosakitug compared to placebo in approximately 96 patients with moderate to severe

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atopic dermatitis. The primary endpoint is percent change from baseline in EASI at week 24. Secondary endpoints at week 24 include EASI response (EASI-50, EASI-75, EASI-90), validated IGA response, body surface area (“BSA”) response, and Peak Pruritus Numerical Rating Scale (“PP-NRS”) score, relative to baseline. We expect to announce top-line data in the second half of 2026. Bosakitug is also currently being studied in severe asthma, chronic rhinosinusitis with nasal polyps and moderate to severe chronic obstructive pulmonary disease in China by CTTQ. CTTQ licenses bosakitug from Biosion in Greater China. Our clinical focus for bosakitug will remain on dermatological immuno-inflammatory indications and further global (excluding Greater China) development in respiratory indications will be dependent on entering into potential partnerships.

ATI-2138, an Investigational, Oral Covalent ITK/JAK3 Inhibitor

ATI-2138 is a highly potent and selective novel investigational dual inhibitor of ITK and JAK3 for the potential treatment of T cell-mediated autoimmune diseases. The unique dual pharmacology of ATI-2138 regulates T cell development and function both upstream (ITK) and downstream (JAK3), which may provide a more potent and complete anti-inflammatory response.

In July 2025, we announced positive top-line results from our open-label, single-arm Phase 2a trial of ATI-2138 in patients with moderate to severe atopic dermatitis. The trial met the primary and key secondary endpoints. The trial was designed to investigate the safety, tolerability, PK, efficacy, and PD of 10 mg of ATI-2138 administered twice daily (“BID”) for 12 weeks. The trial enrolled 14 patients in the United States, with 12 patients completing treatment and up to 10 patients available for the per protocol analysis. The primary endpoints were safety related parameters and the secondary endpoints included PD and efficacy related measures. No meaningful safety findings were observed, and ATI-2138 was very well tolerated. We observed consistent and rapid improvement across the efficacy assessments, with a mean and median improvement in EASI score at week 12 of 61% and 77%, respectively. Excluding one patient determined to be a statistical molecular outlier by more than four standard deviations who demonstrated systemic findings inconsistent with atopic dermatitis alone including significant non-lesional inflammation and who was not fully compliant with study drug administration, the mean and median improvement in EASI score at week 12 was 77% and 82%, respectively. At week 12, 63% of patients experienced a greater than or equal to 4-point improvement (which is considered a clinically meaningful response) in PP-NRS. Additional clinical results presented at the European Academy of Dermatology and Venerology conference in September 2025 further clarified the rapid improvements across efficacy measures, including week 4 decreases of 64% in BSA response (p<0.001), 77% in EASI score (p<0.001), and 45% in PP-NRS (p<0.01). These results were sustained through end of treatment at week 12. ATI-2138 demonstrated near complete and sustained inhibition and occupancy of ITK ranging from approximately 90% at peak to 60% to 70% at trough, and a high level of inhibition of JAK3. Proteome and transcriptome lesional skin tap strip analyses showed significant ATI-2138-dependent reduction of multiple inflammatory pathways associated with ITK, including strong downregulation of Th2, Th17, and T cell receptor (“TCR”) pathways, along with the Th1 pathway and fibrosis-related markers. The decreases in inflammatory and fibrosis-related markers positively and strongly correlated with improvements in clinical scores.

We are exploring the potential of ATI-2138 in additional indications that are relevant to the dual pharmacology and mechanism of action, including certain alopecias and other inflammatory disorders.

ATI-052, an Investigational, Novel Anti-TSLP and Anti-IL-4RaBispecific Antibody

ATI-052 is an investigational, novel, humanized anti-TSLP and anti-IL-4Ra bispecific antibody that exhibits high binding affinity to and dual blockage of both the upstream TSLP receptor signal transduction and downstream IL-4Ra activation thereby inhibiting this central proinflammatory pathway. ATI-052 binds TSLP, which sits at the top of the inflammatory cascade; by targeting IL-4Ra, it blocks downstream signaling of both IL-4 and IL-13, two anti-inflammatory cytokines, which are critical components of Th2-mediated immunity and play a crucial role in the pathogenesis of inflammation and allergic diseases. ATI-052 utilizes the same TSLP antigen-binding fragment (“Fab”) as bosakitug but is engineered to bind more tightly to the neonatal Fc receptor (“FcRn”), potentially extending its half-life. In addition, the AQQ mutation in the Fc limits effector functionality, reducing off-target binding and potential toxicity. ATI-052 has the potential to treat a variety of atopic, immunologic and respiratory diseases. We exclusively license global rights (excluding Greater China) to ATI-052 from Biosion.

In January 2026, we announced positive interim results from our Phase 1a single ascending dose (“SAD”) and multiple ascending dose (“MAD”) portion of our first-in-human study evaluating ATI-052 in healthy volunteers. The

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randomized, blinded, placebo-controlled study enrolled 48 participants across four SAD cohorts (receiving single doses of 30, 120, 360, or 720 mg or placebo) and two MAD cohorts (receiving five doses of 240 or 480 mg or placebo administered every seven days). ATI-052 demonstrated a favorable safety and tolerability profile across all dose levels, with treatment-emergent adverse events (“TEAEs”) being predominantly Grade 1 in severity. The most common TEAE was mild, self-resolving injection site redness, and notably, no conjunctivitis was observed in any cohort. No Grade 3 TEAEs related to study drug, serious adverse events, or discontinuations due to adverse events occurred. The PK profile showed dose proportionality across the pharmacologic dose range with an effective half-life of at least 26 days. PD results demonstrated robust target engagement with concentration-dependent inhibition of IL-4 and TSLP stimulated CCL17/TARC at all doses tested. At 360 mg, ATI-052 achieved complete and sustained inhibition through week three, with near complete inhibition of TSLP stimulated CCL17/TARC observed at least six weeks after administration. These combined PK and PD characteristics support the potential for dosing intervals of up to every three months. We expect to announce complete top-line results from the SAD and MAD cohorts in the second quarter of 2026.

Based on these positive results, we initiated a Phase 1b proof-of-concept trial in atopic dermatitis in January 2026 and a Phase 1b proof-of-concept trial in asthma in February 2026, with top-line data from both studies expected in the second half of 2026. We plan to initiate a Phase 2b program for ATI-052 with asthma and atopic dermatitis as potential first indications, in the second half of 2026.

ATI-9494, an Investigational, Oral Covalent ITK Inhibitor, and Other JAK-Sparing ITK Inhibitors

We are developing ATI-9494, a highly potent, oral, covalent, investigational dual inhibitor of ITK and Resting Lymphocyte Kinase (TXK), and other covalent JAK-sparing ITK inhibitors with differentiated pharmacological properties and selectivity profiles. These inhibitors have the potential to differentially modulate T cell biology across a broad range of disease indications with extended half-lives and potential best-in-class potency, ITK occupancy, and ITK activation at low doses. We expect to file an IND application for ATI-9494 in the second half of 2026.

Discovery and Preclinical Programs

We conduct small molecule drug discovery through KINect, our proprietary drug discovery platform. We also engage in discovery efforts for novel, injectable, multi-specific antibodies. Through our integrated discovery approach, we can progress product candidates from concept through lead optimization, employing robust screening cascades and protein characterization techniques to identify molecules with desired therapeutic properties.

Our KINect platform allows us to address challenges associated with difficult to drug kinases including selectivity and biochemical efficiency, through a unique combination of our proprietary chemical library of kinase inhibitors, our novel approaches to inhibitor modalities, our expertise in SBDD, and our custom kinase assays. Our approach involves the following mechanisms: (1) reversible and irreversible covalent inhibitors, (2) molecular glue/complex targeted inhibitors, (3) tissue specific inhibitors, and (4) targeted protein degraders. These novel approaches are currently being utilized to prosecute additional validated, difficult to drug kinase targets with the goal of demonstrating broad target utility. Our small molecule discovery efforts center on targeting kinases that play pivotal roles in various inflammatory and autoimmune pathways.

Reversible and Irreversible Covalent Inhibitors (small molecules inhibiting kinases by forming irreversible bonds with a cysteine at the active site): Central to the KINect platform is our novel chemical library of several hundred compounds specifically designed to target non-catalytic cysteine residues near the adenosine triphosphate (“ATP”) binding site of more than 300 kinases. Furthermore, using state-of-the-art drug modeling software, we are able to elaborate the structure of viable drug-like compounds culled from our library and extensive in silico libraries to optimize reversible binding to the target kinase and allow them to selectively form a covalent bond with the cysteine residue near the ATP site on the specific kinase target. This approach delivers inhibitors exhibiting enhanced potency, selectivity and biochemical efficiency thereby allowing pharmacological access to ‘hard to drug’ kinases. We then assess the function of the newly created compounds with physiologically relevant custom assays that effectively translate to human diseases.

Molecular Glue/Complex Targeted Inhibitors (small molecules that stabilize kinases in an inactive confirmation or ready them for degradation): Targeting kinase complexes with small molecule drugs designed to either stabilize (molecular glue) and/or generate inactive complexes provides several potential advantages over those designed against a single protein target including: (1) utilizing a more physiological translatable complex as the target, (2) providing novel protein interfaces devoid of competing endogenous ligands to target, and (3) identifying new chemical matter and

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modalities for difficult to drug kinase targets.

Tissue Specific Inhibitors (small molecules that inhibit kinases in target tissues with minimal systemic exposure): Target-specific inhibitors are drugs, often small molecules, designed to block specific proteins (like kinases) or pathways driving diseases including immunologic and inflammatory disorders. We believe that such inhibitors provide a unique opportunity to target certain diseases with highly specific compounds which may allow us to overcome potential systemic safety concerns and raise the efficacy ceiling.

Targeted Protein Degraders (small molecules that trigger the degradation of specific proteins by the ubiquitin/proteasome pathway): We believe targeted protein degraders represent a powerful approach to develop drugs against biologically important but difficult to drug proteins including kinases. This approach harnesses cellular protein clearing machinery to selectively remove proteins from the cell in contrast to inhibiting their function. This approach is particularly useful for kinases that have both catalytic and scaffolding functions for which inhibitors will only partially impact biology. We are exploring selective degraders of kinase targets with multiple biological functions in addition to the catalytic activity.

Our discovery efforts to develop multi-specific antibodies are focused on generating antibodies with superior target affinity, specificity, and potency utilizing combinations of (a) two or more clinically validated targets with non-overlapping biology, (b) clinically validated targets with novel biology, and/or (c) synergistic target combinations in an effort to address shortcomings of single drug administration. This complementary approach to our small molecule programs enables us to pursue optimal therapeutic modalities for each target and indication of interest. For example, we are progressing several bispecific antibodies utilizing the bosakitug anti-TSLP binding region paired with binding fragments targeting other undisclosed cytokine signaling pathways.

We intend to evaluate both internal and external development options, including strategic partnerships, for these assets.

Other Investigational Product Candidates

Lepzacitinib, an Investigational Topical “Soft” JAK 1/3 Inhibitor

Lepzacitinib (ATI-1777) is an investigational topical “soft” JAK 1/3 inhibitor for the potential treatment of atopic dermatitis and potentially other dermatologic conditions. “Soft” JAK inhibitors are designed to be topically applied and active in the skin, but rapidly metabolized and inactivated when they enter the bloodstream, which may result in low systemic exposure. We are currently seeking a global development and commercialization partner for this program (excluding Greater China). In 2022, we granted Pediatrix Therapeutics, Inc. (“Pediatrix”) exclusive rights to develop and commercialize lepzacitinib in Greater China.

Manufacturing and Supply

We do not have any manufacturing facilities. We rely on third parties for the manufacture of preclinical and clinical supplies for our product candidates.

Competition

The pharmaceutical industry is characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary drugs. While we believe that our knowledge, experience and scientific resources provide us with competitive advantages, we face potential competition from many different sources, including major pharmaceutical, biotechnology and specialty pharmaceutical companies, academic institutions and governmental agencies and public and private research institutions. Our product candidates, if approved, will compete with existing treatments and new treatments that may become available in the future.

With respect to bosakitug, we are aware of a number of companies with monoclonal antibodies also targeting the TSLP ligand, and one company targeting the TSLP receptor, including Amgen and AstraZeneca (Tezepelumab, AMG-104), KeyMed Biosciences (CM326), Uniquity Bio (solrikitug), Windward Bio and Harbour BioMed and Kelun-Biotech (WIN378/HBM9378), GlaxoSmithKline (“GSK”) (GSK5784283), Generate Biomedicines (GB-0895), Qyuns

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Therapeutics (QX008N), and UpStream Bio (verekutig).

With respect to ATI-052, our primary competitors include those developing multi-specific antibodies designed to inhibit both TSLP and IL-4Rα activity, such as Innovent Biologics (IBI3002) and Pfizer (PF-07275315).

Competitors for ATI-052 may also include those developing or commercializing multi-specific antibodies targeting two or more of TSLP, IL-4, and IL-13. For example, we are aware of Regeneron Pharmaceuticals and Sanofi (dupilumab), Sanofi (lunsekimig), Pfizer (PF-07264660), and KeyMed Biosciences (CM512).

With respect to bosakitug and ATI-052 as a potential treatment for atopic dermatitis, there are several different types of therapies in the atopic dermatitis market, such as biologics, oral and topical corticosteroids, oral and topical calcineurin inhibitors, oral mycophenolate products, JAK inhibitors, other oral antibiotics and antihistamines and phototherapy. There are also several prescription, non-prescription and over-the-counter topical products, including PDE4 inhibitors, utilized to treat atopic dermatitis. These types of drugs are produced and sold, or are approved for marketing, by large pharmaceutical companies, including AbbVie (upadacitinib), Incyte (ruxolitinib), LEO Pharma A/S (delgocitinib, tralokinumab), Pfizer (crisaborole; abrocitinib), Eli Lilly (lebrikizumab), Dermavant Sciences (tapinarof), Galderma (nemolizumab), and Regeneron Pharmaceuticals and Sanofi (dupilumab). In addition, we are aware of a number of companies developing and conducting clinical trials for investigational product candidates that could compete with bosakitug and ATI-052 in each case if approved, for the treatment of atopic dermatitis. With respect to ATI-052 as a potential treatment for asthma, existing therapeutics for asthma include controller medications, reliever medications, as well as biologics from Genentech and Novartis (omalizumab), Sanofi and Regeneron (dupilumab), GSK (mepolizumab, depemokimab), Amgen and AstraZeneca (tezepelumab), and AstraZeneca (benralizumab), with other products in development.

With respect to ATI-2138, there are several companies that are developing or have approved drugs that target either ITK or JAK that could compete with ATI-2138, if approved. For example, Corvus Pharmaceuticals is currently developing a selective, covalent inhibitor of ITK (soquelitinib). In addition, several companies are developing or have commercialized JAK inhibitors that may compete with ATI-2138, if approved, including Pfizer (tofacitinib, abrocitinib, and ritlecitinib), Eli Lilly (baricitinib), AbbVie (upadacitinib), and Sun Pharmaceutical (deuruxolitinib).

The commercial opportunity for our product candidates, if approved, could be reduced or eliminated if our competitors develop and commercialize drugs that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any drug we may develop. Our competitors also may obtain FDA or other regulatory approval for their product candidates more rapidly than our potential third-party partners may obtain approval for our product candidates, which could result in our competitors establishing a strong market position before our product candidates are able to enter the market.

Many of the companies against which we are competing, or against which we may compete in the future, have significantly greater financial resources and expertise in research and development, manufacturing, and preclinical and clinical development than we do. Mergers and acquisitions in the pharmaceutical and biotechnology industries may result in even more resources being concentrated among a smaller number of our competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with us in recruiting and retaining qualified scientific and management personnel and establishing clinical trial sites and subject registration for clinical trials, as well as in acquiring technologies complementary to, or that may be necessary for, our development programs.

Intellectual Property

Our success depends in large part upon our ability to obtain and maintain proprietary protection for our product candidates and to operate without infringing the proprietary rights of others. We seek to avoid the latter by monitoring patents and publications that may affect our business, and to the extent we identify such developments, evaluating and taking appropriate courses of action. Our policy is to protect our proprietary position by, among other methods, filing patent applications on inventions that are important to the development and conduct of our business with the U.S. Patent and Trademark Office (“USPTO”) and its foreign counterparts.

With respect to our TSLP monoclonal antibody development program, we exclusively license an issued patent and pending applications in the United States, European Union, Japan and South Korea directed to TSLP monoclonal

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antibodies, including bosakitug. Our issued U.S. patent expires in 2043 with its patent term adjustment, and the pending applications in the United States and foreign countries, if issued, would naturally expire in 2040, subject to any applicable patent term adjustment or extension that may be available in a particular country. We also exclusively license a pending international patent application filed under the Patent Cooperation Treaty (“PCT”) directed to methods of using TSLP monoclonal antibodies for the treatment of atopic dermatitis, which, if issued, would naturally expire in 2045, subject to any applicable patent term adjustment or extension that may be available in a particular country.

With respect to our ITK inhibitor development program, we own numerous issued patents and pending applications in the United States and foreign countries directed to novel inhibitors of ITK, including ATI-2138 and ATI-9494, and methods of use that expire, or would expire, between 2035 and 2046, subject to any applicable patent term adjustment or extension that may be available in a particular country. For example, we own multiple U.S. patent and pending U.S., European Union and other foreign country applications directed to ATI-2138 and analogs thereof and methods of using the same, which, if issued, would expire in 2039, subject to any applicable adjustment or extension. We also own a pending PCT application directed to methods of using ATI-2138, which if issued, would expire in 2043, subject to any applicable adjustment or extension. We also own pending PCT applications directed to crystal forms of ATI-2138 and to methods of synthesizing such ITK inhibitors, including ATI-2138, which if issued, would expire in 2044, and to methods of using ATI-2138 for treating atopic dermatitis, which if issued, would expire in 2045, in each case subject to any applicable adjustment or extension. We also own provisional applications on novel JAK-sparing inhibitors of ITK, including ATI-9494, which if issued, would expire in 2046.

With respect to our bispecific antibody development program, we exclusively license pending applications in the United States, Europe and other foreign countries directed to such bispecific antibodies, including ATI-052, which, if issued, would naturally expire in 2043, subject to any applicable patent term adjustment or extension that may be available in a particular country.

Patents extend for varying periods according to the date of patent filing or grant and the legal term of patents in various countries where patent protection is obtained. The actual protection afforded by a patent, which can vary from country to country, depends on the type of patent, the scope of its coverage and the availability of legal remedies in the country. In most countries in which we file, the patent term is 20 years from the earliest date of filing a non-provisional patent application. In the United States, a patent term may be shortened if a patent is terminally disclaimed over another patent or as a result of delays in patent prosecution by the patentee, and a patent’s term may be lengthened by patent term adjustment, which compensates a patentee for administrative delays by the USPTO in granting a patent or by patent term extension, which compensates a patentee for delays at the FDA. The patent term of a European patent is 20 years from its filing date; however, unlike in the United States, the European patent is not subject to patent term adjustments. The European Union does have a compensation program similar to patent term extension called supplementary protection certificate that would effectively extend patent protection for up to five years.

We also use other forms of protection, such as trademark, copyright, and/or trade secret protection, to protect our intellectual property, particularly where we do not believe patent protection is appropriate or obtainable. We aim to take advantage of all of the intellectual property rights that are available to us and believe that this comprehensive approach will provide us with proprietary positions for our product candidates, where available.

We also protect our proprietary information by requiring our employees, consultants, contractors and other advisors to execute nondisclosure and assignment of invention agreements upon commencement of their respective employment or engagement. Agreements with our employees also prevent them from bringing the proprietary rights of third parties to us. In addition, we also require confidentiality or service agreements from third parties that receive our confidential information or materials.

Acquisition and License Agreements

Exclusive License Agreement with Biosion

In November 2024, we entered into an exclusive license agreement (the “Biosion Agreement”) with Biosion, pursuant to which we received exclusive rights to develop, manufacture and commercialize bosakitug and ATI-052 worldwide, excluding Greater China. In connection with the Biosion Agreement, we also entered into a collaboration agreement (the “CTTQ Agreement”, and together with the Biosion Agreement, the “Biosion Agreements”) with Biosion and CTTQ, a licensee of bosakitug in Greater China.

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Under the Biosion Agreements, we paid, in the aggregate, $30.0 million in upfront cash consideration, $4.5 million for the reimbursement of certain development costs, plus $6.2 million for the reimbursement of certain development costs and drug product material. We also issued warrants in the aggregate to purchase 14,281,985 shares of our common stock with an exercise price of $0.00001 per share. The warrants are immediately exercisable, subject to any required overseas direct investment filings, and terminate when exercised in full. We also agreed to pay, in the aggregate (i) up to $125 million upon the achievement of specified regulatory milestones beginning with product approval, (ii) up to $795 million upon the achievement of specified sales milestones, (iii) a tiered low-to-mid single digit royalty based upon a percentage of annual net sales, subject to specified reductions, and (iv) a portion of any sublicense consideration received from granting sublicense or similar rights under any of the rights or licenses granted to us.

Agreement and Plan of Merger with Confluence

In 2017, we entered into an Agreement and Plan of Merger (the “Confluence Agreement”) with Confluence, Aclaris Life Sciences, Inc., our wholly owned subsidiary (“Merger Sub”), and Fortis Advisors LLC, as representative of the former equity holders of Confluence. Pursuant to the terms of the Confluence Agreement, Merger Sub merged with and into Confluence, with Confluence surviving as our wholly owned subsidiary, resulting in our acquisition of 100% of the outstanding shares of Confluence. As part of the Confluence acquisition we acquired, among others, our investigational product candidates lepzacitinib and ATI-2138.

Under the Confluence Agreement, we agreed to pay the former Confluence equity holders aggregate remaining contingent consideration of up to $75.0 million based upon the achievement of specified regulatory and commercial milestones set forth in the Confluence Agreement. In addition, we agreed to pay the former Confluence equity holders future royalty payments calculated as a low single-digit percentage of annual net sales, subject to specified reductions, limitations and other adjustments, until the date that all of the patent rights for that product have expired, as determined on a country-by-country and product-by-product basis or, in specified circumstances, ten years from the first commercial sale of such product. In addition to the payments described above, if we sell, license or transfer any of the intellectual property acquired from Confluence pursuant to the Confluence Agreement to a third party, we will be obligated to pay the former Confluence equity holders a portion of any consideration received from such sale, license, or transfer in specified circumstances.

Government Regulation and Product Approval

Governmental authorities in the United States, at the federal, state and local level, and analogous authorities in other countries extensively regulate, among other things, the research, development, testing, manufacture, safety surveillance, efficacy, quality control, labeling, packaging, distribution, record keeping, promotion, storage, advertising, distribution, marketing, sale, export and import, and the reporting of safety and other post-market information of products such as the ones we are developing. A drug or biological product candidate must be approved by the FDA before it may be legally promoted in the United States and by comparable foreign regulatory authorities before marketing in other jurisdictions. The process of obtaining regulatory approvals and the subsequent compliance with applicable federal, state, local and foreign statutes and regulations require the expenditure of substantial time and resources. Failure to comply with the applicable U.S. requirements at any time during the product development process, approval process or after approval may subject an applicant and/or sponsor to a variety of administrative or judicial sanctions, including refusal by regulatory authorities to approve applications, withdrawal of an approval, imposition of a clinical hold, import/export delays, issuance of warning letters and untitled letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, refusals of government contracts, restitution, disgorgement of profits, or civil or criminal investigations and penalties brought by FDA and the Department of Justice or other governmental entities.

United States Government Regulation

NDA and BLA Approval Processes

In the United States, the FDA regulates drugs under the Federal Food, Drug, and Cosmetic Act (“FDCA”) and its implementing regulations, and biologics under the FDCA, the Public Health Service Act (“PHSA”) and their implementing regulations. Drugs and biologicsalsoaresubjectto otherfederal,state,localand foreignstatutesand regulations.The processrequiredby theFDAbeforenew drug and biologicproduct candidatesmaybe marketedin theUnitedStates

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generallyinvolvesthefollowing:

● review of the NDA or BLA by an FDA advisory committee, if applicable;

● payment of user fees and securing FDA approval of the NDA or BLA; and

Once a drug or biological product candidate is identified for development, it enters the preclinical or nonclinical testing stage. Preclinical studies include laboratory evaluations of product chemistry, pharmacology, toxicity and formulation. An IND sponsor must submit the results of the preclinical studies, together with manufacturing information and analytical data, to the FDA as part of the IND. Some preclinical studies may continue even after the IND is submitted. In addition to including the results of the preclinical studies, the IND will also include a protocol detailing, among other things, the objectives of the clinical trial, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated if the first phase lends itself to an efficacy determination. The IND automatically becomes effective 30 days after receipt by the FDA, unless the FDA, within the 30-day time period, places the IND on clinical hold. In such a case, the IND sponsor and the FDA must resolve any outstanding concerns before clinical trials can begin. A clinical hold may occur at any time during the life of an IND, and may affect one or more specific clinical trials or all clinical trials conducted under the IND.

All clinical trials must be conducted under the supervision of one or more qualified investigators in accordance with current GCP regulations. They must be conducted under protocols detailing the objectives of the trial, dosing procedures, research subject selection and exclusion criteria, and the safety and effectiveness criteria to be evaluated. Each protocol must be submitted to the FDA as part of the IND, and progress reports detailing the status of the clinical trials must be submitted to the FDA annually, as well as safety reporting. An IRB for each site participating in the clinical trial must review and approve the protocol before the clinical trial commences at that institution and must also approve the information regarding the trial and the consent form that must be provided to each research subject or the subject’s legal representative, monitor the study until completed and otherwise comply with IRB regulations.

Clinical trials are typically conducted in three sequential phases that may overlap or be combined:

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Phase 4 clinical trials are conducted after approval to gain additional experience from the treatment of patients in the intended therapeutic indication and to document a clinical benefit in the case of drugs or biologics approved under accelerated approval regulations, or when otherwise requested by the FDA in the form of post-market requirements or commitments. Failure to promptly conduct any required Phase 4 clinical trials could result in withdrawal of approval of an NDA or BLA.

Clinical trials are inherently uncertain, and Phase 1, Phase 2 and Phase 3 testing may not be successfully completed. The FDA or the sponsor may suspend a clinical trial at any time for a variety of reasons, including a finding that the research subjects or patients are being exposed to an unacceptable health risk. Similarly, an IRB can suspend or terminate approval of a clinical trial at its institution if the clinical trial is not being conducted in accordance with the IRB’s requirements or if the drug or biological product candidate has been associated with unexpected serious harm to patients. In some cases, clinical trials are overseen by an independent group of qualified experts organized by the trial sponsor, which is called the clinical monitoring board or data safety monitoring board. This group provides authorization for whether or not a trial may move forward at designated check points. These decisions are based on the limited access to data from the ongoing trial.

During the development of a new drug or biologic, sponsors are given opportunities to meet with the FDA at certain points. These points may be prior to the submission of an IND, at the end of Phase 2 and before an NDA is submitted. Meetings at other times may be requested. These meetings can provide an opportunity for the sponsor to share information about the data gathered to date and for the FDA to provide advice on the next phase of development. Sponsors typically use the meeting at the end of Phase 2 to discuss their Phase 2 clinical trial results and present their plans for the pivotal Phase 3 clinical trial or trials that they believe will support the approval of the new drug or biologic.

Concurrent with clinical trials, sponsors usually complete additional animal safety studies and also develop additional information about the chemistry and physical characteristics of the drug or biologic and finalize a process for manufacturing commercial quantities of the product in accordance with cGMP requirements. The manufacturing process must be capable of consistently producing quality batches of the drug or biologic and the manufacturer must develop methods for testing the quality, purity and potency of the drug or biologic. Additionally, appropriate packaging must be selected and tested, and stability studies must be conducted to demonstrate that the drug or biological product candidate does not undergo unacceptable deterioration over its proposed shelf-life.

The results of product development, preclinical studies and clinical trials, along with descriptions of the manufacturing process, analytical tests and other control mechanisms, proposed labeling and other relevant information are submitted to the FDA as part of an NDA or BLA requesting approval to market the product. The submission of an NDA or BLA is subject to the payment of user fees, but a waiver of such fees may be obtained under specified circumstances. The FDA reviews all NDAs and BLAs submitted for a period of 60 days to ensure that they are sufficiently complete for substantive review before it accepts them for filing. It may request additional information rather than accept an NDA or BLA for filing. In this event, the NDA or BLA must be resubmitted with the additional information. The resubmitted application also is subject to review before the FDA accepts it for filing.

During the approval process, the FDA also will determine whether a risk evaluation and mitigation strategy (“REMS”) is necessary to assure the safe use of the product. If the FDA concludes a REMS is needed, the sponsor of the NDA or BLA must submit a proposed REMS, and the FDA will not approve the application without an approved REMS, if required. A REMS can substantially increase the costs of obtaining approval. The FDA could also require a special warning, known as a boxed warning, to be included in the product label in order to highlight a particular safety risk.

Once the submission is accepted for filing, the FDA begins an in-depth review. The FDA reviews an NDA to determine, among other things, whether a product is safe and effective for its intended use, and a BLA to determine, among other things, whether the product is safe, pure and potent for its intended use. As part of the NDA and BLA review, the FDA also evaluates whether the manufacturing of the drug or biologic product candidate is cGMP-compliant to assure and preserve the product’s identity, strength, quality, and purity. The FDA may refer the NDA or BLA to an advisory committee for review and recommendation as to whether the application should be approved and under what conditions. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendations. NDAs and BLAs receive either standard or priority review. A drug or biological product candidate representing a significant improvement in treatment, prevention or diagnosis of disease may receive priority review. A priority review

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designation is intended to direct overall attention and resources to the evaluation of such applications, and to shorten the FDA’s goal for taking action on the NDA or BLA from ten months to six months from filing of the NDA or BLA. After the FDA evaluates the NDA or BLA and conducts inspections of manufacturing facilities where the drug or biological product candidate and/or its active pharmaceutical ingredient will be produced, it may issue an approval letter or a Complete Response Letter. An approval letter authorizes commercial marketing of the drug or biologic with specific prescribing information for specific indications. A Complete Response Letter indicates that the review cycle of the application is complete, and the application is not ready for approval. A Complete Response Letter may require additional clinical data and/or an additional pivotal Phase 3 clinical trial(s), and/or other significant, expensive and time-consuming requirements related to clinical trials, preclinical studies or manufacturing. Even if such data and information are submitted, the FDA may ultimately decide that the NDA or BLA does not satisfy the criteria for approval.

Post-approval Requirements

Drugs and biologics manufactured or distributed pursuant to FDA approvals are subject to pervasive and continuing regulation by the FDA and other governmental agencies, including, among other things, requirements relating to recordkeeping, periodic reporting, product sampling and distribution, advertising and promotion, and reporting of adverse experiences with the product. Once an approval is granted, the FDA may withdraw the approval if compliance with regulatory requirements is not maintained or if problems occur after the product reaches the market. Later discovery of previously unknown problems with a product may result in restrictions on the product or even complete withdrawal of the product from the market. After approval, some types of changes to the approved product, such as adding new indications, manufacturing changes and additional labeling claims, are subject to further FDA review and approval. There are also continuing annual user fee requirements for products, as well as new application fees for certain supplemental applications. In addition, the FDA may require testing and surveillance programs to monitor the effect of approved products that have been commercialized, and the FDA has the power to prevent or limit further marketing of a product based on the results of these post-marketing programs.

Drug and biologic manufacturers and other entities involved in the manufacture and distribution of approved products are required to register their establishments with the FDA and certain state agencies and are subject to periodic unannounced inspections by the FDA and some state agencies for compliance with GMP regulations and other laws. The FDA has promulgated specific requirements for drug and biologic cGMPs. Changes to the manufacturing process are strictly regulated and often require prior FDA approval before being implemented. FDA regulations also require investigation and correction of any deviations from cGMP requirements and impose reporting and documentation requirements upon the sponsor and any third-party manufacturers that the sponsor may decide to use. Accordingly, manufacturers must continue to expend time, money, and effort in the area of production and quality control to maintain cGMP compliance.

Failure to comply with the applicable U.S. requirements at any time during the product development process or approval process, or after approval, may subject us to administrative or judicial sanctions, any of which could have a material adverse effect on us. These sanctions could include:

● refusal to approve pending applications;

● withdrawal of an approval;

● imposition of a clinical hold;

● warning letters;

● restrictions on the marketing or manufacturing of the product;

● injunctions, fines, disgorgement, or civil or criminal penalties.

The FDA strictly regulates the marketing, labeling, advertising and promotion of drug and biological products that are placed on the market. Drugs and biologics may be promoted only for the approved indications and in accordance with the provisions of the approved label. However, companies may share truthful and not misleading information that is otherwise consistent with the product’s FDA approved labeling. The FDA and other agencies actively enforce the laws and regulations prohibiting the promotion of off-label uses, and a company that is found to have improperly promoted off-label uses may be subject to significant liability. However, physicians may, in their independent medical judgment,

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prescribe legally available products for off-label uses. The FDA does not regulate the behavior of physicians in their choice of treatments, but the FDA does restrict sponsor communications on the subject of off-label use.

From time to time, legislation is drafted, introduced and passed in Congress that could significantly change the statutory provisions governing the approval, manufacturing and marketing of products regulated by the FDA. In addition, FDA regulations and guidance are often issued revised or reinterpreted by the agency in ways that may significantly affect our business and our product candidates. It is impossible to predict whether legislative changes will be enacted, or whether FDA regulations, guidance or interpretations will be issued or changed or what the impact of such changes, if any, may be.

Non-patent Exclusivity

The FDCA provides a five-year period of non-patent marketing exclusivity within the United States to the first applicant to obtain approval of an NDA for a new chemical entity (“NCE”). A drug is an NCE if the FDA has not previously approved any other new drug containing the same active moiety, which is the molecule or ion responsible for the action of the drug substance. If market exclusivity is granted for an NCE, during the exclusivity period, the FDA may not accept for review or approve an abbreviated new drug application (“ANDA”) or a 505(b)(2) NDA submitted by another company for another version of such drug where the applicant does not own or have a legal right of reference to all the data required for approval. However, an application may be submitted after four years if it contains a certification of patent invalidity or non-infringement to one of the patents listed with the FDA by the innovator NDA holder.

The FDCA also provides three years of marketing exclusivity for an NDA, or supplement to an existing NDA if new clinical investigations, other than bioavailability studies, that were conducted or sponsored by the applicant are deemed by the FDA to be essential to the approval of the application, for example new indications, dosages, dosage forms or strengths of an existing drug. This three-year exclusivity covers only the conditions associated with the new clinical investigations and prohibits the FDA from approving an ANDA or a 505(b)(2) NDA submitted by another company with overlapping conditions associated with the new clinical investigations for the three-year period. Clinical investigation exclusivity does not prohibit the FDA from approving ANDAs for drugs containing the original active agent. Five-year and three-year exclusivity will not delay the submission or approval of an NDA for the same drug. However, an applicant submitting an NDA would be required to conduct or obtain a right of reference to all of the preclinical studies and adequate and well-controlled clinical trials necessary to demonstrate safety and effectiveness.

Biosimilars and Exclusivity

The Biologics Price Competition and Innovation Act of 2009 (“BPCIA”) created an abbreviated approval pathway in the PHSA for biological products that are biosimilar to or interchangeable with an FDA-licensed reference biological product. Biosimilarity, which requires that there be no clinically meaningful differences between the biological product and the reference product in terms of safety, purity, and potency, can be shown through, as applicable, analytical studies, animal studies, and a clinical study or studies. Interchangeability means that a product is biosimilar to the reference product and can be expected to produce the same clinical results as the reference product in any given patient and, for products that are administered multiple times to an individual, the biologic and the reference biologic may be alternated or switched after one has been previously administered without increasing safety risks or risks of diminished efficacy relative to exclusive use of the reference biologic.

Under the BPCIA, an application for a biosimilar product may not be submitted to the FDA until four years following the date that the reference product was first licensed by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first licensed. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing that applicant’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity and potency of its product. The BPCIA also established an exclusivity period for biosimilars approved as interchangeable products. Substitution at the pharmacy level of biosimilar products deemed to be interchangeable is governed by state pharmacy law.

A biologicalproductcan alsoobtainpediatricmarketexclusivityin theUnitedStates.Pediatric exclusivity,ifgranted,adds sixmonthsto existingexclusivityprotection.This six-monthexclusivity,which runs fromtheend of otherexclusivityprotection,maybe grantedbasedon thevoluntarycompletionof a pediatric studyin accordancewith an FDA-issued “WrittenRequest”forsuch a study.

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Regulation Outside of the United States

Even if we obtain FDA approval for a drug or biological product candidate, we must obtain approval by the comparable regulatory authorities of countries outside of the United States before we can commence clinical trials in such countries, and our potential third-party partners must obtain approval of the regulators of such countries or economic areas, such as the European Union, before they may market any of our product candidates in those countries or areas. The approval process and requirements governing the conduct of clinical trials, product licensing and promotion, pricing and reimbursement vary greatly by geographic region, and the time may be longer or shorter than that required for FDA approval.

In the European Economic Area (“EEA”) which is composed of the Member States of the European Union plus Norway, Iceland and Liechtenstein, medicinal products can only be commercialized after obtaining a Marketing Authorization (“MA”).

There are two types of MAs:

In the EEA, upon receiving marketing authorization, NCEs generally receive eight years of data exclusivity and an additional two years of market exclusivity. If granted, data exclusivity prevents regulatory authorities in the EEA from referencing the innovator’s data to assess a generic application. During the additional two-year period of market exclusivity, a generic marketing authorization can be submitted, and the innovator’s data may be referenced, but no generic product can be marketed until the expiration of the market exclusivity. However, there is no guarantee that a product will be considered by the EEA’s regulatory authorities to be an NCE, and products may not qualify for data exclusivity.

Other Health Care Laws

Our current and future activities, as well as our potential third-party partners’ activities, may, directly or indirectly, expose us and them to broadly applicable fraud and abuse and other health care laws and regulations, including, without limitation, the federal Anti-Kickback Statute and the federal civil False Claims Act, that may constrain the business or financial arrangements and relationships through which any products for which marketing approval is obtained is sold, marketed and distributed. In addition, we and our potential third-party partners may be subject to transparency laws and patient privacy regulation by the federal government and by the U.S. states and foreign jurisdictions in which we or they conduct business.

The federal Anti-Kickback Statute makes it illegal for any person or entity, including a prescription drug manufacturer (or a party acting on its behalf) to knowingly and willfully, directly or indirectly, solicit, receive, offer, or pay any remuneration that is intended to induce the referral of business, including the purchase, order, or lease of any

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good, facility, item or service for which payment may be made under a federal health care program, such as Medicare or Medicaid. The term “remuneration” has been broadly interpreted to include anything of value. The Anti-Kickback Statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand and prescribers, purchasers, formulary managers, and beneficiaries on the other. Although there are a number of statutory exceptions and regulatory safe harbors protecting some common activities from prosecution, the exceptions and safe harbors are drawn narrowly. Practices that involve remuneration that may be alleged to be intended to induce prescribing, purchases or recommendations may be subject to scrutiny if they do not qualify for an exception or safe harbor. Failure to meet all of the requirements of a particular applicable statutory exception or regulatory safe harbor does not make the conduct per se illegal under the Anti-Kickback Statute. Instead, the legality of the arrangement will be evaluated on a case-by-case basis based on a cumulative review of all its facts and circumstances. Several courts have interpreted the statute’s intent requirement to mean that if any one purpose of an arrangement involving remuneration is to induce referrals of federal health care covered business, the Anti-Kickback Statute has been violated.

Additionally, the intent standard under the Anti-Kickback Statute was amended by the Patient Protection and Affordable Care Act of 2010, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively, the “Affordable Care Act”), to a stricter standard such that a person or entity no longer needs to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation. In addition, the Affordable Care Act codified case law that a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the federal civil False Claims Act.

Federal false claims and false statement laws, including the federal civil False Claims Act, prohibit, among other things, any person or entity from knowingly presenting, or causing to be presented, for payment to, or approval by, federal programs, including Medicare and Medicaid, claims for items or services, including drugs, that are false or fraudulent or not provided as claimed. Entities can be held liable under these laws if they are deemed to “cause” the submission of false or fraudulent claims by, for example, providing inaccurate billing or coding information to customers, promoting a product off-label, or for providing medically unnecessary services or items. In addition, activities relating to the sale and marketing of products are subject to scrutiny under such laws.

The federal Health Insurance Portability and Accountability Act of 1996 (“HIPAA”) prohibits among other actions, knowingly and willfully executing, or attempting to execute, a scheme to defraud any health care benefit program, including private third-party payors, knowingly and willfully embezzling or stealing from a health care benefit program, willfully obstructing a criminal investigation of a health care offense, and knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statement in connection with the delivery of or payment for health care benefits, items or services. Like the Anti-Kickback Statute, the Affordable Care Act amended the intent standard for the health care fraud statute under HIPAA such that a person or entity no longer needs to have actual knowledge of the statute or specific intent to violate it in order to have committed a violation.

The civil monetary penalties statute imposes penalties against any person or entity that, among other things, is determined to have presented or caused to be presented a claim to a federal health program that the person knows or should know is for an item or service that was not provided as claimed or is false or fraudulent.

Also, many states have similar fraud and abuse statutes or regulations that may be broader in scope and may apply regardless of payor, in addition to items and services reimbursed under Medicaid and other state programs. Additionally, to the extent that a product is sold in a foreign country, the seller may be subject to similar foreign laws.

In addition, legislation imposing marketing restrictions and transparency requirements on pharmaceutical manufacturers has been enacted at the state and federal levels. For example, the Affordable Care Act imposed, among other things, annual reporting requirements to the Centers for Medicare & Medicaid Services (“CMS”) for covered manufacturers for certain payments and other transfers of value provided to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors), other health care professionals (such as physician assistants and nurse practitioners) and teaching hospitals, as well as information regarding ownership and investment interests held by physicians and their immediate family members. Certain states also mandate implementation of compliance programs, impose restrictions on drug manufacturer marketing practices, require registration of certain employees engaged in marketing activities in the location, and/or require the tracking and reporting of gifts, compensation and other remuneration to health care professionals, including physicians.

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We may also be subject to data privacy and security regulation by both the federal government and the states in which we conduct our business. HIPAA, as amended by the Health Information Technology for Economic and Clinical Health Act (“HITECH”) and their implementing regulations, among other things, imposes standards relating to the privacy and security of individually identifiable health information on HIPAA covered entities, which include certain healthcare providers, healthcare clearing houses and health plans, and individuals and entities that provide services on their behalf that involve individually identifiable health information, known as business associates, as well as their covered subcontractors. In addition, certain state laws govern the privacy and security of health information in certain circumstances, some of which are more stringent than HIPAA and many of which differ from each other in significant ways and may not have the same effect, thus complicating compliance efforts.

Failure to comply with these laws, where applicable, can result in the imposition of significant penalties, including, without limitation, administrative, civil, and criminal penalties, damages, fines, disgorgement, imprisonment, contractual damages, reputational harm, diminished profits and future earnings, the curtailment or restructuring of our operations, exclusion from participation in federal and state health care programs, additional reporting requirements and oversight if we become subject to a corporate integrity agreement or similar agreement to resolve allegations of non-compliance with these laws and individual imprisonment.

Health Care Reform

In the United States, there have been and continue to be a number of significant legislative initiatives to contain health care costs. For example, in March 2010, the Affordable Care Act was passed, which has had, and is expected to continue to have, a significant impact on the health care industry. The Affordable Care Act was designed to, among other things, expand coverage for the uninsured and at the same time contain overall health care costs.

There have been executive branch, judicial and Congressional challenges and amendments to certain aspects of the Affordable Care Act. For example, on July 4, 2025, the One Big Beautiful Bill Act (the “OBBBA”), was signed into law, which narrowed access to Affordable Care Act marketplace exchange enrollment and declined to extend the Affordable Care Act enhanced advanced premium tax credits that expired at the end of 2025, which, among other provisions in the law, are anticipated to reduce the number of Americans with health insurance. The OBBBA also is expected to reduce Medicaid spending and enrollment by implementing work requirements for some beneficiaries, capping state-directed payments, reducing federal funding, and limiting provider taxes used to fund the program. Congress is considering proposed legislation intended to further reduce healthcare costs with alternatives to replace the expired Affordable Care Act subsidies. We expect that additional United States federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that the federal government will pay for healthcare products and services.

In addition, other legislative changes have been proposed and adopted since the Affordable Care Act was enacted. For example, in August 2011, the Budget Control Act of 2011, among other things, included aggregate reductions in Medicare payments to providers of 2% per fiscal year, which began in 2013 and will stay in effect through 2032 unless additional Congressional action is taken.

The current administration is pursuing policies to reduce regulations and expenditures across government agencies including at the U.S. Department of Health and Human Services (“HHS”), the FDA, CMS and related agencies. These actions, presently directed by executive orders or memoranda from the Office of Management and Budget, may propose policy changes that create additional uncertainty for our business. For example, the current administration has announced agreements with several pharmaceutical companies that require the drug manufacturers to offer, through a direct-to-consumer platform, U.S. patients and Medicaid programs prescription drug Most-Favored Nation pricing equal to or lower than those paid in other developed nations, with additional mandates for direct-to-patient discounts and repatriation of foreign revenues. Other recent actions, for example, include (1) directing agencies to reduce agency workforce and cut programs; (2) directing HHS and other agencies to lower prescription drug costs through a variety of initiatives, including by improving upon the Medicare Drug Price Negotiation Program and establishing Most-Favored-Nation pricing for pharmaceutical products; (3) imposing tariffs on imported pharmaceutical products; and (4) as part of the Make America Healthy Again Commission’s Strategy Report released in September 2025, working across government agencies to increase enforcement on direct-to-consumer pharmaceutical advertising. Additionally, the current administration recently called on Congress to enact “The Great Healthcare Plan,” to codify and expand Most-Favored Nation pricing, lower government subsidies to private insurance companies, increase healthcare price transparency, expand pharmaceutical drugs available for over-the-counter purchase, and enact restrictions on pharmacy benefit manager

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payment methodologies, among other things. These actions and policies may significantly reduce U.S. drug prices, potentially impacting manufacturers’ global pricing strategies and profitability, while increasing their operational costs and compliance risks. In June 2024, in Loper Bright Enterprises v. Raimondo, the United States Supreme Court greatly reduced judicial deference to regulatory agencies, which could increase successful legal challenges to federal regulations affecting our or our potential partners’ operations. Congress may introduce and ultimately pass health care related legislation that could impact the drug approval process and make changes to the Medicare Drug Price Negotiation Program.

At the state level, legislatures have become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access and marketing cost disclosure and transparency measures, and, in some cases, designed to encourage importation from other countries and bulk purchasing. Any such importation plans, if implemented, may result in lower drug prices for products covered by those programs.

Existing and future federal and state health care reform measures could harm our future revenue. Additional legislative actions may be taken in the future which may change current regulations, guidance and interpretations. The impact of such actions on our business, if any, cannot presently be determined.

The Hatch Waxman Amendments to the FDCA

Orange Book Listing

In seeking approval for a drug through an NDA, applicants are required to list with the FDA each patent whose claims cover the applicant’s product or a method of using the product. Upon approval of a drug, each of the patents listed in the application for the drug is then published in the FDA’s Approved Drug Products with Therapeutic Equivalence Evaluations, commonly known as the Orange Book. Drugs listed in the Orange Book can, in turn, be cited by potential competitors in support of approval of an ANDA or an application covered by Section 505(b)(2) of the FDCA. An ANDA provides for marketing of a drug product that has the same active ingredients, generally in the same strengths and dosage form, as the listed drug and has been shown through PK testing to be bioequivalent to the listed drug. Drugs approved in this way are commonly referred to as “generic equivalents” to the listed drug and can often be substituted by pharmacists under prescriptions written for the original listed drug. Other than the requirement for bioequivalence testing, ANDA applicants are generally not required to conduct, or submit results of, preclinical studies or clinical tests to prove the safety or effectiveness of their drug product. Section 505(b)(2) applications provide for marketing of a drug product that may have the same active ingredients as the listed drug and contains full safety and effectiveness data as an NDA, but at least some of this information comes from studies not conducted by or for the applicant. This alternate regulatory pathway enables the applicant to rely, in part, on the FDA’s findings of safety and efficacy for an existing product, or published literature, in support of its application. The FDA may then approve the new product candidate for all or some of the labeled indications for which the referenced product has been approved, as well as for any new indication sought by the 505(b)(2) applicant.

The ANDA or Section 505(b)(2) applicant is required to certify to the FDA concerning any patents listed for the approved product in the FDA’s Orange Book. Specifically, the applicant must certify that: (i) the required patent information has not been filed; (ii) the listed patent has expired; (iii) the listed patent has not expired, but will expire on a particular date and approval is sought after patent expiration; or (iv) the listed patent is invalid or will not be infringed by the new product. The ANDA or Section 505(b)(2) applicant may also elect to submit a statement certifying that its proposed ANDA label does not contain, or carves out, any language regarding a patented method of use rather than certify to such listed method of use patent. If the applicant does not challenge the listed patents by filing a certification that the listed patent is invalid or will not be infringed by the new product, the ANDA or Section 505(b)(2) application will not be approved until all the listed patents claiming the referenced product have expired.

A certification that the new product will not infringe the already approved product’s listed patents, or that such patents are invalid, is called a Paragraph IV certification. If the ANDA or Section 505(b)(2) applicant has provided a Paragraph IV certification to the FDA, the applicant must also send notice of the Paragraph IV certification to the NDA and patent holders once the ANDA or Section 505(b)(2) application has been accepted for filing by the FDA. The NDA and patent holders may then initiate a patent infringement lawsuit in response to the notice of the Paragraph IV certification. The filing of a patent infringement lawsuit within 45 days of the receipt of a Paragraph IV certification automatically prevents the FDA from approving the ANDA or Section 505(b)(2) application until the earliest of 30 months, expiration of the patent, settlement of the lawsuit, and a decision in the infringement case that is favorable to

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the ANDA or Section 505(b)(2) applicant. This prohibition is generally referred to as the 30-month stay. Thus, approval of an ANDA or 505(b)(2) NDA could be delayed for a significant period of time depending on the patent certification the applicant makes and the reference drug sponsor’s decision to initiate patent litigation.

The ANDA or Section 505(b)(2) application also will not be approved until any applicable non-patent exclusivity listed in the Orange Book for the referenced product has expired.

Patent Term Extension

In the United States, after NDA approval or BLA licensure, owners of relevant drug patents may apply for up to a five-year patent extension, which provides patent term restoration as compensation for the patent term lost during the FDA regulatory review process for the first permitted commercial marketing of a drug product. The Drug Price Competition and Patent Term Restoration Act of 1984 (the “Hatch-Waxman Act”), permits a patent term extension of up to five years beyond the expiration of the patent. The allowable patent term extension is calculated as half of the drug’s testing phase, which is the time between the IND submission becoming effective and the NDA or BLA submission, and all of the review phase, which is the time between NDA or BLA submission and approval, up to a maximum extension of five years. The time can be shortened if the FDA determines that the applicant did not pursue approval with due diligence. Patent extension cannot extend the remaining term of a patent beyond a total of 14 years from the date of product approval and only one patent applicable to an approved drug may be extended.

Similar provisions are available in the European Union and other foreign jurisdictions to extend the term of a patent that covers an approved drug. For example, in Japan, it may be possible to extend the patent term for up to five years and in the European Union, it may be possible to obtain a supplementary protection certificate that would effectively extend patent protection for up to five years.

Coverage and Reimbursement

We believe the success of our product candidates, if approved, will depend on obtaining and maintaining coverage and adequate reimbursement as a prescription treatment or in the absence of coverage and adequate reimbursement, on the extent to which patients will be willing to pay out of pocket for our prescription drug products.

Third-party payors determine which prescription drug products they will cover and establish reimbursement levels. Reimbursement by a third-party payor may depend upon a number of factors, including: the third-party payor’s determination that a product is safe, effective, and medically necessary; appropriate for the specific patient; cost-effective; supported by peer-reviewed medical journals or current clinical practice guidelines; and whether there are competitive products, either branded or generic, and the pricing of those products. Many private third-party payors, such as managed care plans, manage access to drug products’ coverage partly to control costs for their plans, and may use drug formularies and medical policies to limit their exposure. Obtaining and maintaining favorable reimbursement can be a time-consuming and expensive process, and our potential third-party partners may not be able to negotiate or continue to negotiate reimbursement or pricing terms for our product candidates, if approved, with third-party payors at levels that are profitable to us, or at all. Further coverage policies and third-party reimbursement rates may change at any time. Even if favorable coverage and reimbursement status is attained for one or more products which receive regulatory approval, less favorable coverage policies and reimbursement rates may be implemented in the future.

In addition to uncertainties surrounding coverage policies, there are periodic changes to reimbursement. Third-party payors regularly update reimbursement amounts and also from time to time revise the methodologies used to determine reimbursement amounts. Accordingly, these updates could impact the demand for our product candidates, if approved. Our product candidates, if approved, may not be considered cost effective, and government and third-party private health insurance coverage and reimbursement may not be available to patients or sufficient to allow our potential third-party partners to sell our product candidates, if approved, on a competitive and profitable basis. Further, the containment of healthcare costs also has become a priority of federal, state and foreign governments and the prices of drugs have been a focus in this effort. For example, HHS imposes rebates on many Medicare Part B and Medicare Part D products to penalize price increases that outpace inflation on an annual basis. HHS has also been empowered to negotiate the price of certain single-source drugs that have been on the market for at least seven (7) years covered under Medicare as part of the Medicare Drug Price Negotiation Program. Each year up to twenty (20) products will be selected by HHS for the Medicare Drug Price Negotiation Program. Products subject to the Medicare Drug Price Negotiation Program are expected to experience a significant reduction in reimbursement from the Medicare program on a per unit basis. In addition, increasing emphasis on managed care in the United States will continue to put pressure on the pricing of pharmaceutical products. Cost control initiatives could decrease the price that our potential third-party partners could receive for any of

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our product candidates, if approved, and could adversely affect our profitability. We cannot predict how pending and future health care legislation will impact our business, and any changes in coverage and reimbursement that further restricts coverage of our product candidates could harm our business.

Foreign governments also have their own health care reimbursement systems, which vary significantly by country and region, and we cannot be sure that coverage and adequate reimbursement will be made available with respect to our product candidates, if approved, under any foreign reimbursement system. In some foreign countries, including major markets in the European Union and Japan, the pricing of prescription pharmaceuticals is subject to governmental control. In these countries, pricing negotiations with governmental authorities can take up to 12 months or longer after the receipt of regulatory marketing approval for a product. To obtain reimbursement or pricing approval in some countries, we may be required to conduct a pharmacoeconomic study that compares the cost-effectiveness of our product to other available therapies. Such pharmacoeconomic studies can be costly and the results uncertain. Our business could be harmed if reimbursement of our product candidates, if approved, is unavailable or limited in scope or amount or if pricing is set at unsatisfactory levels.

Employees and Human Capital Resources

As of December 31, 2025, we had 73 total employees, of which 69 were full-time employees. None of our employees are represented by a labor union or covered by a collective bargaining agreement. We consider our relationship with our employees to be good. In addition to our employees, we engage consultants and independent contractors to provide flexibility in support of our business execution and objectives.

Our human capital resources objectives include, as applicable, identifying, recruiting, retaining, incentivizing and integrating our existing and new employees, advisors and consultants. The principal purposes of our equity incentive plans are to attract, retain and reward personnel through the granting of stock-based compensation awards in order to increase stockholder value and the success of our company by motivating such individuals to perform to the best of their abilities and achieve our objectives.

Corporate Information

We were incorporated under the laws of the State of Delaware in July 2012. Our principal executive offices are located at 701 Lee Road, Suite 103, Wayne, PA 19087. Our telephone number is (484) 324-7933. Our common stock is listed on the Nasdaq Global Select Market under the symbol “ACRS.”

Available Information

Our internet website address is www.aclaristx.com. In addition to the information contained in this Annual Report, information about us can be found on our website. Our website and information included in or linked to our website are not part of this Annual Report.

Our annual reports on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K and amendments to those reports filed or furnished pursuant to Section 13(a) or 15(d) of the Exchange Act are available free of charge through our website as soon as reasonably practicable after they are electronically filed with or furnished to the Securities and Exchange Commission (“SEC”). The SEC also maintains a website that contains our reports, proxy and information statements and other information. The address of the SEC’s website is www.sec.gov.

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Item 1A. Risk Factors

Our business is subject to numerous risks. You should carefully consider the following risks and all other information contained in this Annual Report, as well as general economic and business risks, together with any other documents we file with the SEC. If any of the following events actually occur or risks actually materialize, it could have a material adverse effect on our business, operating results and financial condition and cause the trading price of our common stock to decline.

Summary of Risk Factors

Risks Related to Our Business, Our Financial Position and Capital Needs

We have incurred significant losses since our inception. We expect to incur losses over the next several years and may never achieve or maintain profitability.

Since inception, we have incurred significant net losses. We incurred net losses of $64.9 million and $132.1 million for the years ended December 31, 2025 and 2024, respectively. As of December 31, 2025, we had an accumulated deficit of $967.8 million. We have financed our operations over the last several years primarily from sales of equity securities and non-dilutive financing.

We have devoted substantially all of our financial resources and efforts to the development of our product candidates, including preclinical studies and clinical trials. Our net losses may fluctuate significantly from quarter to quarter and year to year. We expect to continue to incur significant expenses and operating losses in the near term as we:

● continue to develop our product candidates;

● continue to discover and develop additional product candidates;

● maintain, expand and protect our intellectual property portfolio; and

To become and remain profitable, we must succeed in a range of challenging activities, including completing preclinical testing and clinical trials of our product candidates and identifying and consummating transactions with third-

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party partners for the further development and/or commercialization of our product candidates, as well as discovering and developing additional product candidates. We are in the early stages of most of these activities. We may never succeed in these activities and, even if we do, may never earn revenue from our product candidates that is significant enough to achieve profitability.

For any of our product candidates, our revenue will be dependent, in part, upon our ability to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize those product candidates. Further, we will be dependent on our potential third-party partners’ ability to obtain marketing approval and successfully commercialize the product, upon the size of the markets in the territories where marketing approval is obtained, the accepted price for the product, and the ability to obtain coverage and reimbursement, if any. If we fail to identify and enter into partnerships with third parties to further develop, obtain marketing approval for and/or commercialize our product candidates, any partnerships we enter into do not result in the successful development, marketing approval for and commercialization of our product candidates, the number of addressable patients is not as significant as estimated by our potential third-party partners, the indication approved by regulatory authorities is narrower than expected, or the treatment population is narrowed by competition, physician choice or treatment guidelines, we may not earn significant revenue from agreements with potential third-party partners for such product candidates, even if the product candidates are approved for marketing.

Because of the numerous risks and uncertainties associated with drug development, we are unable to accurately predict the timing or amount of expenses or when, or if, we will be able to achieve profitability. If we are required by regulatory authorities to perform studies in addition to those expected, or if there are any delays in the initiation and completion of our clinical trials, the development of any of our product candidates or the identification and consummation of transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, our expenses could increase.

Even if we achieve profitability, we may not be able to sustain or increase profitability on a quarterly or annual basis. Our failure to become and remain profitable would depress the value of our company and could impair our ability to raise capital, expand our business, maintain our development efforts or continue our operations. A decline in the value of our company could also cause you to lose all or part of your investment.

We will need substantial additional funding to meet our financial obligations and to pursue our business objectives. If we are unable to raise capital when needed, we could be forced to curtail our planned operations.

Identifying potential product candidates and conducting preclinical testing and clinical trials is a time-consuming, expensive and uncertain process that takes years to complete, and we may never generate the necessary data or results required to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates. We expect to incur significant expenses and operating losses for the foreseeable future as we advance our product candidates from discovery through preclinical and clinical development. In addition, we may not be able to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, and our product candidates, if approved, may not achieve commercial success. Furthermore, we incur and expect to continue to incur significant costs associated with operating as a public company, including legal, accounting, investor relations and other expenses.

As of December 31, 2025, we had cash, cash equivalents and marketable securities of $151.4 million. We believe that our existing cash, cash equivalents and marketable securities as of the date of this Annual Report will enable us to fund our operating expenses and capital expenditure requirements for a period greater than 12 months from the date of this report based on our current operating assumptions. These assumptions may prove to be wrong, and we could use our available capital resources sooner than we expect. Changes may occur beyond our control that would cause us to consume our available capital before that time, including changes in and progress of our development activities, acquisitions of products or product candidates, and changes in regulation. Our future capital requirements will depend on many factors, including:

● the costs, timing and outcome of regulatory review of our product candidates;

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We will require additional capital to develop our product candidates and to support our discovery efforts. Additional funds may not be available on a timely basis, on commercially acceptable terms, or at all, and such funds, if raised, may not be sufficient to enable us to continue to implement our long-term business strategy. Our ability to raise additional capital may be adversely impacted by potential worsening global economic conditions caused by a variety of factors including geopolitical tensions, tariff policies, and inflationary pressures.If we are unable to raise sufficient additional capital or generate revenue from transactions with potential third-party partners for the development and/or commercialization of our product candidates, we could be forced to curtail our planned operations.

Raising additional capital may cause dilution to our stockholders, restrict our operations or require us to relinquish rights to our technologies, intellectual property, potential future revenue streams or product candidates.

Until such time, if ever, as we can earn substantial revenue, we expect to finance our cash needs through a combination of equity offerings, debt financings and license and partnership agreements or other non-dilutive financing. To the extent that we raise additional capital through the sale of equity securities or convertible debt securities, our stockholders’ ownership interest will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of holders of our common stock. Debt financing and preferred equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends.

If we raise additional funds through partnerships, strategic alliances or marketing, distribution or licensing arrangements with potential third-party partners, we may be required to relinquish valuable rights to our technologies, intellectual property, potential future revenue streams, or product candidates or grant licenses on terms that may not be favorable to us. If we are unable to raise additional funds through equity or debt financings or other arrangements with third parties when needed, we may be required to delay, limit, reduce or terminate our drug development efforts or grant rights to third parties to develop technologies, intellectual property, or product candidates that we would otherwise prefer to develop ourselves.

We have a limited history as a clinical-stage biopharmaceutical company developing and partnering our product candidates, which may make it difficult to evaluate the success of our business to date and to assess our future viability.

Our operations over the last several years have been largely focused on undertaking preclinical studies and conducting clinical trials, drug discovery, acquiring new product candidates and related intellectual property, and raising capital. We have had limited time to demonstrate our ability to successfully develop, manufacture and identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates. Consequently, any predictions you make about our future success or viability may not be as accurate as they could be if we had a longer history of being a clinical-stage biopharmaceutical company focused on developing and partnering product candidates. We may also encounter unforeseen expenses, difficulties, complications, delays and other known or unknown factors in achieving our business objectives.

Certain estimates of market opportunity and forecasts may prove to be smaller than we believe.

The estimates of market opportunity and forecasts of market growth included in documents that we file with the SEC may prove to be smaller than we believe, and even if the markets in which we compete achieve the forecasted growth, our business may not grow at similar rates, or at all. Our projections of addressable patient populations within the indications we pursue are based on our estimates and independent market research, industry and general publications obtained from third parties. Market opportunity estimates and growth forecasts included in this Annual Report and the other documents that we file with the SEC are subject to significant uncertainty and are based on assumptions and estimates. These estimates, which have been derived from a variety of sources, including scientific literature and market research, may prove to be incorrect. Further, new studies may change the estimated incidence or prevalence of these indications. Additionally, the potentially addressable patient population may not ultimately be amenable to treatment with

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our product candidates. Our market opportunity may also be limited by current and future products of our competitors that are already available in the market or may enter the market for such patients. If any of our estimates prove to be inaccurate, the market opportunity for our product candidates could be significantly diminished and have an adverse material impact on our business.

Risks Related to the Development and Potential Commercialization of Our Product Candidates

Biologics carry unique risks and uncertainties, which could have a negative impact on future results of operations.

The successful discovery, development, manufacturing and sale of biologics is a long, expensive and uncertain process subject to more complex regulatory requirements than small molecule drugs. There are unique risks and uncertainties with biologics. For example, access to and supply of necessary biological materials, such as cell lines, may be limited and governmental regulations restrict access to and regulate the transport and use of such materials. In addition, the development, manufacturing and sale of biologics is subject to regulations that are often more complex and extensive than the regulations applicable to other pharmaceutical products. Manufacturing biologics, especially in large quantities, is often complex and may require the use of innovative technologies. The types of analytical development data necessary for verifying structural biocomparability when changing manufacturing sites is also more difficult and complex to generate for biologics than for other pharmaceutical products. Such manufacturing also requires facilities specifically designed and validated for this purpose and sophisticated quality assurance and quality control procedures. Biologics are also frequently costly to manufacture because production inputs are derived from living animal or plant material, and some biologics cannot be made synthetically. In addition, the regulatory scrutiny of and landscape for the chemistry, manufacturing and analytical controls information is also considered to be more complex for biologics than other pharmaceutical products. Failure to successfully discover, develop and manufacture our biological product candidates would adversely impact our business and future results of operations.

We may not be successful in our efforts to identify and develop additional product candidates, including through leveraging our KINect drug discovery platform.

A key element of our approach is to identify and develop additional novel product candidates, including through leveraging our KINect drug discovery engine. Our platform is powered by a unique combination of our proprietary chemical library of kinase inhibitors, our novel approaches to inhibitor modalities, our expertise in SBDD, and our custom kinase assays. Our ability to identify and develop additional product candidates is subject to numerous risks, including that:

In addition, discovery programs require substantial technical, financial and human resources. We may not be able to maintain sufficient resources and expertise to discover additional product candidates. It could take years to identify a viable product candidate, and there is a risk that we may never do so. If we are unable to identify successful product candidates for preclinical and clinical development and regulatory approval in a timely matter or at all, we could experience significant delays or an inability to successfully identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, which could harm our business.

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The rapid advancement of artificial intelligence and computational drug discovery technologies could make our KINect platform and discovery approaches less competitive or obsolete, and our failure to successfully adopt and integrate artificial intelligence technologies could put us at a competitive disadvantage.

The pharmaceutical and biotechnology industries are experiencing rapid transformation through artificial intelligence (“AI”), machine learning (“ML”), and computational approaches to drug discovery and development. Large pharmaceutical companies and well-funded biotechnology companies are making substantial investments in AI-driven drug discovery platforms that may:

Our KINect drug discovery platform, while innovative, may become less competitive if we fail to successfully integrate advanced AI and ML capabilities. Specifically:

Furthermore, the use of AI in drug discovery and development raises new regulatory uncertainties. Regulatory agencies including the FDA are still developing frameworks for evaluating AI-generated data and AI-assisted drug development processes. If we utilize AI technologies, we may face uncertainty about what data and documentation regulators will require regarding AI-generated discoveries, potential challenges to the patentability of AI-discovered compounds or methods, questions about data integrity, bias, or validity of AI-generated predictions, and/or additional regulatory scrutiny or requirements that could delay our development timelines.

Our ability to remain competitive will depend on our capacity to adopt and integrate appropriate AI and computational technologies, which will require significant investment in technology infrastructure, data systems, and personnel with specialized expertise. If we are unable to successfully leverage these technologies, or if we make substantial investments in AI approaches that do not yield productive results, our competitive position and financial condition could be materially harmed.

Additionally, the potential use of AI by contract research organizations, clinical trial sites, or regulatory agencies could change the standards and expectations for drug development, requiring us to adapt our processes and potentially increasing our costs and development timelines.

If we are unable to successfully develop our product candidates and identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, or experience significant delays in doing so, our business will be harmed.

We have invested significant efforts and financial resources in the development of our product candidates and the identification of potential product candidates. Our ability to earn substantial revenue from our product candidates will depend heavily on our ability to successfully develop and identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize these product candidates. The success of any product candidates that we develop will depend on several factors, including:

● successful completion of preclinical studies and our clinical trials;

● successful development of manufacturing processes;

● receipt of timely approvals from applicable regulatory authorities;

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● maintaining compliance with regulatory requirements, including cGMPs;

Whether marketing approval will be granted is unpredictable and depends upon numerous factors, including the substantial discretion of the regulatory authorities. Our product candidates’ success in clinical trials will not guarantee marketing approval. Following submission, the NDA or BLA for any product candidate may not be accepted for substantive review, or even if it is accepted for substantive review the FDA or other comparable foreign regulatory authorities may require additional studies or clinical trials, additional data, or additional manufacturing steps, or require other conditions before they will reconsider or approve the application, which could increase costs and cause delays in the marketing approval process and which may require the expenditure of additional resources. These delays would also impact our ability to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates. In addition, the FDA or other comparable foreign regulatory authorities may not consider sufficient any additional required studies, clinical trials, data or information that we perform and complete or generate, or we may decide to abandon the program.

It is possible that our product candidates currently in development will never obtain marketing approval. If we do not achieve one or more of these factors in a timely manner or at all, we could experience significant delays or an inability to successfully identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, which would harm our business.

Clinical drug development involves a lengthy and expensive process, with an uncertain outcome. We may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development of our product candidates or the identification and consummation oftransactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates.

The risk of failure for our product candidates is high. It is impossible to predict when or if any of our product candidates will prove effective or safe in humans or will receive marketing approval. Before obtaining regulatory approval for the sale of any product candidate, we must complete preclinical development and then conduct extensive clinical trials to demonstrate the safety and efficacy of our product candidates in humans for use in the target indication. Clinical testing is expensive, difficult to design and implement, can take many years to complete and is inherently uncertain as to outcome.

A failure of one or more clinical trials can occur at any stage of testing. The outcome of preclinical testing and early clinical trials may not be predictive of the success of later clinical trials, and interim results of a clinical trial do not necessarily predict final results. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain marketing approval of their drugs.

Additionally, we may utilize an “open-label” clinical trial design. For example, our Phase 2a trial of ATI-2138 in patients with atopic dermatitis was an “open label” trial. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational product candidate or either an existing approved drug or placebo. Most open-label clinical trials test only the investigational product candidate and sometimes may do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may

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be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. The results from an open-label trial may not be predictive of future clinical trial results of a product candidate when studied in a controlled environment with a placebo or active control.

We may experience numerous unforeseen events during or as a result of clinical trials that could delay or prevent our ability to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, including:

We could also encounter delays if a clinical trial is suspended or terminated by us, by the IRBs of the institutions in which such trials are being conducted, by a data safety monitoring board for such trial or by the FDA or other regulatory authorities. Such authorities may impose such a suspension or termination due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or our clinical protocols, inspection of the clinical trial operations or trial site by the FDA or other regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from using a drug, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial.

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If we experience delays in the completion of, or termination of, any clinical trial of our product candidates, our costs will increase, our product candidate development process will be slowed, the commercial prospects of our product candidates will be harmed, and our ability to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates will be delayed. Any of these occurrences may harm our business, financial condition and prospects significantly. In addition, many of the factors that cause, or lead to, a delay in the commencement or completion of clinical trials may also ultimately lead to the denial of marketing approval of our product candidates. If we are required to conduct additional clinical trials or other testing of our product candidates beyond those that we currently contemplate, if we are unable to successfully complete clinical trials of our product candidates or other testing, if the results of these trials or tests are not favorable or if there are safety concerns, we may not be able to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates, and our potential third-party partners may:

● be delayed in obtaining marketing approval for our product candidates;

● not obtain marketing approval at all;

● be subject to additional post-marketing testing requirements; or

● have the drug removed from the market after obtaining marketing approval.

Our drug development costs will also increase if we experience delays in testing. We do not know whether any of our preclinical studies or clinical trials will begin as planned, will need to be restructured or will be completed on schedule, or at all. Significant preclinical study or clinical trial delays also could shorten any periods during which our potential third-party partners may have the exclusive right to commercialize our product candidates or allow competitors to bring drugs to market before such third-party partners do, which would impact our ability to successfully identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates.

If we experience delays or difficulties in the enrollment of subjects in clinical trials, our ability to identify and consummatetransactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates could be delayed or prevented.

Successful and timely completion of clinical trials will require that we enroll a sufficient number of subjects. Recruiting and retaining patients for clinical trials has become increasingly difficult and expensive, which could delay or prevent completion of our trials. Subject enrollment, a significant factor in the timing of clinical trials, is affected by many factors including the size and nature of the patient population. Trials may be subject to delays as a result of subject enrollment taking longer than anticipated or subject withdrawal, including as a result of factors beyond our control. We may not be able to initiate or continue clinical trials for our product candidates if we are unable to locate and enroll a sufficient number of eligible patients to participate in these trials as required by the FDA or similar regulatory authorities outside the United States. We cannot predict how successful we will be at enrolling subjects in future clinical trials. Subject enrollment is affected by other factors including:

● the eligibility criteria for the trial in question;

● the perceived risks and benefits of the product candidate in the trial;

● the availability of drugs approved to treat the disease in the trial;

● the efforts to facilitate timely enrollment in clinical trials;

● the patient referral practices of physicians;

● the ability to monitor subjects adequately during and after treatment; and

Our inability to enroll a sufficient number of subjects for clinical trials would result in significant delays and could require us or them to abandon one or more clinical trials altogether. Enrollment delays in these clinical trials may result in increased development costs for our product candidates, which would cause the value of our company to decline and limit our ability to obtain additional financing. Furthermore, we rely on and expect to continue to rely on CROs and clinical trial sites to ensure the proper and timely conduct of our clinical trials and we will have limited influence over

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their performance. Any delays in completing clinical trials would delay or prevent our ability to identify and consummate transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates.

Our clinical trials may fail to demonstrate the safety and efficacy of our product candidates, or serious adverse or unacceptable side effects or other unfavorable safety findings may be identified during the nonclinical or clinical development of our product candidates, which could increase our costs or necessitate the abandonment or limitation of the development of our product candidates or prevent or delay our ability identify and consummatetransactions with third-party partners to further develop, obtain marketing approval for and/or commercialize our product candidates.

If our product candidates are associated with side effects in clinical trials, exhibit adverse toxicological findings in nonclinical studies or have characteristics that are unexpected, our costs could increase or we may need to abandon their development or limit development to more narrow uses in which the side effects or other characteristics are less prevalent, less severe or more acceptable from a risk-benefit perspective. The FDA or an IRB may also require that we suspend, discontinue, or limit our clinical trials based on nonclinical or clinical safety information. Such findings could further result in regulatory authorities failing to provide marketing authorization for our product candidates. Many product candidates that initially showed promise in early-stage testing have later been found to cause side effects or exhibit toxicological profiles in animal models that prevented further development of the product candidate.

Before any potential third-party partners can obtain marketing approvals for the commercial sale of our product candidates, we must demonstrate through lengthy, complex and expensive preclinical testing and clinical trials that our product candidates are both safe and effective for use in each target indication, and failures can occur at any stage of testing. Our nonclinical studies may yield results that are not predictive of future clinical results or that reveal safety concerns that preclude further development.Clinical trials often fail to demonstrate safety and efficacy of the product candidate studied for the target indication.

Additionally, if we or others identify undesirable side effects orunfavorable nonclinical safety findings caused by our product candidates, a number of potentially significant negative consequences could result, including:

● regulatory authorities may withdraw approval to market such product;

● regulatory authorities may require additional warnings on the labels;

● we could be sued and held liable for harm caused to patients;

Any of these events could prevent us from identifying and consummating transactions with third-party partners to further develop, obtain marketing approval for and/or commercialize the particular product candidate and could significantly harm our business, results of operations and prospects.

Interim, topline and preliminary data from our clinical trials that we announce or publish from time to time may change as more subject data become available and are subject to audit and verification procedures that could result in material changes in the final data.

From time to time, we may publicly disclose interim, topline or preliminary data from our clinical trials, which are based on a preliminary analysis of then-available data, and the results and related findings and conclusions are subject to change following a full analysis of all data related to the particular trial. For example, we recently announced interim Phase 1a data for ATI-052. We also make assumptions, estimations, calculations and conclusions as part of our analyses of data, and we may not have received or had the opportunity to fully and carefully evaluate all data. In addition, we may report preliminary analyses of only certain endpoints rather than all endpoints. As a result, the interim, topline or preliminary results that we report may differ from future results of the same trials, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated. Topline data also remain subject to audit and verification procedures that may result in the final data being materially different from the

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preliminary data we previously published. As a result, interim, topline and preliminary data should be viewed with caution until the final data are available. Interim data from clinical trials that we may complete are subject to the risk that one or more of the clinical outcomes may materially change as subject enrollment continues and more subject data become available. Adverse differences between interim, topline or preliminary data and final data could significantly harm our reputation and business prospects. Further, disclosure of interim, topline or preliminary data by us or by our competitors could result in volatility in the price of our common stock.

ACRS US Equity

ACRS · 10-K · period ended 2025-12-31

Item 1. Business

Item 1A. Risk Factors

ACRS US Equity☆

ACRS · 10-K · period ended 2025-12-31

Item 1. Business

Item 1A. Risk Factors

ACRS US Equity