Aclaris公布ATI-0522在特应性皮炎和哮喘的1b期阳性POC数据，并优先推进EoE 2b期

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UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
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FORM
8-K
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CURRENT REPORT
Pursuant to Section 13 or 15(d) of
The Securities Exchange Act of 1934
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Date of Report (Date of earliest event reported):
October 27, 2026
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Aclaris Therapeutics, Inc.
(Exact name of registrant as specified in its charter)
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Delaware
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001-37581
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46-0571712
(State or other jurisdiction of incorporation)
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(Commission File Number)
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(IRS Employer
Identification No.)
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701 Lee Road
,
Suite 103
Wayne
,
PA
19087
(Address of principal executive offices, including zip code)
​
(
484
)
324-7933
(Registrant’s telephone number, including area code)
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N/A
(Former name or former address, if changed since last report)
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Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:
☐
Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)
☐
Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)
☐
Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))
☐
Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))
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Securities registered pursuant to Section 12(b) of the Act:
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Title of Each Class:
​ ​ ​
Trading Symbol(s)
​ ​ ​
Name of Each Exchange on which Registered
Common Stock, $0.00001 par value
ACRS
The Nasdaq Stock Market, LLC
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Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).
​
Emerging growth company
☐
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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.
☐
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Item 2.02 Results of Operations and Financial Condition.
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The information disclosed under the heading “Cash, Cash Equivalents and Marketable Securities as of September 30, 2026” under Item 8.01 of this Current Report on Form 8-K is incorporated herein by reference.
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Item 7.01 Regulation FD Disclosure.
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On October 27, 2026, Aclaris Therapeutics, Inc. (the “
Company
”) issued a press release announcing primary analysis results from the Phase 1b proof-of-concept (“
POC
”) trials of its anti-TSLP/IL-4Rα bispecific antibody ATI-052 in atopic dermatitis (“
AD
”) and asthma
(the “
Results
”). The Company also announced it would hold a webcast and conference call with slides related to the Results.  A copy of the press release and the presentation that will accompany the webcast and conference call are furnished as Exhibit 99.1 and Exhibit 99.2, respectively, to this Current Report on Form 8-K.
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In accordance with General Instruction B.2. of Form 8-K, the information in this Item 7.01 and Item 9.01 (including Exhibits 99.1 and 99.2) shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “
Exchange Act
”), or otherwise subject to the liability of that section, nor shall it be deemed incorporated by reference in any of the Company’s filings under the Securities Act of 1933, as amended, or under the Exchange Act, whether made before or after the date hereof, regardless of any incorporation language in such a filing, except as expressly set forth by specific reference in such a filing.
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Item 8.01 Other Events.
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Cash, Cash Equivalents and Marketable Securities as of September 30, 2026
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Based upon preliminary estimates and information available to the Company, it estimates that its cash, cash equivalents and marketable securities were approximately $204.6 million as of September 30, 2026.  This amount has not been audited, reviewed, or compiled by the Company’s independent registered public accounting firm. The Company’s actual cash, cash equivalents and marketable securities as of September 30, 2026 may differ from this amount after it completes its comprehensive accounting procedures for the quarter ended September 30, 2026, and any such differences may be material.
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Primary Analysis Results
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The Results announced are summarized below.
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Phase 1b POC Trial in AD
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The randomized, double-blind, placebo-controlled Phase 1b trial evaluated the safety and tolerability of ATI-052 compared with placebo in 14 patients with severe AD. Patients were randomized 3:1 to receive five weekly doses of 480 mg of ATI-052 or placebo from weeks 0 through 4. Endpoints for the primary analysis were assessed at day 57.
​
Four patients were excluded from the prespecified per-protocol analysis for reasons defined before unblinding. Two patients in the ATI-052 arm were excluded because one received only two doses and one did not meet the eligibility criteria. Two patients in the placebo arm were excluded because they took rescue medication early in the study. The resulting per-protocol population consisted of nine patients in the ATI-052 arm and one patient in the placebo arm. Among per-protocol patients in the ATI-052 arm, 78% had severe disease at baseline, as defined by a score of 4 on the Validated Investigator’s Global Assessment (“
vIGA
”).
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Primary analysis results from the AD trial included:
​
Eczema Area and Severity Index (“
EASI
”) Score:
​
●
Patients treated with ATI-052 experienced a 45% placebo-adjusted mean improvement in EASI score from baseline at day 57, reflecting a 58% mean improvement in the ATI-052 arm compared with a 13% mean improvement in the placebo arm. Patients treated with ATI-052 experienced a 62% mean improvement from baseline in EASI score at week 10 and EASI improvement was maintained through week 16, for the subset of patients with available data.
​
2
●
In post hoc analyses of patients treated with ATI-052, mean improvements from baseline in EASI score at week 10 were 82% among patients with a baseline vIGA of 3 and 56% among those with a baseline vIGA of 4.
●
Patients treated with ATI-052 experienced a 78% placebo-adjusted EASI-50 at day 57. Of those, in a post-hoc analysis, 100% of patients with a baseline severity of vIGA 3 achieved placebo-adjusted EASI-50 at day 57 compared to 71% of patients with a baseline severity of vIGA 4.
●
In a post-hoc analysis, 89% of subjects treated with ATI-052 achieved EASI-50 during the study.
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Peak Pruritus Numerical Rating Scale (“
PP-NRS
”):
​
●
Improvement in itch was observed in the first week and continued to deepen through week 10 in patients with available data.
●
At week 4, patients that received ATI-052 experienced a 40% placebo-adjusted mean improvement from baseline and absolute mean improvement from baseline in PP-NRS.
●
At day 57, patients that received ATI-052 experienced a 43% placebo-adjusted mean improvement in PP-NRS, reflecting a 38% mean absolute improvement in the ATI-052 arm compared with a 5% mean worsening in the placebo arm.
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At day 57, patients treated with ATI-052 achieved a placebo-adjusted response rate of 33% for a ≥4-point improvement from baseline in PP-NRS.
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Pharmacodynamic Results:
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●
At day 57, patients treated with ATI-052 experienced a 95% overall improvement in the difference between lesional and non-lesional skin proteome.
●
ATI-052 broadly downregulated inflammatory pathways, with modulation across multiple inflammatory mediators in AD, including Th1, Th2 and Th17/Th22, fibrosis/extracellular matrix remodeling and itch-associated molecular pathways.
●
ATI-052 produced a pronounced reduction of established dupilumab-associated biomarkers and additionally suppressed Th1, Th17 innate and myeloid pathways. Endogenous serum biomarkers, including CCL17, IL-5, and blood eosinophils, were also reduced.
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Phase 1b POC Trial in Asthma
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The randomized, double-blind, placebo-controlled Phase 1b trial evaluated the safety and tolerability of a single 480 mg dose of ATI-052 compared with placebo in 16 patients with mild-to-moderate asthma and baseline fractional exhaled nitric oxide (“
FeNO
”) of at least 35 parts per billion. Patients were randomized 3:1 to receive a single 480 mg dose of ATI-052 or placebo. Endpoints for the primary analysis were assessed through day 29. The analysis population consisted of 12 patients in the ATI-052 arm and four patients in the placebo arm.
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Primary analysis results from the asthma trial included:
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FeNO:
​
●
At day 15, patients that received ATI-052 experienced a 59% mean reduction from baseline in FeNO, representing a mean absolute reduction of 45 parts per billion, compared with a 15% mean reduction in the placebo arm.
●
A 40% mean reduction from baseline in FeNO was observed at day 29 in patients that received ATI-052.
●
At day 15, 58% of patients that received ATI-052 achieved FeNO normalization, defined as FeNO of 25 parts per billion or less.
●
In a post-hoc analysis, at day 15, patients treated with ATI-052 experienced FeNO reductions of 60% in the eosinophil ≥300 subgroup (T2-high) and 58% in the eosinophil <300 subgroup (T2-low).
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3
Forced Expiratory Volume in One Second (“
FEV1
”):
​
●
At day 15, patients that received ATI-052 experienced a 200 mL placebo-adjusted and absolute mean improvement in FEV1.
●
In a post hoc subgroup analysis of patients with baseline pre-bronchodilator FEV1 of less than 80% predicted and qualifying reversibility, patients that received ATI-052 experienced a 350 mL mean improvement from baseline in FEV1 at day 15, compared with a 140 mL mean decrease from baseline in the placebo arm.
●
In a post-hoc analysis, FEV1 improvement was also observed in T2-high and T2-low subgroup populations.
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Area Under Reactance Curve (“
AX
”):
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●
In a post-hoc analysis, at day 15, patients treated with ATI-052 experienced a placebo-adjusted AX change of −28 cmH
₂
O·L
⁻
¹ in patients with baseline FEV1 <80% predicted and qualifying reversibility.
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Safety and Tolerability
​
ATI-052 was well tolerated across both trials and demonstrated a favorable safety profile. Treatment-emergent adverse events (“
TEAE
s”) were predominantly Grade 1. There were no Grade 3 or Grade 4 TEAEs, and no adverse events led to study discontinuation. Injection-site reactions were transient, almost exclusively Grade 1 and observed at a low frequency. No conjunctivitis was observed.
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Pipeline Update
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The Company intends to prioritize the clinical development of ATI-052 initially in eosinophilic esophagitis (“
EoE
”). The Company intends to initiate a Phase 2b trial of ATI-052 in EoE in early 2027 and expects to provide an update regarding plans for the potential development of ATI-052 in an additional indication in the near term.
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​
Cautionary Note Regarding Forward-Looking Statements
​
This Current Report on Form 8-K contains “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Exchange Act, and such forward-looking statements are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as “anticipate,” “believe,” “expect,” “intend,” “may,” “plan,” “potential,” “will,” and similar expressions, and are based on the Company’s current beliefs and expectations. These forward-looking statements include expectations regarding the Company’s development plans for ATI-052, including its intention to prioritize development of ATI-052 initially in EoE, the timing to initiate a Phase 2b trial of ATI-052 in EoE and the timing and plans to pursue development of ATI-052 in additional indications, the therapeutic potential for ATI-052, and the Company’s preliminary estimate of its cash, cash equivalents and marketable securities as of September 30, 2026. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the conduct of clinical trials, potential changes to interim, topline and preliminary data as more subject data become available, the Company’s reliance on third parties over which it may not always have full control, the Company’s ability to enter into strategic partnerships on commercially reasonable terms, the uncertainty regarding the macroeconomic environment and other risks and uncertainties that are described in the Risk Factors section of the Company’s Annual Report on Form 10-K for the year ended December 31, 2025, and other filings the Company makes with the U.S. Securities and Exchange Commission from time to time. These documents are available under the “SEC Filings” page of the “Investors” section of the Company’s website at www.aclaristx.com. Any forward-looking statements speak only as of the date of this Current Report on Form 8-K and are based on information available to the Company as of the date of this Current Report on Form 8-K, and the Company assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise.
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4
Item 9.01 Financial Statements and Exhibits.
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(d) Exhibits
Exhibit
Number
Exhibit Description
99.1
​
Press Release.
99.2
​
Company Presentation.
104
The cover page from Aclaris Therapeutics, Inc.’s Form 8-K filed on October 27, 2026, formatted in Inline XBRL.
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​
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5
SIGNATURES
Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.
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ACLARIS THERAPEUTICS, INC.
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​
​
​
By:
/s/ Kevin Balthaser
Date: October 27, 2026
​
Kevin Balthaser
​
​
Chief Financial Officer
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6

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EX-99.1
2
acrs-ex99d1.htm
EX-99.1
Exhibit 99.1
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Aclaris Therapeutics Announces Positive Phase 1b Proof-of-Concept Primary Analysis Results for its Anti-TSLP/IL-4Rα Bispecific ATI-052 in Atopic Dermatitis (AD) and Asthma
- Results Demonstrated Breadth and Rapidity of Response to ATI-052 in Heterogeneous Patient Populations; Pharmacodynamic Results Demonstrated Potential for Additivity/Synergy of Targeting TSLP and IL-4R
α
-
- Rapid and Durable Improvement in Skin and Itch Observed in Severe AD Population with ATI-052; Single Dose Rapidly Improved Airway Inflammation and Lung Function in Diverse Asthma Population -
- ATI-052 Demonstrated Favorable Safety and Tolerability Profile Including No Observations of Conjunctivitis -
- Aclaris to Prioritize Development in Eosinophilic Esophagitis (EoE), Consistent with Development Strategy -
- Aclaris to Host Conference Call this Morning at 8:00 AM ET-
WAYNE, Pa., October 27, 2026 --
Aclaris Therapeutics, Inc. (NASDAQ: ACRS), a clinical-stage biopharmaceutical company focused on developing novel product candidates for immuno-inflammatory diseases, today announced positive primary analysis results from the Phase 1b proof-of-concept (POC) trials of its anti-TSLP/IL-4Rα bispecific antibody ATI-052 in atopic dermatitis and asthma. Both trials demonstrated strong proof-of-concept with rapid and broad responses to ATI-052, further validating the additive/synergistic potential of simultaneously targeting TSLP, IL-4, and IL-13 with a bispecific anti-TSLP/IL-4Rα antibody, and achieved the primary objective, showing a favorable safety profile including no observations of conjunctivitis. Slides accompanying this announcement will be available for download at the time of the conference call
here
.
Aclaris intends to prioritize Phase 2b development of ATI-052 initially in EoE, where the Company believes a focused development program is well aligned with its development strategy and disciplined capital management.
“These strong results convey ‘the art of the possible’ with this bispecific mechanism in heterogeneous diseases across diverse patient populations and support that this is a potent, broadly acting compound with potential best-in-class activity,” said Dr. Neal Walker, Chief Executive Officer of Aclaris. “Across heterogeneous patient populations, we observed breadth and depth of response, normalization of the immune proteome, encouraging early durability, evidence of potential synergy of targets, and a favorable safety profile associated with ATI-052 – all of which clarify its potential across indications. Consistent with our development strategy, we intend to prioritize initiating a Phase 2b trial in EoE early next year and provide an update on plans for a potential additional indication in the near term.”
Primary Analysis Results: Safety
ATI-052 was well tolerated across both trials and demonstrated a favorable safety profile. Treatment-emergent adverse events (TEAEs) observed in these POC trials were predominantly Grade 1. There were no Grade 3 or 4 TEAEs, and no adverse events led to study discontinuation. Injection site reactions (ISR) were transient, almost exclusively Grade 1, and observed at a low frequency. No conjunctivitis was observed.
Phase 1b POC Trial in Atopic Dermatitis (AD)
The randomized (3:1), double-blind, placebo-controlled Phase 1b trial evaluated the safety and tolerability of ATI-052 compared with placebo in 14 patients with severe AD. Enrolled patients received five weekly doses of 480 mg of ATI-052 or placebo from weeks 0 through 4, and endpoints for the primary analysis were assessed at day 57. Four patients were excluded from the prespecified per-protocol analysis for reasons defined before unblinding: Two in the
​
1
ATI-052 arm (only two doses taken; eligibility criteria not met) and two in the placebo arm (both began rescue medication early on). Among per-protocol patients in the active arm, 78% had severe disease at baseline, as defined by a score of 4 on the Validated Investigator’s Global Assessment (vIGA), setting a high bar for success.
Primary Analysis Results: AD
Eczema Area and Severity Index (EASI) Score
·
Patients treated with ATI-052 experienced a 45% placebo-adjusted mean change in EASI score from baseline at day 57 (absolute change of 58% in the active arm vs 13% in the placebo arm). Responses were durable for the subset of patients with available data at week 16 (follow up ongoing).
·
Patients treated with ATI-052 experienced a 78% placebo-adjusted EASI-50 at day 57. Of those, 100% of patients with a baseline severity of vIGA 3 achieved placebo-adjusted EASI-50 at day 57 compared to 71% of patients with a baseline severity of vIGA 4.
Peak Pruritus Numerical Rating Scale (PP-NRS)
·
Itch relief emerged in the first week and continued to deepen through week 10 in patients with available data despite high baseline disease severity. At week 4, patients that received ATI-052 experienced a 40% placebo-adjusted and absolute mean improvement from baseline in itch (PP-NRS).
·
Patients that received ATI-052 experienced a 43% placebo-adjusted mean improvement in itch (PP-NRS) at day 57 (38% absolute improvement in the active arm vs a 5% worsening in the placebo arm).
·
At day 57, 33% of patients experienced a placebo-adjusted mean improvement of ≥4-points in itch (PP-NRS4).
“These ATI-052 data in AD are very noteworthy, not only in strength of response at day 57 but also in rapidity and durability of response,” said Dr. Michael Cameron, M.D., FAAD, CEO of Equity Medical and Assistant Clinical Professor, Department of Dermatology at Mount Sinai in New York, and an investigator in the trial. “Given the mechanism of ATI-052, one would expect reductions in EASI and itch from baseline to be rapid and sustained due to blockade of IL-4 and IL-13 via their shared receptor IL-4R
α
, and durable through blockade of the TSLP alarmin. This is consistent with my experience during the trial. For example, one of my longstanding refractory patients responded quickly to ATI-052 and had a durable response that lasted months beyond their last dose. This bodes well for the mechanism in future clinical trials.”
Pharmacodynamic (PD) Results
·
95% normalization in the lesional skin proteome was observed at week 8 in patients that received ATI-052, with immune protein expression resembling that of non-lesional skin.
·
ATI-052 broadly downregulated pathways, with modulation across multiple inflammatory mediators in AD, including Th1, Th2 and Th17/Th22, fibrosis/ECM remodeling, and itch-associated molecular pathways.
·
ATI-052 produced a pronounced reduction of the established dupilumab biomarkers, additionally suppressing Th1, Th17 innate, and myeloid pathways, suggesting a potential best-in-class footprint.
“These ATI-052 pharmacodynamic biomarker results in patients with AD are clear, and significantly correlated to the efficacy results,” said Emma Guttman, M.D., Ph.D., Waldman Professor of Dermatology and Immunology and Health System Chair of the Kimberly and Eric J. Waldman Department of Dermatology at the Icahn School of Medicine at Mount Sinai in New York City. “Among the most important findings were the overall improvements to the immune
​
2
proteome in patients receiving ATI-052; key immune proteins were significantly downregulated by ATI-052 compared to placebo, potentially highlighting the contribution of added benefit of blocking TSLP in this indication, with the proteomic phenotype of lesional skin closely resembling that of non-lesional skin already at week 8. These results, including ATI-052’s ability to modulate all three T helper cell related markers, are suggestive of early potent anti-inflammatory clinical activity.”
Phase 1b POC Trial in Asthma
The randomized (3:1), double-blind, placebo-controlled Phase 1b trial evaluated the safety and tolerability of a single 480 mg dose of ATI-052 compared with placebo in 16 patients with mild-to-moderate asthma and baseline fractional exhaled nitric oxide (FeNO) of at least 35 parts per billion (ppb). Endpoints were assessed through day 29.
Primary Analysis Results: Asthma
Fractional Exhaled Nitric Oxide (FeNO)
·
Following a single dose of ATI-052, patients experienced a rapid 59% mean absolute reduction in FeNO (45 ppb) only 15 days after administration compared to 15% in the placebo arm, and a 40% reduction at day 29.
·
58% of patients on ATI-052 achieved FeNO normalization (≤25 ppb) at day 15 after a single dose, highlighting the rapid onset of response.
Forced Expiratory Volume in One Second (FEV1)
·
Following a single ATI-052 dose, patients responded rapidly, experiencing a placebo adjusted and absolute mean improvement of 200 ml in FEV1 only 15 days after administration.
·
In a post hoc subgroup analysis of the enrolled patients with FEV1 of <80% at baseline with reversibility, which models the typical Phase 2b/3 eligible population of patients, an absolute mean improvement in FEV1 of 350 ml from baseline was observed at day 15 compared to a worsening of FEV1 of -140 ml in the placebo arm.
“In such a Phase 1b trial, the goals are to ensure safety and to develop some encouraging signals; in this case, the results are significantly better than encouraging,” said Dr. Chris Brightling, Clinical Professor in Respiratory Medicine at the University of Leicester and Deputy Director and Respiratory and Infection Theme Lead, NIHR Biomedical Research Centre: Leicester. “Of particular interest are the rapid improvements in the breath biomarker FeNO, both in the overall population and when stratified by baseline eosinophils, and the lung function test FEV1, with maximum effects that are at least as good if not improving on those seen by comparator compounds.”
Webcast and Conference Call
Aclaris will host a webcast and conference call with slides today at 8:00 AM ET to discuss the Phase 1b POC primary analysis results in asthma and AD. The live and archived webcast will be available on the Events page of the Company’s website: https://investor.aclaristx.com/events. The webcast will be archived on the same page for 30 days following the event. If you would rather access the call via telephone: To register and receive a dial in number and unique PIN to access the live conference call, please
follow this link
to register online. Upon registering you will receive the dial-in info and a unique PIN to join the call as well as an email confirmation with the details.
About ATI-052
ATI-052 is an investigational humanized anti-TSLP and anti-IL-4R
α
bispecific antibody that simultaneously inhibits thymic stromal lymphopoietin (TSLP) and interleukin-4 receptor (IL-4R
α
) with high affinity and potency. By targeting TSLP, which sits at the top of the inflammatory cascade, it inhibits a broad range of inflammation; by targeting IL-4R
α
,
​
3
it blocks downstream signaling of both IL-4 and IL-13, which are key cytokines involved in Th2-mediated inflammation and allergic diseases. The TSLP binding interface of ATI-052 allows it to extensively bind TSLP, uniquely binding all six light chain and heavy chain CDRs. ATI-052 demonstrates very slow dissociation kinetics from TSLP with a residence time up to 116x longer than comparator antibodies. It exhibits potential best-in-class potency and utilizes the same TSLP antigen-binding fragment (Fab) region as the Company’s monoclonal antibody bosakitug (ATI-045), retaining the dissociation kinetics, long residence time, and high potency advantages over comparator antibodies, but is engineered to bind more tightly to the neonatal Fc receptor (FcRn) to extend its half-life. ATI-052 has the potential to treat a variety of atopic, immunologic and respiratory diseases. Aclaris has the exclusive worldwide rights to ATI-052, excluding Greater China.
About Aclaris Therapeutics, Inc.
Aclaris Therapeutics, Inc. is a clinical-stage biopharmaceutical company developing a pipeline of novel product candidates to address the needs of patients with immuno-inflammatory diseases who lack satisfactory treatment options. The company has a multi-stage portfolio of product candidates powered by a robust R&D engine. For additional information, please visit www.aclaristx.com and follow
Aclaris on
LinkedIn
.
Cautionary Note Regarding Forward-Looking Statements
Any statements contained in this press release that do not describe historical facts may constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as “anticipate,” “believe,” “expect,” “intend,” “may,” “plan,” “potential,” “will,” and similar expressions, and are based on Aclaris’ current beliefs and expectations. These forward-looking statements include expectations regarding its development plans for ATI-052, including its intention to prioritize development of ATI-052 initially in EoE, the timing to initiate a Phase 2b trial of ATI-052 in EoE and the timing and plans to pursue development of ATI-052 in additional indications, the therapeutic potential for ATI-052, including the potential for ATI-052 to be best-in-class, the potential for ATI-052 to provide additive or synergistic activity through the simultaneous inhibition of TSLP and IL-4Rα, and the potential for ATI-052 to treat atopic, immunologic, and respiratory diseases. These statements involve risks and uncertainties that could cause actual results to differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include uncertainties inherent in the conduct of clinical trials, risks associated with interim, topline and preliminary data, Aclaris’ reliance on third parties over which it may not always have full control, Aclaris’ ability to enter into strategic partnerships on commercially reasonable terms, the uncertainty regarding the macroeconomic environment and other risks and uncertainties that are described in the Risk Factors section of Aclaris’ Annual Report on Form 10-K for the year ended December 31, 2025 and other filings Aclaris makes with the U.S. Securities and Exchange Commission from time to time. These documents are available under the “SEC Filings” page of the “Investors” section of Aclaris’ website at www.aclaristx.com. Any forward-looking statements speak only as of the date of this press release and are based on information available to Aclaris as of the date of this release, and Aclaris assumes no obligation to, and does not intend to, update any forward-looking statements, whether as a result of new information, future events or otherwise.
Aclaris Therapeutics Contact:
Will Roberts
Senior Vice President
Corporate Communications and Investor Relations
(484) 329-2125
wroberts@aclaristx.com
​
4
5

----- acrs-ex99d2.htm -----
EX-99.2
3
acrs-ex99d2.htm
EX-99.2
Exhibit 99.2
EMPOWERING PATIENTS THROUGH
THERAPEUTIC
INNOVATION
October 27, 2026
ATI-052
Phase 1b Primary Analysis Results
Atopic Dermatitis and Asthma
2
Any statements contained in this presentation that do not describe historical facts may constitute forward-looking statements as that term is
defined in the Private Securities Litigation Reform Act of 1995. These statements may be identified by words such as “anticipate,” “believe,”
“expect,” “intend,” “may,” “plan,” “potential,” “will,” and similar expressions, and are based on Aclaris’ current beliefs and expectations. These
forward-looking statements include expectations regarding the therapeutic potential of ATI-052, an investigational bispecific antibody, including
the potential for ATI-052 to be best-in-class and have best-in-class attributes, the potential to increase the efficacy ceiling and show superior
activity compared to other therapies, the potential for ATI-052 to have up to quarterly dosing, the potential for synergy of TSLP and IL-4Rα, the
market opportunity for ATI-052, and the development of ATI-052 and Aclaris’ other product candidates, including the potential targets and
indications Aclaris may pursue, the timing and number of regulatory filings, the design of future clinical trials, the timing for the initiation of clinical
trials, and the availability and timing of data from clinical trials. These statements involve risks and uncertainties that could cause actual results to
differ materially from those reflected in such statements. Risks and uncertainties that may cause actual results to differ materially include
uncertainties inherent in the conduct of clinical trials, potential changes to interim, topline and preliminary data as more subject data become
available, Aclaris’ reliance on third parties over which it may not always have full control, Aclaris’ ability to enter into strategic partnerships on
commercially reasonable terms, the uncertainty regarding the macroeconomic environment and other risks and uncertainties that are
described in the “Risk Factors” section of Aclaris’ Annual Report on Form 10-K for the year ended December 31, 2025, and other filings Aclaris
makes with the U.S. Securities and Exchange Commission from time to time. These documents are available under the “SEC Filings” page of the
“Investors” section of Aclaris’ website at www.aclaristx.com. Any forward-looking statements speak only as of the date of this presentation and
are based on information available to Aclaris as of the date of this presentation, and Aclaris assumes no obligation to, and does not intend to,
update any forward-looking statements, whether as a result of new information, future events or otherwise.
Tradenames, trademarks and service marks of other companies appearing in this presentation are the property of their respective owners.
This presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and other
data about our industry. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such
estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we
operate are necessarily subject to a high degree of uncertainty and risk.
All future development, clinical, and regulatory timelines are expectations, are based on current beliefs and assumptions, and are subject to
change based on a variety of factors.
Disclaimer and Cautionary Note Regarding Forward-Looking Statements
3
4x
More potent than dupilumab +
tezepelumab combined
$19B+1
In annual sales across the
mechanisms it targets
ATI-052: Potential Best-in-Class Bispecific mAb
Phase 1b POC Results Validate Preclinical Potency Differentiation
OVERVIEW: PROOF-OF-CONCEPT RESULTS
400+ hours
Up to 116x longer residence time on
TSLP than comparator antibodies
Combines two significant
mechanisms in one molecule:
anti-TSLP, anti-IL-4Rα
Demonstrated potential for
additivity/synergy of targets
Proof-of-Concept Achieved in
Atopic Dermatitis (AD) & Asthma
Modulated all three TH cell
endotypes: Th1, Th2, Th17
Potential to raise efficacy ceiling +
provide rapid response
Favorable tolerability profile observed
Up to
Quarterly
Dosing potential
1. Regeneron Pharmaceuticals, Q4 and Full Year 2025 Financial and Operating Results, Jan. 30, 2026 (FY’25 Dupixent® annual sales) and AstraZeneca, Full Year and Q4 2025 Results, Feb. 10, 2026 (FY‘25
Tezspire® annual sales).
4
OVERVIEW: MECHANISM OF ACTION
Two Validated Mechanisms
A More Complete Approach to Inflammatory Disease
ATI-052 Pathways
Simultaneous control of upstream disease initiation and downstream Type 2 effector pathways
ATI-052
IgG1 anti-TSLP / anti-IL-4Rα bispecific antibody
Molecular architecture
• Bivalent for both TSLP and IL-4Rα
(four total binding sites)
• Unique multi-paratopic TSLP binding
• Potential best-in-class potency for TSLP with
long retention time
• YTE Fc mutation engineered for T1/2 extension
Anti-IL-4Rα scFv Anti-IL-4Rα scFv
Anti-TSLP Fab Anti-TSLP Fab
YTE Mutation
FcRn-mediated
half-life extension
Individual Components of ATI-052 are Both Important
ATI-052 Targets The Two Most Broadly Validated Nodes In Type 2 Disease:
TSLP and IL-4Rα
Approval Status by Indication/Mechanism
TSLP IL-4Rα IL-13
EoE ✓ ✓ ✕
Asthma ✓ ✓ ✕
COPD ✕ ✓ ✕
CRSwNP ✓ ✓ ✕
AD ✓ ✓
Validated 3/5 5/5 1/5
✓ Approved ✕ Not approved
IL-13–selective antibodies have failed to show competitive efficacy
to dupilumab in late-stage trials in asthma and EoE
0
of 8
IL-13–selective
programs
approved in
asthma or EoE
ASTHMA 6 programs, none approved
✕
Lebrikizumab
Roche ✕
Tralokinumab
AstraZeneca ✕
GSK679586
GSK
✕
Anrukinzumab
Pfizer ✕
IMA-026
Pfizer ✕
Dectrekumab
Novartis
EoE 2 programs, none approved
✕
Dectrekumab
Novartis ✕
Cendakimab
BMS
SOURCE: DUPIXENT, TEZSPIRE, ADBRY and EBGLYSS U.S. Prescribing Information; AstraZeneca. TEZSPIRE Phase III CROSSING trial in EoE. Press release, Oct. 20, 2026.
OVERVIEW: TARGET BIOLOGY
NOTE: Approved = FDA-approved. EoE = Eosinophilic Esophagitis; COPD = Chronic Obstructive Pulmonary Disease; CRSwNP = Chronic Rhinosinusitis with Nasal Polyps; AD = Atopic Dermatitis
Blocking IL-4Rα blocks both IL-4 and IL-13
IL-4 biology is directly implicated in asthma
and other Th2 diseases
5
NDA Filing Expected
✕
Lebrikizumab: Absolute EASI
Response (%) at Week 16
0
20
40
60
80
63.5
46.1
EASI ≤7
56.5
40.0
EASI ≤5
41.7
30.8
EASI ≤3
24.2
16.6
EASI ≤1
Moderate (IGA3) Severe (IGA4)
Baseline Severity Impacts Response Rates
PHASE 1b POC TRIAL I SIGNIFICANCE OF BASELINE SEVERITY IN AD % of patients
Difficulty in Treating Severe AD
Understanding Severity:
• Two ways to determine severity: EASI and vIGA;
both must be assessed
• EASI incorporates both extent and severity; vIGA
provides a direct measure of disease severity
Absolute vs. Relative Reduction:
• Patients with severe disease need a larger
improvement in score than those with milder
disease to reach the same target score.
Severe AD represents a higher bar
for success
NOTE: EASI = Eczema Area and Severity Index; vIGA = Validated Investigator’s Global Assessment; PP-NRS4 = ≥4 points of reduction from baseline in weekly averages of Peak Pruritus Numerical Rating Scale
SOURCE: Dupilumab: SOLO 1 and 2 pooled (Weidinger S, et al. JEADV Clin Pract. 2023;2:247–260). Lebrikizumab: Advocate trials 250 mg q2w (Thaçi D, et al. Acta Derm Venereol. 2026;106:0160).
50
59
40
24
36 36
0
20
40
60
80
vIGA 0/1 EASI-75 PP-NRS4
% of patients
Dupilumab: Absolute
Response Rate (%) at Week 16
Moderate (IGA3) Severe (IGA4)
6
ATI-052 Positive Phase 1b Primary Analysis Results: AD
Strong POC in Severe AD (78% vIGA4); Efficacy Signals Support Advancement to Phase 2
CLINICAL RESULTS OVERVIEW: AD
Favorable safety profile with no conjunctivitis observed
ATI-052 has the potential to set a new efficacy ceiling in AD
and other Th2 driven diseases
Measure (D57)
ATI-052
Load-in Doses
(480 mg)
Placebo
% Reduction from
Baseline in EASI 58% 13% 45%
EASI-50 78% 0% 78%
% PP-NRS Reduction 38% -5% 43%
NOTE: ATI-052 efficacy results presented on per-protocol population. Missing data were not imputed. Sample sizes vary by endpoint and visit. PBO = placebo; PP-NRS = Peak Pruritus Numerical
Rating Scale; EASI = Eczema Area and Severity Index; PD = pharmacodynamic; vIGA = Validated Investigator’s Global Assessment
Sustained skin
improvement
Encouraging
Early Endpoints
Itch
Improvement
PBO-Adj. Change Objective
PD Biomarker
Analysis
Deep reduction of established AD biomarkers & suppression
of Th1, Th2, Th17 and myeloid inflammatory pathways observed
Evidence of
Additivity /
Synergy
7
Safety and
Tolerability
Strong tolerability
profile
ATI-052 Positive Phase 1b Primary Analysis Results: Asthma
Strong POC in Mild-to-Moderate Asthma; Rapid Response Supports Advancement to Phase 2
CLINICAL RESULTS OVERVIEW: ASTHMA
Measure (D15)
ATI-052
Single Dose
(480mg)
Placebo PBO-Adj. Change
% Reduction in
FeNO 59% 15% 44%
200 mL 0 mL 200 mL
Increase in FEV1
(FEV1 <80% at BL) 350 mL -140 mL 490 mL
NOTE: FEV1 <80% at BL = pre-BD FEV1 value of < 80% at baseline + post-BD reversibility of FEV1 ≥ 12% and ≥ 200 mL or documented history of post-BD FEV1 reversibility during last 12 months at screening.
BD = bronchodilator; FEV1 = Forced expiratory volume in 1 second; PBO = placebo; BL = baseline; ITT = intent-to-treat; FeNO = fractional exhaled nitric oxide.
Target
Engagement
Large Airway
Improvement
Objective
8
Increase in FEV1 (ITT)
Favorable safety profile with no conjunctivitis observed Safety and
Tolerability
Strong Tolerability
profile
ATI-052 has the potential to set a new efficacy ceiling in asthma
and other Th2 driven diseases
ATI-052 POC in Atopic
Dermatitis (AD)
Data cutoff date: August 20, 2026
10
Screening/
Washout
Randomization
3:1 Active
to Placebo
Primary Endpoint Safety and tolerability
Phase 1b POC Trial in Severe Atopic Dermatitis
14 AD Patients
Placebo Q1wk (five doses)
ATI-052 Q1wk (five doses, 480 mg)
12-week follow-up
Day 57 (Week 8)
Primary analysis
Other Endpoints AD clinical efficacy assessments (EASI, PP-NRS, etc.)
PD endpoints measured by assays including lesional and non-lesional skin tape strips
CLINICAL STRATEGY: ATI-052 IN AD
Location United States: Multi-site
Strategy
First signal-finding clinical trial to assess the efficacy of load-in doses only
(no doses after week 4) in severe AD patient population
Load-in Injections
Wk0 Wk1 Wk2 Wk3 Wk4
NOTE: EASI = Eczema Area and Severity Index; PP-NRS = Peak Pruritus Numerical Rating Scale
Baseline Demographics and Disease Severity
11
PHASE 1b POC TRIAL I ATI-052 IN AD: BASELINE CHARACTERISTICS
Increased Percentage of African American and vIGA 4 Provides a More Severe / Difficult-to-Treat Patient Population1
SOURCE: 1. Sanyal RD, Guttman-Yassky E, et al. Ann Allergy Asthma Immunol. 2019.
NOTE: vIGA = Validated Investigator Global Assessment for Atopic Dermatitis; EASI = Eczema Area and Severity Index; PP-NRS = Peak Pruritus Numerical Rating Scale; BSA = Body Surface Area;
NC = not calculable
Characteristic ATI-052
(N=11)
Placebo
(N=3)
Age, mean (SD), y 27.8 (6.0) 38.3 (13.1)
Female, n (%) 6 (54.5) 1 (33.3)
Weight, mean (SD), kg 82.4 (18.5) 102.0 (4.8)
Duration of AD from diagnosis, mean (SD), y 21.8 (8.2) 23.1 (4.8)
Race, n (%)
White 4 (36.4) 2 (66.7)
Black or African American 5 (45.5) 1 (33.3)
Asian 2 (18.2) 0
Baseline EASI, mean (SD) 28.3 (7.5) 23.2 (0.8)
Baseline vIGA=4, n (%) 9 (81.8) 1 (33.3)
Baseline weekly PP-NRS, mean (SD) 6.7 (1.7) 7.1 (1.5)
BSA affected, mean (SD) 41.4 (13.7) 35.0 (14.4)
Reasons for Exclusion ATI-052 Placebo
Received rescue
medication 0 2
Took only 2 doses 1 0
Eligibility criteria not met 1 0
Per Protocol
Analysis Population
Defined prior to unblinding
ATI-052 Was Well Tolerated, With a Favorable
Safety Profile
12
Safety Summary ATI-052
N=11 (%)
Placebo
N=3 (%)
Patients reporting ≥1 TEAE 6 (54.5) 2 (66.7)
Patients reporting ≥1 serious TEAE 0 0
Patients reporting ≥1 Grade 3 or 4 TEAE 0 0
Patients who discontinued due to TEAE 0 0
Patients reporting ≥1 TRAE (only ISRs) 2 (18.2) 1 (33.3)
PHASE 1b POC TRIAL I ATI-052 IN AD: SAFETY AND TOLERABILITY
• Tolerability similar between active and placebo arms
• Injection site reactions (ISR) were transient, almost exclusively Grade 1, and observed only at two timepoints
• Preliminary safety observed after Day 57 consistent with that observed through Day 57
• No conjunctivitis observed in the Phase 1a/1b ATI-052 program
NOTE: Safety results presented for safety population. Data after Day 57 are preliminary and based on partial dataset. TEAE = Treatment emergent adverse event. TREA = Treatment related adverse event.
ADA = anti-drug antibody
-80%
-60%
-40%
-20%
0%
Baseline Week 4 Week 5 Week 6 Week 8 Week 10
ATI-052 Placebo
ATI-052 Demonstrated Robust EASI Improvement
Enrolled a Challenging Population to Treat: 78% Baseline vIGA4
Mean % Change in Baseline EASI Over Time Mean % Change in Baseline EASI
Week 10
-62%
-82%
-56%
-15%
-90%
-70%
-50%
-30%
-10%
ATI-052
(All)
vIGA 3 vIGA 4 Placebo
(All)
EASI Improvement Maintained in Severe Patient Population Through Week 16 after Load-In Doses Only
Pbo-adjusted:
-45%
Last dose
Week 4
13
Week 16
PHASE 1b POC TRIAL I ATI-052 IN AD: EASI
Expected Phase 2b
Repeat Dosing
Window
Mean % change from baseline in EASI
NOTE: Efficacy results presented for per protocol population Missing data were not imputed; number of participants may vary by endpoint and visit. Data after Day 57 are preliminary and based on
partial dataset. All subgroup analyses were conducted post hoc. PBO = placebo.
Load-in doses
Mean % change from baseline in EASI
Early Efficacy Signal In Severe Disease Supports
Advancement to Phase 2b
45%
38%
33%
36%
0
10
20
30
40
50
ATI-052 Dupilumab Zumilokibart Lebrikizumab
% Severe (vIGA 4) Subjects at
Baseline
78%
PHASE 1b POC TRIAL I ATI-052 IN AD: EASI
14
% Severe (vIGA 4) Subjects at
Baseline
49%
% Severe (vIGA 4) Subjects at
Baseline
35%
% Severe (vIGA 4) Subjects at
Baseline
39%
SOURCE: Dupilumab: SOLO 1/2, 300 mg q2w pooled, approx. (Thaçi D, Simpson EL, et al. J Dermatol Sci. 2019;94(2):266–275.). Zumilokibart: APEX Part A/B mid dose averaged (Apogee, APEX Part A 16-
week data presentation July 7, 2025; APEX Part B 16-week data presentation, May 27, 2026). Lebrikizumab: ADvocate1/2, 250 mg q2w averaged, approx. (Silverberg, NEJM 2023;388:1080).
NOTE: ATI-052 results presented for per protocol population. Missing data were not imputed. Sample sizes vary by endpoint and visit. Data are derived from different clinical trials conducted at different
times, with differences in trial design and patient populations. As a result, cross-trial comparisons cannot be made, and no head-to-head clinical trials have been conducted. PBO = placebo.
Mean Placebo-adj. Change from Baseline in EASI (%), Week 8
Mean Pbo-adjusted change from baseline
in EASI (%)
Active: N=564
PBO: N=287
Active: N=167
PBO: N= 129
Active: N=465
PBO: N=456
Active: N=9
PBO: N=1
15
ATI-052 Demonstrated Robust EASI-50 Response
100%
71%
42%
ATI-052 (vIGA 3) ATI-052 (vIGA 4) Dupilumab
SOURCE: Dupilumab: SOLO 1/2, 300 mg q2w pooled, approx. (Thaçi D, Simpson EL, et al. J Dermatol Sci. 2019;94(2):266–275).
PHASE 1b POC TRIAL I ATI-052 IN AD: EASI
Overall = 78%
Pbo-adj. EASI-50 Response (%), Week 8
89%
of ATI-052 Subjects Achieved
EASI-50 During the Study1
NOTE: ATI-052 results presented for per-protocol population. Missing data were not imputed. Sample sizes vary by endpoint and visit. ATI-052 placebo-adjusted results use the overall placebo group as the
comparator. All subgroup analyses were conducted post hoc. Data are derived from different clinical trials conducted at different times, with differences in trial design and patient populations. As a
result, cross-trial comparisons cannot be made, and no head-to-head clinical trials have been conducted. PBO = placebo.
1. Post hoc analysis including unscheduled visits. Each subject counted once if the criterion was met at any visit.
-50
-40
-30
-20
-10
0
10
20
Baseline Week 1 Week 2 Week 4 Week 5 Week 6 Week 8 Week 10 Week 16
% change from baseline
ATI-052 Placebo
PHASE 1b POC TRIAL I ATI-052 IN AD: PP-NRS
Rapid, Deep and Durable Reductions in Itch Observed
Itch Relief Emerged Week One and Continued to Deepen Through Week 10
16 SOURCE: Dupilumab: SOLO 1/2, 300 mg q2w pooled, approx. (Thaçi D, Simpson EL, et al. J Dermatol Sci. 2019;94(2):266–275.). Zumilokibart: APEX Part A mid dose (Apogee, APEX Part A 16-week data
presentation July 7, 2025).
Pbo-adjusted:
-43%
Placebo-Adj. Change in PP-NRS (%), Week 8
43%
29%
23%
0%
20%
40%
ATI-052 Dupilumab Zumilokibart
Change From Baseline in PP-NRS (%) Over Time
Last dose
Week 4
Expected Phase 2b
Repeat Dosing
Window
NOTE: ATI-052 results presented for per protocol population. Missing data were not imputed. Sample sizes vary by endpoint and visit. Data after Day 57 are preliminary and based on partial dataset.
Data are derived from different clinical trials conducted at different times, with differences in trial design and patient populations. As a result, cross-trial comparisons cannot be made, and no head-to-head clinical trials have been conducted. Placebo-Adj. change from baseline in PP-NRS (%)
Load-in doses
PHASE 1b POC TRIAL I ATI-052 IN AD: PP-NRS
17
SOURCE: Dupilumab: PP-NRS4 - SOLO 1/2, 300 mg q2w pooled, approx. (Thaçi D, Simpson EL, et al. J Dermatol Sci. 2019;94(2):266–275.). Zumilokibart: APEX Part B mid dose (Apogee, APEX Part B 16-week
data presentation, May 27, 2026). Lebrikizumab: ADvocate1/2, 250 mg q2w averaged, approx. (Silverberg, NEJM 2023;388:1080). Tilrekimig: 400mg + 200 mg q4w averaged (Active: N=70, PBO: N=20) (EADV
2026, Vienna, Sept 30 to Oct 3, 2026).
33%
26%
20%
27% 25%
ATI-052 Dupilumab Zumilokibart Lebrikizumab Tilrekimig
% Severe (vIGA 4)
at Baseline
78%
% Severe (vIGA 4)
at Baseline
35%
% Severe (vIGA 4)
at Baseline
49%
% Severe (vIGA 4)
at Baseline
37%
% Severe (vIGA 4)
at Baseline
39%
Pbo-adj. PP-NRS4 Response (%), Week 8
ATI-052 Showed Clinically Meaningful Improvements in Itch
Improved Placebo-Adjusted PP-NRS Response Observed
NOTE: ATI-052 results presented for per protocol population. Missing data were not imputed. Sample sizes vary by endpoint and visit. Data are derived from different clinical trials conducted at different
times, with differences in trial design and patient populations. As a result, cross-trial comparisons cannot be made, and no head-to-head clinical trials have been conducted. PBO = placebo; PP-NRS4 = ≥4
points of reduction from baseline in weekly averages of Peak Pruritus Numerical Rating Scale (PP-NRS).
Photographic Examples of Clinical Activity
18
PHASE 1b POC TRIAL I ATI-052 IN AD: SKIN CLEARANCE
Baseline Week 8
ATI-052
Load-in doses only
Subject #1
vIGA 3 at
Baseline
Subject #2
vIGA 4 at
Baseline
Potential Best-in-Class Pharmacodynamic Profile
TSLP + IL-4Rα | Evidence of Potential Additivity/Synergy Between Targets
Broad Pathway Modulation
Marked downregulation of
inflammatory mediators pertinent
to AD observed
Pathways modulated
Th1 Th2 Th17/Th22
Fibrosis Itch
Normalization of Skin
Proteome
Immune protein expression in
lesional skin closely resembled
non-lesional skin
Proteome shift
Lesional → Non-lesional
Pronounced Biomarker
Reduction
Pronounced reduction of
established dupilumab biomarkers
observed
Additional suppression
Th1 Th17 Myeloid
19
PHASE 1b POC TRIAL I ATI-052 IN AD: PD AND TAPE STRIPS
DR. EMMA GUTTMAN LAB· MT SINAI
Skin Tape Strip Analysis
O-link proteomics (300+ analytes)
INTERNAL ANALYSIS
Endogenous Serum Biomarkers (MSD-Select)
CCL17/TARC, IL-5
Innate
PHASE 1b POC TRIAL I ATI-052 IN AD: PD AND TAPE STRIPS
ATI-052 Normalized Skin Proteome
ATI-052 Activity in Lesional Skin | Potential for Disease Modification
KEY RESULTS
95%
overall improvement in LS vs.
NL proteome observed by
Week 8
66%
overall improvement in LS vs.
NL skin with dupilumab by
Week 16
% IMPROVEMENT Percent Improvement (%)
Placebo ATI-052
LS vs. NL Proteome, Week 8
PROTEOME HEATMAP
Results provided validation of additive/synergistic activity of dual IL-4Rα + TSLP inhibition by ATI-052
NOTE: ATI-052 results presented for all patients who completed study through Week 8. *** p<0.001. Data are derived from different clinical trials conducted at different times, with differences in trial design and
patient populations. As a result, cross-trial comparisons cannot be made, and no head-to-head clinical trials have been conducted.
SOURCE: Dupilumab: 300 mg q2w (He H, et al. Front Immunol. 2020;11:1768).
20
Baseline
NL LS
Placebo W8
NL LS
ATI-052 W8
NL LS
n 13 13 3 3 10 10
Z-score
2
0
−2
LS: Lesional Skin
NL: Non-Lesional Skin
ATI-052 Demonstrated Broad and Deep Biomarker
Reductions
Median % Change from Baseline, Week 8
−76
−45 −43
−4
−16
-100
-75
-50
-25
0
25
50
75
CCL17 IL-5 Eosinophils
(Week 12)
NOTE: Sample sizes vary by endpoint and visit. GSVA: patients completing Week 8. ** p≤0.01, *** p≤0.001; + p<0.1. Navy asterisks: Week 8 vs. baseline; orange: ATI-052 vs. placebo. NL = non-lesional;
LS = lesional skin.
PHASE 1b POC TRIAL I ATI-052 IN AD: PD AND TAPE STRIPS
Median % change from baseline
+176
21
PATHWAY DOWNREGULATION BY GSVA NL LS
Placebo ATI-052
Th1
(CCL2, CXCL9,
CXCL10, IL8, TNF,
etc.)
Placebo ATI-052
Th2
(IL13, CCL13,
CCL17, CCL24,
etc.)
Placebo ATI-052
Th17/22
(TGFB1, IL17A,
IL6R, S100A12,
etc.)
Placebo ATI-052
Pruritus
(OSM, CTSS, etc.)
Y-axis: lgFCH vs. baseline
BIOMARKER REDUCTIONS
■ ATI-052 ■ Placebo
Downregulation of Th1, Th2, Th17/22 and Pruritus Signatures Observed
ATI-052 POC in
Asthma
Data cutoff date: September 24, 2026
23
Placebo (single dose)
ATI-052 (single dose, 480 mg)
Screening/
Washout Six-week follow-up
Randomization
3:1 Active
to Placebo
Primary analysis through
Day 29
Primary Endpoint Safety and tolerability
Phase 1b POC Trial in Asthma
16 Patients
Key Clinical Efficacy Assessment:
FEV1, AX Other endpoints PD assessments: FeNO, Blood Eos, TARC (CCL17),
Periostin, Cytokines
CLINICAL STRATEGY I ATI-052 IN ASTHMA
Location United States and Europe: Multi-site
Strategy Clinical trial to assess a single dose of ATI-052 in a mild-to-moderate asthma population
NOTE: FEV1 = Forced Expiratory Volume in 1 Second; FeNO = Fractional Exhaled Nitric Oxide; AX = Area of Reactance.
Single Injection
24
Characteristic ATI-052
(N=12)
Placebo
(N=4)
Age, mean (SD), y 44.4 (12.6) 39.8 (17.6)
Female, n (%) 3 (25.0) 3 (75.0)
Weight, mean (SD), kg 86.0 (12.8) 75.8 (23.2)
Duration of asthma from diagnosis, mean (SD), y 23.6 (12.0) 22 (20.8)
FeNO, mean (SD), ppb 72.3 (33.3) 97.3 (62.5)
Blood eosinophil count, mean (SD), cells/µL 378.3 (227.6) 395.0 (183.6)
<300 n (%) 5 (41.7) 2 (50.0)
≥300 n (%) 7 (58.3) 2 (50.0)
FEV1, mean L, (SD) 2.85 (0.98) 3.16 (0.71)
FEV1, mean % predicted, (SD) 75.6 (22.1) 98.7 (22.8)
<80% n (%) 6 (50.0) 1 (25.0)
≥80% n (%) 6 (50.0) 3 (75.0)
BASELINE CHARACTERISTICS I ATI-052 IN ASTHMA
Baseline Demographics and Asthma Severity
NOTE: FEV1 = Forced Expiratory Volume in 1 Second; FeNO =Fractional Exhaled Nitric Oxide
Strong Tolerability Profile Observed with ATI-052
Favorable Safety Profile
25
Safety Summary ATI-052
(N=12)
Placebo
(N=4)
Patients reporting ≥1 TEAE, n (%) 6 (50) 1 (25)
Patients reporting ≥1 serious TEAE, n (%) 0 0
Patients reporting ≥1 Grade 3 or 4 TEAE, n (%) 0 0
Patients who discontinued due to TEAE, n (%) 0 0
Patients reporting ≥1 TRAE, n (%) (ISR) 1 (8.3) 0
• ATI-052 was well tolerated with Grade 1 ISRs as the most frequent AE
• No conjunctivitis observed in the Phase 1a/1b ATI-052 program
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: SAFETY AND TOLERABILITY
NOTE: TEAE = Treatment emergent adverse events; TRAE = Treatment related adverse events; ISR = injection site reaction
Rapid FeNO Suppression Observed from Single Dose of ATI-052
Maximum FeNO Reduction of 59% and 45ppb Validate Potency of ATI-052
26
-59%
-70%
-60%
-50%
-40%
-30%
-20%
-10%
0%
Day 0 Day 8 Day 15 Day 29
% change from baseline
ATI-052 Placebo
-50 -45
-40
-30
-20
-10
0
Day 0 Day 8 Day 15 Day 29
Absolute change from baseline
ATI-052 Placebo
Percent Change from Baseline in FeNO Absolute Change from Baseline in FeNO
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: FeNO
Rapidity and Depth of FeNO Suppression Observed After a Single Dose of ATI-052;
Provides Strong Signal and Proof-of-Concept
Single Injection Single Injection
NOTE: Data from one placebo participant were excluded from the Day 29 analysis following investigation of a testing event that affected the measurement. FeNO =Fractional Exhaled Nitric Oxide;
PPB = parts per billion.
-59%
-31%
-36%
-80%
-70%
-60%
-50%
-40%
-30%
-20%
-10%
0%
ATI-052 (Day 15)
Anti-TSLP / IL-4Rα
Dupilumab (Week 2)
Anti-IL-4Rα
Tezepelumab (Week 4)
Anti-TSLP
Single Dose of ATI-052 Demonstrated Deep
Reduction in FeNO
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: FeNO
Maximum Mean FeNO % Reduction, Through Week 4
27
NOTE: Data are derived from different clinical trials conducted at different times, with differences in trial design and patient populations. As a result, cross-trial comparisons cannot be made, and no
head-to-head clinical trials have been conducted.
480mg 400/600mg (Loading) 210mg
Maximum Mean FeNO % Reduction
SOURCE: Tezepelumab: approx. (Menzies-Gow et al., N Engl J Med. 2021;384:1800-1809). Dupliumab: approx. (Pavord ID, et al. J Allergy Clin Immunol Pract. 2024;12(7):1763-177).
Active: N=1,160
PBO: N=583
Active: N=528
PBO: N=531
Active: N=12
PBO: N=4
Similar Results Observed in Both T2-Low and T2-High
Sub-Populations
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: FeNO & FEV1
28 NOTE: All subgroup analyses were conducted post hoc. T2-Low = <300 Eosinophils at baseline; T2-High = ≥300 eosinophils at baseline; PPB = parts per billion.
58%
of ATI-052 Subjects Achieved
FeNO Normalization (≤25 ppb)
at Day 15
60%
FeNO Reduction in Eos ≥300
Subgroup (T2-High) at Day 15
58%
FeNO Reduction in Eos <300
Subgroup (T2-Low) at Day 15
FEV1 Improvement Was Also Observed in T2-High and T2-Low Sub-Populations
-200 mL
-100 mL
+0 mL
+100 mL
+200 mL
Baseline Day 8 Day 15 Day 29
Mean pre-BD FEV1 change from
baseline (mL)
ATI-052 Placebo
FEV1 Improvement Over Time FEV1 Improvement at Day 15
in Subjects with FEV1 <80% at Baseline
+350 mL
-140 mL -200 mL
-100 mL
+0 mL
+100 mL
+200 mL
+300 mL
+400 mL
ATI-052
(FEV1 <80% at BL)
Placebo
(FEV1 <80% at BL)
29 NOTE: All subgroup analyses were conducted post hoc. FEV1 <80% at Baseline = pre-BD FEV1 value of < 80% at baseline + post-BD reversibility of FEV1 ≥ 12% and ≥ 200 mL or documented history of post-BD
FEV1 reversibility during last 12 months at screening. BD = bronchodilator; FEV1 = Forced expiratory volume in 1 second; PBO = placebo; BL = baseline.
FEV1 Improvement Aligned with FeNO Suppression; Strong Signal and Proof-of-Concept
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: FEV1
Rapid FEV1 Improvement Observed
Single Dose of ATI-052 Increased Absolute and Pbo-Adjusted FEV1
Pbo-adjusted:
+200 mL
Mean pre-BD FEV1 change from
baseline (mL)
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: FEV1
SOURCE: Tezepelumab: approx. (Menzies-Gow et al., N Engl J Med. 2021;384:1800-1809). Dupilumab: approx.(Castro et al. N Engl J Med. 2018;378:2486-2496).
NOTE: All subgroup analyses were conducted post hoc. FEV1 <80% at BL = pre-BD FEV1 value of < 80% at baseline + post-BD reversibility of FEV1 ≥ 12% and ≥ 200 mL or documented history of post-BD FEV1
reversibility during last 12 months at screening. BD = bronchodilator; FEV1 = Forced expiratory volume in 1 second; PBO = placebo; BL = baseline. Data are derived from different clinical trials conducted
at different times, with differences in trial design and patient populations. As a result, cross-trial comparisons cannot be made, and no head-to-head clinical trials have been conducted.
ATI-052 Improved FEV1 at Day 15
350 mL
280 mL
165 mL
490 mL
150 mL
112 mL
0
100
200
300
400
500
ATI-052
(FEV1 <80% at BL)
Dupilumab
(Week 2)
Tezepelumab
(Week 2)
Mean pre-bronchodilator FEV1
change from baseline (mL)
Mean FEV1 % Pred at Baseline
63%
Mean FEV1 % Pred at Baseline
59%
Mean FEV1 % Pred at Baseline
57%
480mg 600mg (Loading) 210mg
Baseline lung
function
Dose
Active: N=633
PBO: N=321
Active: N=528
PBO: N=531
Active: N=5
PBO: N=1
Absolute
change
Pbo-Adjusted
change
Absolute
change
Pbo-Adjusted
change
Absolute
change Pbo-Adjusted
change
30
-28
-2
-35
-30
-25
-20
-15
-10
-5
0
ATI-052 (480mg) Dupilumab (600mg Loading; Week 4)
Placebo-adjusted change from baseline
in pre-BD AX at Day 15 (cmH O·L 2 −1
)
31
PHASE 1b POC TRIAL I ATI-052 IN ASTHMA: AX
ATI-052 Demonstrated Rapid Small Airway Disease
(SAD) Improvement
AX (Area Under Reactance Curve) as a Marker of SAD Improvement
• Highly prevalent in
asthma across GINA Steps
• More than doubles
exacerbation risk
• Nearly 3X the risk when
small airway disease is
severe
• 1 in 3 ‘well-controlled’
patients has hidden SAD
NOTE: All subgroup analyses were conducted post hoc. FEV1 <80% at BL = pre-BD FEV1 value of < 80% at baseline + post-BD reversibility of FEV1 ≥ 12% and ≥ 200 mL or documented history of post-BD
FEV1 reversibility during last 12 months at screening. BD = bronchodilator; FEV1 = Forced expiratory volume in 1 second; PBO = placebo; BL = baseline. Unit conversion: 1 kPa/L = 10.1972 cmH2O·L−1.
Data are derived from different clinical trials conducted at different times, with differences in trial design and patient populations. As a result, cross-trial comparisons cannot be made, and no
head-to-head clinical trials have been conducted.
SOURCE: Dupilumab: (Washko GR, et al. J Allergy Clin Immunol. 2025). Galant S, et al. Lancet Respir Med. 2025;13:990–1000.
Placebo-Adjusted AX Change at Day 15 in Subjects with FEV1 <80% at Baseline
Active: N=5
PBO: N=1
Active: n=72
PBO: n=37
Small Airway Disease
Key Learnings
Additivity/synergy potential demonstrated across preclinical, clinical,
and PD measures
Breadth and depth of response:
• Clinical and PD evidence of activity against all 3 inflammatory endotypes
in severe AD
• Both FENO & FEV1 improvements in T2 high & T2 low asthma patients
Strong evidence of TSLP involvement in AD
• Complete normalization of skin proteome
• Reduction in IL-5 and eosinophils
Encouraging early durability in severe AD patients
• Maintenance of response to at least week 16 (12 weeks after load in doses)
• Maintenance dosing expected to be the same in asthma and AD
Strong and potentially differentiated tolerability profile throughout the
Phase 1 program including no conjunctivitis
32
ATI-052: Key Learnings and Next Steps
Go Forward Plan
ATI-052 is a potent, broadly acting compound
with potential best-in-class activity
Moving into staged Phase 2b program
CORPORATE STRATEGY: COMMITMENT TO THERAPEUTIC INNOVATION
Opportunity to raise the efficacy ceiling with ATI-052 for patients
Continued Clinical Momentum Through 2027
Bosakitug (ATI-045)
Anti-TSLP monoclonal antibody
Phase 2 top line results in AD:
4Q 2026
ATI-052
Anti-TSLP / Anti-IL4Rα bispecific antibody
Phase 2b program:
Eosinophilic Esophagitis
Atopic Dermatitis Asthma
Modzatinib (ATI-2138)
ITK/JAK3 Inhibitor
Lichen planus
(Fast Track designation)
Phase 2b trial start: 4Q 2026
Oral/Mucosal
(Topline data 2027)
Cutaneous
Lichen planopilaris
ATI-9494
ITK Inhibitor
IND: 4Q 2026
Phase 1 start: 1Q 2027
Innovation
Driven
Patient
Focused
33 All future development, clinical, and regulatory timelines are expectations, are based on current beliefs and assumptions, and are subject to change based on a variety of factors
CORPORATE STRATEGY: COMMITMENT TO THERAPEUTIC INNOVATION
NOTE: ITK = Interleukin-2-inducible T-cell kinase; JAK3 = Janus Kinase 3; IND = Investigational New Drug application
EMPOWERING PATIENTS THROUGH
THERAPEUTIC
INNOVATION
October 27, 2026
ATI-052
Phase 1b Primary Analysis Results
Atopic Dermatitis and Asthma