Aclaris Therapeutics, Inc. · NASDAQ:ACRS
Aclaris Therapeutics — Technical Presentation (January 2026)
26 slides from Aclaris Therapeutics's technical presentation, Jan 6, 2026
Slide 1: ATI-052: Anti-TSLP x IL-4Rα Bispecific Antibody Program
ATI-052: Anti-TSLP x IL-4Rα Bispecific Antibody Program Highly Potent and Bioactive Investigational Product Candidate January 6, 2026
Slide 2: Forward-looking statements
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,” “int
Slide 3: ATI-052: Potential Best-in-Class Bispecific mAb
ATI-052: Potential Best-in-Class Bispecific mAb Effective Dual Binding of TSLP and IL-4Rα ATI-052 CH2 CH3 CH2 CH3 3 Same anti-TSLP antibody binding regions of Bosakitug, designed to inhibit TSLP upstream of the Th2 cascade • Retains dissociation kinetics, residence time, and potency advantages of bo
Slide 4: ATI-052: Longest Residence Time on TSLP
Dissociation of TSLP from mAbs (TR-FRET) 0 1000 2000 3000 4000 0.0 0.5 1.0 Time (min) Fractional Response (yi/yo) ATI-045 ATI-052 GSK-5784283 V1 (hu3-13)* GSK-5784283 V2 (hu179-33)* Solrikitug/MK-8226** Tezepelumab** Residence Time (hours) 416 402 14.3 8.11 22.1 3.59 20.7 ATI-052 ATI-045 Tezepelumab
Slide 5: Concurrent Binding of TSLP and sIL-4Rα to ATI-052
Concurrent Binding of TSLP and sIL-4Rα to ATI-052 High Affinity to Both TSLP and IL-4Rα 5 a ATI-052 Binds Both Targets Effectively High affinity to either target is not altered by the binding to the other Comparison of Affinity for sIL-4Rα Binding to ATI-052 or ATI-052:TSLP Complex Comparison of Aff
Slide 6: Concurrent Binding of TSLP and sIL4Rα to ATI-052
Concurrent Binding of TSLP and sIL4Rα to ATI-052 Simultaneous Binding of TSLP and IL-4Rα 6 a ATI-052 Demonstrated High Affinity to Both Targets Simultaneously: ATI-052 binds ~two molecules of TSLP and sIL-4Rα with the potential to saturate all 4 binding sites at the same time TSLP:ATI-052 sIL-4Ra:AT
Slide 7: Comparison of ATI-052 vs Dupilumab + Tezepelumab
Comparison of ATI-052 vs Dupilumab + Tezepelumab ATI-052 Demonstrates Greater Potency than the mAb Combination ATI-052 is Substantially More Potent than the Combination of Dupilumab and Tezepelumab mAb Concentration Antibody IC50 (nM) ATI-052 0.016 Dupilumab + Tezepelumab 0.069 Fold change 4.3 7
Slide 8: Comparison of IL-4/IL-13 Monoclonal Antibodies
Comparison of IL-4/IL-13 Monoclonal Antibodies IL-4-induced CCL17 release IL-13-induced CCL17 release TSLP-induced CCL17 release IL-4+IL-13-induced CCL17 release Antibody concentration [nM] 0.00001 0.0001 0.001 0.01 0.1 1 10 100 CCL17 (% stim) 0 20 40 60 80 100 120 140 160 Antibody concentration [nM
Slide 9: ATI-052: Binding Attributes and Clinical Opportunity
9 ATI-052: Binding Attributes Clinical Opportunity Multispecific Binding Potential Clinical Efficacy Simultaneous Binding of TSLP and IL-4Rα High affinity to both targets simultaneously: ATI-052 binds ~two molecules of TSLP and sIL4Rα Effective Binding of TSLP and IL-4Rα ATI-052 binds both targets e
Slide 10: Positive Interim Data: ATI-052 Healthy Volunteer Phase 1a SAD and MAD Trial
Positive Interim Data: ATI-052 Healthy Volunteer Phase 1a SAD and MAD Trial Patient Focused Innovation Interim results as of December 31, 2025
Slide 11: Interim ATI-052 Results Exceeded Expectations
Interim ATI-052 Results Exceeded Expectations 11 Result ATI-052 was found to be well tolerated with a favorable safety profile across all SAD and MAD cohorts, with doses of up to 720 mg No conjunctivitis observed in any cohort Confirm Favorable Tolerability and Safety Profile Confirm Pharmacokinetic
Slide 12: ATI-052 Placebo Controlled Phase 1a Program
ATI-052 Placebo Controlled Phase 1a Program 12 Cohort 1 (30mg): SC, N=8 D1-113 Screening Randomization 3:1 Cohort 3 (360mg): SC, N=8 D1-113 Cohort 4 (720mg): SC, N=8 D1-113 Cohort 2 (120mg): SC, N=8 D1-113 Part A Single Ascending Dose (SAD) in Healthy Volunteers (HV): Dosing Complete Part B Multiple
Slide 13: Baseline Characteristics
Single ascending dose (SAD) Multiple ascending dose (MAD) ATI-052 Cohort 1 (30 mg) N=6 ATI-052 Cohort 2 (120 mg) N=6 ATI-052 Cohort 3 (360 mg) N=6 ATI-052 Cohort 4 (720 mg) N=6 Placebo N=8 ATI-052 Cohort 1 (240 mg) N=6 ATI-052 Cohort 2 (480 mg) N=6 Placebo N=4 Total N=48 Age (yrs), mean (SD) 40.0 (9
Slide 14: Safety and AE Summary
ATI-052-PKPD-001 FIH, Phase 1a Healthy Volunteer, SAD and MAD Cohorts Safety and AE Summary
Slide 15: ATI-052 Well Tolerated with a Favorable Safety Profile Across Cohorts
Single ascending dose Multiple ascending dose Overall trial ATI-052 Cohort 1 (30 mg) N=6 ATI-052 Cohort 2 (120 mg) N=6 ATI-052 Cohort 3 (360 mg) N=6 ATI-052 Cohort 4 (720 mg) N=6 Placebo N=8 ATI-052 Cohort 1 (240 mg) N=6 ATI-052 Cohort 2 (480 mg) N=6 Placebo N=4 Total N=48 ≥1 TEAE (n, %) 4 (66.7) 1
Slide 16: Favorable Tolerability and Safety Profile Provides Confidence in Continued Development
16 Favorable Tolerability and Safety Profile of ATI-052 Provides Confidence in Continued Development • No SAEs; no adverse events led to study discontinuation • Low rate of adverse events (AEs); Predominantly Grade 1 • The most common AE: Injection site redness; self-resolving and generally mild (Gr
Slide 17: Pharmacokinetics Summary
ATI-052-PKPD-001 FIH, Phase 1a Healthy Volunteer, SAD and MAD Cohorts Pharmacokinetics Summary
Slide 18: Strong Pharmacokinetic Profile
18 Strong Pharmacokinetic Profile Dose proportional PK observed across pharmacologic dose range BLQ imputed as zero; mean concentrations below 0.1 not shown
Slide 19: Strong PK Profile Support Potential Extended Dosing
19 Strong PK Profile Support Potential Extended Dosing Dose Proportional PK Observed Across Pharmacologic Dose Range • Dose proportional PK was observed; dose proportional increases in Cmax and AUC observed • PK results provide an effective half-life of at least 26 days Potential best-in-class PK pr
Slide 20: Pharmacodynamics Summary
ATI-052-PKPD-001 FIH, Phase 1a Healthy Volunteer, SAD and MAD Cohorts Pharmacodynamics Summary
Slide 21: Ex-Vivo Stimulated PD Assay Bridging to Human Whole Blood
Ex-Vivo Stimulated PD Assay Bridging to Human Whole Blood (HWB) • TSLP and IL-4R both modulated CCL17 release in PBMC • For the SAD/MAD study, this assay was adapted to human whole blood to assess the following: o TSLP stimulated CCL17 in whole blood o IL-4 stimulated CCL17 in whole blood Robust PD
Slide 22: Strong and Sustained Effect of ATI-052
Strong and Sustained Effect of ATI-052 ATI-052 binds both targets effectively with complete inhibition at pharmacologically relevant doses for an extended time beyond the PK profile Sustained, complete / near complete inhibition of ex-vivo stimulated responses observed for at least 3 weeks at 360 mg
Slide 23: Strong Pharmacodynamic Response
23 Strong Pharmacodynamic Response Robust Target Engagement + Near Complete Occupancy at Low Doses ATI-052 exhibited a potential best-in-class PD profile: • Dose and concentration dependent inhibition of IL-4 and TSLP-stimulated CCL17 release observed • Cohort 1 (30 mg), 2 (120 mg) and 3 (360 mg) da
Slide 24: Unique Binding Attributes and Clinical Potential
24 Unique Binding Attributes Clinical Potential Simultaneous Binding of TSLP and IL-4Rα High affinity to both targets simultaneously: ATI-052 binds two molecules of TSLP and sIL-4Rα Effective Binding of TSLP and IL-4Rα ATI-052 binds both targets effectively; high affinity of either targets is not al
Slide 25: ATI-052: Next Steps
25 ATI-052: Next Steps Positive Interim Results Validate ATI-052; Clinical Program Rapidly Advancing Ongoing / Next Steps • Phase 1b AD POC trial imminent • Initiate Phase 1b asthma POC trial: 1Q 2026 • Phase 1b top line POC results: 2H 2026 • Initiate Phase 2b AD trial: 2H 2026 • Complete assessmen
Slide 26: ATI-052: Anti-TSLP x IL-4Rα Bispecific Antibody Program
ATI-052: Anti-TSLP x IL-4Rα Bispecific Antibody Program Highly Potent and Bioactive Investigational Product Candidate January 6, 2026
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