Anaptysbio, Inc. · NASDAQ:ANAB
Anaptysbio — ACR Convergence 2025
20 slides from Anaptysbio's conference presentation, 2025
Slide 1: Rosnilimab Demonstrates Efficacy, Safety and Translational Proof of Mechanism in RA Phase 2B Trial
Rosnilimab, a Selective and Potent Depleter of Pathogenic T Cells, Demonstrates Efficacy, Safety and Translational Proof of Mechanism in a Rheumatoid Arthritis Phase 2B Trial Jonathan Graf,1 Amy M. Archer,2 Sergii Kovalenko,3 Katarzyna Kolossa,4 John Serpa,5 Tamta Kobakhidze,6 Daniela Cepoi,7 Andrea
Slide 2: Disclosures
Disclosures J Graf: grant/research support from Amgen, AnaptysBio, Fate therapeutics, Sonoma Biotherapeutics; consultant for AnaptysBio, ImmPACT Bio. C Pitzalis: consultant for AbbVie/Abbott, AnaptysBio, Novartis; grant/research support from AbbVie/Abbott, Novartis, Pfizer, Roche, Sanofi; independen
Slide 3: Background
Background • Pathogenic T cells (e.g., PD-1high Tfh/Tph, Teff) play a role in inflammation, are upstream to a broad range of clinically validated targets in RA including TNF-α, IL-6, and B cells and are found in very low levels in healthy individuals1,2 ― These cells are enriched in patients with RA
Slide 4: Objective
Objective Report complete study results for safety and efficacy of rosnilimab in a Phase 2B study in patients with moderate-to-severe rheumatoid arthritis 4
Slide 5: Global, Randomized, Placebo-controlled Phase 2B Trial with Rosnilimab in Moderate-to-Severe RA
Global, Randomized, Placebo-controlled Phase 2B Trial with Rosnilimab in Moderate-to-Severe Rheumatoid Arthritis Blinded Placebo- Blinded All-Active All-Active Off Drug Screening Key Inclusion Criteria Controlled Treatment Treatment Follow-Up • Seropositive RA On csDMARD • ≥6 swollen and ≥6 tender j
Slide 6: Statistical Analysis
Statistical Analysis Analysis populations and associated imputation • ITT population (all randomized) ― Dichotomous outcomes • NRI at Week 12 • NRI at Week 28 • Participants with CDAI>10 at Week 14 could not continue in the all-active period regardless of meeting ACR20, ACR50 or ACR70 • Thus, in the
Slide 7: Baseline Demographics
Baseline Demographics Rosnilimab Rosnilimab Rosnilimab Placebo Overall Baseline Characteristic 100mg Q4W 400mg Q4W 600mg Q2W (N=106) (N=424) (N=106) (N=107) (N=105) Age, years, mean (SD) 58 (11) 57 (10) 57 (12) 56 (11) 57 (11) Female, n (%) 83 (78%) 79 (75%) 79 (74%) 80 (76%) 321 (76%) Weight (kg),
Slide 8: Baseline Disease Characteristics
Baseline Disease Characteristics Rosnilimab Rosnilimab Rosnilimab Placebo Overall Baseline Characteristic 100mg Q4W 400mg Q4W 600mg Q2W (N=106) (N=424) (N=106) (N=107) (N=105) Duration of disease, years, mean (SD) 11 (9) 11 (10) 9 (8) 10 (9) 10 (9) Prior b/tsDMARD, n (%) 44 (41.5%) 44 (41.5%) 45 (42
Slide 9: Primary and Select Secondary and Exploratory Endpoints Show Statistical Significance at Week 12
Primary and Select Secondary and Exploratory Endpoints Show Statistical Significance at Week 12 ITT population, MMRM and NRI analysis Primary Endpoint: Mean Change from Baseline in DAS28-CRP at Week 12 Secondary Endpoints at Week 12 Exploratory Endpoint at Week 12 0.0 Week 12 Statistical Significanc
Slide 10: Responses Increase from Week to Week in Overall and b/tsDMARD Experienced Population
Responses Increase from Week 12 to Week 28 in Overall and b/tsDMARD Experienced Population ITT population, NRI analysis ACR50 ACR70 CDAI ≤ 10 (LDA) CDAI ≤ 2.8 (remission) 70 70 70 20 62.9 17.9 58.1 16.8 60 60 60 52.8 54.2 16.2 48.6 49.5 15 50 46.7 50 50 46.2 44.3 45.3 44.8 % Response 40.6 38.1 40 36
Slide 11: Improvement in Patient Reported Outcome Measures from Week 2 to Week 28
Improvement in Patient Reported Outcome Measures from Week 12 to Week 28 in Overall and b/tsDMARD Experienced Population ITT population, MI-LMCF analysis HAQ-DI Pain VAS FACIT-F 0 0 15 MCID:-10 MCID:-0.22 -0.2 -10 10.7 10.4 LS Mean Change 10.5 9.6 from Baseline 10 9.4 8.6 Overall -0.4 -20 Patients -
Slide 12: Responses Were Durable Off Study Drug for Months
Responses Were Durable Off Study Drug for 3 Months Week 28 Responders Maintaining Response Off-Drug (Week 38) Mean CDAI Over Time 40 35 90 30 Mean CDAI 84% 82% 25 79% 80% 80% 79% 80 78% 77% 77% 20 75% 15 CDAI 70 69% 67% 10 LDA 5 ≤10 60 0 % Response PBO All Active Off Drug 50 W0 W12 W28 W30 W34 W38 4
Slide 13: Responses Across Endpoints Based on Prior Therapeutic Agent
Responses Across Endpoints Based on Prior Therapeutic Agent (Rosnilimab Pooled Doses) ITT population, NRI analysis Week 28 Anti-TNFα Anti-IL6R JAKi >1 b/tsDMARD N=72 N=28 N=38 N=27 60 57% 54% 50 47% 43% 40% 40 % Response 33% 32% 30% 30 26% 26% 21% 22% 19% 20 18% 15% 13% 10 0 ACR50 ACR70 CDAI LDA CDA
Slide 14: Safety and Tolerability: Treatment Initiation Through Week 38
Safety and Tolerability: Treatment Initiation Through Week 38 (End of Follow Up) Placebo** Rosnilimab Rosnilimab Rosnilimab All Rosnilimab N=106 100mg q4w 400mg q4w 600mg q2w N=318 • Rosnilimab was well n (Rate) N=106 N=107 N=105 n (Rate) tolerated with no n (Rate) n (Rate) n (Rate) safety dose effe
Slide 15: Translational Data
Translational Data
Slide 16: Rosnilimab Potently Reduced Pathogenic T Cells in Blood
Rosnilimab Potently Reduced Pathogenic T Cells in Blood Peripheral T Cell Changes Over Time • >90% reduction in PD-1high T cell numbers (including Tph cells) at highest doses Placebo 100mg Q4W — Reductions persist 12 Weeks after last dose 100 100 80 EOT 80 EOT • No changes in overall T cell numbers
Slide 17: Rosnilimab Demonstrated Pathogenic T cell Depletion and Broad Downregulation of Pathways in Synovium
Rosnilimab Demonstrated Pathogenic T cell Depletion and Broad Downregulation of T cell, B cell and Myeloid Pathways in Synovium Synovial immunohistochemistry Impact on Synovial Synovial bulk RNA-seq (rosnilimab pooled doses) n= 39 paired samples PD-1+ T cells n= 24 paired samples, responders & nonre
Slide 18: Summary
Summary • At Week 12, the primary endpoint of mean change in DAS28-CRP was achieved across all doses of rosnilimab compared to placebo, as was ACR20 • At Week 28, improvements observed in ACR50/70, CDAI LDA and CDAI remission ― Responses independent of prior therapy type (including JAKi) • At Week 3
Slide 19: Conclusions
Conclusions • Rosnilimab, with a novel MoA, demonstrated a meaningful and durable clinical benefit along with a favorable safety profile in this large Phase 2B rheumatoid arthritis trial • Clinical proof-of-concept for pathogenic T cell depletion was achieved and corroborated by translational valida
Slide 20: Thank You!
to Patients Caregivers Thank Investigators Study Staff You! & Everyone involved in this study! Medical writing assistance and graphics support was provided by Susan Sutch, PharmD of Get-it-Write Med Coms, Ellen Zigmont, PharmD, BCOP, and Cynthia Alexander, PhD of Anaptys, Lori Chollar and team of TL