Dianthus Therapeutics, Inc. · NASDAQ:DNTH
Dianthus Therapeutics — Investor Presentation (June 2026)
94 slides from Dianthus Therapeutics's investor presentation, Jun 12, 2026
Slide 1: Advancing a leading autoimmune-focused company
Advancing a leading autoimmune-focused company June 2026 Exhibit 99.1
Slide 2: Forward-looking statements
Forward-looking statements Certain statements in this presentation, other than purely historical information, may constitute “forward-looking statements” within the meaning of the federal securities laws, including for purposes of the safe harbor provisions under the United States Private Securities
Slide 3: Developing two autoimmune therapeutics with best-in-disease potential
Developing two autoimmune therapeutics with best-in-disease, pipeline-in-a-product potential and targeting patient-friendly, infrequent S.C. self-administration Advancing a leading autoimmune-focused company with neuromuscular and rheumatology franchises Highly potent, ~8-week half-life, classical p
Slide 4: Building on the promise of claseprubart
Building on the promise of claseprubart to be a potential pipeline-in-a-product and best-in-disease therapy in growing and underserved markets Ph.2 MaGic Showed Rapid & Robust Improvements in gMG Q3’25 CAPTIVATE Part A Early GO Decision in CIDP Q1’26 Ph. 2 MoMeNtum Top-line Data Anticipated Q4’26 Q4
Slide 5: Two clinical-stage candidates with best-in-disease potential
Two clinical-stage candidates with best-in-disease, pipeline-in-a-product potential Indications Market Insight Our Opportunity Next Milestone gMG: >100,000 gMG U.S. patients from Komodo claims data accessed 2013-2025; approx. 85% of gMG patients have AChR autoantibody-driven disease https://www.ncbi
Slide 6: Claseprubart: Building a Best-in-Disease Neuromuscular Franchise
Claseprubart: Building a Best-in-Disease Neuromuscular Franchise
Slide 7: Pursuing the power of consistent control with one-click
Pursuing the power of consistent control…with one-click! Targeting a best-in-disease, first-line biologic treatment for neuromuscular diseases CLASSICAL CONVENIENCE Upstream Inhibition Prevents Pro-inflammatory C3a/C3b <10-Second Autoinjector Targeting No Boxed Warning or REMS Self-Administered At H
Slide 8: Opportunity as potential 1L biologic in three large US neuromuscular markets
Claseprubart has opportunity to compete as a potential 1L biologic in three large and growing US neuromuscular markets >100K patients >140K patients >150K patients AChR+ gMG patients Positive Ph. 2 data reported Sept. ’25 >40K CIDP patients Early GO decision announced Mar. ‘26 Ph. 2 top-line data ex
Slide 9: Claseprubart: Opportunity in Generalized Myasthenia Gravis
Claseprubart: Opportunity to be a Best-in-Disease, First-Line Biologic for Generalized Myasthenia Gravis
Slide 10: Ultomiris sales growth in Q1'26
Ultomiris sales grew 18% in Q1’26... “driven by patient demand across indications, including the competitive myasthenia gravis and PNH markets.” Ultomiris sales grew 15% in Q4’25... “driven by patient demand across indications, including the competitive gMG and PNH markets. In 2026, we expect Ultomi
Slide 11: US gMG market has significant potential to expand
The US gMG market has significant potential to expand as <20% of AChR+ patients1 are treated with biologics Note: Positioning of claseprubart’s target profile is illustrative. 1. Komodo claims data accessed 2013-2025, adjusted to account for 70% capture of real-world patient counts; AChR+ 85% of gMG
Slide 12: Claseprubart aims to address unmet needs in gMG
Claseprubart aims to address the significant unmet needs in the gMG market Survey of US Neurologists confirms significant opportunity for differentiated biologic in gMG market Dianthus 2025 Neurologist MG quantitative survey (n=81, N = 54 Neuromuscular specialists, N = 27 General Neurologists), fiel
Slide 13: MaGic Ph. 2 Results Support a Potentially Best-in-Disease Treatment for gMG
MaGic Ph. 2 Results Support a Potentially Best-in-Disease Treatment for gMG
Slide 14: MaGic Ph. 2 top-line results summary
MaGic Ph. 2 top-line results support a potentially best-in-disease treatment for gMG Strong results support claseprubart potential as a best-in-disease complement inhibitor Rapid, sustained, statistically significant symptom improvements as measured by MG-ADL, QMG, MSE, MGC, MG-QoL-15r Safety Endpoi
Slide 15: MaGic is a global Ph. 2 trial in AChR+ gMG patients
MaGic is a global Ph. 2 trial in AChR+ gMG patients A global, multicenter, randomized, double-blind, placebo-controlled study to evaluate the safety, efficacy, and PK / PD of claseprubart administered S.C. following initial loading dose Trial enrollment exceeded target, with 65 participants enrolled
Slide 16: AChR+ gMG participant baseline characteristics
AChR+ gMG participants Placebo (N=22) Claseprubart 300mg/2mL Q2W (N=21) Claseprubart 600mg/4mL Q2W (N=22) Age, mean (SD), years 52.2 (16.5) 57.1 (13.7) 55.3 (12.0) Male, n (%) 13 (59%) 14 (67%) 10 (45%) Weight, mean (SD), pounds 195.0 (48.0) 192.5 (35.5) 179.0 (35.4) Duration of disease, median (ran
Slide 17: Statistically significant improvement in MG-ADL score at Week 13
Statistically significant improvement in MG-ADL score for both claseprubart arms vs. placebo at Week 13 Statistically significant and clinically meaningful reductions in MG-ADL across both treatment arms Mean Change in MG-ADL Score from Baseline at Week 13 The change from baseline in MG-ADL was anal
Slide 18: Statistically significant improvement in QMG score at Week 13
Statistically significant improvement in QMG score for both claseprubart arms vs. placebo at Week 13 Statistically significant and clinically meaningful reductions in QMG across both treatment arms The change from baseline in QMG was analyzed using a mixed effect model for repeated measures (MMRM) w
Slide 19: Rapid, sustained improvements in MG-ADL score
-1.8 -2.6 P=0.0113* P=0.0006* Claseprubart arms demonstrated rapid, sustained, and clinically meaningful improvements in MG-ADL score MG-ADL improvements for participants treated with claseprubart were rapid, sustained, clinically meaningful and statistically significant as early as Week 1 The chang
Slide 20: Rapid, sustained improvements in QMG score
Claseprubart arms demonstrated rapid, sustained, and clinically meaningful improvements in QMG score QMG improvements for participants treated with claseprubart were rapid, sustained, clinically meaningful and statistically significant as early as Week 1 The change from baseline in QMG was analyzed
Slide 21: >60% achieved ≥5 point improvement in MG-ADL
>60% of participants on claseprubart 300mg/2mL achieved ≥5 point improvement in MG-ADL Participants across both treatment arms achieved robust improvements in MG-ADL at Week 13 Improvement in MG-ADL Total Score Claseprubart 300mg/2mL Q2W Placebo Claseprubart 600mg/4mL Q2W Placebo
Slide 22: >60% achieved ≥5 point improvement in QMG
>60% of participants on claseprubart 300mg/2mL achieved ≥5 point improvement in QMG Participants across both treatment arms achieved robust improvements in QMG at Week 13 Improvement in QMG Total Score Claseprubart 300mg/2mL Placebo Claseprubart 600mg/4mL Placebo
Slide 23: Minimal Symptom Expression on MG-ADL at Week 13
37% of 300mg/2mL claseprubart-treated participants achieved Minimal Symptom Expression on MG-ADL at Week 13 MSE supports potential best-in-class profile Minimal Symptom Expression (MSE) % of Participants Achieving MG-ADL Score of 0 or 1 at Week 13 P=0.0550* P=0.1031 The proportion of participants wh
Slide 24: Statistically significant improvement in MGC at Week 13
Statistically significant improvement in MGC for both claseprubart arms vs. placebo at Week 13 Mean Change in MGC Score from Baseline at Week 13 Mean Change in MGC Summed Muscle Score from Baseline at Week 13 (post-hoc analysis) The change from baseline in MGC and MGC Summed Muscle Score were separa
Slide 25: Improvement in MG-QoL-15r score at Week 13
Statistically significant improvement in MG-QoL-15r score for 300mg/2mL vs. placebo at Week 13 The change from baseline in MG-QoL 15r was analyzed using a general linear model with treatment group, stratification factors, and baseline measure included. *One-sided p-values are presented for compariso
Slide 26: Robust and clinically meaningful responses across key efficacy measures
Across key efficacy measures, claseprubart demonstrated robust and clinically meaningful responses Placebo Claseprubart 300mg/2mL Q2W Claseprubart 600mg/4mL Q2W Absolute Placebo-adjusted Absolute Placebo-adjusted MG-ADL mean change from baseline at Week 13 -2.8 -4.6 -1.8 (P=0.0113)* -5.4 -2.6 (P=0.0
Slide 27: Improvements in MG-ADL vs. other approved therapies
Claseprubart demonstrated statistically significant and clinically meaningful improvements in MG-ADL Claseprubart S.C. Zilbrysq QD PFS Δ1.8 Δ2.6 Note: For illustrative purposes only. Efficacy data are derived from different clinical trials conducted at different times, with differences in trial desi
Slide 28: Additional secondary efficacy measures
Additional secondary efficacy measures support claseprubart potential as best-in-class complement inhibitor Claseprubart S.C. Ph II MAGIC Week 13 n = 43 | BL = 13.2 Mean Change from Baseline in QMG Score Ultomiris IV Ph III CHAMPION MG Week 26 n = 78 | BL = 14.8 % of Participants Achieving MG-ADL Sc
Slide 29: Generally well tolerated with favorable safety profile in Phase 2
Claseprubart was generally well tolerated, with a favorable, potentially differentiated safety profile in Phase 2 Comparable clinical safety profile to placebo with remarkably benign administration, no infection signal and no symptoms indicative of autoimmune activation or DIL4 Placebo (N=22) Clasep
Slide 30: Rationale for Q4W 300mg/2mL Dosing in gMG
Rationale for Q4W 300mg/2mL Dosing & Potential for Enhanced, Best-in-Disease Efficacy in gMG
Slide 31: OLE data support addition of 300mg/2mL Q4W in Ph. 3
OLE data support addition of 300mg/2mL Q4W in Ph. 3 Mean Change in PBO Patients’ MG-ADL and QMG Score from RCT Baseline to OLE Week 6 QMG: 14.2 RCT Period OLE Period PBO Patients Entering OLE Received 600mg/4mL Q2W w/ No Loading Dose PK of ~65 µg/mL at week 4 after only two 600mg/4mL doses is substa
Slide 32: Adding QMG screening criteria in Ph. 3
Patients with QMG ≥10 Adding QMG screening criteria in Ph. 3, similar to zilucoplan Ph. 31, may better control for placebo response Claseprubart MG-ADL Change from Baseline P=0.0006* -3.0 P=0.0113* -1.8 The change from baseline in ADL was analyzed using a mixed effect model for repeated measures (MM
Slide 33: Potential for improved efficacy vs. C5 inhibitors via upstream inhibition
Potential for improved efficacy vs. C5 inhibitors with claseprubart may be due to upstream inhibition Upstream inhibition prevents the creation of pro-inflammatory C3a and C3b as well as MAC, potentially providing additional efficacy benefits for AChR+ gMG patients C3a Formation1 C3b Deposition2* 10
Slide 34: EMERGE global Ph. 3 trial in AChR+ gMG
EMERGE is a global Ph. 3 trial evaluating Q4W and Q2W S.C. claseprubart in AChR+ gMG; top-line data 2H’28 Potential to further enhance best-in-disease differentiation on efficacy and dosing convenience with QMG screening criteria and 300mg/2mL Q4W dosing No ANA screening exclusion criteria or routin
Slide 35: Target profile as potential best-in-disease treatment for gMG
Achieving this profile could position claseprubart as a potential best-in-disease treatment for gMG Similar or superior MG-ADL to FDA-approved C5 inhibitors with continuous, effective symptom control C1s SAFETY (Enjaymo) C5 OR SUPERIOR EFFICACY (ULTOMIRIS/SOLIRIS/ZILBRYSQ) AUTOINJECTOR CONVENIENCE (
Slide 36: Claseprubart: Opportunity in CIDP
Claseprubart: Opportunity to Change the Treatment Paradigm in Chronic Inflammatory Demyelinating Polyneuropathy
Slide 37: US CIDP market offers substantial growth potential
The US CIDP market offers substantial growth potential given high unmet need and limitations of current standard of care Opportunity for an active C1s inhibitor with the target profile of claseprubart to replace the standard of care Note: Positioning of claseprubart’s target profile is illustrative.
Slide 38: Survey of US Neurologists in CIDP
Survey of US Neurologists supports potential transformative opportunity in CIDP of Neurologists strongly prefer treatment options without a boxed warning or REMS program ~54% Total Neurologists 80 Neuromuscular Specialist 81% Generalist 19% Academic 58% Community based 42% Sample Demographics ~13 ye
Slide 39: Neurologists want safer, more effective, convenient options than IVIg
% of Surveyed Neurologists Who Strongly Believe… Surveyed Neurologists want safer, more effective and convenient treatment options than IVIg for CIDP patients Significant unmet need for effective therapies for patients who don’t respond to IVIg 75% IVIg imposes a high treatment burden due to frequen
Slide 40: CAPTIVATE Interim Responder Analysis design
Interim Responder Analysis in CAPTIVATE was planned with first 40 patients completing Open-Label Part A Claseprubart 300mg/2mL S.C. Q2W (N=64) Placebo (N=64) Claseprubart 600mg/4mL S.C. Q2W (N=64) Screen PART A: Up to 13-Week Open-Label Claseprubart Only PART B: 52-Week Pbo- controlled RCT CIDP diag
Slide 41: Significant differences between CAPTIVATE and ADHERE
Significant differences between CAPTIVATE and ADHERE Source: Company filings, presentations and clinicaltrials.gov. Ig refers to IVIg and SCIg Data are derived from different clinical trials conducted at different times, with differences in trial design and patient populations. As a result, cross-tr
Slide 42: Active C1s inhibition with riliprubart has clinical proof-of-concept
Active C1s inhibition with riliprubart has demonstrated clinical proof-of-concept across broad patient groups Claseprubart is being evaluated with a convenient, low volume dose of 300mg/2mL Q2W Riliprubart Phase 2 at PNS 2024 Based on riliprubart patent filing (Pg 76) Ph. 2 Riliprubart Data in Activ
Slide 43: Claseprubart in vitro affinity and potency
Claseprubart in vitro affinity and potency Note: Riliprubart is produced using sequence from patent WO2018071676A1 1. Data shown is dissociation constant (KD) and the average of 3 different experiments performed at independent laboratories. 2. Data is quantitative analysis of active C1s protease inh
Slide 44: Early GO decision reached in March 2026
Announced early GO decision reached with less than 40 planned participants completing Part A in March’26 GO decision reached early after 20 confirmed responders were achieved with less than 40 planned participants completing Part A Independent DSMB reviewed the data to date and confirmed GO decision
Slide 45: 75% response rate in Interim Responder Analysis
75% response rate observed in Interim Responder Analysis from first 40 participants completing Part A of CAPTIVATE Breakdown of First 40 Participants Completing CAPTIVATE Part A 75% Confirmed Responders 12.5% Relapse 12.5% Stable Consistent and clinically meaningful results across multiple efficacy
Slide 46: CAPTIVATE Part A baseline characteristics
CAPTIVATE Part A baseline patient group characteristics are similar to precedent aC1s Ph. 2 study1 Broad representation of patients across North America, Europe, and Asia in CAPTIVATE Part A Data from CAPTIVATE and riliprubart Ph. 2 are derived from different clinical trials conducted at different t
Slide 47: Early responder rates support 300mg/2mL Q2W dose and trial updates
Early responder rates support 300mg/2mL Q2W dose and updates to CAPTIVATE Trial Design Element Original Design Anticipated New Design Claseprubart CAPTIVATE Implications Part A Dose 300mg/2mL S.C. Q2W 300mg/2mL S.C. Q2W No change to Part A dose given results observed to date Study Arms in Part B 300
Slide 48: Revised CAPTIVATE study design
PART B: 52-Week Pbo- controlled RCT Revised CAPTIVATE study design going forward Claseprubart 300mg/2mL S.C. Q2W (N=64) Placebo (N=64) Screen PART A: Up to 13-Week Open-Label Claseprubart Only CIDP diagnosis confirmed by an Independent CIDP Review Panel (ICRP) Open-Label Extension: 104 Weeks Loading
Slide 49: Target profile as potential blockbuster treatment for CIDP
Achieving this target profile could position claseprubart as a potential blockbuster treatment for CIDP Improvement over SoC (i.e. Ig) with continuous, effective symptom control C1s SAFETY (Enjaymo) EFFICACY (IVIg/SCIg) AUTOINJECTOR CONVENIENCE (DUPIXENT) Comparable safety to FDA-approved C1s & Clas
Slide 50: Claseprubart: Opportunity in Multifocal Motor Neuropathy
Claseprubart: Opportunity to be Best-in-Disease in Multifocal Motor Neuropathy
Slide 51: US MMN market is a growing blockbuster opportunity
The US MMN market is a growing blockbuster market opportunity for claseprubart Opportunity for the target profile of claseprubart to become the new standard of care in MMN Note: Positioning of claseprubart’s target profile is illustrative. 1. 2024 patients projected from 2023 count due to unreliable
Slide 52: Survey of US Neurologists on MMN
Survey of US Neurologists supports MMN underdiagnosis and large unmet need Claseprubart aims to offer a uniquely effective, safe, convenient classical pathway inhibitor of Neurologists strongly believe there is a high unmet need for therapies with a more favorable dosing schedule ~63% of Neurologist
Slide 53: Despite SoC, 1/3 of patients remain refractory
% of Surveyed Neurologists Who Strongly Believe… Despite SoC, 1/3 of patients remain refractory and face risk of clinical deterioration Patients on IVIg often report residual or unaddressed symptoms 58% 51% Clinical efficacy of IVIg remains is incomplete, inconsistent, and/or short-lived 51% Over ha
Slide 54: Classical Pathway inhibition has demonstrated PoC in MMN
Classical Pathway inhibition has demonstrated PoC in MMN Phase 2 MoMeNtum trial of claseprubart, a potent & selective Classical Pathway inhibitor, is ongoing in MMN “We hypothesize that targeting the classical complement pathway is a potential therapeutic approach in MMN. We investigated the interac
Slide 55: Superior classical pathway potency vs. empasiprubart
Claseprubart demonstrates superior classical pathway potency vs. empasiprubart Claseprubart Demonstrates Superior Classical Pathway Potency Head-to-head vs. Empasiprubart Using Same Assay claseprubart empasiprubart IC50 (µg/mL) 3.8 ± 0.8 22.1 ± 5.7 IC90 (µg/mL) 9.9 ± 2.5 375 ± 266 Empasiprubart Publ
Slide 56: Phase 2 MoMeNtum top-line data anticipated Q4'26
Phase 2 MoMeNtum top-line data in MMN anticipated Q4’26 A global, multicenter, randomized, double-blind, placebo-controlled study to evaluate the safety, efficacy, and PK / PD of claseprubart administered S.C. following initial loading dose Top-line data expected in Q4’26 MoMeNtum Trial: https://cli
Slide 57: Key differences between ARDA and MoMeNtum trials
Key differences between ARDA and MoMeNtum trials make cross-trial comparisons challenging Considerations Empasiprubart (C2) ARDA Trial Claseprubart (aC1s) MoMeNtum Trial Key Differentiators of MoMeNtum Study Size & Treatment Duration Placebo N = 18 10mg/kg Q2W IV, N = 18 5mg/kg Q4W IV, N = 18 Length
Slide 58: Key differentiators of claseprubart vs. empasiprubart
Considerations Empasiprubart (C2)* Claseprubart (active C1s)* Key Differentiators of Claseprubart MMN is an IgM and classical pathway driven disease1 Published classical pathway3 EC50 = 30.5 ±4.5 µg/mL using Quidel MicroVue CH50 Claseprubart has demonstrated potent inhibition of classical pathway in
Slide 59: Target profile as potential blockbuster treatment for MMN
Achieving this target profile could position claseprubart as a potential blockbuster treatment for MMN Improvement over SoC (i.e., Ig) with continuous, effective symptom control C1s SAFETY (Enjaymo) EFFICACY (IVIg/SCIg) AUTOINJECTOR CONVENIENCE (DUPIXENT) Comparable safety to FDA-approved C1s & Clas
Slide 60: DNTH212: Potential Best-in-Disease Bispecific Fusion Protein
DNTH212: Potential Best-in-Disease Bispecific Fusion Protein for Multiple Autoimmune Indications
Slide 61: DNTH212 is a bifunctional BDCA2 and BAFF/APRIL inhibitor
Inhibiting BDCA2 reduces Type 1 interferon production from plasmacytoid dendritic cells (pDCs) Single CRD2 domain of TACI designed to deliver robust B cell modulation via BAFF/APRIL inhibition DNTH212 targets both the innate and adaptive immune systems with complementary disease modifying mechanisms
Slide 62: Targeting both innate and adaptive immune systems
Potential to drive superior clinical efficacy by targeting both the innate and adaptive immune systems Panda SK, et al., Plasmacytoid dendritic cells in autoimmunity. Curr Opin Immunol. 2017 Feb;44:20-25. Minaga K, et al., Plasmacytoid Dendritic Cells as a New Therapeutic Target for Autoimmune. Fron
Slide 63: Superior pDC depletion compared to litifilimab in vitro
DNTH212 achieves superior pDC depletion compared to litifilimab in vitro Comparable Suppression of Pro-Inflammatory Cytokine IFN-α1 Deeper Depletion of pDC2 Method: Human PBMCs from a healthy donor were co-cultured with a TLR9 agonist and serially diluted antibodies for 24 hours. IFN-α release in th
Slide 64: Superior Ig inhibition compared to povetacicept in NHPs
DNTH212 shows superior inhibition of IgM, IgA, and IgG compared to povetacicept following single dose in NHPs S.C. DNTH212 IV povetacicept and telitacicept1 Note: These data are derived from different studies at different points in time, with differences in methodology, design and populations. As a
Slide 65: Priority indications with high unmet need
Priority indications with high unmet need and dual involvement of both innate and adaptive immune systems DNTH212 Priority Rheumatology Indications Sjögren’s disease (SjD) ~350,000 U.S. patients Systemic lupus erythematosus (SLE) ~225,000 U.S. patients Dermatomyositis (DM) ~50,000 U.S. patients Buil
Slide 66: SLE: BDCA2 and BAFF/APRIL validation
SLE: Strong BDCA2 and BAFF / APRIL validation with a proven development path support DNTH212 opportunity BDCA2/Type 1 IFN (Innate) BAFF/APRIL (Adaptive) DNTH212 Target Opportunity ~225K U.S. Patients Supportive Evidence SLE is a systemic autoimmune disease affecting multiple organs such as the kidne
Slide 67: SLE: dual mechanism to address unmet needs
Utilized concurrently with steroids SLE: Potential for dual mechanism to address key unmet needs despite approved treatments Litfilimab Ph. 2 data1 and multiple approvals (Saphnelo, Benlysta) support dual-mechanism approach in SLE Biogen Lupus Virtual Investor Seminar (2025) Lupus Sci Med. 2025 Dec
Slide 68: SjD: unmet need for a single therapy
BDCA2/Type 1 IFN (Innate) BAFF/APRIL (Adaptive) SjD: High unmet need for a single therapy that can address multiple disease manifestations Supportive Evidence Sjögren’s destroys mucosal exocrine glands causing extreme dry eyes and mouth (sicca) and leads to debilitating systemic symptoms such as fat
Slide 69: SjD: increased efficacy from dual-mechanism approach
SjD: Potential for increased efficacy from dual-mechanism approach vs. targeting BAFF receptor only Fatigue, pain and cognitive dysfunction are significant drivers of patient disability2 70% increased mortality compared with the general population due to infections, cancer and cardiovascular disease
Slide 70: DM: unmet need for a single therapy
BDCA2/Type 1 IFN (Innate) BAFF/APRIL (Adaptive) DM: High unmet need for a single therapy that can more effectively address the disease Supportive Evidence DM causes progressive muscle weakness, painful rash, pruritus and interstitial lung disease; limited therapeutic options beyond corticosteroids (
Slide 71: DM: dual-mechanism approach may more effectively address disease
DM: Dual-mechanism approach may more effectively address the disease Dazukibart Ph. 2 data1 and IVIg2 lays foundation for multi-organ efficacy in DM Dazukibart Phase 2 publication Trial of Intravenous Immune Globulin in Dermatomyositis Christopher-Stine; BMC Rheumatology 2025 George et al. RMD Open
Slide 72: Ph. 1 study initiated in China Dec. '25
Ph. 1 study initiated in China in Dec. ’25 with top-line Part A HV results anticipated in 2H’26 5mg N = 2:0 S.C. Administration Healthy Volunteers (Part A) ~46 HVs enrolled into seven cohorts: Treated (N= up to 6) Placebo (N= up to 2) ~30 patients enrolled into three cohorts: Treated (N= up to 10) H
Slide 73: DNTH212 TPP
DNTH212 TPP aims to deliver superior efficacy in a safe and well-tolerated therapy with patient friendly convenience Achieving the TPP could position DNTH212 as a first-line biologic across a range of indications Bifunctional approach has potential for superior efficacy in various disease states ver
Slide 74: DNTH212 as first-line, best-in-disease therapy across indications
Achieving DNTH212 TPP could position DNTH212 as a first-line, best-in-disease therapy across multiple indications Type 1 interferon and BAFF/APRIL are known drivers of autoimmune disease Potential S.C. self-administration Q4W or less frequent Targeting innate and adaptive immune systems has potentia
Slide 75: Recap of Dianthus Leadership in Severe Autoimmune Diseases
Recap of Dianthus Leadership in Severe Autoimmune Diseases
Slide 76: Foundation in Neurology, Expansion into Rheumatology
Claseprubart: Foundation in Neurology Establishing our vision as the leading autoimmune focused biotech through potential best-in-disease innovation DNTH212: Expansion into Rheumatology Continued Expansion Ph. 3 gMG Ph. 3 CIDP Ph. 2 MMN Leverage Core Competencies to Expand Leadership Across Severe A
Slide 77: Two clinical stage programs and upcoming milestones
Advancing a leading autoimmune-focused biotech with two clinical stage programs Program Indication Ph. 1 Ph. 2 Ph. 3 Upcoming Milestones Claseprubart aC1s gMG* >100,000 U.S. Patients Initiation of Ph. 3 study expected in mid-26 Ph. 3 top-line data expected in 2H’28 CIDP >40,000 U.S. Patients Part B
Slide 78: Appendix
Appendix
Slide 79: C1s is a clinically validated target in the classical complement pathway
C1q lgG antibody Cell Surface C1s is a clinically validated target in the classical complement pathway with an FDA approved therapy The C1 complex The initial component of the classical complement pathway consisting of C1q, C1r and C1s 3 2 2 3 Active C1s A serine protease that executes catalytic fun
Slide 80: Selectively targeting classical pathway for safer complement inhibition
Membrane Attack Complex (MAC) Selectively targeting classical pathway aims to provide effective but safer complement inhibitor Targeting aC1s aims to deliver efficacy demonstrated with terminal inhibitors while preserving the critical immune activity of lectin and alternative pathways, leading to a
Slide 81: ENJAYMO has no boxed warning, REMS or antibiotic requirement
Unlike C5 inhibitors, ENJAYMO® has no FDA boxed warning and REMS, or prophylactic antibiotic requirement prior to vaccination Source: ULTOMIRIS prescribing information & ENJAYMO prescribing information Boxed Warning and REMS Antibiotic Prophylaxis Required if not Fully Vaccinated No Boxed Warning or
Slide 82: Lower risk of Neisseria meningitidis infections in vitro
Claseprubart in vitro study indicates lower risk of Neisseria meningitidis infections Anti-capsular antibody (Anti -Nm) mimics N. meningitidis vaccination 0 50 100 150 % Bacterial Survival Serum +Anti - Nm 0.3 uM 1.0 uM DNTH103 Anti - C5 No treatment Results further validate the potential different
Slide 83: Consistent symptom control with Q2W S.C. dosing
Indicates VYVGART® dose administered Source: VYVGART® prescribing information and ULTOMIRIS® prescribing information 1. Pane et al. A real-life experience with eculizumab and efgartigimod in generalized myasthenia gravis patients. J Neurol 271, 6209–6219 (2024) Claseprubart aims to provide consisten
Slide 84: Real-world evidence: eculizumab vs. efgartigimod
Patients on eculizumab showed a greater reduction in MG-ADL over time than those on efgartigimod Eculizumab showed statistically significant, deeper QMG reduction and higher responder rate than efgartigimod Eculizumab patients had a statistically significant greater reduction in rate of clinical eve
Slide 85: Improves neurotransmission and muscle contraction in AChR+ MG model
Claseprubart improves neurotransmission and muscle contraction in an AChR+ MG model Results provide further scientific rationale for DNTH103 in gMG Serum from MG patients used in a validated in vitro MG model1,2,3 Assessed improvement in neurotransmission and muscle contraction of ravulizumab* and D
Slide 86: Restores neuronal conduction velocity in in vitro CIDP model
Claseprubart restores neuronal conduction velocity in an in vitro CIDP model Results provide further scientific rationale for DNTH103 in CIDP Serum from 3 CIDP patients was evaluated in a , commercially available in vitro CIDP model1 Assessed improvement in neuronal conduction velocity of two doses
Slide 87: Phase 1 healthy volunteer study design
SAD 1 (1 mg/kg) SAD 3 (30 mg/kg) SAD 2 (10 mg/kg) MAD 1 Q2W (300mg/2mL) MAD 2 Q2W (600mg/4mL mg) SAD 1 (300mg/2mL) SAD 2 (600mg/4mL) I.V. Administration S.C. Administration S.C. Administration SAD MAD Claseprubart Phase 1 healthy volunteer study was designed to validate extended half-life, potency a
Slide 88: Deep and sustained complement inhibition in healthy volunteers
Claseprubart has demonstrated deep and sustained complement inhibition in healthy volunteers Claseprubart demonstrated a ~60-day half-life and IC90 of 87 µg/mL I.V. SAD: Linear PK with Exposure Proportional Across Doses S.C. MAD: Strong Accumulation with Q2W Dosing PK/PD: Analysis Demonstrates IC90
Slide 89: Ph. 1 data confirms target dose of 300mg/2mL
15mg/kg I.V. on Day 0 300mg S.C. Q2W starting Day 7 Phase 1 data estimated IC90 at ~87 µg/mL, leading to target dose of 300mg/2mL in Ph. 2 to achieve steady state >IC90 ~60-day half-life IC90 calculated at 87 µg/mL Ph. 1 Data Confirms Simulation using data from 60 healthy volunteers dosed across mul
Slide 90: Generally well tolerated in Phase 1
Claseprubart was generally well tolerated, with a favorable safety profile in Phase 1 No standard safety lab findings (hematology, chemistry, coagulation LFTS and renal function) No serious adverse events No infection adverse event signal and no infections related to encapsulated bacteria Five parti
Slide 91: C3a and C3b elevated in AChR+ gMG
C3a and C3b Are Elevated in AChR+ gMG – Both Cause Inflammatory Damage1,2 C3a C3b Anaphylotoxin2,3 Initiates mast cell degranulation4 Promotes neutrophil-mediated acute phase reactions5 driven by pro-inflammatory cytokines6 – particularly IL-6 in gMG7 Has the potential to directly act on NMJ via smo
Slide 92: aC1s inhibition could change the CIDP landscape
Classical pathway / aC1s inhibition has the potential to change the CIDP landscape aC1s inhibitors enroll a broad patient population including SOC-refractory patients ≥1-point aINCAT improvement used as efficacy measure in ongoing studies No requirement for disease worsening in ongoing complement tr
Slide 93: DNTH212 opportunity across multiple diseases
Biological Rationale Clinical Evidence Primary Sjögren’s Disease ~350,000 U.S. Patients B Cell: ianalumab positive Ph. 3; telitacicept positive Ph. 3 Systemic Lupus Erythematosus ~225,000 U.S. Patients Type 1 interferon: anifrolumab approved; litifilimab positive Ph. 2 B Cell: belimumab approved
Slide 94: Senior management and board of directors
SENIOR MANAGEMENT Accomplished team of biotech industry veterans and scientists committed to bringing innovation to market Select Experience Includes: BOARD OF DIRECTORS Alison Lawton Chair of the Board Board Member, ProQR and X4, Prior Chair of Board, Magenta Sujay Kango Board Member, Adanate, Inc.
Dianthus Therapeutics — Investor Presentation (June 2026) on 6ix