Dianthus Therapeutics, Inc. · NASDAQ:DNTH
Dianthus Therapeutics — Investor Presentation (November 2025)
72 slides from Dianthus Therapeutics's investor presentation, Nov 3, 2025
Slide 1: Corporate Presentation November 2025
Corporate Presentation November 2025 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: Advancing a leading autoimmune-focused company
Developing two autoimmune therapeutics with best-in-class, pipeline-in-a-product potential and targeting patient-friendly, infrequent S.C. self-administration Advancing a leading autoimmune-focused company Highly potent classical pathway inhibitor targeting active C1s Positive Ph. 2 gMG results demo
Slide 4: Two clinical candidates with pipeline-in-a-product potential
Two clinical candidates with pipeline-in-a-product potential Two Clinical-Stage Programs with First-Line, Best-in-Class Potential Across Multiple Severe Autoimmune Indications Indications Market Insight Our Opportunity Next Milestone gMG: >100,000 gMG U.S. patients from Komodo claims data accessed 2
Slide 5: Claseprubart: Building a Best-in-Class Neuromuscular Franchise
Claseprubart: Building a Best-in-Class Neuromuscular Franchise
Slide 6: Pursuing the power of consistent control with one-click
Pursuing the power of consistent control…with one-click! Targeting a best-in-class, first-line biologic treatment for neuromuscular diseases CLASSICAL CONVENIENCE Upstream Inhibition of Classical Pathway Only <10-Second Autoinjector Targeting No Boxed Warning or REMS Self-Administered At Home or On-
Slide 7: Claseprubart opportunity as first-line biologic in U.S. neuromuscular market
Claseprubart has opportunity to compete as a first-line biologic in large and growing U.S. neuromuscular market >100K patients >140K patients >150K patients AChR+ gMG patients Positive Ph. 2 data reported Sept. ’25 >40K CIDP patients Ph. 3 interim responder expected in Q2’26 Ph. 2 top-line data expe
Slide 8: Claseprubart Opportunity in Generalized Myasthenia Gravis
Claseprubart Opportunity in Generalized Myasthenia Gravis
Slide 9: Ultomiris growth driven by first-line biologic use in gMG
“Currently, less than 20% of (gMG) patients are on branded treatments, and we expect this to increase to approximately 50% in the next 3 years. Additionally, self-administered medicine represent only a small part of this market today, and we expect this segment to grow substantially.” Ultomiris sale
Slide 10: Multibillion-dollar US gMG market has significant potential to expand
The multibillion-dollar US gMG market has significant potential to expand as <20% of AChR+ patients1 currently 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 patie
Slide 11: Claseprubart aims to address unmet needs in the gMG market
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 12: MaGic Ph. 2 Results
MaGic Ph. 2 Results
Slide 13: MaGic Ph. 2 top-line results support potentially best-in-class treatment for gMG
MaGic Ph. 2 top-line results support a potentially best-in-class treatment for gMG Strong results support claseprubart potential as a best-in-class complement inhibitor Rapid, sustained, statistically significant symptom improvements as measured by MG-ADL, QMG, MSE, MGC, MG-QoL-15r Safety Endpoints
Slide 14: 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 15: AChR+ gMG participants 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 16: 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 17: 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 18: 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 19: 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 20: >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 21: >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 22: 37% achieved Minimal Symptom Expression on MG-ADL
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 23: 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 24: Improvement in MG-QoL-15r score for 300mg/2mL
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 25: 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 26: Improvements in MG-ADL compared with 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 27: Additional secondary efficacy measures support best-in-class potential
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 28: Generally tolerated with favorable safety profile in Phase 2
Claseprubart was generally 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 Placebo (N=22) Claseprubart 300mg/
Slide 29: Rationale for Adding Q4W Dosing and QMG Screening in Ph. 3
Rationale for Adding 300mg/2mL Q4W Dosing & Screening Patients for QMG > 10 in Proposed Ph. 3 Trial
Slide 30: Evidence of efficacy at <IC90 supports 300mg/2mL Q4W
Mounting internal and external evidence of efficacy at <IC90 support including 300mg/2mL Q4W in proposed Ph. 3 300mg/2mL Q4W dosing could result in robust, clinically meaningful efficacy similar to Q2W dosing and would further enhance best-in-class differentiation of claseprubart Claseprubart IC90 (
Slide 31: OLE data supports addition of 300mg/2mL Q4W
OLE data supports 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 subst
Slide 32: MG-ADL change in patients with QMG ≥10
Claseprubart MG-ADL Change from Baseline in Patients with QMG ≥10 Adding QMG screening criteria in Ph. 3, similar to zilucoplan Ph. 31, may result in enhanced efficacy on MG-ADL P=0.0006* -3.0 For claseprubart the change from baseline in ADL was analyzed using a mixed effect model for repeated measu
Slide 33: Best-in-class efficacy may be due to upstream inhibition
Potential for best-in-class efficacy with claseprubart may be due to upstream inhibition Upstream inhibition prevents the creation of pro-inflammatory C3a and C3b as as MAC, potentially providing additional efficacy benefits for AChR+ gMG patients C3a Formation1 C3b Deposition2* 100 80 60 40 20 0 %
Slide 34: Ph. 3 trial design with Q4W arm and QMG screening
Ph. 3 trial design to include additional Q4W arm, and new screening criteria of QMG >10 as as MG-ADL >6 Potential to further enhance best-in-class differentiation on efficacy and dosing convenience with QMG screening criteria and 300mg/2mL Q4W dosing Final Ph. 3 trial design TBD after regulatory con
Slide 35: Target product profile reflects Ph. 2 learnings
Enhanced efficacy and dosing in claseprubart target product profile reflects key learnings from Ph. 2 MaGic trial Similar or superior MG-ADL to FDA-approved C5 inhibitors with continuous, effective symptom control Targeting best-in-class efficacy C1s SAFETY (Enjaymo) C5 OR SUPERIOR EFFICACY (ULTOMIR
Slide 36: Claseprubart Opportunity in CIDP
Claseprubart Opportunity in Chronic Inflammatory Demyelinating Polyneuropathy
Slide 37: US CIDP market offers substantial growth given high unmet need
The US CIDP market offers substantial growth given the high unmet need and limitations of the current standard of care Opportunity for an active C1s inhibitor with the target profile of claseprubart to replace the standard of care Current Ig and biologics account for >$3.5B3,4,5 Despite SoC, many (3
Slide 38: Neuromuscular indication with high unmet medical need
Neuromuscular indication with high unmet medical need Evidence supports classical complement role in disease Active C1s inhibition has demonstrated clinical POC with potential for equal or superior efficacy to current SOC IVIG Claseprubart target dose of 300mg/2mL S.C. every two weeks may offer more
Slide 39: Claseprubart has superior affinity and potency vs. riliprubart
Claseprubart has superior affinity and potency vs. riliprubart 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 acti
Slide 40: CIDP Ph. 3 pivotal trial design
CIDP Ph. 3 pivotal trial includes open-label Part A testing the target dose of 300mg/2mL S.C. Q2W CIDP interim responder analysis with first 40 patients in Part A anticipated in Q2’26 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
Slide 41: Claseprubart Opportunity in MMN
Claseprubart Opportunity in Multifocal Motor Neuropathy
Slide 42: US MMN market is underdiagnosed
The US MMN market is underdiagnosed with a need for more effective and convenient treatment options US MMN Market Opportunity Opportunity for the target profile of claseprubart to become the new standard of care in MMN 1. 2024 patients projected from 2023 count due to unreliable 2024 data from the C
Slide 43: Neuromuscular indication with high unmet medical need
Neuromuscular indication with high unmet medical need Evidence supports classical complement role in disease MMN is an attractive opportunity with clinical PoC demonstrated via classical pathway inhibition Phase 2 trial of claseprubart, a low-volume Q2W S.C., ongoing in MMN No approved targeted biol
Slide 44: 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 C2 inhibitor that targets classical and lectin pathways Active C1s inhibitor targeting classical pathway only Demonstrated potent classical pathway in
Slide 45: MMN Ph. 2 top-line data anticipated 2H'26
MMN Phase 2 top-line data anticipated 2H’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 2H’26 MoMeNtum Trial: https://clinicaltrials.
Slide 46: DNTH212: Potential Best-in-Class Bispecific Fusion Protein
DNTH212: Potential Best-in-Class Bispecific Fusion Protein for Multiple Autoimmune Indications
Slide 47: 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 48: 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 49: DNTH212 achieves superior pDC depletion vs. litifilimab
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 50: Superior inhibition of IgM, IgA, IgG vs. 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 51: Validation of BDCA2 and BAFF/APRIL targeted therapies
Validation of both BDCA2 and BAFF/APRIL targeted therapies support DNTH212 bifunctional approach Note: Company press releases and investor presentations Positive Litifilimab (BDCA2) Data in SLE / CLE BAFF/APRIL Validation Across Multiple Autoimmune Indications and Strategic Activity
Slide 52: Broad opportunity for DNTH212 across multiple diseases
Biological Rationale Clinical Evidence Primary Sjögren's Syndrome ~350,000 U.S. Patients B Cell: ianalumab positive Ph. 3; telitacicept positive Ph. 3 Cutaneous Lupus Erythematosus ~300,000 U.S. Patients Type 1 interferon: litifilimab positive Ph. 2 Systemic Lupus Erythematosus ~225,000 U.S. Pat
Slide 53: Ph. 1 study design and timing for DNTH212
Expect to start Ph. 1 study in China in Q4’25 with top-line Part A HV results 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) Healthy Vo
Slide 54: DNTH212 target product profile
DNTH212 TPP aims to deliver superior efficacy in a safe and well-tolerated therapy with patient friendly convenience Achieving the TPP would 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 55: Achieving DNTH212 TPP would position it as first-line therapy
Achieving DNTH212 TPP would position DNTH212 as a first-line, best-in-class 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 potential
Slide 56: Recap of Dianthus Leadership in Severe Autoimmune Diseases
Recap of Dianthus Leadership in Severe Autoimmune Diseases
Slide 57: Building a leading biotech company in severe autoimmune diseases
Building a leading biotech company focused in severe autoimmune diseases 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.nlm.nih.gov/pmc/articles/PMC7033452/# CIDP & MMN: Komodo claims data
Slide 58: Appendix
Appendix
Slide 59: C1s is a clinically validated target in the classical complement pathway
C1q lgG antibody Cell Surface C1s is a clinically 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 function of t
Slide 60: Selectively targeting classical pathway aims for safer complement inhibitor
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 61: ENJAYMO has no boxed warning or REMS unlike C5 inhibitors
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 62: In vitro study indicates lower risk of Neisseria meningitidis infections
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 63: Consistent symptom control with convenient 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 64: Real-world evidence: complement inhibitors vs. FcRns
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 65: Claseprubart improves neurotransmission 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 in vitro MG model1,2,3 Assessed improvement in neurotransmission and muscle contraction of ravulizumab* and DNTH103, as
Slide 66: Claseprubart restores neuronal conduction velocity in 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 67: Claseprubart 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 68: Ph. 1 data confirms IC90 and target dose
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 69: 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 70: Generally tolerated with favorable safety profile in Phase 1
Claseprubart was generally 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 participan
Slide 71: C3a and C3b are 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 72: 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.
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