Pepgen Inc. · NASDAQ:PEPG
Pepgen — Investor Presentation (May 2026)
27 slides from Pepgen's investor presentation, May 21, 2026
Slide 1: Company Presentation May 2026
Exhibit 99.1 Company Presentation May 2026
Slide 2: Forward-Looking Statements
Forward-Looking Statements This presentation contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. These statements may be identified by words such as “aims,” “anticipates,” “believes,” “could,” “estimates,” “expects,” “forecasts,
Slide 3: Leveraging EDO Platform to Drive Meaningful Impact for Patients
Leveraging EDO Platform to Drive Meaningful Impact for Patients PGN-EDODM1: Myotonic Dystrophy Type 1 OUR VISION • Best-in-class potential; selectively targets only pathogenic DMPK RNA • Favorable emerging safety profile and FREEDOM2 5mg/kg results Develop therapies that address supportive of the on
Slide 4: PepGen's EDO Platform Designed to Solve the Delivery Challenge of Oligonucleotides
PepGen’s EDO Platform Has Been Designed and Developed to Solve the Delivery Challenge of Oligonucleotides PGN-EDODM1 Delivery to DM1 Patient Myotubes EDO platform results in nuclear delivery of oligonucleotide Red = oligo therapeutics Immortalized myoblasts from a DM1 patient with 2600 CTG repeats w
Slide 5: EDO Technology Can Improve Endosomal Escape and Increase Nuclear Uptake up to 98-Fold
EDO Technology Can Improve Endosomal Escape and Has Been Shown to Increase Nuclear Uptake up to 98-Fold PMO Delivery in DM1 Cells 73x NUCLEAR UPTAKE 2.0 1.5 98x 1.0 55x 0.5 0.0 1 5 10 20 Concentration (nmol) Immortalized myoblasts from a healthy individual or a DM1 patient with 2600 CTG repeats were
Slide 6: PGN-EDODM1: A Differentiated Drug with Best-in-Class Potential
PGN-EDODM1: A Differentiated Drug with Best-in-Class Potential 1 Differentiated Delivery Technology • Receptor-independent EDO peptide delivery • Designed to escape the endosome – unlike TfnR targeting 2 Differentiated Target • Selectively targets pathogenic RNA (CUG repeat in DMPK) 1 • Demonstrated
Slide 7: PGN-EDODM1 – Myotonic Dystrophy Type 1 (DM1)
PGN-EDODM1 – Myotonic Dystrophy Type 1 (DM1)
Slide 8: Myotonic Dystrophy Type 1 Overview and Unmet Medical Need
Myotonic Dystrophy Type 1 Overview and Unmet Medical Need Overview Market Opportunity Jubal, retired professor living with DM1 • CUG expansion in the DMPK • U.S. and EU over 115,000 gene patients • Onset of symptoms variable- • No approved therapies that childhood to adulthood address underlying cau
Slide 9: PGN-EDODM1 Blocking Approach Targets the Pathogenic CUG Repeats DMPK RNA
exp PGN-EDODM1 Blocking Approach Targets the Pathogenic CUG Repeats DMPK RNA PGN-EDODM1 binds selectively to the pathogenic DM1 is caused by pathogenic DMPK transcripts DMPK transcript Trapped Liberated MBNL1 is MBNL1 inactive and restores correct results in splicing mis-splicing exp • DM1 is caused
Slide 10: PGN-EDODM1 Reduced Nuclear Foci, Liberated MBNL1 and Corrected Mis-Splicing in Patient Cells
PGN-EDODM1 Reduced Pathogenic Nuclear Foci, Liberated MBNL1 and Corrected Mis-Splicing in Patient Cells with Long CUG Repeats Foci Reduction MBNL1 Liberation Mis-Splicing Correction Not Treated Not Treated Across multiple transcripts 69% correction 54% reduction in PGN-EDODM1 Treated PGN-EDODM1 Trea
Slide 11: Multiple Doses Led to Greater Splicing Correction and Myotonia Improvement Preclinically
Multiple Doses of PGN-EDODM1 Led to Greater Improvement in Splicing Correction and Myotonia vs Single Dose in Preclinical Studies Tissue Concentration Mis-Splicing Correction Correction of Myotonia Skeletal muscle Across multiple transcripts Pinch test 99% 120 68% 56 Correction of 76% myotonia 0 0%
Slide 12: PGN-EDODM1 – FREEDOM SAD Trial in DM1
PGN-EDODM1 – FREEDOM SAD Trial in DM1
Slide 13: FREEDOM: Phase 1 Single-Ascending Dose Study Design
Biopsy Biopsy Biopsy Biopsy Biopsy Biopsy Biopsy Biopsy Biopsy FREEDOM SAD FREEDOM: Phase 1 PGN-EDODM1 Single-Ascending Dose Study Design Single Dose PGN-EDODM1 or Placebo (randomized 3:1) Baseline DSMB D28 Wk 16 15 mg/kg FREEDOM Phase 1 n=8 or PBO Study Overview Multinational, randomized, double-bl
Slide 14: Dose-Dependent Best-in-Class Splicing Correction Following Single Dose
FREEDOM SAD PGN-EDODM1 Produced Dose-Dependent Best-in-Class Splicing Correction Following Single Dose * Splicing Index Changes: 22-Gene Panel at D28 3.3% 87.5% of participants across all doses -12.3% showed improved splicing -29.1% -53.7% 1 2 3 Placebo 5 mg/kg 10 mg/kg 15 mg/kg (n=5) (n=6) (n=4) (n
Slide 15: Natural History: ~11% of Untreated DM1 Patients Show >20% Splicing Improvement
Natural History ~11% of Untreated DM1 Patients Demonstrate >20% Splicing Improvement over a 2 to 3 Month Time Period Natural History Data in Untreated DM1 Patients* ~15% OF UNTREATED PATIENTS ~74% OF UNTREATED PATIENTS ~11% OF UNTREATED PATIENTS >20% ±20% >20% Worse Splicing Midrange Correction Spli
Slide 16: PGN-EDODM1 Demonstrated >20% Splicing Correction in Majority of Patients at ≥10 mg/kg
FREEDOM SAD PGN-EDODM1 Demonstrated >20% Splicing Correction in a Majority of DM1 Patients after a Single Dose ≥10 mg/kg ±20% >20% Splicing Midrange Correction 74% of Untreated Patients Splicing Improves (% Change from Baseline) Improvement Worsening +20% 0% −20% −50% −70% Placebo SAD: 5 mg/kg SAD:
Slide 17: Greater Than Dose-Proportional Increase in Muscle Tissue Concentration
FREEDOM SAD Robust, Greater Than Dose-Proportional Increase in Muscle Tissue Concentration Following Single Dose Muscle Tissue Concentration at D28 Mean TA muscle 300 Mean TA Muscle 160.6 160.6 200 100 44.1 44.1 13.7 13.7 0 1,2 1 5 mg/kg 15 mg/kg 10 mg/kg 5mg/kg 10mg/kg 15mg/kg * (n=6) (n=5) (n=5) 1
Slide 18: PGN-EDODM1 Generally Well Tolerated, with TEAEs Primarily Mild to Moderate
FREEDOM SAD PGN-EDODM1 Was Generally Well Tolerated, with TEAEs Primarily Mild to Moderate Across Dose Cohorts • Most frequent TEAEs: nausea, nasopharyngitis, Placebo Cohort 1 Cohort 2 Cohort 3 Total and headache (n=6) 5 mg/kg 10 mg/kg 15 mg/kg (n=24) N (events) (n=6) (n=6) (n=6) • No electrolyte-re
Slide 19: PGN-EDODM1 – FREEDOM2 MAD Trial in DM1
PGN-EDODM1 – FREEDOM2 MAD Trial in DM1
Slide 20: FREEDOM2: Phase 2 MAD Study Design
Safety FU Biopsy Safety FU Biopsy Safety FU Biopsy Biopsy Biopsy Biopsy FREEDOM2 MAD FREEDOM2: Phase 2 MAD Study Design 4 Doses of PGN-EDODM1 or Placebo (randomized 3:1) DSMB * FREEDOM2 Phase 2 12.5 mg/kg n=8 or PBO Study Overview Multinational, randomized, double- 7d post final dose blind, placebo-
Slide 21: Favorable Emerging Safety Profile; No Increase in Toxicity with Multiple Doses
FREEDOM2 MAD Favorable Emerging Safety Profile of PGN-EDODM1; No Increase in Toxicity with Multiple Doses at 5 mg/kg PGN-EDODM1 was Generally Well-Tolerated, Summary of Treatment Emergent 5 mg/kg (n=8) 1 with All AEs Mild or Moderate in Severity 1 Adverse Events (TEAEs) n(%) • All participants compl
Slide 22: FREEDOM2 5 mg/kg Splicing Correction
FREEDOM2 MAD FREEDOM2 5 mg/kg Splicing Correction 5 mg/kg Collective Splicing Data 5 mg/kg Individual Splicing Data FREEDOM2 5mg/kg Mean splicing data Splicing Analysis FREEDOM2- 5mg/kg Individual Splicing data 20 Excluding 100 80 70.8 notable splicing outlier 10 60 mean splicing correction of 0 40
Slide 23: Myotonia (vHOT): Promising Middle Finger vHOT Trends at Lowest Dose
FREEDOM2 MAD FREEDOM2 5 mg/kg Myotonia (vHOT): PGN-EDODM1 Shows Promising Middle Finger vHOT Trends at Lowest Dose vHOT Analysis 6 +2.5s 4 (52% CFB) • Excluding notable splicing outlier, the active group 2 remained below baseline (n=5) 0 • Splicing outlier demonstrated -2 22 sec difference between -
Slide 24: FREEDOM2 MAD at 10 & 12.5 mg/kg Has Potential to Build Upon Single-Dose Splicing Correction
FREEDOM SAD FREEDOM2 MAD FREEDOM2 MAD at 10 & 12.5 mg/kg has Potential to Build Upon Robust Single-Dose Splicing Correction ±20% >20% Splicing Midrange Correction 74% of Untreated Patients Splicing Improves (% Change from Baseline) Improvement Worsening +20% 0% −20% −50% −70% Placebo SAD 5 mg/kg SAD
Slide 25: Promising Safety, Splicing and vHOT Data in FREEDOM2 Lowest Dose
FREEDOM2 MAD Promising Safety, Splicing and vHOT Data in FREEDOM2 Lowest Dose – Supports Ongoing 10 mg/kg MAD Cohort • PGN-EDODM1 was generally well-tolerated; all AEs were mild or SAFETY & moderate in severity, with no SAEs or cumulative toxicity with repeat TOLERABILITY dosing observed • Mean spli
Slide 26: Summary of PGN-EDODM1 and FREEDOM Program
Summary of PGN-EDODM1 and FREEDOM Program 1 Differentiated Delivery Technology PHASE 2 FREEDOM2 MAD & OLE Differentiated Target 2 Promising Safety, Splicing and vHOT Data in FREEDOM2 Lowest Dose – Supports Ongoing 10 mg/kg MAD Cohort FREEDOM STUDY: • Company has completed enrollment in the 10 mg/kg
Slide 27: Thank you
o Thank you