Passage Bio, Inc. · NASDAQ:PASG
Passage Bio — Merger or Acquisition (June 2026)
36 slides from Passage Bio's merger presentation, Jun 24, 2026
Slide 1: Modulating RNA Processing to Target the Undruggable
CONFIDENTIAL Modulating RNA Processing TO TARGET THE UNDRUGGABLE Investor Presentation June 2026
Slide 2: Disclaimers
CONFIDENTIAL 2 Disclaimers Important Information for Investors This confidential presentation (“Presentation”) is for informational purposes only and is being provided to interested partie s s olely in their capacity as potential investors for the purpose of evaluating a potential private offering o
Slide 3: Risk Factors
CONFIDENTIAL 3 Risk Factors Risk Factors Both Remix and Passage are subject to various risks associated with their businesses and their industries. In addition, the P rop osed Transaction, including the possibility that the Proposed Transaction may not be completed, poses a number of risks to each c
Slide 4: Merger of Remix Therapeutics and Passage Bio Overview
CONFIDENTIAL 4 Merger of Remix Therapeutics and Passage Bio Overview Transaction Summary Management and Board • Remix, a clinical - stage biotechnology company developing novel small molecule therapies designed to reprogram RNA processing and address disease drivers at their origin intends to merge
Slide 5: Remix Therapeutics
CONFIDENTIAL 5 Remix Therapeutics • REM - 422, the first drug candidate observed to inhibit MYB with clinically meaningful activity in Adenoid Cystic Carcinoma (ACC) • Durable RECIST responses (43% ORR observed) in biomarker positive patients at RP2D; 100% Disease Control Rate • 24 mg Recommended Ph
Slide 6: Experienced management team with deep domain expertise
CONFIDENTIAL 6 INVESTORS BOARD Experienced management team with deep domain expertise PETE SMITH Co - Founder, President & CEO H3 Biomedicine, Takeda, Millennium HEATHER WASSERMAN Chief Business / Operating Officer Eli Lilly, Human Genome Sciences MYTHILI KONERU Chief Medical Officer Legend, Marker,
Slide 7: Small molecule pipeline targeting high value oncology targets
CONFIDENTIAL 7 Small molecule pipeline targeting high value oncology targets Anticipated Milestone Rights Clinical Pre - Clinical Discovery Indications Mechanism Target/Compound ORR / DoR Data Mid ’27 Adenoid Cystic Carcinoma mRNA degrader MYB/REM - 422 RP2D Data Mid '27 AML/MDS Entering clinic in ‘
Slide 8: Adenoid Cystic Carcinoma has a high unmet medical need
CONFIDENTIAL 8 Adenoid Cystic Carcinoma has a high unmet medical need • Malignant epithelial tumor arising predominantly in salivary glands and other glandular tissues; high rates of perineural invasion and relentless growth/metastasis • 1,500+ new patients ¹ per year in the US; prevalence is ~13K –
Slide 9: Surgery is the standard of care, and up to 75% of patients will relapse
CONFIDENTIAL 9 Surgery is the standard of care, and up to 75% of patients will relapse *Lenvatinib, ¹Tchekmedyian et al., ²J Clin Oncol. 2019, Locati et al., Cancer, 2020, ³ Laurie SA et al., Lancet Oncol 2011 ⁴P utnam Associates, Qualitative Research (Q1 2021) & KOL discussions Patients under activ
Slide 10: The first MYB inhibitor in clinical development
CONFIDENTIAL 10 REM - 422 the first MYB inhibitor in clinical development Majority of ACC patients express oncogenic MYB REM - 422 designed to induce degradation of MYB mRNA MYB Expression* MYB translocation drives high expression MYB Expression The majority of ACC patients expressing oncogenic MYB
Slide 11: Tumor regressions observed in additional 2 ACC PDX models
CONFIDENTIAL 11 ACC PDX model Tumor regressions observed in additional 2 ACC PDX models Biomarker positive treated with REM - 422 REM - 422 demonstrated antitumor activity in biomarker positive ACC PDX models Biomarker/Poison Exon positive MYB NFIB ACC PDX model Biomarker/Poison Exon negative MYB NF
Slide 12: A Poison Exon in MYB defines the majority of High-Risk ACC Patients
CONFIDENTIAL 12 A Poison Exon in MYB defines the majority of High - Risk ACC Patients ~25% ACC - I ~ 75% ACC - II ~25 - 30% ACC - I ~70 - 75% ACC - II 86% PE + ve 53% PE + ve Molecular profiling data from 307 ACC patients 1 Poor prognosis regardless of ACC subtype 1 PE + ve PE - ve • MYB biomarker (
Slide 13: Potential to become the new standard of care for ACC
CONFIDENTIAL 13 REM - 422 offers potential to become the new standard of care for ACC REM - 422 U.S. Sales Estimate: $600M + Potential projected US launch: 2028 CDx Testing Education Patient Support Scaling Potential U.S. Commercial Capabilities for REM - 422 ACC Patient Flow • Over the course of tr
Slide 14: Phase 1/2 studies: ACC and AML/High-Risk MDS
CONFIDENTIAL 14 NON - CONFIDENTIAL CONFIDENTIAL 14 REM - 422 Phase 1 studies: • Adenoid Cystic Carcinoma • AML and High - Risk MDS
Slide 15: Phase 1/2 ARIA study design
CONFIDENTIAL 15 18 and 24mg doses evaluated to identify optimal dose Ph1 DOSE ESCALATION (all - comers): N = 69 Abbreviations: PK = Pharmacokinetics; PD = Pharmacodynamics; RP2D = Recommended Phase 2 Dose; R/M = Recurrent/Metastatic; ACC = Adenoid Cyst ic Carcinoma; DL = Dose Level; N = Number; ORR
Slide 16: Demographics and disease characteristics
CONFIDENTIAL 16 Phase 1 enrolled all - comers ACC and determined biomarker status retrospectively Datacut: 24Apr2026 Abbreviations: ECOG = Eastern Cooperative Oncology Group (Performance Status) *MYB PE positive + MYB IHC high/PE unknown & A CC Subtype as defined by Ferrarotto et al., 2021 41 (59%)
Slide 17: PK/PD plasma exposure by dose level
CONFIDENTIAL 17 REM - 422 PK/PD REM - 422 plasma exposure by dose level Abbreviations: PK = Pharmacokinetics; PD = Pharmacodynamics; RP2D = Recommended Phase 2 Dose 0 500 1000 1500 2000 Dose (mg) A U C 0 - 2 4 ( h * n g / m L ) R 2 = 0.80 C1D15 3 6 12 18 24 30 38 48 30mg Protein (IHC) Screening On T
Slide 18: Treatment-emergent adverse events summary
CONFIDENTIAL 18 Notes: TEAEs were reported using Medical Dictionary for Regulatory Activities, version 28.0; P ercentages rounded to nearest whole number ; # of subjects (%) reported in table Abbreviations: TEAE = Treatment - Emergent Adverse Event; TRAE = Treatment - Related Adverse Event; SAE = Se
Slide 19: Treatment-related adverse events by dose
CONFIDENTIAL 19 TOTAL N = 69 48mg QD N = 6 38mg QD N = 9 30mg QD N = 9 24mg QD N = 15 18mg QD N = 16 12mg QD N = 4 6mg QD N = 4 3mg QD N = 6 8 (12) 2 (33) 3 (33) 1 (11) 0 1 (6) 0 0 1 (17) Lymphocyte count decreased 2 (3) 1 (17) 1 (11) 0 0 0 0 0 0 Neutrophil count decreased 2 (3) 1 (17) 1 (11) 0 0 0
Slide 20: Change in tumor size from baseline by biomarker status
CONFIDENTIAL 20 Radiographic images Baseline On - treatment (M5) Note: Efficacy dataset includes all patients with measurable target lesions at baseline and at least 1 post - treatment scan (N = 60) -80 -60 -40 -20 0 20 40 Subjects B e s t % c h a n g e i n t a r g e t l e s i o n s Biomarker Status
Slide 21: Best percentage change in tumor size by dose
CONFIDENTIAL 21 DCR (%) ORR (%) # of Responders N Response evaluable subgroup 95% 37% 7 19 BM+ ≥ 24mg 100% 43% 3 7 BM+ at 24mg Notes: 1) ORR includes uPR ; 2) Patients with starting doses ≥30mg who remain on treatment reduced to 24mg; 3) One patient (30mg) excluded due to treatment d isc ontinuation
Slide 22: Sustained objective responses across ACC-I/II
CONFIDENTIAL 22 Notes: *Treatment beyond progression; + = ongoing ; † Pt on tx - hold; A CC Subtype as defined by Ferrarotto et al., 2021 Abbreviations: cPR = confirmed PR; uPR = unconfirmed PR; Pt = Patient, TL = Target Lesions; Tx = treatment; DOT = Duration of Treatment; DOR = Duration of Respons
Slide 23: Compelling value proposition in ACC
CONFIDENTIAL 23 REM - 422 offers compelling value proposition in ACC • High unmet need in ACC, with no FDA - approved treatments • Therapeutic candidate designed to target molecular driver of ACC • Favorable clinical results • Robust results – 43% ORR at RP2D, 100% disease control rate • Long durabi
Slide 24: AML and High-Risk MDS are MYB-driven malignancies
CONFIDENTIAL 24 AML and High - Risk MDS are MYB - driven malignancies • Acute myelogenous leukemia (AML) & high - risk myelodysplastic syndrome (HR - MDS ) • ~25,000 treatable AML/HR - MDS patients in the US • MYB is a master transcriptional regulator of leukemogenesis • REM - 422 is active across m
Slide 25: Robust monotherapy/combination activity in AML models
CONFIDENTIAL 25 REM - 422: Robust monotherapy/combination activity in AML models M4 (myelomonocytic) AML pt relapsed after chemotherapy with complex cytogenetics Vehicle REM - 422 10 mg/kg SURVIVAL BENEFIT IN PDX MODEL Monotherapy Activity ERADICATED hCD45+ AML BLASTS Combination Activity ADDITIVE/
Slide 26: Ph1 Study in Patients with R/R AML or HR-MDS
CONFIDENTIAL 26 Ph1 Study in Patients with R/R AML or HR - MDS DOSE ESCALATION Up to 2 dose levels evaluated to identify optimal dose PRIMARY OBJECTIVE — SAFETY, MTD, RP2D Secondary and exploratory objectives — PK, PD and efficacy DL1 (1mg) No. treated = 3 DL2 (3mg) No. treated = 4 DL3 (6mg) No. tre
Slide 27: Preliminary Anti-tumor Activity in AML/MDS
CONFIDENTIAL 27 Preliminary Anti - tumor Activity. RP2D not reached Dose dependent reduction of MYB mRNA levels was observed in bone marrow biopsies Additional patients with blast count reductions observed in ongoing dose escalation study From live database last updated Mar 18, 2026 Response Cytogen
Slide 28: Indication expansion potential in heme and solid tumors
CONFIDENTIAL 28 REM - 422 indication expansion potential in heme and solid tumors Breast Cancer MYB dysregulation MYB high expression Lymphoma Overexpression Colon Cancer Overexpression Disease Tumor agnostic Fusion & amplification MYB DEPENDENCY ACROSS SEVERAL LINEAGES (D epMap ) MYB DYSREGULATION
Slide 29: Pipeline programs
CONFIDENTIAL 29 CONFIDENTIAL 29 Pipeline programs
Slide 30: Genetically Defined Diseases Patient Selection Criteria
Genetically Defined Diseases Patient Selection Criteria REMIX TARGETS & DRUGS DATA SCIENCE Integrated database of >350k internal and external transcriptome datasets Proprietary algorithms & AI/ML BIOLOGY & BIOMOLECULAR SCIENCES Functional & genetic validation of targets Fit for purpose high - throug
Slide 31: Targeting MYC, an oncogenic transcription factor dysregulated across cancer
CONFIDENTIAL 31 Non - confidential Targeting MYC, an oncogenic transcription factor dysregulated across cancer • MYC amplification/activation occurs in ~28% of all tumors • Remix developing a novel mRNA degrader approach targeting a regulator of MYC t o prevent signaling via all 3 MYC paralogs MYC d
Slide 32: Discovery program targeting oncogenic MYC signaling
CONFIDENTIAL 32 Discovery program targeting oncogenic MYC signaling high prevalence dysregulation across multiple solid and heme malignancies MYC - dependent upregulated pathways MYC - dependent downregulated pathways Small molecule mRNA degrader phenocopies genetic knockdown Regulator siRNA MYC siR
Slide 33: RXSM-1244 target engagement and tumor growth inhibition in CDX model
CONFIDENTIAL 33 RXSM - 1244 demonstrated potent mRNA and protein target engagement and robust tumor growth inhibition in a mouse CDX model protein reduction mRNA reduction Vehicle RXSM-1244 0 2 4 6 F o l d c h a n g e o v e r V e h i c l e Vehicle RXSM-1244 0.00 0.25 0.50 0.75 1.00 1.25 F o l d c h
Slide 34: Remix Therapeutics is Well-Positioned For Significant Growth
CONFIDENTIAL 34 Remix Therapeutics is Well - Positioned For Significant Growth Near - Term Inflection Points Experienced Management Team and Investors Strong Pro - Forma Balance Sheet • REM - 422 in ACC - ORR and DoR data expected in mid’27 • REM - 422 in AML/MDS: RP2D and initial data expected in m
Slide 35: Disclaimers: Additional Information and Where to Find It
CONFIDENTIAL 35 Disclaimers Additional Information and Where to Find It This presentation relates to a proposed transaction involving Passage Bio and Remix and may be deemed to be solicitation mate ria l in respect of the proposed transaction. In connection with the proposed transaction, Passage Bio
Slide 36: Thank you
NON - CONFIDENTIAL CONFIDENTIAL 35 Thank you.