X4 Pharmaceuticals, Inc. · NASDAQ:XFOR

X4 Pharmaceuticals — Investor Presentation (May 2025)

32 slides from X4 Pharmaceuticals's investor presentation, May 1, 2025

  1. Slide 1: Living with Chronic Neutropenia: Investor Deck – May 2025

    ABBEY Living with Chronic Neutropenia Driving progress for patients with chronic neutropenic disorders Investor Deck – May 2025 Exhibit 99.2

  2. Slide 2: Forward-looking statements

    This presentation including any printed or electronic copy of these slides, the talks given by the presenters, the information communicated during any delivery of the presentation and any question and answer sessions and any documents or materials distributed at or in connection with the presentatio

  3. Slide 3: Addressing unmet needs in rare immune disorders

    Addressing unmet needs in rare immune disorders Fully Integrated Company Delivering on the Promise of Mavorixafor 3 1. WHIM (Warts, Hypogammaglobulinemia, Infections, Myelokathexis), a rare primary immunodeficiency and chronic neutropenic disorder. 2. Funds include restricted cash. 3. Assuming conti

  4. Slide 4: No Innovation for People with Chronic Neutropenia in More Than 30 years

    4 1. U.S. Prevalence Based on ICD-10 Code Research, Average Across 3 Years (2018, 2019, & 2021); >90% greater than 18 years of age, ~2/3 female, mixed G-CSF use. 2. . https://www.cancernetwork.com/view/fda-approves-new-indication-neupogen-chronic-neutropenia No Innovation for People with Chronic Neu

  5. Slide 5: Mavorixafor: Only Oral Agent Targeting Rare Immunodeficiencies

    Validated mechanism shown to alleviate neutropenia and lymphopenia, decrease infections Mavorixafor: Only Oral Agent Targeting Rare Immunodeficiencies 5 1. Bainton DF (1980) The Cell Biology of Inflammation, vol 2, pp 1–25. Amsterdam: Elsevier/North-Holland 2. Furze RC, et al, Immunology. 2008. 3. M

  6. Slide 6: Mavorixafor: Pipeline and Partners

    6 Mavorixafor: Pipeline and Partners Indication Pre-clinical Phase 1 Phase 2 Phase 3 Approved Partners Expected Milestones M av or ix af or WHIM Syndrome (Warts, Hypogammaglobulinemia, Infections, Myelokathexis) Launched as XOLREMDI® in U.S. in May 2024 EU approval/ launch possible in 1H 2026 Chroni

  7. Slide 7: WHIM Syndrome

    WHIM Syndrome

  8. Slide 8: WHIM Syndrome: a Combined Primary Immunodeficiency and CN Disorder

    8 1. Dale DC, Firkin F, Bolyard AA, et al, Blood. 2020;136(26):2994-3003. 2. Geier CB, Ellison M, Cruz R, et al, J Clin Immunol. 2022;42(8):1748- 1765; 3. Dotta L, Notarangelo L, Moratto D, et al. J Allergy Clin Immunol. 2019;7(5):1568-1577; 4. Beaussant Cohen S, Fenneteau O, Plouvier E, et al. Orph

  9. Slide 9: 4WHIM Pivotal Phase 3 Clinical Trial Overview

    9ANC = absolute neutrophil count; ALC = absolute lymphocyte count 4WHIM Pivotal Phase 3 Clinical Trial Overview Baselines: 100% of patients had severe chronic neutropenia (median ANC ~200 cells/µL) and chronic lymphopenia (median ALC ~500 cells/µL) Primary & First Secondary Endpoint: Time above Thre

  10. Slide 10: Reduced rate of infections

    10 1. Published Trial Results: Badolato R, et al., A phase 3 randomized trial of mavorixafor, a CXCR4 antagonist, for WHIM syndrome, Blood (2024) 144 (1): 35–45 (https://doi.org/10.1182/blood.2023022658) Reduced RATE of infections 1

  11. Slide 11: U.S. Launch in May 2024

    111. Footnote Placeholder U.S. Launch in May 2024 (zōl-RĔM-dee) For use in patients 12 years of age and older with WHIM syndrome (warts, hypogammaglobulinemia, infections and myelokathexis) to increase the number of circulating mature neutrophils and lymphocytes. See full prescribing information at

  12. Slide 12: Leveraging Our Experience and Success in WHIM into Chronic Neutropenic Disorders

    12 Leveraging Our Experience and Success in WHIM into Chronic Neutropenic Disorders 4WHIM Phase 3 Success1 Provides Proof of Concept Supporting CN Phase 3 Study • Mean TATANC was 15.04 hours for mavorixafor vs. 2.75 hours for placebo • 5.5-fold improvement in TATANC compared with placebo Significant

  13. Slide 13: Strong Overlap of WHIM and Chronic Neutropenia Stakeholders

    13 *Claims analysis, Oct 2024; XOLREMDI (mavorixafor) is being exclusively promoted in the U.S. for its approved indication of WHIM syndrome; mavorixafor is currently being studied as an investigational therapy for use in chronic neutropenia and has yet to be approved for the treatment for chronic n

  14. Slide 14: fel

    a = ® fel fe) i — =) ® 2a — c fe) be f= O

  15. Slide 15: Risk of Serious, Recurrent Infections Correlates with Neutrophil Counts in CN

    15 1. https://ctep.cancer.gov/protocoldevelopment/electronic_applications/docs/ctcae_v5_quick_reference_8.5x11.pdf. 2. Palmblad J, Dufour C, Papadaki HA. Haematologica. 2014 Jul;99(7):1130-1133. 3. Sicre de Fontbrune F, et al. Blood. 2015;126(14):1643-1650. 4. Donadieu J, et al. Expert Rev Hematol.

  16. Slide 16: Unmet Needs in Chronic Neutropenia: Need for Oral Well Tolerated Alternatives

    16 1. X4 Market Research, July 2023 – data on file; ICD-10 Code Research (2017-2023). 2. https://www.cancernetwork.com/view/fda-approves-new- indication-neupogen-chronic-neutropenia Unmet Needs in Chronic Neutropenia: Need for Oral Well Tolerated Alternatives 1Only One ~50,0001 U.S. Prevalence: tota

  17. Slide 17: Successful Phase 2 Study of Mavorixafor in Chronic Neutropenia

    17 Successful Phase 2 Study of Mavorixafor in Chronic Neutropenia (CN) Phase 2 Study Enrolled a Total of 23 Participants Baseline Assessed Safety and Durability of ANC Levels over 6-Month Period Once-Daily Oral Mavorixafor: Monotherapy +/-G-CSF DAY -1 Month 1 Month 3 Month 6 Study Visits Assessments

  18. Slide 18: Phase 2 Clinical Study in Chronic Neutropenia: Participant Disposition

    Study group representative of typical CN population Phase 2 Clinical Study in Chronic Neutropenia: Participant Disposition 18 1. Congenital CN participants included those with ELANE variant (n=2), VPS13B variant (Cohen syndrome), G6PC3 variant/ deficiency, SRP54 variant (SDS-like syndrome), WASp var

  19. Slide 19: Mavorixafor Monotherapy Durably & Meaningfully Increased Mean ANC in Trial

    19 1. Data set contains two LOCF (last observation carried forward) values: one value missing at M3 assessment, one value missing at M6. 2. One patient discontinued prior to Month 3 assessment (no change from data set presented on 6/27/2024). 3. One patient discontinued prior to Month 6 assessment (

  20. Slide 20: Physicians Substantially Reduced G-CSF, Maintaining Normal Mean ANC

    201. One participant discontinued prior to M1 assessment. Physicians Substantially Reduced G-CSF, Maintaining Normal Mean ANC G-CSF: • Given the option, physicians chose to substantially reduce injectable G-CSF therapy in 9 of 12 (75%) eligible1 patients • 89% (8 of the 9) had G-CSF adjusted at earl

  21. Slide 21: Analysis of Previous Clinical Results Raise Confidence in Success of 4WARD Trial

    Analysis of Previous Clinical Results Raise Confidence in Success of 4WARD Trial Post-hoc analysis applying 4WARD trial ANC response criteria to 4WHIM and CN Phase 2 trials 21 Baseline (pre-dose) + Weeks 13, 26, 39, 52 ∆ANC = subtracting baseline mean ANC from mean ANC at assessment ∆ANC ≥ 500 cells

  22. Slide 22: WHIM Phase 3 Trial: Post-Hoc Individual ∆ANC Response Analysis

    22 Subject Number Week 13 Week 26 Week 39 Week 52 1 * 2 Missing Sample 3 4 * 5 * 6 7 8 9 10 11 12 13 14 15 Missing Sample 16 WHIM Phase 3 Trial: Post-Hoc Individual ∆ANC Response Analysis Response “Heat Map” of Placebo and Mavorixafor participants across 52-week trial PLACEBO: Baseline Mean ANC=200

  23. Slide 23: CN Phase 2 Trial: Post-Hoc Individual ∆ANC Response Analysis

    23 MAVORIXAFOR CN Phase 2 Trial: Post-Hoc Individual ∆ANC Response Analysis Response “Heat Map” of Participants on Mavorixafor +/-Stable G-CSF across 26-week trial (G) = Mavorixafor dosed in combination with stable G-CSF dose. All other subjects treated with mavorixafor monotherapy. Supports CN Phas

  24. Slide 24: 4WARD Phase 3 Trial On Track to Fully Enroll 3Q/4Q 2025

    ~90% of planned sites now initiated; participants being dosed across multiple countries 4WARD Phase 3 Trial On Track to Fully Enroll 3Q/4Q 2025 24 Note: For those treated with G-CSF (or other therapies) at baseline, dose and frequency are required to remain constant throughout the trial unless adjus

  25. Slide 25: 4WARD on Track to Deliver Potentially Transformative Results

    4WARD on Track to Deliver Potentially Transformative Results 25 12-month 4WARD trial is highly powered (>90%) to meet study’s co-primary endpoints Annualized infection rate and ANC response: co-primary endpoints Clinical operations in full swing and delivering Trial sites are nearly fully activated

  26. Slide 26: Continuing to Deliver Progress for Patients

    26 Continuing to Deliver Progress for Patients >1,000 U.S. patients >15,000 U.S. patients Potential Market Opportunities +WHIM Chronic Neutropenia EU MAA WHIM submission and acceptance by EMA XOLREMDI commercial uptake in US Ex-U.S. partners secured (EU, ANZ & MENA) 4WARD trial fully enrolled in 3Q

  27. Slide 27: www.x4pharma.com Corporate Headquarters North Beacon Street, 4th Floor Boston, MA 02134

    www.x4pharma.com Corporate Headquarters 61 North Beacon Street, 4th Floor Boston, MA 02134 Nasdaq: XFOR

  28. Slide 28: Appendix

    PHARMACEUTICALS : Appendix

  29. Slide 29: Significant Opportunity to Address Unmet Needs in CN Community

    291. X4 Market Research, July 2023 – data on file; ICD-10 Code Research (2017-2023). Significant Opportunity to Address Unmet Needs in CN Community Broad Opportunity for Mavorixafor: Monotherapy or in Combination with G-CSF High unmet needs in ~15,000 patients in the U.S.1 • Diagnosis of idiopathic,

  30. Slide 30: Phase 2 Chronic Neutropenia Study Safety Summary

    Chronic mavorixafor generally well tolerated as monotherapy and in combination with G-CSF Phase 2 Chronic Neutropenia Study Safety Summary 301. TEAE: treatment-emergent adverse event; 2. No further discontinuations once education on GI symptoms and support were implemented. Combination (n=13), n (%)

  31. Slide 31: X4's Leadership Team

    Experience spans research, development, & commercialization of first-in-class, innovative therapies X4’s Leadership Team – Strength Delivering For Patients 31 c ADAM MOSTAFA Chief Financial Officer c PAULA RAGAN, Ph.D. President & CEO c MARY DIBIASE, Ph.D. Chief Operating Officer c MARK BALDRY Chief

  32. Slide 32: Balance Sheet Supports Expected Upcoming Milestones

    32 1. Funds as of March 31, 2025, including restricted cash; 2. Assuming continued compliance with debt covenants as described in the company’s Form 10-Q filed on May 1, 2025. Balance Sheet Supports Expected Upcoming Milestones Funds expected to support operations into 1H 20262 $87.7 million1 Analys

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