X4 Pharmaceuticals (XFOR) Corporate presentation summary

Mavorixafor and development milestones

• Mavorixafor (XOLREMDI) is approved for WHIM syndrome in the U.S. and EU; a pivotal Phase 3 study is underway in chronic neutropenia.

• Full 4WARD enrollment is expected in Q4 2026, topline data in H1 2028, and potential U.S. FDA approval in late 2028 or early 2029.

• The oral CXCR4 antagonist is designed to promote white blood cell migration from bone marrow and raise circulating neutrophil and lymphocyte levels; U.S. patent protection is expected through 2038.

• XOLREMDI launched in the U.S. in 2024 and was approved in the EU in 2026; approvals are being sought in the MENA region.

Chronic neutropenia opportunity

• Estimated U.S. target market is ~15,000 patients with moderate or severe primary chronic neutropenia and recurrent serious infections.

• Oral treatment was ranked as the leading unmet need by surveyed chronic neutropenia-treating physicians.

• Potential use includes monotherapy for patients not using, intolerant of, or unresponsive to G-CSF, and combination therapy or G-CSF dose reduction.

Phase 2 findings

• In monotherapy patients, mean ANC reached normal levels (≥1,500 cells/µL) at Months 3 and 6; assessments included 9 patients at Month 3 and 8 at Month 6.

• Mean G-CSF use declined 52% at Month 3 and 70% at Month 6; physicians reduced G-CSF in 9 of 12 eligible patients, including discontinuation in 3 by Month 6.

• With mavorixafor plus G-CSF, mean ANC was 3,121 cells/µL at Month 6, following a baseline mean of 4,034 cells/µL.

• Safety was consistent with prior studies; treatment-related adverse events were mostly mild or moderate and GI-related, with no drug-related serious adverse events.