X4 Pharmaceuticals Inc (NASDAQ:XFOR) shares are trading lower despite releasing what it described as positive phase 2 data for mavorixafor for WHIM syndrome, a rare congenital immune deficiency.

• In a poster presentation at the American Society of Hematology Annual Meeting, treatment with mavorixafor led to increases in neutrophils, lymphocytes, and monocytes and sustained improvements in infections and warts ongoing Phase 2 open-label extension trial.
• Infection rates also decreased as the mavorixafor dose increased.
• Top-line data from a 52-week phase 3 trial is expected in Q4 2022.
• In a separate poster, the Company posted new efficacy and safety data from the ongoing Phase 1b trial of mavorixafor + ibrutinib for Waldenström's macroglobulinemia (WM).
• A 100% overall response rate was observed for the combination treatment in frontline and refractory patients.
• Study enrollment ongoing at the highest dose of mavorixafor; longer-term response data, dose selection, and regulatory updates expected in 2022.
• Price Action: XFOR shares are down 34.6% at $2.51 during the market session on the last check Monday.
• Check out our coverage of the American Society of Hematology (ASH) Annual Meeting 2021 here.