X4 Pharmaceuticals has announced positive results from its completed Phase 2 study of mavorixafor in patients with chronic neutropenia (CN). The data indicate that the oral, once-daily drug was well-tolerated and significantly increased blood neutrophil counts in study participants.
Mavorixafor's Impact on Neutrophil Counts
The Phase 2 study demonstrated that mavorixafor treatment led to durable and meaningful increases in mean absolute neutrophil counts (ANC). Notably, physicians were able to reduce injectable granulocyte colony-stimulating factor (G-CSF) therapy in participants also treated with mavorixafor, while maintaining mean ANC levels within the normal range. A sub-study also indicated that the mean percentage of functional circulating neutrophils in representative CN study participants remained comparable to that of healthy donors after six months of mavorixafor dosing.
Advancing to Phase 3 with 4WARD Trial
Building on these positive results, X4 Pharmaceuticals is actively enrolling patients in its global, pivotal Phase 3 clinical trial, known as the 4WARD trial (NCT06056297). This trial is evaluating the efficacy, safety, and tolerability of oral, once-daily mavorixafor (with or without stable doses of G-CSF) in individuals with congenital, acquired primary autoimmune, or idiopathic CN. The company anticipates completing enrollment in the 4WARD trial by mid-2025.
XOLREMDI® Launch and WHIM Syndrome Awareness
In addition to the progress in chronic neutropenia, X4 Pharmaceuticals is also focused on the U.S. launch of XOLREMDI® (mavorixafor) for WHIM syndrome, which received FDA approval in April 2024. The company is generating revenues from product sales and has initiated a patient-targeted campaign to increase disease awareness and screening among likely prescribers. Market research indicates high awareness of WHIM syndrome (>75%), increases in screening for WHIM syndrome, and a growing number of likely prescribers (>80%) considering XOLREMDI for their patients.
Financial Position
As of September 30, 2024, X4 Pharmaceuticals reported $135.8 million in cash, cash equivalents, restricted cash, and short-term marketable securities. The company believes it has sufficient funds to support operations into late 2025, not including potential future XOLREMDI revenue.
