X4 Pharma Raises $65 Million Private Placement to Advance Potential WHIM Treatment

Rare Daily Staff

X4 Pharmaceuticals, a company focused on the discovery and development of novel small molecule therapeutics to benefit people with rare diseases of the immune system, raised $65 million in a private placement, before deducting fees and expenses.

X4 expects to use these funds for continued clinical development and commercial readiness of its lead candidate, mavorixafor, and for working capital, and general corporate purposes.

In November, X4 reported positive top-line results from the global, pivotal 4WHIM phase 3 clinical trial of its lead investigational therapy, mavorixafor in people with WHIM syndrome, which met primary and secondary endpoints.

WHIM (warts, hypogammaglobulinemia, infections, and myelokathexis) syndrome is a rare, inherited, combined immunodeficiency disease caused by reduced mobilization and trafficking of white blood cells from the bone marrow due to over-signaling of the CXCR4/CXCL12 pathway. People with WHIM syndrome characteristically have very low blood levels of neutrophils (neutropenia) and lymphocytes (lymphopenia), and as a result, experience frequent, recurrent infections with a high risk of lung disease, refractory warts from underlying human papillomavirus (HPV) infection, limited antibody production due to low levels of immunoglobulin, and an increased risk of developing certain types of cancer. Mavorixafor is an investigational small-molecule antagonist of CXCR4 being developed as a once-daily oral therapy to correct the dysfunction resulting from the underlying genetic causes of WHIM.

For the WHIM indication, mavorixafor has been granted Breakthrough Therapy, Fast Track, and Rare Pediatric designations in the United States, and Orphan Drug Status in both the U.S. and European Union.

With the current financing, X4 expects its cash and cash equivalents to fund operations into the fourth quarter of 2024, excluding the potential proceeds from the sale of a priority review voucher, for which the company is eligible and may receive in the first half of 2024.

In addition, X4 will present additional results from the 4WHIM trial evaluating the safety and efficacy of mavorixafor in people with WHIM syndrome at a company webinar to be held later today.