X4 Pharmaceuticals Announces $125 Million from Voucher Sale and Loan Drawdown

X4 Pharmaceuticals, a company focused on improving the lives of people with rare immune system disorders, has announced significant financial developments. The company has completed the sale of its Rare Pediatric Disease Priority Review Voucher (PRV) for $105 million and has drawn an additional $20 million from an existing loan facility with Hercules Capital, Inc. These financial moves follow the U.S. Food and Drug Administration's (FDA) approval of X4's first drug, XOLREMDI™ (mavorixafor), in late April 2024.

Adam Mostafa, Chief Financial Officer of X4 Pharmaceuticals, stated that this non-dilutive capital infusion extends the company's projected cash runway into late 2025, excluding expected commercial sales of XOLREMDI. The additional financial resources will provide the company with increased strength and flexibility to support the launch of XOLREMDI for WHIM syndrome and further develop mavorixafor for potential new indications, including a planned Phase 3 trial for chronic neutropenic disorders.

The FDA awards PRVs to sponsors of rare pediatric disease product applications that meet specific criteria to encourage the development of new drugs for rare pediatric diseases. The sale of the PRV and the additional funds from the Hercules Capital loan facility add to X4's cash reserves, which stood at $82 million as of March 31, 2024. The loan facility with Hercules Capital allows for up to $115 million in term loans, available in multiple tranches and currently in an interest-only period until July 2027.

WHIM syndrome, which stands for warts, hypogammaglobulinemia, infections, and myelokathexis, is a rare primary immunodeficiency and chronic neutropenic disorder. Patients with WHIM syndrome typically have low levels of neutrophils and lymphocytes, leading to frequent and severe infections. XOLREMDI (mavorixafor), a selective CXCR4 receptor antagonist, has been approved in the U.S. for patients aged 12 and older with WHIM syndrome. The drug works by increasing the number of circulating mature neutrophils and lymphocytes in the blood.

X4 Pharmaceuticals is dedicated to developing and commercializing innovative therapies for rare immune system diseases. Leveraging expertise in CXCR4 and immune system biology, the company has successfully brought mavorixafor to market under the name XOLREMDI. Additionally, X4 is exploring other potential uses for mavorixafor in different indications. The company is headquartered in Boston, Massachusetts, with a research center of excellence in Vienna, Austria.

The financial boost from the PRV sale and the Hercules Capital loan will enable X4 Pharmaceuticals to continue its mission of delivering transformative therapies for patients with rare diseases. The extended cash runway into late 2025, coupled with the planned commercialization of XOLREMDI for WHIM syndrome, positions the company to make significant strides in the field of rare immune system disorders.