X4 Pharmaceuticals, LLS Collaborate to Develop Mavorixafor to Treat Waldenström’s Macroglobulinemia

X4 Pharmaceuticals and The Leukemia & Lymphoma Society (LLS) have joined forces to accelerate the development of X4’s lead product candidate, mavorixafor, for the treatment of Waldenström’s macroglobulinemia, a rare form of non-Hodgkin’s lymphoma.

Under LLS’ Therapy Acceleration Program (TAP), X4 will conduct a Phase 1/2 clinical trial to evaluate mavorixafor in combination with Imbruvica (ibrutinib) in previously treated Waldenström’s macroglobulinemia patients with MYD88 and CXCR4 mutations.

The trial is expected to begin this year, and aims to explore the combination’s safety, behavior throughout the body, and response rates, according to an X4 presentation.

Lee Greenberger, PhD, chief scientific officer of LLS, will serve as a member of an advisory board to X4, and provide strategy and partnership guidance throughout the trial.

“LLS’s selection of mavorixafor for TAP collaboration and investment reinforces its potential as a novel therapy for Waldenström’s macroglobulinemia,” Paula Ragan, PhD, president and CEO of X4 Pharmaceuticals, said in a press release.

“We look forward to working closely with Dr. Greenberger and the LLS TAP team to gain valuable data and insights throughout the upcoming clinical trial as we work to bring a new therapeutic option to patients with this rare form of cancer,” she said.

Mavorixafor, formerly known as X4P-001, is an orally available small molecule inhibitor of the CXCR4 receptor. It is being developed for the treatment of rare primary immunodeficiency diseases and certain cancers, including lymphomas, where mutations in CXCR4 cause an abnormal trafficking of white blood cells and support disease progression.

Nearly 30% to 40% of Waldenström’s macroglobulinemia (WM) patients have a CXCR4 mutation. These patients have a very poor prognosis and often fail to respond to available therapies. They are also four times more likely to discontinue treatment with Imbruvica, a standard of care for patients who have failed prior treatments.

“Through TAP, LLS is committed to advancing the development of promising investigational therapies that we believe have potential to improve standards of care for patients, especially in disease areas with high unmet medical need, such as Waldenström’s macroglobulinemia,” Greenberger said.

“Mavorixafor has demonstrated early promise in other disease areas with CXCR4 mutations, including solid tumors, and its potential application among CXCR4-mutant WM patients makes it an excellent fit and an important asset within our program,” he added.