EMA Grants Orphan Drug Status to Bexobrutideg for Waldenström Macroglobulinemia Treatment

In a significant development for treatments targeting rare diseases, Nurix Therapeutics, Inc., a biopharmaceutical company headquartered in San Francisco, has announced that the European Medicines Agency (EMA) has awarded Orphan Drug Designation to bexobrutideg (NX-5948) for combating lymphoplasmacytic lymphoma. This condition, also known as Waldenström macroglobulinemia (WM), is a rare form of blood cancer affecting B lymphocytes, a type of white blood cell. These cells grow and persist abnormally, accumulating in the bone marrow, lymph nodes, and spleen, leading to several health complications.

The Orphan Drug Designation by the EMA is part of a program aimed at encouraging the development of treatments for rare diseases affecting fewer than 5 in 10,000 individuals within the European Union. This designation provides important incentives for pharmaceutical companies, such as 10 years of market exclusivity following approval, reduced regulatory fees, and eligibility for centralized marketing authorization. It also includes access to protocol assistance to aid in the development of these crucial medicines.

Bexobrutideg is an investigational drug designed as a degrader of Bruton’s tyrosine kinase (BTK), a key protein involved in the survival and proliferation of B cells. Notably, bexobrutideg is orally bioavailable and capable of penetrating the brain, which is significant for its therapeutic potential. The drug is currently undergoing a Phase 1a/b clinical trial involving adults with relapsed or refractory B-cell malignancies, which includes WM.

Dr. Arthur T. Sands, the President and CEO of Nurix, emphasized the importance of the Orphan Drug Designation, noting that it underscores the critical unmet medical need for improved WM treatments. He highlighted the potential of bexobrutideg to provide a promising new therapeutic option for patients suffering from this rare condition.

In addition to the recent EMA designation, bexobrutideg has received several other acknowledgements that mark its significance in cancer treatment. The U.S. Food and Drug Administration (FDA) granted the drug Fast Track designation twice, once in December 2024 for WM and again in January 2024 for treating chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) in adults who have already undergone at least two lines of therapy. These therapies typically include a BTK inhibitor and a B-cell lymphoma 2 (BCL2) inhibitor. Furthermore, the EMA granted PRIME designation to bexobrutideg in November 2024 for relapsed or refractory CLL/SLL.

Preliminary results from the Phase 1a/b clinical trial of bexobrutideg have been promising, indicating potential safety and efficacy in patients with WM. Nurix Therapeutics plans to continue enrolling patients in an expanded Phase 1b cohort and is preparing to release additional clinical data in 2025.

Nurix Therapeutics is committed to advancing the field of targeted protein degradation, which represents a novel approach in drug development aimed at improving therapies for cancer and inflammatory diseases. The company’s pipeline includes other investigational drugs targeting BTK and CBL-B, a protein involved in regulating immune cells. Partnered with major pharmaceutical companies like Gilead Sciences, Sanofi, and Pfizer, Nurix is at the forefront of innovative drug design, utilizing AI capabilities and ligase expertise to drive advancements in clinical treatments. The company envisions a future where degrader-based therapies become integral to patient care, paving the way for transformative outcomes in the battle against complex diseases.