CDX Development Update

Hemogenyx Pharmaceuticals plc (LSE: HEMO), a clinical-stage biopharmaceutical group focused on developing treatments for cancers and viral diseases, is pleased to announce that it has developed a new and improved version of its bi-specific antibody ("CDX") for the treatment of relapsed/refractory acute myeloid leukaemia ("AML"), a subset of acute lymphoblastic leukaemia ("ALL"), and potentially for conditioning in bone marrow transplantations.

The Company's scientists utilised Lonza's bYlok bispecific pairing technology to develop a new and improved version of CDX, which has demonstrated significantly enhanced efficacy in in vitro testing. Additional in vivo studies are currently underway.

• Vladislav Sandler, CEO and Co-Founder of Hemogenyx Pharmaceuticals, commented:

"The development of an improved version of our CDX bi-specific antibody holds significant promise for enhancing treatment outcomes for patients battling often incurable blood cancers. This advancement could accelerate the progress of this product candidate and allow us to resume its development toward the clinic. It may also attract new industry partners interested in fast-tracking the co-development of CDX."

About AML

AML, the most common type of acute leukemia in adults, has poor survival rates (a five-year survival rate of less than 30% in adults) and is currently treated using chemotherapy, rather than the potentially more benign and effective form of therapy being developed by Hemogenyx Pharmaceuticals. The successful development of the new therapy for AML would have a major impact on treatment and survival rates for the disease.

About ALL

Acute Lymphoblastic Leukemia (ALL) is a cancer of the blood and bone marrow that primarily affects children, although it can also occur in adults. Unlike Acute Myeloid Leukemia (AML), ALL is characterized by the rapid proliferation of immature lymphocytes, a type of white blood cell. ALL is the most common childhood cancer, representing approximately 25% of cancer diagnoses in children. It progresses quickly and requires prompt treatment. While the overall prognosis for ALL is generally more favorable than AML, certain subtypes remain challenging to treat. Hemogenyx Pharmaceuticals is developing innovative treatments specifically targeting a subset of ALL that has proven particularly difficult to treat, especially in children. The Company's R&D focuses on addressing the limitations of current therapies and improving outcomes for patients with these hard-to-treat forms of ALL.