15 August 2022

Hemogenyx Pharmaceuticals plc

("Hemogenyx Pharmaceuticals" or the "Company")

Approval and Issuance of Chinese Bi-specific Antibody Patent

Hemogenyx Pharmaceuticals plc (LSE: HEMO), the biopharmaceutical group developing new therapies and treatments for blood diseases, is pleased to announce that China National Intellectual Property Administration has issued a Notification to Grant Patent Right for the patent application entitled METHOD OF ELIMINATING HEMATOPOIETIC STEM CELLS/HEMATOPOIETIC PROGENITORS (HSC/HP) IN A PATIENT USING BI-SPECIFIC ANTIBODIES. The grant was issued on 20 July 2022 under Patent Application Number 201780034711.2.

This patent covers a method of use of a bi-specific antibody ("CDX") for conditioning patients for bone marrow/hematopoietic stem cell ("BM/HSC") transplantation. It also covers composition of matter (a subset of sequences) of monoclonal antibodies against target proteins existing on the surface of hematopoietic stem cells/hematopoietic progenitors ("HSC/HP"), and/or a number of leukemias such as acute myeloid leukemia ("AML") as well as a protein that exists on the surface of immune cells (T cells).

The Company's patents form a suite of intellectual property ("IP") protections for CDX. If fully and successfully developed, the method has potential to obviate the need for highly toxic conditioning protocols, including chemotherapy, in patients who require BM/HSC transplantation and would result in the development of a superior pharmaceutical for the treatment of blood cancers, for which survival rates are currently very poor.

The original provisional patent application was filed in April 2016 and later converted into an international patent application under the Patent Cooperation Treaty ("PCT") and then refiled and subdivided into divisional patent applications in 2019. Both divisional patent applications were granted patent rights in the US in 2021.

Dr Vladislav Sandler, CEO & Co-Founder of Hemogenyx Pharmaceuticals, commented:

"The grant of the patent right on the territory of China is significant for the Company because it protects the Company's IP in one of the largest global markets and further affirms the Company's leading position in the field of the development of groundbreaking therapies for the treatment of blood cancers and BM/HSC transplantation conditioning."

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About Hemogenyx Pharmaceuticals plc

Hemogenyx Pharmaceuticals is a publicly traded company (LSE: HEMO) headquartered in London, with its US operating subsidiaries, Hemogenyx Pharmaceuticals LLC and Immugenyx LLC, located in New York City at its state-of-the-art research facility.

The Company is a pre-clinical stage biopharmaceutical group developing new medicines and treatments to treat blood and autoimmune disease and to bring the curative power of bone marrow transplantation to a greater number of patients suffering from otherwise incurable life-threatening diseases. Hemogenyx Pharmaceuticals is developing several distinct and complementary product candidates, as well as platform technologies that it uses as engines for novel product development.

For more than 50 years, bone marrow transplantation has been used to save the lives of patients suffering from blood diseases. The risks of toxicity and death that are associated with bone marrow transplantation, however, have meant that the procedure is restricted to use only as a last resort. The Company's technology has the potential to enable many more patients suffering from devastating blood diseases such as leukemia and lymphoma, as well as severe autoimmune diseases such as multiple sclerosis, aplastic anemia and systemic lupus erythematosus (Lupus), to benefit from bone marrow transplantation.

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.