Hemogenyx Pharmaceuticals Plc 

("Hemogenyx Pharmaceuticals" or the "Company")

U.S. Approval and Issuance of Monoclonal Antibody Patent

Hemogenyx Pharmaceuticals plc (LSE: HEMO), the biopharmaceutical group developing new therapies and treatments for blood diseases, is pleased to announce that a further patent application entitled MONOCLONAL ANTIBODIES TO HUMAN FLT3/FLK2 RECEPTOR PROTEIN has been approved and issued by the United States Patent and Trademark Office. The patent was issued on 31 August 2021 as Patent Number US 11,104,738. This follows the issuance of the patent METHOD OF ELIMINATING HEMATOPOIETIC STEM CELLS/HEMATOPOIETIC PROGENITORS (HSC/HP) IN A PATIENT USING BI-SPECIFIC ANTIBODIES, as announced on 2 June 2021. Both patents represent a further important step in the development of the Company's suite of intellectual property (IP) and protection of its products candidates including CDX antibody and HEMO-CAR-T.

This new patent covers composition of matter (sequences) of monoclonal antibodies to the human FLT3/FLK2 receptor protein that is found on the surface of acute myeloid leukemia (AML) cells, hematopoietic (blood forming) stem cells and progenitors (HSC/HP), and dendritic cells.

The monoclonal antibodies discovered and validated by Hemogenyx Pharmaceuticals have allowed the Company to develop both a bi-specific CDX antibody and HEMO-CAR-T as treatments for AML as well as potential treatments for other types of blood cancers, and bone marrow transplant (BM/HSC) conditioning. The patent now granted is particularly relevant to the chimeric antigen receptor (CAR) used in the HEMO-CAR-T product candidate for the treatment of AML. HEMO-CAR-T remains wholly owned by the Company and work is continuing in association with the University of Pennsylvania to take the therapy through to an IND (Investigational New Drug) application in preparation for clinical trials.

The issued patent discloses and protects several sequences of monoclonal antibodies as well as their unique properties. The discovery and validation of these antibodies were originally done by Dr. Vladislav Sandler, CEO of Hemogenyx Pharmaceuticals and further developed and refined by the Company's team of scientists in the Company's laboratory facilities in New York City.

The unique properties of the patented monoclonal antibodies, the original idea of how these antibodies could be exploited, and the data regarding their use for BM/HSC transplantation conditioning were the primary driver in bringing the leading global pharmaceutical company with which the Company has been working ("GlobalCo") to enter into an agreement to develop the Company's lead product candidate CDX bi-specific antibody (https://tinyurl.com/ebmv6pbj).

The Company has made further patent applications in relation both to HEMO-CAR-T and to the CDX bi-specific antibodies, the latter being a joint application with GlobalCo. Further information will be disclosed regarding these in due course.

Dr Vladislav Sandler, CEO & Co-Founder of Hemogenyx Pharmaceuticals, commented: "The issue of this patent is of considerable significance for the Company because it protects the IP for both CDX and HEMO-CART-T product candidates, 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."

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.

Further information about the development of the Company's bi-specific antibody technology can be found on Hemogenyx Pharmaceutical's web site: https://hemogenyx.com.

This announcement contains inside information for the purposes of Article 7 of Regulation (EU) 596/2014.

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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 leukaemia and lymphoma, as well as severe autoimmune diseases such as multiple sclerosis, aplastic anaemia and systemic lupus erythematosus (Lupus), to benefit from bone marrow transplantation.