• Bisantrene discovered to consist of three photoisomers with different biological and anticancer activities
• Race has created processes to enable the controlled infusion of the pure active (E,E)-bisantrene isomer
• Three patent applications filed, which if granted, will provide composition of matter IP protection of (E,E)-bisantrene until 2045

Race Oncology Ltd is pleased to announce significant scientific discoveries into the nature of bisantrene that have enabled the company to submit a new composition of matter patent application. Careful observations by the Race team uncovered that bisantrene is composed of a mixture of three different cis-trans isomers ((E,E)-bisantrene, (E,Z)-bisantrene and (Z,Z)-bisantrene), with each isomer having differing biological properties and anticancer activity. These bisantrene isomers are generated during chemical synthesis, or by exposure to visible light and heat, with only the (E,E)-bisantrene ('all trans') isomer having significant anticancer activity. Based on these discoveries, three patent applications were filed on 12 September 2025 covering the chemical structure, manufacture, formulation, storage, and uses of the active (E,E)-bisantrene isomer and isomeric mixtures. These patents, if granted, will provide composition of matter IP protection of (E,E)-bisantrene until 2045. This new intellectual property fundamentally changes the commercial prospects of Race Oncology, as it will enable 20 years of the strongest IP protection possible for the RC220 and RC110 formulations containing (E,E)-bisantrene.

Race Oncology expects to have 20 years of composition of matter IP protection for the (E,E)-bisantrene isomer, which is used in the RC220 and RC110 formulations.

The new composition of matter and associated patent applications provide several important value generators for Race Oncology, including resetting the patent clock with the strongest IP protection for the active (E,E)-bisantrene isomer until 2045, preventing generic versions of bisantrene, and enabling pharma licensing and/or partnership discussions to advance RC110 into a pivotal Phase 3 trial in AML without compromising the commercial value of RC220.