Race Oncology Ltd (ASX:RAC, OTC:RAONF) has filed three new patent applications after uncovering fresh insights into the chemistry of its lead cancer drug bisantrene.
The company’s scientists found that bisantrene is composed of three light-sensitive photoisomers, with one — the (E,E)-bisantrene isomer — showing significant anticancer activity. Based on this discovery, Race has submitted patent applications covering the isomer’s chemical structure, as well as its manufacturing, formulation and use. If granted, the patents would extend composition of matter protection until 2045.
Composition of matter protection
The filings include a composition of matter patent for the (E,E)-bisantrene isomer, the strongest form of intellectual property (IP) protection in pharmaceuticals. Such patents secure exclusivity over the chemical structure of an active pharmaceutical ingredient, regardless of how it is synthesised or delivered.
Race noted that composition of matter patents are especially valued in pharma licensing and acquisition deals, with global partners typically seeking at least 8–10 years of remaining patent life at launch.
If approved, the new filings would reset the clock for bisantrene and provide two decades of protection — with potential extensions in some jurisdictions. Race said the findings apply directly to its lead formulations, RC220 and RC110, both of which contain the purified (E,E)-bisantrene isomer.
Commercial significance
CEO and managing director Dr Daniel Tillett said the discovery and associated IP filings strengthen Race’s commercial position.
“Being able to generate new composition of matter IP covering the active isomer of bisantrene fundamentally changes the commercial prospects of Race Oncology,” Tillett said. “We now expect to have 20 years of the strongest IP protection possible for the RC220 and RC110 formulations containing (E,E)-bisantrene.
“These discoveries highlight the commercial value of undertaking new preclinical research on clinically established pharmaceutical assets,” he added. “I congratulate the entire Race preclinical team for their inspiration and extraordinary efforts in making this fundamental discovery and turning science into a valuable outcome for all our investors.”
The company added that regulators would not approve generic formulations based on older mixed-isomer versions of bisantrene, due to dosing variability and the presence of inactive isomers — effectively preventing competitors from entering the market.
Scientific breakthrough
Race’s team determined that historical formulations of bisantrene, developed in the 1980s, rapidly converted into different isomers when exposed to light, producing inconsistent mixtures that may have affected past trial outcomes.
In contrast, all recent and ongoing Race-sponsored trials — including two Phase 2 acute myeloid leukaemia studies and the current Phase 1 solid tumour program — have used the purified (E,E)-bisantrene isomer.
Next steps
Race has requested accelerated examination of the patents to support ongoing licensing discussions and will outline the findings in more detail during a webinar on Thursday, September 18, 2025 (registration available here).
If granted, the new IP would give Race Oncology a stronger negotiating position with potential partners as it progresses plans for pivotal trials of its bisantrene formulations.