The European Patent Office upheld FibroGen Inc.'s patent for small molecule inhibitors meant to treat iron deficiency.
The patent covers inhibitors of hypoxia-inducible factor prolyl hydroxylase, an enzyme that allows cells to respond to low oxygen concentrations.
The patent was challenged by Akebia Therapeutics Inc., Bayer Intellectual Property GmbH, Bayer Pharma AG and Bayer Animal Health GmbH. Another patent claim from Glaxo Group Ltd. was deemed invalidly filed.
The European Patent Office also handed down a decision against FibroGen in a related patent challenge from the same parties. FibroGen has appealed the decision and expects a resolution in three to four years.
FibroGen is conducting global phase 3 clinical trials for its Roxadustat small molecule inhibitor.