Court of Appeal issues judgment in FibroGen and Astellas Pharma v Akebia Therapeutics and Otsuka Pharmaceutical

The Court of Appeal today handed down its judgment in the combined appeals of FibroGen, Inc. and Astellas Pharma Inc., v Akebia Therapeutics Inc. and Otsuka Pharmaceutical Company Ltd.

In a unanimous decision, Philips LJ, Birss LJ, and Sir Christopher Floyd found for Astellas Pharma Inc., and FibroGen, Inc. on the elements of their appeal, overturning the majority of the findings of the first instance judgment from the High Court, which found that certain patents owned by FibroGen and exclusively licensed to Astellas in the UK and Europe (amongst other jurisdictions) to be invalid.

The patents in question, which were split into two “families”, relate to the use of inhibitors of the enzyme HIF-PH (hypoxia inducible factor-prolyl hydroxylase) to treat types of anaemia. Astellas had initially obtained marketing authorisation in Japan in September 2019 for the first oral HIF-PH inhibitor, roxadustat, with plans to launch the product in Europe. In 2018, Akebia and Otsuka sought to clear the way for launch of their drug vadadustat in the UK, with an action to revoke patents owned by FibroGen. Consequently, Astellas filed a cross-claim for threatened infringement.

In a significant departure from the interpretation of the High Court, the Court of Appeal found that the key claims of the relevant Family A patents (EP ‘823 and EP 301) had been sufficiently disclosed and were therefore valid. 

In relation to literal infringement, the Court of Appeal upheld the first instance ruling that vadadustat fell within the relevant claims of the Family A patents.

While it was found that the relevant claims in the Family A patents were valid and infringed, it was held that the relevant claims of the Family B patents were invalid, due to a lack of inventive step.

The handing down of the decision coincides with Astellas receiving European Commission approval for its First-in-Class EVRENZO™ (roxadustat) for adult patients with symptomatic anaemia of chronic kidney disease (CKD). Roxadustat is the first orally administered hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitor available for adult patients with anaemia associated with CKD in Europe.