Akebia defends anaemia drug patents at EPO amid huge Fibrogen battle

Biotechnology company Akebia has successfully combatted attempts to invalidate two patents at the European Patent Office. Opponents Fibrogen and Sandoz mounted the challenge, amid a wider litigation battle involving multiple patents for anaemia drugs.

EP 3 277 270 and EP 3 357 911 both cover Vafseo, a drug which uses active ingredient vadadustat. This is an HIF-prolyl hydroxylase inhibitor for the treatment of chronic kidney disease (CKD) in adults. The global market value of anaemia treatment drugs is vast and ever-expanding: experts predict that, by 2028, it will be worth around $15 billion.

EPO for Akebia

Akebia Therapeutics is involved in an ongoing patent dispute with Fibrogen concerning vadadustat. The company alleges that Fibrogen’s patents’ claims for a broad class of compounds, defined by structure and function, infringe Akebia’s drug. The medication is an oral treatment for dialysis-dependent patients with symptomatic anaemia associated with CKD.

On 6 February, the EPO Opposition Division heard the case on EP 270, which is a formulation patent. Akebia was successful, with the board rejecting the opposition in its entirety, thus maintaining it as granted with no amendments. JUVE Patent cannot confirm whether its opponent in the proceedings, Sandoz, will appeal.

Akebia was again successful regarding product patent EP 911. The EPO rejected an opposition put forward by Fibrogen, again maintaining the patent as granted. In this case, Fibrogen has withdrawn its opposition and, based on Akebia’s written defence, the Opposition Division did not continue opposition proceedings. Both patents are commercially important for Akebia.

New drug on the market

Akebia and Fibrogen have battled over the patents for several years. In 2018, Akebia and licence partner Otsuka filed revocation proceedings against Fibrogen’s two patent families, aiming to pave the way for their product. Astellas, the Fibrogen licensee in the UK, counter-claimed for infringement regarding the family A patents. It also brought a ‘quia timet’ infringement case concerning family B.

In August 2021, the UK Court of Appeal declared Fibrogen’s patents EP 14 63 823, EP 2 289 531 and EP 22 98 301 (family A) and EP 16 33 333, EP 23 22 153 and EP 23 22 155 (family B) valid. The decision partially overturned a ruling by the first-instance High Court, which had found that most of the patents were invalid.

Family A patents’ claims all concern a class of compounds defined for use in the treatment of CKD. The family B patents concern the same compounds, but for the treatment of anaemia of chronic disease (ACD).

In the same month that the second-instance judgment was handed down, Fibrogen received approval from the European Medical Agency (EMA) for the drug Evrenzo. Its active ingredient roxadustat is an HIF-prolyl hydroxylase inhibitor intended for the treatment of CKD.

Supreme Court pending

However, Akebia also aimed to launch its own anaemia drug containing vadadustat. In April 2023, Akebia announced that the European Commission had granted marketing authorisation for Vafseo, with active ingredient vadadustat, for the treatment of symptomatic anaemia associated with CKD in adults on chronic maintenance dialysis.

Nevertheless, Fibrogen still believes that Akebia could market its compound in a way that infringes the family B patents and their use for treating anaemia of chronic disease (ACD). Following the Court of Appeal decision, Akebia sought permission to appeal to the Supreme Court, which it granted. The UK’s highest instance should hear the case in the course of 2024.

First time for CMS

The EPO opposition proceedings are the first time that Akebia has worked with the London office of global firm, CMS Cameron McKenna Nabarro Olswang. The company’s in-house team sought out representation by CMS partner and patent attorney Jane Evenson, following work done on a multi-party opposition for the Broad Institute.

In litigation proceedings, Hogan Lovells’ London office is the counsel of choice for the respondent. The case, which began in 2020, was the international firm’s first instruction by Akebia for patent litigation matters. Previously, the firm had worked with the innovator company on regulatory cases.

Mixed IP firm Carpmaels & Ransford represents Fibrogen, both in litigation proceedings and at the EPO. The companies have worked together for around 20 years.

German patent attorney firm Ter Meer Steinmeister represents client Sandoz. The firm’s pharma practice often works for both generic and original drug manufacturers; the firm’s good relations with Novartis have secured the patent attorney’s relationship with its former subsidiary.

For Akebia
CMS Cameron McKenna (London): Jane Evenson (partner); associate: Lianne Leith (both patent attorneys)

For Fibrogen
Carpmaels & Ransford (London): Daniel Wise (partner, patent attorney)

For Sandoz
Ter Meer Steinmeister (Munich): No information