Vifor buys priority review voucher for vadadustat filing

Vifor Pharma has struck a deal to buy a priority review voucher (PRV). The PRV sets Vifor and partner Akebia Therapeutics up to benefit from a fast review at the FDA when they file for approval of chronic kidney disease drug vadadustat.

St. Gallen, Switzerland-based Vifor left many key details out of its statement (PDF) to disclose the PRV. At first, it was unclear who Vifor bought the PRV from, how much it paid and how it intended to use the voucher. 

Akebia Therapeutics cleared up arguably the most important unknown when it published a financial regulatory filing that revealed a plan to use the PRV to shave four months off the FDA review of oral hypoxia-inducible factor prolyl hydroxylase inhibitor vadadustat. The agreement will see Akebia pay Vifor $10 million. In return, Vifor will assign the PRV to Akebia for use on its vadadustat filing.

As Vifor lacks U.S. rights to most of its clinical assets, vadadustat was identified as a likely target for the PRV even before Akebia ended the uncertainty. However, the structure of the deal with Akebia means Vifor will share the benefits of the accelerated approval. While Vifor has an exclusive U.S. license to sell vadadustat to an affiliate of Fresenius Medical Care North America, Akebia will receive most of the profits on those sales.

Akebia’s statement reveals it is paying $10 million to bring forward the date on which Vifor begins to make those sales. It remains unclear exactly what Vifor paid for the PRV, although it is possible to make an informed guess. After surging in the early years of the initiative, PRV prices have settled at around $100 million recently, suggesting Vifor paid roughly that amount.

A long list of companies could have sold the PRV to Vifor. While many of the PRVs issued by the FDA have already been submitted to accelerate regulatory reviews, companies including Alexion, Sanofi and Vertex have obtained vouchers and not publicly disclosed their use, suggesting they are still in play.