Ropes & Gray Advises LianBio on License Agreement with Pfizer for Respiratory Virus Treatment

Pfizer and LianBio announced on December 19, 2022 that Pfizer has opted in to the right to develop and commercialize sisunatovir, a respiratory syncytial virus (RSV) therapeutic candidate, in Mainland China, Hong Kong, Macau, and Singapore pursuant to the companies’ existing strategic collaboration to expand patient access to novel therapeutics in Greater China. Ropes & Gray represented LianBio on the agreement.

Under the terms of Pfizer’s opt-in to sisunatovir rights, LianBio will receive a $20 million upfront payment, to be released from previously restricted cash paid by Pfizer to LianBio in 2020 under the companies’ existing strategic collaboration. Additionally, LianBio is eligible to receive up to $135 million in potential development and commercial milestone payments and tiered low single digit percent of sisunatovir net sales in the territories. Pfizer will assume all development and commercial activities and costs in the region and will release LianBio from its royalty and milestone obligations for sisunatovir.

Sisunatovir is an investigational, orally administered fusion inhibitor designed to block RSV replication by inhibiting F-mediated fusion with the host cell. Sisunatovir is being evaluated for the potential treatment of RSV infection in pediatric and adult patients.

The Ropes & Gray China life sciences team representing LianBio was led by life sciences partner Eric Wu.