Pfizer Opts in for Rights to RSV Candidate in China

Pfizer Inc. and LianBio, a biotechnology company in China, announced that Pfizer 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 under the companies’ existing strategic collaboration.
 
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.

LianBio will receive $20 million upfront and is eligible to receive up to $135 million in potential development and commercial milestones and tiered low single digit percent of sisunatovir 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.
 
“Like LianBio, Pfizer recognizes the promise of sisunatovir to address significant treatment gaps for patient populations vulnerable to severe complications of RSV,” said Yizhe Wang, Ph.D., Chief Executive Officer of LianBio. “During typical RSV seasons, more than 400,000 pediatric and elderly patients in China are hospitalized with RSV-associated lower respiratory tract infections. Pfizer is a leader in advancing research and development for RSV vaccines and therapeutics, and their expertise studying different modalities of treatment is expected to be instrumental in bringing a new therapeutic option to as many patients in need as possible.”

In June 2022, Pfizer acquired ReViral Ltd. and its portfolio of RSV therapeutic candidates with the exception of development and commercialization rights for sisunatovir in Mainland China, Hong Kong, Macau, and Singapore, which LianBio had previously in-licensed from ReViral in March 2021.
 
“At Pfizer, we are committed to advancing potentially critical vaccines and therapies to help address significant unmet need in infectious diseases around the world, including RSV, and we’re pleased that this ongoing collaboration with LianBio has the potential to provide more patients with access to a much-needed treatment,” said Jean-Christophe Pointeau, China President for Pfizer Global Biopharma Business. “We believe that, if clinically successful and approved, sisunatovir may help change the standard of care for patients with RSV disease, for whom treatment options are currently limited.”