Amid a backdrop of recent RSV vaccine approvals, GSK and Pfizer find themselves locked in a legal spat over alleged patent infringements. Both Big Pharma giants now possess the FDA’s blessing for their respective respiratory syncytial virus (RSV) vaccines. Pfizer’s recent win came with the second approval for its Abrysvo vaccine, which the company now highlights as the first FDA-approved maternal vaccine to guard infants against RSV.
In early May, GSK’s Arexvy became the first to win FDA’s blessing to protect individuals aged 60 and above from RSV complications. By the end of the month, Pfizer had won approval for Abrysvo in the same age group.
Yet, behind the scenes of these approvals, legal clouds gather. GSK has taken its grievances to a federal court in Delaware, alleging that Pfizer infringed on four of its patents related to its Arexvy vaccine. In a Reuters-posted filing, GSK claims it began work on its RSVPreF antigen in the early 2000s. In the filing, GSK claims ownership of the patents, which it summarizes as the ‘002, ‘239, ‘181 and ‘284 patents, which cover RSV vaccine compositions and methods of manufacture.
GSK claims RSV focus since 2000s
GSK says it has invested over 15 years in RSV vaccine R&D. The company claims Pfizer’s Abrysvo vaccine, approved shortly after Arexvy in May 2023, infringes the GSK patents because it contains similar RSV antigens and trimerization domains covered by the patents.
The company claims Pfizer’s infringement is willful and deliberate, with knowledge of the GSK patents at least since Abrysvo’s approval. GSK is seeking damages, lost profits, injunction on sales of Abrysvo for adults more than 60, treble damages, attorney fees and other relief. Pfizer has denied wrongdoing.
The company’s latest regulatory approval is based on phase 3 data from a trial in more than 7,000 pregnant women showing the vaccine was safe and effective at preventing RSV lower respiratory tract disease in their infants.
RSV is a common cause of infant hospitalizations globally.
Moderna and Sanofi are also pursuing RSV vaccine approvals. The former’s MRNA-1345 appears to be closer to the finish line as Moderna announced at the start of the year that a trial of the vaccine met its primary endpoint in older adults.