As RSV vaccine clash kicks off, GSK sues Pfizer for patent infringement

In the latest clash of the vaccine titans, GSK is locking horns with Pfizer over claims the company’s competing respiratory syncytial virus (RSV) shot Abrysvo treads on patents belonging to its own immunization Arexvy.

In a new lawsuit, GSK says Pfizer’s vaccine—approved in late May—infringes four patents related to its RSV antigen shot Arexvy, which itself snagged a green light in the U.S. earlier that same month.

Arexvy and Abrysvo’s race to the regulatory finish line was a historic event, with GSK and Pfizer delivering the world’s first RSV immunizations for adults in rapid succession.

But in court documents filed this week, GSK argues Pfizer began the project that led to Abrysvo no earlier than 2013, at least seven years after GSK started its own RSV program.

“In the US, GSK has initiated legal proceedings against Pfizer to enforce several patents relating to RSV vaccines,” a GSK spokesperson told Fierce Pharma. “Intellectual property protections are the foundation of research-based companies’ ability to drive innovation.”

The spokesperson added that the lawsuit won’t impinge on GSK’s ability to launch its own shot Arexvy, and the company remains “fully focused on making our RSV vaccine for older adults available in the U.S. following recent approval by the FDA.”

In a separate emailed statement, a Pfizer spokesperson said the company is “confident in its intellectual property position” and will “strongly defend” its right to bring Abrysvo to patients.”

The GSK patents at issue in the lawsuit claim inventions relating to compositions used in RSV vaccines, and methods for preparing those compositions. The company claims that Pfizer “knowingly uses GSK’s claimed inventions in Abrysvo without permission.”

The British drugmaker is demanding a jury trial. It’s also seeking damages or royalties and, should it prevail in court, a permanent enjoinder on future sales and manufacturing of Pfizer’s RSV vaccine in the U.S.

The RSV vaccine market is one of the pharma industry's next major battlegrounds, with analysts pegging the potential opportunity at more than $10 billion. Aside from Pfizer and GSK, Moderna has posted positive phase 3 vaccine results.

Meanwhile, partners Sanofi and AstraZeneca recently won U.S. approval for their preventive antibody. The companies are positioning that drug for all infants to protect against their first RSV season. The antibody is also approved in Europe and goes by the trade name Beyfortus.

Editor's note: This story has been updated to include a comment from Pfizer.