Enanta Pharma has announced its intentions to sue Pfizer in the United States District Court for the District of Massachusetts for Paxlovid (nirmatrelvir and ritonavir) patent infringement.
The company specialises in developing small molecule treatments for liver diseases and infection. Among these drugs, Enanta has produced therapies to address respiratory syncytial virus (RSV), human metapneumovirus (hMPV) chronic hepatitis B virus (HBV) and focused R&D efforts for COVID-19 early into the pandemic.
The lawsuit claims Pfizer’s oral COVID-19 antiviral infringes on one of Enanta’s patents – patent 11,358,953 – and therefore seeks to claim damages from the company.
The patent in question covers “compounds and pharmaceutically acceptable salts which inhibit coronavirus replication activity, and methods of treating a coronavirus infection” and was awarded in early June.
Enanta is seeking compensatory damages for both the infringement and costs incurred.
The company gave a statement in which it said it “recognises the importance of Paxlovid’s availability to patients and does not intend to seek an injunction or take other action in this litigation that would impede the production, sale or distribution of Paxlovid”.
Despite acknowledging the potential for disruption in Paxlovid’s availability and production caused by legal matters, Enanta was resolute in its actions, adding that it “seeks fair compensation for Pfizer’s use of a coronavirus 3CL protease inhibitor claimed in the ‘953 patent”.
The lawsuit claims for damages at an amount “no less than a reasonable royalty for the use made by Pfizer of Enanta’s invention”.
Should the courts uphold the complaint, Enanta could benefit from a share in Pfizer’s Paxlovid revenues, which is tipped to make $22bn in sales this year.