Pfizer Sues MSN Pharmaceuticals After ANDA for Breast Cancer Treatment

On Tuesday, pharmaceutical company Pfizer filed a lawsuit against fellow pharmaceuticals company MSN Pharmaceuticals Inc. for allegedly infringing on their drug patent. 

This suit comes in response to a letter sent by MSN notifying Pfizer that they have submitted an abbreviated new drug application (ANDA) to the FDA in an attempt to engage in commercial manufacturing of generic palbociclib tablets, which are used for breast cancer treatment. This was done pursuant with the Hatch-Waxman act, which sets forth the procedure for regulatory approval and commercial marketing of pharmaceuticals, including generic drugs. 

Under Hatch-Waxman, each ANDA must include a certification or statement for each patent listed in the Orange Book. In this case, the defendant is citing paragraph IV of 21 U.S.C. Sec. 355(j)(2)(a)(vii), which states that the patent is not valid or will not be infringed by the new drug.After receiving the notice, Pfizer, the  holder  of  New  Drug  Application (NDA) on palbociclib, decided to file the lawsuit allegedly because the defendant’s offer of confidential access to the ANDA was too restrictive and they did not want to involve themselves in prolonged negotiation. 

The plaintiff stated that contrary to the claims made in the notice letter, the defendant’s generic version of the drug does directly infringe upon 3 claims within its patent and its relation to their brand name drug IBRANCE. Pfizer argued that this ANDA was filed for the specific purpose of infringing upon the patent and will do so immediately once it is approved. 

The plaintiff said the filing was dishonest on the defendant’s part because MSN made it  for the sole purpose of infringement. The plaintiff said the defendant’s product has no non-infringing uses and had no reason to think that it did. The plaintiff said it fears that MSN’s intent to manufacture, offer for sale, sell, distribute, and/or import their ANDA Products, therefore infringing on the patent, will cause substantial and irreparable harm to Pfizer.

The plaintiff requests that their accusation of infringement is affirmed and that there is an injunction enjoining MSN, and all persons acting in concert with MSN, from the commercial manufacture, use, sale, offer for sale, or importation into the United States of MSN’s ANDA Products, or any other drug product whose use is covered by the patent.

The plaintiff is represented by Morris, Nichols, Arsht & Tunnell.