Pfizer Alleges MSN Pharmaceuticals Infringed on Ibrance Patent

In the second suit in just over one week concerning the same patent, on Wednesday in the District of Delaware, Pfizer and two subsidiaries filed a complaint against MSN Pharmaceuticals and a subsidiary alleging infringement of Pfizer’s patent for metastatic breast cancer drug Ibrance.

Pfizer, as the owner of U.S. Patent No. 10,723,730 (the ’730 patent) for Ibrance, received a letter dated Jan. 20 from MSN notifying Pfizer that it had filed abbreviated new drug application (ANDA) No. 14758 with the Food and Drug Administration (FDA) to manufacture and sell 75, 100, and 125 mg capsules of palbociclib, the generic version of Ibrance, according to the complaint. Pfizer holds the new drug application (NDA) No. 207103 for 75, 100, and 125 mg capsules of palbociclib.

MSN’s letter included an “Offer of Confidential Access” regarding MSN’s ANDA — “(t)he offer, however, was subject to various unreasonably restrictive conditions,” the complaint states. The letter also claimed that Pfizer’s ’730 patent is “invalid, unenforceable, and/or will not be infringed” by MSN’s ANDA products. Pfizer disagrees and argues that MSN’s ANDA products would infringe multiple claims of the Pfizer patent.

Pfizer claimed that MSN has acted with full knowledge of the ’730 patent and that it will continue to pursue manufacturing, selling, and distributing its ANDA products before the expiration of Pfizer’s patent. If MSN is not ordered from infringing, “actively inducing infringement,” and “contributing” to others’ infringement of the patent, Pfizer will suffer “irreparable injury,” the company argued.

The relief requested by Pfizer includes declaratory judgment that its patent has been infringed, an order explaining that the effective date of any of MSN’s ANDA products may not be earlier than the expiration date of Pfizer’s ’730 patent, and attorneys’ fees and other expenses.

The plaintiffs are represented by Morris, Nichols, Arsht & Tunnell.