IP Law Daily, PATENT—D. Del.: Generic chemotherapy drugs did not infringe patent’s ‘ready to use’ limitation, (Oct 26, 2022)

By Kevin M. Finson, J.D.

A pair of new drug applications seeking authorization for generic versions of a patented cancer medication did not infringe a patent owned by Eagle Pharmaceuticals because they were not sold in “ready to use” form as the patent required.

Two manufacturers of generic bendamustine-containing chemotherapy drugs did not infringe the patent owned by Eagle Pharmaceuticals claiming a “ready to use liquid bendamustine-containing composition,” the federal district court in Wilmington, Delaware, has held. The asserted patent claims required that the drug be “ready to use” and neither proposed generic formulations met that limitation (Eagle Pharmaceuticals, Inc. v. Slayback Pharma LLC, October 25, 2022, Connolly, C.).

Eagle Pharmaceuticals, Inc. (Eagle) was the assignee of U.S. Patent No. 11,103,483 (the ’483 patent), which claimed a "ready to use liquid bendamustine-containing composition” and sold an FDA-approved medication known as BELRAPZO ® (bendamustine hydrochloride) Injection. Slayback Pharma, LLC (Slayback) and Apotex Inc. and Apotex Corp. (collectively, Apotex) separately filed New Drug Applications with the FDA seeking approval to manufacture equivalent generic bendamustine hydrochloride drugs. Eagle filed suit against both Slayback and Apotex alleging that the New Drug Applications constituted infringement of the ’483 patent. The defendants denied infringement and contested the validity of the ’483 patent.

Infringement. The only contested issue of infringement was whether the accused products met the “ready to use” limitation in the patent claims. The parties agreed that the proper construction of “ready to use” was “able to be dispensed with minimal if any effort or preparation; prepackaged.”

Reviewing the testimony of both parties’ experts, the court found that bendamustine was a highly toxic drug and that dispensing of the accused products must take place in a clean room in order to protect both the dispenser and the person administering the drugs. The court reviewed 13 steps that a provider must go through in order to safely administer the accused products and held that none of them could be performed with “minimal effort or preparation” because of the highly toxic nature of the drug and the small difference between a dose that would have the necessary therapeutic effect and a dose that could be lethal to the patient. Eagle’s expert also admitted that the accused products were not prepackaged. The dourt held that the accused products did not meet the “ready to use” limitation and therefore did not infringe.

Because the accused products did not infringe, the court did not reach the validity of the ’483 patent.

The case is No. 1:21-cv-01256-CFC-JLH.

Attorneys: Daniel M. Silver (McCarter & English, LLP) and Daniel G. Brown (Latham & Watkins LLP) for Eagle Pharmaceuticals, Inc. Neal C. Belgam (Smith, Katzenstein & Jenkins LLP) for Slayback Pharma LLC. Kenneth L. Dorsey (Morris James LLP) for Apotex Inc. and Apotex Corp.

Companies: Eagle Pharmaceuticals, Inc.; Slayback Pharma LLC; Apotex Inc.; Apotex Corp.

Cases: Patent DelawareNews