Bendamustine – USA

On Dec. 16, 2019, Delaware court granted-in-part & denied-in-part Hospira’s motion to dismiss infringement of Cephalon’s composition patent covering Bendeka®.

Plaintiffs Eagle Pharmaceuticals, Inc., Teva Pharmaceuticals International GMBH, and Cephalon, Inc. have sued Defendant Hospira, Inc., alleging infringement of nine OB patents. These patents cover liquid formulations of the cancer drug Bendeka®(bendamustine). Plaintiffs alleged that Hospira' s submission of NDA to the FDA constituted an artificial act of infringement of the these patents. Hospira' s filed motion to dismiss pursuant to Federal Rule of Civil Procedure 12(b)(6).

The claims of eight of the asserted patents require some combination of two solvents in the claimed liquid bendamustine formulation: propylene glycol and polyethylene glycol (PG patents). Plaintiffs allege that Hospira's NDA product, which contains polyethylene glycol but uses ethanol instead of propylene glycol as its second solvent, infringes the PG patents under the doctrine of equivalents. The ninth asserted patent, U.S. Patent No. 9,572,887 requires a "non-aqueous" bendamustine formulation. Plaintiffs allege that Hospira's NDA product, which contains 2%-4% water, infringes the claims of the ‘887 patent both literally and under the doctrine of equivalents.

Infringement of US’887 patent:

Hospira contends that its NDA product does not literally infringe the ‘887 patent because it contains some amount of water. It similarly contends that claim vitiation bars application of the doctrine of equivalents to its NDA product because "the term 'non-aqueous' presents a black-or-white proposition: either a composition is non-aqueous [i.e. completely lacking in water] or, if it is not, it is the complete opposite (i.e., aqueous)." And, finally, Hospira contends that prosecution history estoppel applies because the patentee amended the claims to specify that the claimed formulations are "non-aqueous" in order to overcome prior art that referenced "aqueous" solutions. Plaintiffs, however, argue that "non-aqueous" to a person of ordinary skill in the art (POSITA) does not require the complete absence of water, and they point to the fact that Hospira represented to the FDA that its NDA product is "predominantly a non-aqueous formulation." Court said that, Hospira's arguments boil down to a claim construction dispute that is not suitable for resolution in the context of a motion to dismiss. Thus court denied Hospira' s motion to dismiss Plaintiffs' claim of infringement of the ‘887 patent.

Infringement of PG patent:

Hospira argues that Plaintiffs' claims of equivalence infringement of the PG patents fail as a matter of law because they are barred by the disclosure-dedication rule and prosecution history estoppel. Court agreed with Hospira & said that a corollary to the principle that only the claims define the scope of a patented invention is the disclosure-dedication rule. That rule precludes a finding of infringement that is based on subject matter disclosed in the written description but not claimed. For the disclosure-dedication rule to apply, "[t]he disclosure must be of such specificity that one of ordinary skill in the art could identify the subject matter that had been disclosed and not claimed ["PSC Comput. Prods. v. Foxconn Int'!, Inc., 355 F.3d 1353, 1360 (Fed. Cir. 2004)], and the "unclaimed subject matter must have been identified by the patentee as an alternative to a claim limitation,["Pfizer, Inc. v. Teva Pharm. USA, Inc., 429 F.3d 1364, 1379 (Fed. Cir. 2005)].

Court further said that the written description of the ‘533 patent explicitly and repeatedly identifies Hospira' s second solvent, ethanol, as an alternative to propylene glycol in embodiments of the patented invention. In light of the clear and unambiguous disclosure of ethanol as a substitute for propylene glycol in the ‘533 patent's written description and the fact that the PG patents do not claim ethanol as the second solvent in the claimed liquid bendamustine formulation, the disclosure-dedication rule bars Plaintiffs from alleging that Hospira's NDA product infringes the PG patents under the doctrine of equivalents.