In a significant ruling for pharmaceutical patent litigation, Judge Mary M. Rowland of the US District Court for the Northern District of Illinois has determined that Ingenus Pharmaceuticals LLC can continue its patent infringement lawsuit against Nexus Pharmaceuticals Inc., while dismissing co-plaintiff Leiutis Pharmaceuticals LLP from the case.
The court granted in part and denied in part Nexus Pharmaceuticals' motion for summary judgment for lack of standing in the dispute over US Patent No. 10,993,952, which covers cyclophosphamide liquid formulations used in cancer treatment.
Standing Issues Central to Court's Decision
Judge Rowland's May 6 opinion addressed complex questions of constitutional and statutory standing in pharmaceutical patent litigation. The court found that while Ingenus maintained both constitutional and statutory standing to pursue the case, Leiutis had relinquished all rights to the patent before trial, necessitating its dismissal from the proceedings.
The ruling highlights the importance of maintaining patent rights throughout litigation. Despite Ingenus subsequently licensing the drug to Dr. Reddy's Laboratories Ltd. after filing the lawsuit, the court determined that Ingenus had retained sufficient legal authority to enforce the patent.
Implications for Cyclophosphamide Formulations
At the center of this dispute is cyclophosphamide, an alkylating agent commonly used in chemotherapy regimens for various cancers, including lymphomas, leukemias, and solid tumors. The patent in question (US Patent No. 10,993,952) specifically covers liquid formulations of cyclophosphamide, which can offer advantages over powder formulations in terms of stability, dosing precision, and ease of administration.
The case underscores the competitive landscape for cancer therapeutics, where formulation patents can extend market exclusivity and provide significant commercial advantages. Cyclophosphamide has been a mainstay of cancer treatment for decades, but innovations in formulation continue to drive patent disputes among pharmaceutical manufacturers.
Pharmaceutical Patent Enforcement Strategies
This case illustrates the complex web of licensing agreements and patent enforcement rights that characterize the pharmaceutical industry. Companies must carefully structure their licensing agreements to preserve standing in patent litigation, particularly when deals are made during ongoing litigation.
"Patent standing issues are becoming increasingly complex in pharmaceutical litigation as companies enter into various licensing and commercialization agreements," notes a patent attorney familiar with similar cases but not involved in this dispute. "This ruling reinforces the importance of maintaining enforcement rights when structuring such agreements."
Next Steps in the Litigation
With Leiutis dismissed from the case, Ingenus will proceed alone against Nexus Pharmaceuticals. The court's partial grant of Nexus's motion for summary judgment narrows the scope of the litigation but allows the core patent infringement claims to move forward.
The case will now likely proceed to address the substantive patent infringement claims regarding the cyclophosphamide formulations. Industry observers will be watching closely, as the outcome could impact the market for this important cancer treatment and set precedents for pharmaceutical patent enforcement strategies.
