Jenner & Block Secures Reversal of Preliminary Injunction in High-Stakes Pharmaceutical Battle

In a significant victory for pharmaceutical competition and access to generic drugs, Jenner & Block secured a key litigation win on behalf of client MSN Pharmaceuticals. A federal judge denied a pharmaceutical company’s request for injunctive relief, removing an obstacle to MSN’s planned launch of a generic version of Entresto, a widely used heart failure medication.

On July 15, 2025, US District Judge Evelyn Padin issued a comprehensive opinion denying both a Motion for a Preliminary Injunction and Motion for an Injunction Pending Appeal. The ruling marks a step forward in the effort to expand access to lower-cost treatment options for the millions of patients who rely on Entresto. 
 
The decision also establishes a crucial precedent limiting branded pharmaceutical companies' ability to assert trade dress claims based on pill design. The court found that the trade dress elements of the branded product were functional, not protectable, reinforcing the legal pathway for future generic challengers.

This outcome marks a notable reversal of the court’s earlier decision granting injunctive relief.

The Jenner & Block team included Partners Gianni Servodidio, Rémi Jaffré, and Adam Unikowsky, and Associates Jackie Carrero, Abby Schmidt, Kevin Si, and Karen Lou. 

Read Law360’s coverage of the case here. 

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© 2026 Jenner & Block LLP. Attorney Advertising. Jenner & Block LLP is an Illinois Limited Liability Partnership including professional corporations. This publication, presentation, or event is not intended to provide legal advice but to provide information on legal matters and/or firm news of interest to our clients and colleagues. Readers or attendees should seek specific legal advice before taking any action with respect to matters mentioned in this publication or at this event. The attorney responsible for this communication is Brent E. Kidwell, Jenner & Block LLP, 353 N. Clark Street, Chicago, IL 60654-3456. Prior results do not guarantee a similar outcome. Jenner & Block London LLP, an affiliate of Jenner & Block LLP, is a limited liability partnership established under the laws of the State of Delaware, USA and is authorised and regulated by the Solicitors Regulation Authority with SRA number 615729. Information regarding the data we collect and the rights you have over your data can be found in our Privacy Notice. For further inquiries, please contact dataprotection@jenner.com.

Jenner & Block Secures Reversal of Preliminary Injunction in High-Stakes Pharmaceutical Battle

In a significant victory for pharmaceutical competition and access to generic drugs, Jenner & Block secured a key litigation win on behalf of client MSN Pharmaceuticals. A federal judge denied a pharmaceutical company’s request for injunctive relief, removing an obstacle to MSN’s planned launch of a generic version of Entresto, a widely used heart failure medication.

On July 15, 2025, US District Judge Evelyn Padin issued a comprehensive opinion denying both a Motion for a Preliminary Injunction and Motion for an Injunction Pending Appeal. The ruling marks a step forward in the effort to expand access to lower-cost treatment options for the millions of patients who rely on Entresto. 
 
The decision also establishes a crucial precedent limiting branded pharmaceutical companies' ability to assert trade dress claims based on pill design. The court found that the trade dress elements of the branded product were functional, not protectable, reinforcing the legal pathway for future generic challengers.

This outcome marks a notable reversal of the court’s earlier decision granting injunctive relief.

The Jenner & Block team included Partners Gianni Servodidio, Rémi Jaffré, and Adam Unikowsky, and Associates Jackie Carrero, Abby Schmidt, Kevin Si, and Karen Lou. 

Read Law360’s coverage of the case here. 

Related Locations

© 2026 Jenner & Block LLP. Attorney Advertising. Jenner & Block LLP is an Illinois Limited Liability Partnership including professional corporations. This publication, presentation, or event is not intended to provide legal advice but to provide information on legal matters and/or firm news of interest to our clients and colleagues. Readers or attendees should seek specific legal advice before taking any action with respect to matters mentioned in this publication or at this event. The attorney responsible for this communication is Brent E. Kidwell, Jenner & Block LLP, 353 N. Clark Street, Chicago, IL 60654-3456. Prior results do not guarantee a similar outcome. Jenner & Block London LLP, an affiliate of Jenner & Block LLP, is a limited liability partnership established under the laws of the State of Delaware, USA and is authorised and regulated by the Solicitors Regulation Authority with SRA number 615729. Information regarding the data we collect and the rights you have over your data can be found in our Privacy Notice. For further inquiries, please contact dataprotection@jenner.com.

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