Merck Serono S.A. v. TWi Pharmaceuticals, Inc.

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Case Number:

25-1463

Court:

Appellate - Federal Circuit

Nature of Suit:

Companies

Sectors & Industries:

  1. January 22, 2026

    Merck Can't Get Fed. Circ. To Reconsider Axing MS Drug Patents

    The Federal Circuit on Thursday refused to reconsider decisions invalidating Merck KGaA patents on the blockbuster multiple sclerosis drug Mavenclad, turning aside the German drugmaker's claim that the court set an unjust new rule that means inventors' work can later be used against them.

  2. December 01, 2025

    Merck Wants Fed. Circ. Redo On Decision Backing Axed IP

    German drugmaker Merck has asked the Federal Circuit to rethink its decision upholding the invalidation of claims in two patents on the blockbuster multiple sclerosis drug Mavenclad, saying the ruling creates a rule where inventors' work can later be used against them.

  3. October 30, 2025

    Fed. Circ. Explains Rule While Upholding Merck PTAB Loss

    The Federal Circuit sided with generics makers Thursday and upheld the Patent Trial and Appeal Board's invalidation of claims in two Merck KGaA patents on the blockbuster multiple sclerosis drug Mavenclad, while clarifying how to treat invalidity arguments that involve overlapping inventors.