US 11839689

A technical analysis of U.S. Patent 11,839,689 reveals it pertains to specific formulations of the prostate cancer drug enzalutamide, designed to improve its solubility and absorption. The patent is currently active and has been asserted in recent litigation.

Patent Summary:

• Title: Formulations of enzalutamide
• Assignee: Astellas Pharma Inc. and Medivation Prostate Therapeutics LLC
• Inventors: Douglas Alan Lorenz, Sanjay Konagurthu, Randy J. Wald, Jason A. Everett, Sheila Matz, Yuuki Takaishi, Toshiro Sakai, Ryousuke Irie, Shinsuke Oba, Hiroyasu Toyota, Koji Nishimura, and Atsushi Kanbayashi.
• Filing Date: November 11, 2022
• Issue Date: December 12, 2023
• Abstract: The patent describes solid formulations of enzalutamide and their use in treating hyperproliferative disorders. The disclosure focuses on creating a solid dispersion of enzalutamide to enhance its solubility and absorption, thereby improving its effectiveness and allowing for more convenient dosing.

Plain-Language Overview of Independent Claims:

This patent contains several independent claims, which are the broadest statements of the invention. In essence, they protect different facets of the enzalutamide formulation.

• Claim 1: This claim protects a solid pharmaceutical composition, such as a tablet, that contains a specific amount of enzalutamide (around 160 mg). The key aspect is that the enzalutamide is in an amorphous (non-crystalline) state, dispersed within a specific polymer known as hydroxypropylmethylcellulose acetate succinate (HPMCAS). This formulation must also include a disintegrant, an agent that helps the tablet break apart, at a concentration of 6% to 10% by weight.

• Claim 8: This claim is directed at a method of treating prostate cancer. It covers the act of administering the pharmaceutical composition described in Claim 1 to a patient in need. This protects the medical use of the specific enzalutamide formulation.

• Claim 15: This claim focuses on a solid amorphous dispersion. This is the core component of the final pill. It protects the mixture of enzalutamide and the HPMCAS polymer itself, where the enzalutamide makes up 55% to 65% of the dispersion by weight.

Litigation:

U.S. Patent 11,839,689 has been the subject of patent infringement litigation. In August 2024, Astellas Pharma Inc. and Pfizer's Medivation unit filed a lawsuit against Qilu Pharmaceutical Co. in the U.S. District Court for the District of New Jersey. The suit alleges that Qilu's proposed generic version of the drug Xtandi® (enzalutamide) infringes on this patent, among others. The patent is also listed in connection with Abbreviated New Drug Application (ANDA) court cases, which are common when generic drug manufacturers challenge the patents of brand-name drugs. As of today's date, there are no documented proceedings related to this patent in the 2026 dockets of the Court of Appeals for the Federal Circuit (CAFC), indicating that the district court cases are likely ongoing.