Prior art

Analysis of Prior Art Cited in U.S. Patent 12,161,628

This analysis examines the patent references cited during the prosecution of U.S. Patent 12,161,628 to determine their relevance and potential to anticipate the patent's claims under 35 U.S.C. § 102. The core of the invention is Claim 1, which details a method for treating prostate cancer by co-administering a 240 mg daily dose of enzalutamide to a patient who is also being treated with rifampin.

For a prior art reference to anticipate Claim 1, it must expressly or inherently disclose every element of the claim in a single document. The key elements are:

1. A method of treating prostate cancer.
2. The patient is administered rifampin.
3. Co-administration of enzalutamide.
4. A specific daily dose of 240 mg of enzalutamide.

The patent's "Patent Citations" section lists two references, which are analyzed below.

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1. WO2017027660A1: Combination therapy with apalutamide

• Full Citation: WO2017027660A1. "Combination therapy with apalutamide." Assignee: Medivation Technologies, Inc. Publication Date: February 16, 2017. Filing Date: August 11, 2016.
• Brief Description: This patent application describes dosage regimens for co-administering apalutamide (also known as ARN-509), an androgen receptor inhibitor, with strong CYP3A4 inducers like rifampin. It notes that co-administration of rifampin with apalutamide decreases the plasma concentration of apalutamide. To compensate for this drug-drug interaction, the application proposes increasing the daily dose of apalutamide from its standard 240 mg/day to a higher dose, such as 300 mg/day or 360 mg/day. The invention is aimed at treating cancers, including prostate cancer.
• Anticipation Analysis (Claim 1): This reference does not anticipate Claim 1 of US 12,161,628. While it teaches the treatment of prostate cancer and the co-administration of a drug (apalutamide) with rifampin, and it recognizes the need for a dosage increase due to CYP3A4 induction, it fails to meet key requirements of Claim 1.
  • Element 3 (Enzalutamide): The reference discloses apalutamide, not enzalutamide. Although both are androgen receptor inhibitors, they are distinct chemical compounds.
  • Element 4 (240 mg dose): The reference teaches increasing the dose of apalutamide from 240 mg/day to a higher dose (e.g., 360 mg/day). In contrast, the '628 patent claims an increased dose of enzalutamide to 240 mg/day (from a standard 160 mg/day). Therefore, WO2017027660A1 does not disclose the specific 240 mg daily dose for enzalutamide.

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2. US20180228790A1: Combination Therapy with Apalutamide

• Full Citation: US20180228790A1. "Combination Therapy with Apalutamide." Assignee: Medivation Technologies LLC. Publication Date: August 16, 2018. Filing Date: February 9, 2018.
• Brief Description: This document is the U.S. national phase publication of the international application WO2017027660A1, discussed above. Its disclosure is substantively identical. It describes increasing the daily dose of the androgen receptor inhibitor apalutamide when co-administered with a strong CYP3A4 inducer, such as rifampin, to treat prostate cancer. The standard apalutamide dose of 240 mg/day is proposed to be increased to counteract the reduced plasma exposure caused by the inducer.
• Anticipation Analysis (Claim 1): Similar to its international counterpart, this reference does not anticipate Claim 1 of US 12,161,628.
  • Element 3 (Enzalutamide): The document teaches the use of apalutamide, not enzalutamide.
  • Element 4 (240 mg dose): The reference discloses increasing the dose of apalutamide from 240 mg/day and does not teach or suggest a 240 mg dose for enzalutamide.

Conclusion

Neither of the patent references cited during the prosecution of US 12,161,628 anticipates the claimed invention. Both references are directed at a different, albeit functionally similar, compound (apalutamide). Crucially, they do not disclose the specific combination of enzalutamide with rifampin at the claimed 240 mg daily dose. The invention of the '628 patent is based on clinical data specific to enzalutamide, which showed that co-administration with rifampin required an increase from the standard 160 mg dose to 240 mg to maintain therapeutic efficacy. This specific dosage adjustment for this specific drug combination is the novel element not present in the cited prior art.