US 8664239

Patent Summary: US 8,664,239 B2

Title: Tacrolimus for improved treatment of transplant patients

Assignee: Veloxis Pharmaceuticals Inc.

Inventors: Robert D. Gordon, Per Holm, Anne-Marie Lademann, Tomas Norling

Filing Date: June 23, 2011

Issue Date: March 4, 2014

Abstract:
The patent describes an extended-release oral dosage form of tacrolimus, an immunosuppressant drug used in transplant patients. This formulation is designed for once-daily administration and aims to provide improved pharmacokinetic properties compared to conventional, immediate-release tacrolimus formulations. Key features of the invention include a release of the active substance over a prolonged period, leading to a higher bioavailability, a lower peak blood concentration (Cmax), and a more consistent therapeutic level of the drug over a 24-hour period. The claimed formulation is characterized by a specific in vitro dissolution profile, where at most 63.5% of the tacrolimus is released at the 12-hour mark under specified test conditions. The invention also covers methods of treatment using this formulation, including converting patients from other tacrolimus regimens.

Plain-Language Overview of Independent Claims:

At the time of its issuance, US Patent 8,664,239 included several independent claims. Here is a plain-language summary of their core concepts:

• Claim 1: This claim protects a method for the immunosuppressive treatment of a transplant patient by administering a once-daily, extended-release oral dosage form of tacrolimus. The key feature of this dosage form is its specific dissolution rate: when tested in a lab under conditions simulating the gastrointestinal tract (USP II paddle or USP I basket method at pH 4.5 with 0.005% hydroxypropylcellulose at 50 rpm), it releases no more than 63.5% of its tacrolimus content within 12 hours. This controlled release is intended to provide a stable and effective level of the drug in the patient's body over a full 24-hour period.

• Claim 11: This claim is also for a method of immunosuppressive treatment in a transplant patient using a once-daily, extended-release oral tacrolimus dosage form. This claim further specifies the in-vivo (in the body) performance of the drug. It requires that upon administration of a single 5 mg dose to healthy subjects who have fasted, the average maximum blood concentration (Cmax) of tacrolimus does not exceed 15 ng/mL, while the overall drug exposure (mean AUC(0-96 h)) is at least 45 ng·h/L. This ensures that the drug is released slowly to avoid high initial peaks (which can be associated with side effects) but is still well-absorbed over time.

• Claim 18: This claim focuses on a method for converting a transplant patient from a twice-daily immediate-release tacrolimus regimen (like Prograf®) to a once-daily regimen using the extended-release formulation. The method involves administering a total daily dose of the new formulation that is reduced by 20% to 34% compared to the patient's previous total daily dose of the immediate-release tacrolimus. This reduction is possible due to the improved bioavailability of the extended-release formulation.

Litigation:

A search of the CAFC (Court of Appeals for the Federal Circuit) dockets for 2026 did not reveal any litigation specifically involving US Patent 8,664,239 as of April 26, 2026. However, the Google Patents page for this patent indicates that its family has been involved in litigation. Further investigation beyond the scope of this specific search would be required to determine the details of any past or ongoing legal disputes concerning this patent family.