Mylan Loses Duragesic Case; Generic Launch Timing Dispute Moves To FDA

The launch timing for the first generic version of Johnson & Johnson/Alza's Duragesic fentanyl patch will depend on FDA's decision about a six-month pediatric exclusivity extension for the product.

Burlington, Vt. federal Judge William Sessions ruled March 25 that Alza's patent no. 4,588,580 is valid and that Mylan's ANDA infringes.

The ruling blocks Mylan from launching transdermal fentanyl until the '580 patent expires and directs FDA to delay the effective date of ANDA approval until that time. The ANDA was approved by FDA in November, but Mylan did not launch due to the pending litigation.

The '580 patent was originally slated to expire July 23 but received a six-month pediatric extension to Jan. 23, 2005.

J&J said it "intends to submit the judge's order rapidly to the FDA and request that Mylan not be permitted to market before expiration of the period of pediatric exclusivity."

Mylan, however, is arguing that its ANDA should be exempt from the pediatric extension.

Mylan said it "has submitted correspondence to the FDA in support of the FDA's final approval of Mylan's fentanyl ANDA notwithstanding Alza's pediatric exclusivity."

¹ Mylan's letter to FDA reiterates arguments the generic firm asserted in the underlying litigation: J&J's failure to sue within 45 days of receiving notice of Mylan's Paragraph IV certification means that the company cannot retroactively claim credit for the pediatric extension (² (Also see "Mylan Plans Launch Of Generic Duragesic Despite Pediatric Exclusivity" - Pink Sheet, 8 Dec, 2003.), p. 26).

"Because Alza failed to bring an action against Mylan within the statutory 45-day period, resulting in no 30-month injunction and final approval of Mylan's ANDA, there is 'no period during which the application may not be approved'...as required by the pediatric exclusivity statute," Mylan tells FDA.

Mylan further points out that the terms of the injunction appear to leave it to FDA to resolve the issue of whether the pediatric exclusivity can block the ANDA.

The court "declined Alza's request for entry of an injunction extending to Jan. 23, 2005 (the end of its alleged pediatric exclusivity)," the letter states. Instead, "the court ordered the effective approval date for Mylan's ANDA to be no earlier than July 23, 2004, the expiration date of the '580 patent."

Mylan argues that the "plain language" of FDA's regulations do not require the company to convert its Paragraph IV certification to a Paragraph III because J&J did not sue within 45 days.

In the court case, Mylan argued the '580 patent was invalid because it was anticipated by an earlier patent ("the Keith patent"), which disclosed a polymeric diffusion matrix suitable for transdermal delivery. The Keith patent claims did not specifically cover fentanyl.

However, the court said Mylan failed to demonstrate "by clear and convincing evidence" that the '580 patent was anticipated by the Keith patent.

"The Keith patent does not disclose a skin permeable form of fentanyl base as that phrase is used in the '580 patent," the court said. Furthermore, the earlier patent "does not disclose an analgetic dosage" of fentanyl and "does not enable the creation of an analgetically effective fentanyl transdermal patch."

Mylan said it will appeal the court's ruling to the federal circuit. However, an appeal would have to move quickly to have an impact on the timing of a generic launch.

The Duragesic case presents the second significant dispute over the scope of pediatric exclusivity to come before FDA in recent months.

On March 10, a federal judge upheld FDA's determination that Pfizer's pediatric exclusivity for the antifungal Diflucan precludes Ranbaxy's generic fluconazole from entering the market until July (³ , p. 29).

The D.C. Circuit Court of Appeals is hearing Ranbaxy's appeal of that decision on an expedited basis.

[Editor's Note: A version of this story first appeared in ⁴ "The Pink Sheet" DAILY March 26. Visit our website, www.ThePinkSheetDAILY.com, to sign up for a free trial.]