ASCENDIS PHARMA A/S v. BIOMARIN PHARMACEUTICAL INC.

Authored by: Jeremy J. Gustrowsky

When patent litigation heats up in both the International Trade Commission and federal district court simultaneously, respondents have a statutory right to pause the district court case. But there’s a catch: you have to ask for that stay within 30 days. In a recent decision, the Federal Circuit made clear that missing that deadline means missing it for good. You cannot simply dismiss your case and refile to get a fresh 30-day window.

The case involved two pharmaceutical companies developing treatments for achondroplasia, a genetic condition causing short-limbed dwarfism. BioMarin holds U.S. Patent No. RE48,267 covering certain drug compounds, including its FDA-approved treatment Voxzogo. When Ascendis filed a New Drug Application for its competing product TransCon CNP, BioMarin filed a complaint with the ITC. Ascendis responded by filing a declaratory judgment action in district court seeking a ruling that its product did not infringe. More than 30 days passed before Ascendis realized it had missed the statutory deadline to request a mandatory stay under 28 U.S.C. § 1659(a)(2).

In an attempt to reset the clock, Ascendis voluntarily dismissed its original complaint without prejudice and immediately refiled a nearly identical complaint. The company then promptly moved for a mandatory stay, arguing the 30-day period should run from the new filing date. The district court denied the mandatory stay motion, instead granting BioMarin’s request for a discretionary stay that could potentially be lifted if circumstances changed (such as FDA approval of Ascendis’s drug).

The Federal Circuit affirmed, holding that Ascendis could not use voluntary dismissal as an end-run around the statutory deadline. The court relied on the common-law principle that parties cannot use procedural maneuvers to accomplish indirectly what they cannot accomplish directly. Citing cases from other circuits involving jury demands and certification requirements, the court found that Ascendis’s transparent attempt to restart the 30-day clock fell squarely within this prohibition. The court noted that Ascendis’s own filing stated it was refiling specifically “to avoid any possible dispute” about the applicability of the mandatory stay provision to its original, now-stale action.

Legislative history reinforced the court’s reading. Congress included the 30-day deadlines specifically “to avoid abuse of this provision and to encourage prompt adjudication.” Allowing parties to refile whenever convenient would undermine both goals. For practitioners, the lesson is straightforward: if you are named as a respondent in an ITC proceeding and want to pause parallel district court litigation, mark your calendar carefully. The 30-day window is a hard deadline with no reset button.