On June 20, 2025, U.S. District Judge Ronnie Abrams of the Southern District of New York sided with Wilson Sonsini clients Sinovac Biotech, Ltd. and 1Globe Capital LLC, and denied Prime Success, L.P.’s emergency request for injunctive relief in aid of arbitration. Sinovac is a Chinese vaccine manufacturer and developed and commercialized CoronaVac—the leading COVID-19 vaccine in the world.

Petitioner Prime Success had sought an anti-suit injunction to enjoin Sinovac from prosecuting a currently pending Antiguan court proceeding. Instead, Prime Success argued that the same issues should be heard in a Hong Kong arbitration it also brought regarding the same issues at stake in the Antiguan case.

As background, earlier this year, the Judicial Committee for the Privy Council—the highest court for UK overseas territories and Crown dependencies—determined that the former directors of Sinovac, who lost a 2018 board election and refused to cede control thereafter, have been “imposters” ever since. Prime Success is a member of the group that suffered that resounding defeat at the Privy Council.

Prime Success and other similarly situated shareholders received their shares in Sinovac from a PIPE transaction during the time when the “imposter” board was in de facto control of Sinovac. The current board of Sinovac has taken the position that those PIPE shares are invalid and should be set aside. Sinovac filed the Antiguan action to confirm this necessary effect of the Privy Council judgment.

In an effort to collaterally attack the Privy Council judgment and the Antiguan action, Prime Success brought an action in the Southern District of New York for emergency injunctive relief purportedly in aid of the arbitration it also brought against Sinovac in Hong Kong.

Judge Abrams agreed with Wilson Sonsini that the strict requirements for issuing an anti-suit injunction had not been met. Judge Abrams explained that “Sinovac ha[s] asked the Antiguan court to determine, as a matter of Antiguan law, whether Prime Success is a lawful shareholder of Sinovac” and that the Antiguan court is in a better position to decide that question than the Southern District of New York. Accordingly, Judge Abrams denied Prime Success’s petition.

The Wilson Sonsini team was led by partners Moe Fodeman and Sheryl Shapiro Bassin and senior associate Alec Luhring.

For more information, please see the court’s decision. Additional coverage is available in Law360.