ZURICH: Roche and Spark Therapeutics announced another extension of the Swiss drugmaker's $4.3 billion takeover offer for the U.S. gene therapy specialist as regulatory reviews in the United States and Britain continue.

The offer for Spark shares now runs to Sept. 3, Roche said, adding terms and conditions are unchanged. “The parties remain committed to the transaction and are working cooperatively and expeditiously with the Federal Trade Commission and UK Competition and Markets Authority," Roche said.

Copyright Reuters, 2019