The European Medicines Agency said Thursday it had reached a sublet agreement on its London premises after moving headquarters to Amsterdam because of Britain's impending exit from the EU.
The EMA has been trying to wrangle out of the 20 remaining years on its lease at the Canary Wharf business district.
The 900-employee agency evaluates and supervises medicines for human and animal uses and has been based at the old location since 1995.
The remaining rent bill on that property is estimated at £500 million ($630 million, 560 million euros) -- money the EMA was set to lose after relocating to the Netherlands because of Brexit in March.
It lost a London court battle to cancel the lease in February.
The EMA said it had agreed to sublet the entire property at its Canary Wharf location to the office-sharing startup WeWork.
"WeWork will take a new sublease from EMA for a term to the expiry of EMA's lease in June 2039," the European agency said in a statement.
"WeWork is commencing the fitting out and is looking to open in December 2019."
The New York-based startup currently lists more than 30 London properties on its website.
The privately-funded firm is backed by capital from Japan's SoftBank and currently operates in around 600 cities worldwide.
The European regulator's new 300-million-euro headquarters in Amsterdam will not be ready until November.
It is now using stopgap arrangements after the Dutch city beat Italy's Milan in a tense tie-break vote in November 2017.
France got the London-based European Banking Authority.
London remains the headquarter for global organisations such as the Internal Maritime Organization shipping regulator.
The EMA was forced to relocate early because the original Brexit date was scheduled for the end of March.
The process has been delayed twice because of political deadlock in Britain and is now due to be completed on October 31.