The developer of next-generation proton therapy systems for treating cancer has taken a 50-year lease on a Howard De Walden Estate property.
Advanced Oncotherapy will pay £75 per sq ft at 141 and part of 143 Harley Street, W1.
The 8,000 sq ft property will be converted for use as a proton therapy centre.
The grant of the lease is subject to planning, but the building is set to be handed over to Advanced Oncotherapy.
Simon Baynham, property director at Howard de Walden Estate, said: “The estate has been investing significantly in the medical area over the last 10 years or so, to ensure that the facilities in and around Harley Street continue to provide suitable medical buildings.”
