Cambridge-based genomic testing company Foundation Medicine is leasing 580,000 square feet at 400 Summer St., a future 16-story building that will connect the Seaport District to Summer Street via a large outdoor stairway, landlord WS Development confirmed this week.
WS Development anticipates starting construction on 400 Summer St. later this year and wrap up by 2023. The 625,000-square-foot building will house 30,000 square feet of retail space.
The Business Journal reported in March that Foundation…
