Image courtesy of Elkus Manfredi Architects

A speculative life science development completed in June landed its first two leases committing to more than half of the 225,000-square-foot building outside Watertown Square.

LifeMine Therapeutics will occupy the fourth floor of the 66 Galen St. development, while an undisclosed biotech startup leased the entire third floor. Both companies are led by biotech researcher and investor Greg Verdine.

Newton-based Boston Development Group acquired the 5-acre former car dealership property in 2019. The Davis Cos. joined the development team in mid-2021, and ground was broken on the first building in 2021. Citizens Bank provided nearly $175 million in financing.

LifeMine received $175 million in series C venture capital funding in 2022.

“Both of our teams fell in love with this distinctive, differentiated facility,” Verdine said in a statement.

Cushman & Wakefield’s Duncan Gratton, Connor Barnes and Joe Pearce represent ownership in leasing. Colliers’ Evan Gallagher and John Carroll represented the tenants.

Watertown’s Arsenal Street corridor has attracted the bulk of lab leasing activity in recent years, including Boylston Properties’ Arsenal Yards and Alexandria Real Estate Equities’ Arsenal on the Charles projects. In one of the largest previous suburban lab transactions of the year, Treeline Biosciences expanded from 22,000 to 45,000 square feet at 500 Arsenal St.