BioMed Realty Lands Major HQ Lease

Blackstone’s BioMed Realty has signed TransMedics Group Inc. to a 498,000-square-foot, full-building life science lease at Assembly Innovation Park in Somerville, Mass., just outside Boston. The company will move its headquarters from Andover, Mass., under the new agreement.  

In October 2025, the city of Somerville offered the company an incentive package that would give an $18 million tax break over the next 10 years if TransMedics relocated its headquarters to the building, The Somerville Times reported. TransMedics selected Assembly Innovation Park due to the flexibility and long-term growth opportunities the property holds, Waleed Hassanein, president & CEO of TransMedics, said in prepared remarks.

The lease agreement is for the next 16 years. In addition to signing the new lease, TransMedics purchased the adjacent land and part of the parking structure at the campus for future growth. In addition to serving as TransMedics’ new headquarters, the property will also function as a manufacturing hub. BioMed developed the asset in 2024. The building is LEED Platinum and WELL certified. Assembly Innovation Park rises 12 stories in an Opportunity Zone, having more than 500 parking spaces, according to Yardi Matrix.

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Assembly Innovation Park represents the first phase of a larger project. Phase II plans call for 970,000 square feet across two buildings as well as amenities including an indoor-outdoor food hall, cafés and conference centers. Already the development has a wellness café, fitness center and rooftop terrace. CBRE’s McKenna Repko, senior vice president, and Eric Smith, vice chairman, handle leasing at the property, Yardi Matrix shows.

Built at 188 Assembly Park Drive, the office property is located off Interstate 93 and Route 28, close to the Mystic River. Assembly Innovation Park is just over 6 miles from Boston Logan International Airport and 5 miles from the Waterfront District. The larger Assembly Square property features retail options such as Staples, TJ Maxx & HomeGoods, and has access to the MBTA Orange Line at the Assembly station.

Boston’s strong office space demand

As of October, Boston had the nation’s largest office construction pipeline, with 4.7 million square feet underway, according to a Yardi Matrix report. Boston also had one of the lowest vacancy rates among gateway markets, at 15.6 percent, and ranked ninth in the nation for investment activity. The metro saw $1.2 billion in office assets change hands year-to-date through October.

Most recently, Lincoln Property Co. and partner Cross Ocean Partners purchased 140 Kendrick St. from BXP for $132 million in December. It was the second Boston purchase the joint venture made in 2025. In November, State Street expanded its space at 700 District Ave. in Burlington, with the signing of one of Massachusetts’ largest office leases in 2025. The company grew from 147,000 square feet to 162,000 square feet through 2037, occupying most of the building.