CAMBRIDGE, MA—Just eight months after getting back more than 310,000 square feet of space at its Sidney Research Campus here, BioMed Realty Trust has commitments for all the available space there.

Seres Therapeutics, Inc., a microbiome therapeutics company, has signed a lease for approximately 83,000 square feet at Biomed Realty's 200 Sidney St., bringing the approximately 200,000-square-foot building to 100% leased. Seres will relocate its new corporate headquarters in three phases starting in the first quarter of 2016, with each of the leases expiring in November 2023, BioMed Realty states. The firm is currently located at 215 First St. in Cambridge. Seres when fully operational at 200 Sidney will be the building's largest tenant. Other life science tenants at the property include AbbVie, CRISPR Therapeutics, RaNA Therapeutics and Synlogic.

Transwestern | RBJ represented BioMed and Newmark Grubb Knight Frank represented Seres in the lease transaction. The Sidney Research Center includes 200 Sidney as well as 21 and 40 Erie St. buildings. William Kane, senior vice president, Boston market lead for BioMed Realty, says that there are commitments for all the available space at the 21 Erie St. (38,000 square feet) and 40 Erie St. (100,000 square feet) buildings.

BioMed Realty announced on Nov. 5, as part of its third quarter financial results announcement, AbbVie had signed a lease for 43,000 square feet at 200 Sidney St. In addition, a company spokesperson says that BioMed Realty's 450 Kendall St. property in Cambridge had also recently achieved full occupancy. In May, Eli Lilly and Co. leased 16,978 square feet of laboratory and office space at the 63,000-square-foot building.

In October, the Blackstone Group announced it would acquire BioMed Realty in a deal valued at $8 billion. BioMed Realty owns more than 3 million square feet of laboratory and office space in the Boston/Cambridge market.

"We are excited about Seres Therapeutics' entry into the Cambridgeport life science market and look forward to welcoming them in our newly redeveloped 200 Sidney Street building," states Morgan Weinstein, senior director of BioMed Realty. "Premier life science companies like Seres recognize the value of our strategic investment in the building's infrastructure, which allows for future program flexibility, as well as providing an amenity-rich environment."

Seres recently completed a $140-million initial public offering and the microbiome therapeutics firm requires the additional space to support its growth. Back in March of this year, BioMed Realty recaptured approximately 313,000 square feet of space through the termination of Vertex Pharmaceuticals' leases at the three properties that make up the Sidney Research Campus effective Feb. 28, 2015. BioMed Realty received a $14-million termination fee from Vertex and then began a repositioning effort at the property.

Two laboratory and office properties at 200 Sydney and 40 Erie streets totaling 293,000 square feet were leased by Vertex through December 2015. An additional 21,000 square feet was leased by Vertex at 21 Erie St. through May 2017. BioMed Realty is completing upgrades to the properties' entrances and lobbies, is introducing indoor/outdoor collaboration spaces, and is adding modern fitness centers and other amenities. The company is nearly finished on converting all three buildings for multi-tenant use.