King Street Properties, a private real estate investment management firm based in Waltham, has signed two leases in Lexington totaling 18,424 square feet.

The leases were signed with SynapDx Corp. and Promedior Inc. The Richards Barry Joyce & Partners team of Jon Varholak, Eric Smith and Ron Friedman represented King Street Properties in the leases. 

SynapDx Corp., a private company providing laboratory diagnostics with the initial goal of enabling earlier detection of autism spectrum disorders, leased 10,724 square feet of laboratory space at 4 Hartwell Place. SynapDx will consolidate two locations in Woburn and Southborough to 4 Hartwell Place, creating a new corporate headquarters. The company was represented by Kevin Hanna and Ryan Romano of Cassidy Turley. 

Promedior Inc. leased 7,700 square feet of laboratory space at 101 Hartwell Ave. The location is Promedior’s new corporate headquarters, with the company relocating from the Greater Philadelphia area. The lease brings the building to 100 percent occupancy. Promedior, a clinical stage biotechnology company developing novel biologic therapeutics for the treatment of fibrosis, was represented by Mike Shreve and Jeremy Hood of T3 Advisors. 

"Promedior and SynapDx are great additions to King Street Properties’ established and growing roster of life sciences companies, which also includes Sekisui Diagnostics, T2 Biosystems, and Quanterix," Smith, senior vice president, Richards Barry Joyce & Partners, said in a statement.  "The upgrades and improvements implemented by King Street across its three-building Lexington portfolio have resulted in a unique park-like setting that appeals to a wide variety of life sciences companies."