Image courtesy of Boylston Properties

A speculative industrial-to-office conversion in Watertown has landed its first tenant in C4 Therapeutics, which will relocate from Mass Innovation Labs in Cambridge’s Kendall Square.

C4 Therapeutics leased 45,000 square feet at Linx, a former Verizon warehouse at 490 Arsenal St. which has been renovated and expanded by Boston-based Boylston Properties to offer 185,000 square feet of office and lab space.

C4 will begin its buildout this summer and occupy the building during the first quarter of 2018, said Duncan Gratton, an executive director for Cushman & Wakefield which represents ownership.

“Getting the first (lease) is huge from a momentum and credibility perspective. Our goal from day one was to get a quality Kendall Square life science firm,” Gratton said.

Founded at Dana-Farber Cancer Institute, C4 Therapeutics in 2016 received $73 million in series A venture funding led by Cobro Ventures. The new lease more than doubles its space.

Construction of Linx’ shell was completed in April. Approximately 60 percent of tenant inquiries have come from lab users because of the cost and scarcity of space in Kendall Square, Gratton said, prompting companies to consider options in inner-ring suburbs and beyond.

The east end of Watertown has emerged as a development hotspot with digital health records company Athenahealth expanding its Arsenal Street campus. Boylston Properties and The Wilder Cos. are redeveloping the former Arsenal Mall property as a mixed-use development known as Arsenal Yards including 425 multifamily units, 160,000 square feet of office space and a 150-room hotel.