Biotech Tenant Bolts One Alexandria Property for Another

Alexandria Real Estate Equities is losing a tenant in Cambridge. Luckily, it’s gaining one in a nearby suburb.

Foghorn Therapeutics is set to relocate to 99 Coolidge Avenue in Watertown, a city in the Greater Boston area, Banker & Tradesman reported. The lease was disclosed in a filing with the Securities and Exchange Commission.

Foghorn will become the third tenant of the redeveloped Mount Auburn Club, which is co-owned with National Development. Alexandria owns a 75.7 percent ownership interest in the 255,000-square-foot property, which counts Sonata and Matchpoint among its tenant roster.

The nine-year lease begins with an initial base rent of $87 per square foot. Foghorn will pay $3.9 million for the first year of the lease before jumping to $6.3 million.

The relocation marks a minor downsizing for Foghorn, a company working on a class of medicines that can treat disease through abnormal gene expression correction. The company occupied 81,000 square feet at 500 Technology Square in Cambridge, a lease that wasn’t scheduled to expire for another two years.

Foghorn and Alexandria agreed to terminate the Cambridge lease. Foghorn is expected to relocate in October 2026, following tenant fit-out work.

The life sciences vacancy rate in Watertown and other inner suburban markets in Greater Boston remains elevated, featuring more than 66,000 square feet of negative absorption in the first quarter, according to a Colliers report.

But in Boston proper, things are looking up, at least for offices, according to the Boston Business Journal. At the end of the second quarter, the office vacancy rate in Boston was 21.1 percent and the whole metro area sported a 22.9 percent rate, according to a JLL report. The city’s vacancy rate is on a streak of four consecutive quarters with an improvement on that rate.

Last year, Alexandria sold a block of parcels in South Boston, including 99 A Street, for $13.3 million, abandoning plans for a 210,000-square-foot lab complex at the site.

— Holden Walter-Warner