Watertown has undergone one of the most remarkable transformations in Massachusetts’s real estate and life sciences history. The historic U.S. Army Arsenal — once the oldest continuously operating arsenal in American history — is now Arsenal Yards, the anchor of a premier life science cluster in Watertown’s East End. More than 40 companies now occupy over one million square feet of life science real estate here, including Abata Therapeutics (T-cell treatments for inflammatory and autoimmune diseases), Remix Therapeutics, Curie Therapeutics, and Kymera Therapeutics — which relocated from Cambridge specifically to join this community.

The Arsenal on the Charles is itself home to Landmark Bio, a 44,000 sq. ft. cGMP cell and gene therapy manufacturing facility founded by Harvard, MIT, Fujifilm Diosynth, Cytiva, and Alexandria Real Estate in partnership with Mass General Brigham, Dana-Farber, Boston Children’s, and Beth Israel Deaconess. Now part of Artis BioSolutions and expanding through a 2025 collaboration with Mass General Brigham’s Gene and Cell Therapy Institute, Landmark Bio operates eight GMP cleanrooms supporting cell therapy, mRNA, lipid nanoparticle, and genome editing manufacturing. EyePoint Pharmaceuticals, headquartered in Watertown, develops sustained ophthalmic drug delivery technologies, while Recipharm Advanced Bio operates a 13-suite cGMP biologics manufacturing facility nearby — rounding out a town where world-class cell and gene therapy manufacturing sits alongside the newer biotech arrivals.

Watertown’s cleanrooms are largely new construction — purpose-built for modern GMP biotech workflows, with HVAC, HEPA filtration, and classified zone architecture designed from the ground up. These are facilities where GMP culture is built in from day one, and where the quality expectations are as high as anywhere in the Greater Boston ecosystem. They deserve a cleaning partner who matches that standard.