Watertown, MA – Thursday, April 23, 2026 — Boylston Properties, a Boston-based real estate developer, today announced that the ALS Therapy Development Institute (ALS TDI) has signed a 33,310-square-foot lease at 200 Arsenal Yards Blvd., a distinctive life science and office building at the center of Arsenal Yards in Watertown. The lease was signed earlier this month, with landlord delivery and occupancy expected at the end of 2026.

ALS TDI is the world’s largest nonprofit biotech focused solely on ALS research, operating as a fully integrated drug discovery engine dedicated to discovering and developing effective treatments for amyotrophic lateral sclerosis (ALS). The organization will relocate and expand from its existing Watertown location, reinforcing its long-term commitment to the community and its mission to accelerate therapies for people living with ALS.

“ALS TDI has been part of the Watertown life science community for years, and it’s meaningful to see them choose to stay and grow here at Arsenal Yards,” said Mark Deschenes, President of Boylston Properties. “Their work, their team, and their mission are exactly the kind of presence that builds this life science community . We’re proud they’ve chosen Arsenal Yards for this next chapter.”

ALS TDI joins a growing campus of innovative companies at Arsenal Yards, including Mariana Oncology (a Novartis company), Orna Therapeutics (now part of Eli Lilly), Diagonal Therapeutics, Remix Therapeutics, AvenCell Therapeutics, Nexo Therapeutics, and Aleksia Therapeutics, further strengthening Watertown’s position as a dynamic and evolving life science cluster in Greater Boston.

Located within one of the original 1800s Arsenal buildings, 200 Arsenal Yards Blvd. blends historic character with a robust, modern, lab-ready infrastructure, featuring soaring ceilings, exposed trusses, and abundant natural light throughout. With its central location and direct access to the River Green, the building offers a distinctive setting at the heart of Arsenal Yards. The campus brings together lab space, luxury apartments, restaurants, and everyday amenities in one walkable setting, giving teams more than just a place to work, but a place they actually want to be every day.

Fernando Vieira, M.D., CEO, Chief Scientific Officer, and President of ALS TDI, added: “ALS TDI exists for one purpose: to discover and develop effective treatments for ALS as quickly as possible. Expanding our footprint at Arsenal Yards allows us to continue that work in an environment that supports both our science and our people. Being here strengthens our ability to attract top talent, collaborate, and stay deeply connected to the community that fuels our mission. As we grow, this next chapter positions us to accelerate progress for everyone affected by ALS.”

JLL represented Boylston Properties in the transaction, and Newmark represented ALS TDI.

About Boylston Properties

Boylston Properties is a Boston-based real estate developer focused on creating innovative mixed-use destinations that integrate work, life, retail, and community. Its portfolio includes residential, retail, office, hotel, and life science lab projects throughout Greater Boston and beyond.

About ALS Therapy Development Institute

The ALS Therapy Development Institute (ALS TDI) is a nonprofit biotech and the world’s largest drug discovery lab focused solely on ALS. Its mission is to discover and develop effective treatments for ALS and advance them into clinical trials as quickly as possible.