Watertown, MA, August 16, 2025
News Summary
Tishman Speyer closed a $25.2 million mezzanine loan to refinance 500 Forge at Arsenal Yards, paired with a $94.0 million senior loan from LBBW. The financing, provided to a joint venture led by Boylston Properties with institutional investors advised by J.P. Morgan Asset Management, primarily retired a 2021 construction loan and funded leasing costs tied to a new Mariana Oncology lease. This marks the first investment from Tishman Speyer’s new real estate debt platform. 500 Forge is a three‑story, 162,000 sq ft life science building completed in 2023 and now fully leased to life science tenants.
Tishman Speyer Provides $25.2M Mezzanine Loan to Refinance 500 Forge at Arsenal Yards
Key financing announced: Tishman Speyer closed a $25.2 million mezzanine loan to a joint venture led by Boylston Properties and institutional investors advised by J.P. Morgan Asset Management. The mezzanine loan is part of a refinancing package that also includes a $94.0 million senior loan from Landesbank Baden‑Württemberg (LBBW), creating a combined capital stack that refinanced the asset and covered recent leasing costs.
Strategic note: This transaction marks the first investment by Tishman Speyer’s newly launched real estate debt platform, which is targeting institutional‑quality projects in major U.S. cities. The platform plans to provide mezzanine loans, preferred equity, construction financing and loan portfolio acquisitions.
Why the money was used
The proceeds were used primarily to retire the property’s 2021 construction loan and to pay contractual leasing costs tied to a newly executed lease with Mariana Oncology, a subsidiary of Novartis. The refinancing helps convert the project’s construction financing to a more permanent structure while supporting early tenant commitments.
About the property
The building at 500 Forge sits within the Arsenal Yards campus in East Watertown on the edge of West Cambridge and Allston, Massachusetts. Completed in 2023, the three‑story building contains roughly 162,000 square feet of advanced lab and office space. Interior ceiling heights range from 15 to 18 feet. The design includes outdoor balconies and covered parking. The building is now fully leased to life science tenants, including Mariana Oncology, Orna Therapeutics and AvenCell Therapeutics.
Market context and location advantages
500 Forge benefits from proximity to regional research institutions, venture capital firms and a deep pool of skilled biotech workers. Arsenal Yards is a mixed‑use, innovation‑driven campus with more than a million square feet of labs, offices, retail, restaurants and wellness amenities. The broader master plan calls for over 50 retailers and restaurants, a seven‑screen theater, more than 300 residences, a 150‑room hotel and significant public open space with connections to a revitalized Arsenal Park and the Watertown‑Cambridge bike path.
Local leasing and campus activity
The refinancing comes as Arsenal Yards continues to add life science tenants. Boylston Properties announced that cell therapy developer SQZ Biotech signed a 63,477‑square‑foot lease at the campus and will relocate later this year, greatly expanding its local footprint. SQZ recently closed a $72 million Series C and expanded a collaboration with Roche. Cushman & Wakefield represented the ownership in that deal, while Newmark Knight Frank represented SQZ.
Who arranged the refinancing
JLL Capital Markets’ Debt Advisory team arranged the refinancing. The senior loan was provided by LBBW, while the mezzanine component came from Tishman Speyer’s new debt platform and the borrower group led by Boylston Properties and institutional investors advised by J.P. Morgan Asset Management.
Developer and investor roles
Arsenal Yards is being developed by a team that includes Boylston Properties, Wilder and J.P. Morgan. Boylston is a Boston‑based developer with decades of experience in mixed‑use and life science projects. Wilder is a privately held firm focused on retail and mixed‑use development and management. J.P. Morgan Asset Management is one of the institutional investors in the joint venture and manages a global investment platform.
Tishman Speyer in Boston
The deal builds on recent local activity from Tishman Speyer, which is developing the Harvard Enterprise Research Campus in Allston and has previously delivered life science projects through its Breakthrough Properties joint venture. Breakthrough Properties also holds sites in Boston including 232 A Street and One Canal in East Cambridge.
Why this matters
The financing converts construction debt into a longer‑term capital structure for a modern, fully leased life science building in a growing biotech submarket. It is also a signal that Tishman Speyer is putting real capital behind a debt strategy aimed at real estate in gateway markets, offering multiple product types to meet different sponsor and developer needs.
FAQ
What loans make up the refinancing?
The package includes a $94.0 million senior loan from LBBW and a $25.2 million mezzanine loan provided by Tishman Speyer’s debt platform to a joint venture led by Boylston Properties and institutional investors advised by J.P. Morgan Asset Management.
What will the loan proceeds pay for?
Proceeds were used mainly to retire the building’s 2021 construction loan and to fund leasing costs tied to the Mariana Oncology lease.
Who are the tenants at 500 Forge?
Current tenants include Mariana Oncology (a Novartis subsidiary), Orna Therapeutics and AvenCell Therapeutics. The building is fully leased.
What are key features of the building?
500 Forge is a three‑story, roughly 162,000‑square‑foot lab and office building with interior ceiling heights of 15 to 18 feet, outdoor balconies and covered parking.
What is Tishman Speyer’s new platform targeting?
The platform will target institutional‑quality projects across major U.S. cities and offer mezzanine loans, preferred equity, construction financing, and loan portfolio acquisitions.
Who arranged the refinancing?
The refinancing was arranged by JLL Capital Markets’ Debt Advisory team.
Key features at a glance
| Feature | Detail |
|---|---|
| Borrower / JV | Led by Boylston Properties with institutional investors advised by J.P. Morgan Asset Management |
| Mezzanine loan | $25.2 million from Tishman Speyer’s new debt platform |
| Senior loan | $94.0 million from Landesbank Baden‑Württemberg (LBBW) |
| Property | 500 Forge, Arsenal Yards, East Watertown — ~162,000 sq ft, 3 stories, completed 2023 |
| Tenants | Mariana Oncology, Orna Therapeutics, AvenCell Therapeutics |
| Use of proceeds | Retire 2021 construction loan; fund leasing costs tied to Mariana Oncology |
| Platform focus | Institutional‑quality projects in major U.S. cities; mezzanine, preferred equity, construction finance, portfolio buys |
| Arranger | JLL Capital Markets’ Debt Advisory team |
| Campus | Arsenal Yards — mixed‑use campus with labs, offices, retail, residences and public space |
Deeper Dive: News & Info About This Topic
Additional Resources
- Boston Real Estate Times: Tishman Speyer Provides $25.2M Mezzanine Loan to Refinance 500 Forge
- Wikipedia: Tishman Speyer
- ConnectCRE: Tishman Speyer Provides Mezz Debt on Lifescience Property at Arsenal Yards
- Google Search: Tishman Speyer mezzanine loan Arsenal Yards
- Boston Real Estate Times: SQZ Biotech Signs 63,477‑SF Lease at Arsenal Yards
- Google Scholar: SQZ Biotech Arsenal Yards
- Boston Real Estate Times: 500 Forge Refinancing & Market Context
- Encyclopedia Britannica: Arsenal Yards Watertown (search)
- ConnectCRE: Mezzanine Debt Details for Arsenal Yards
- Google News: 500 Forge Arsenal Yards
