BOSTON – November 4, 2025
Oxford Properties Group (“Oxford”), a leading global real estate investor, developer and manager, today announced the signing of a new lease expansion with global pharmaceutical leader, Eli Lilly & Company (“Lilly”), for over 75,000 square feet at 645 Summer Street (“645 Summer”). This milestone transaction marks the largest life sciences lease signed in Boston’s Seaport District in 2025 and establishes Lilly as the sole occupant of the fully leased, 150,000 square feet building.
The lease expansion at 645 Summer will support Lilly’s long-term growth plans in the Boston market and is a testament to Oxford and Lilly’s deep relationship.
“We’re thrilled to be building on our extensive relationship with Lilly through this landmark deal at 645 Summer Street – an expansion that reflects our collective belief in the power of high-quality, purpose-built real estate to empower teams to innovate, scale, and succeed,” said Matthew Polhemus, Vice President, Leasing, at Oxford Properties. “We’ve grown alongside Lilly over the years, supporting their evolving needs and ambitions in Boston’s thriving life sciences ecosystem. This agreement, the largest life sciences lease signed in the city’s Seaport District this year, is a testament to the trust we’ve built with our customers and the shared vision we hold. At Oxford, we remain focused on creating workplace environments where future-thinking companies can succeed.”
Located in Boston’s Seaport neighborhood, 645 Summer is a two-story state-of-the-art lab building designed to support advanced scientific research and development. This new long-term lease doubles Lilly’s footprint in the building.
The building recently underwent a comprehensive modernization including LEED Gold-targeted upgrades, and offers sweeping views of the historic Reserved Channel, high-performance lab space, and a suite of wellness-focused amenities. It is part of the broader Pappas Way campus, a 42-acre business park co-owned by Oxford and Pappas Enterprises which consists of nine industrial and lab buildings, an open-air pedestrian route along the waterfront, and public green space offering scenic views of the Reserved Channel.
The Reserved Channel campus is also the site of a proposed 1.7-million square feet, eight building mixed-use project – which aims to further revitalize the underutilized area in South Boston, a neighborhood that has been undergoing a major transformation over the past two decades.
Oxford has been supporting life sciences companies by delivering and managing best-in-class workplaces since 2016, when it first invested in the sector. This transaction marks yet another milestone for Oxford’s life sciences portfolio, which encompasses high-quality assets in the top six markets in the US, including Boston - a city that remains a cornerstone of its support for cutting-edge research and biopharmaceutical innovation.
“We know that the innovators that drive the life sciences industry forward are not just looking for a place to work, they’re looking for a place to call home. Lilly expanding to fully occupy this two-story lab is a significant moment for both the life sciences community in Boston and Oxford. It not only underscores the strength of the city’s innovation corridor, but our ability to meet the evolving needs of our customers,” said Abby Mondani, Vice President, US Asset Management, at Oxford Properties. “As we welcome Lilly into the remaining space at 645 Summer, we remain committed to delivering tailored, state-of-the-art lab and biomanufacturing solutions to help established and emerging companies advance their mission-driven work tomorrow.”
