Breakthrough Properties and Tishman Speyer Originate $90M Mezzanine Bridge Loan on San Diego Life Sciences Campus
Breakthrough Properties and Tishman Speyer have jointly originated a $90 million mezzanine bridge loan on Aperture Del Mar, a newly built Class A life sciences campus in San Diego's Del Mar Heights submarket, the firms announced Aug. 5.
The sponsor, Gemdale USA, will use the proceeds to refinance existing debt on the four-building lab and office campus located at 6045–6051 Edgewood Drive. The transaction is not a conventional refinance: the senior lender remained in place, making the deal effectively a re-profiling of the capital stack rather than a full take-out, according to a spokesperson for Breakthrough Properties and Tishman Speyer.
Deal Structure and Capital Sources
Breakthrough Properties originated its portion of the loan through its second life sciences fund, which held its first close at the end of 2025. That fund carries an explicit mandate to deploy capital into both equity and credit opportunities tied to lab assets. Tishman Speyer allocated capital through its debt platform, which is designed to originate and acquire loans secured by institutional-quality residential, industrial, life science, office, and mixed-use properties across major U.S. markets.
"Our debt platform is designed to identify credit opportunities by drawing on Tishman Speyer's decades of real estate expertise," said Randall Rothschild, global head of debt at Tishman Speyer.
In originating the loan, the partners drew on Tishman Speyer's origination capabilities and credit platform alongside Breakthrough Properties' life sciences expertise in analyzing lab infrastructure and the credit quality of biopharma end-users, the spokesperson said.
Breakthrough Properties was formed in 2019 as a joint venture between Tishman Speyer and Bellco Capital, a biotech investment firm.
The Asset: Aperture Del Mar
Aperture Del Mar comprises four lab and office buildings totaling approximately 525,000 square feet of rentable area, delivered in 2023. The campus is fully occupied by Neurocrine Biosciences, a biopharmaceutical company focused on discovering, developing, and commercializing treatments for neurological, psychiatric, endocrine, and immunological disorders. Neurocrine Biosciences, which trades on Nasdaq under the ticker NBIX, leases the entire campus on a term running through 2036, providing lenders roughly 12 years of remaining lease term at closing.
The single-tenant, headquarters-style structure of the lease distinguishes Aperture Del Mar from multi-tenant incubator product — a meaningful underwriting consideration in a San Diego market that has been working through elevated vacancy.
Life Sciences Credit Market Context
The financing comes as Breakthrough Properties and Tishman Speyer are seeing what they describe as strong risk-adjusted opportunities in the credit arena for high-quality life sciences properties.
The deal is one of a small number of life sciences loans tracked this year involving a private real estate fund manager. Among others, a $465 million commercial mortgage-backed securities financing — funded by JPMorgan, Deutsche Bank, and Goldman Sachs — was secured by a separate San Diego property owned by Breakthrough Properties.
The broader life sciences sector has been working through oversupply for approximately two years, though demand has since stabilized and new construction has become more disciplined, according to a June report from JLL. The Chicago-based advisory firm is also tracking a trend in which tenants are migrating toward newer, higher-quality buildings. JLL data show that buildings completed over the past six years have seen availability drop by 2.6 million square feet over a nine-month period, while properties constructed prior to 2000 have seen roughly 700,000 square feet of space returned to market over the same span.
That bifurcation places fully leased, modern campuses like Aperture Del Mar at the stronger end of the market, while older or lower-specification lab and research-and-development space faces greater pressure on valuations and financing terms.
Broader Capital Markets Backdrop
The transaction also reflects conditions in the wider commercial real estate credit market. Debt availability rose approximately 52 percent year-over-year in the first quarter of 2026 as lenders expanded originations and bid-ask spreads narrowed. Total commercial real estate transaction volume reached $136 billion in the first quarter of 2026, up 27 percent year-over-year, even as the 10-year Treasury yield remained elevated at around 4.5 percent in May 2026, keeping borrowing costs above pre-tightening norms.
Within that environment, lenders have shown a greater willingness to extend structured credit on core-plus, fully leased assets — a profile that Aperture Del Mar, with its long-term single-tenant lease and newly built lab infrastructure, is positioned to meet.