Image courtesy of Lincoln Property Co.

A biotech company doubled its footprint at a 143,533 square-foot lab building in Waltham, completing the lease-up at the office-to-lab conversion project.

Biocytogen, which originally leased 35,000 square feet at 300 Third Ave. in 2022, is doubling its space to over 70,000 square feet, Lincoln Property Co. announced. The property is now fully leased.

Another tenant, BPG Bio, relocated in 2024 from Framingham, leasing approximately half of the building.

The property is owned by MetLife Investment Management clients. It received $60 million in construction financing from Bank OZK in 2020.

The project entailed conversion and expansion of an office building originally completed in 1966 into office and lab space with 400 parking spaces on a 1.7-acre parcel overlooking Route 128.

“300 Third was expertly designed for best-in-class life science clients and we are honored to have that recognized with a fully leased building,” Lincoln Property Co. Senior Vice President Scott Faber said in a statement.

Lincoln’s Tim Latham, Christopher Scott and Chris Devaux represented ownership in the transaction, while Colliers’ Tim Allen represented Biocytogen.

Headquartered in Beijing, Biocytogen has U.S. offices in Waltham, San Francisco and San Diego.