Image courtesy of Federal Realty Investment Trust

Cambridge-based Bluebird Bio is leaving pricey Kendall Square for Somerville’s Assembly Row in a real estate deal that’s expected to save the company $120 million over the next six years.

The Cambridge-based biotech will relocate its headquarters and 425 employees to 61,000 square feet at 455 Grand Union Blvd., a 250,000-square-foot office tower anchored by the new PUMA North America headquarters. Initial occupancy is scheduled for spring 2022.

“The workspace is designed to enable a distributed work model and to allow for increased engagement and productivity for all employees, as hybrid work is here to stay,” Bluebird Bio said in a statement.

The company will retain its labs at Alexandria Real Estate Equities’ 60 Binney St. in Cambridge through 2023. In 2015, the company signed a 10-year lease for that space, which is owned by Alexandria Real Estate Equities, at base rent of $72.50 per square foot.

In 2019, Bluebird agreed to sublease 267,000 square feet at 50 Binney St. from Sanofi Genzyme at $99.95 per square foot, but never occupied the space amid setbacks in its drug pipeline approvals.

The move comes as part of a corporate reorganization in which Bluebird Bio is focusing on severe genetic disease research while spinning off its oncology business into a new entity, 2seventy bio Inc. The 60 Binney St. lease has been assigned to the new 2seventy bio Inc. entity.

The deal gives Federal Realty Investment Trust’s Assembly Row mixed-use development its first life science tenant.

More large-scale life science development is imminent in the Assembly Square submarket. BioMed Realty is set to build its own biotech cluster at Assembly Row’s doorstep, with plans for a 1.3-million-square-foot office-lab development on a 7.5-acre site off Middlesex Avenue, including a 12-story, 396,500-square-foot lab tower in the initial phase.