Photo courtesy of Cambridge Assessing Department

Generation Bio will exit its Kendall Square headquarters since 2018 following its acquisition by an aggregator of drug royalty rights.

The biotech company negotiated a $21.5 million lease termination with landlord BioMed Realty, according to an SEC filing.

Generation Bio leased the 301 Binney St. for its headquarters in 2018. The lease was amended in 2020 and was scheduled to expire in 2029.

The 417,000 square-foot office-lab building was developed in 2003.

In December, XOMA Royalty Corp. announced an agreement to acquire Generation Bio for $4.29 per share. Zoma acquires drug royalty rights from biotech companies, including those whose stock prices have plummeted, returning cash to shareholders. The acquisition price was estimated at $29 million.

Generation Bio’s went public in 2020. Its stock price peaked at nearly $471 per share in December 2020, but had declined to as low as $5.02 in early November.

While maintaining the region’s highest asking rents at $101.60 per square foot, the 14.2 million square-foot East Cambridge submarket had over 185,000 square feet of negative absorption in 2025, according to a CBRE research report. At year’s end, the vacancy rate was 18 percent and availability rate was 20.8 percent.