A 54,000-square-foot lease by Cambridge-based Mass Innovation Labs will anchor the new Innovation Square Seaport office lab complex which breaks ground today at 6 Tide St. in Boston’s Seaport District.

The life science accelerator is expanding out of Kendall Square into the 375,000-square-foot development in the Raymont L. Flynn Marine Park and another 84,000 square feet at Boston Landing in June. Founded in 2015, Mass Innovation Labs’ has provided turnkey lab and office space and support for early-stage biopharma companies including CRISPR Therapeutics and Editas Medicine.

Developers Related Beal and Kavanagh Advisory Group are partnering on the Innovation Square Seaport project on parcel R owned by the Economic and Development Industrial Corp. of Boston, the sister agency of the Boston Planning and Development Agency.

The first phase of iSQ Seaport includes a 4-story, 125,000-square-foot building. East Boston Savings Bank provided the $51.4 million construction loan for the project scheduled for completion in early 2019.

Built on a parking lot used by the city as a snow farm during the winter of 2015, the development will include a collaboration center, fitness center, interior bike storage, ample parking with electric vehicle charging stations.

Mass Innovation Labs was represented in the transaction by Ted Lyon of Cushman and Wakefield. JLL brokers Pete Bekarian, Don Domoretsky and Ben Hux represented Related Beal. Related Beal Construction and Consigli Construction Co. are the construction managers.

In Brighton, Mass Innovation Labs joins a growing life science cluster at Boston Landing, which has marketed two office and lab buildings at 40 and 80 Guest St. to growing companies from Cambridge. Two life science firms, Cambridge-based Proteostasis Therapeutics Inc. and Roche Diagnostics Operations, previously announced they will move to Boston Landing next year after leasing 30,000 square feet apiece at 80 Guest St.