Alkermes will expand its Waltham campus by 220,000 square feet at a new build-to-suit office and lab building being developed by Davis Marcus Partners at 900 Winter St.

The Irish drugmaker expanded and relocated to Waltham from Cambridge in 2009 and currently has an R&D facility at 852 Winter St. in the 1.3-million-square-foot Reservoir Woods.

Construction is scheduled to begin this spring. The Elkus Manfredi Architects-designed building will include a roof terrace, outdoor amphitheater, fitness center, cafeteria and coffee bar.

As part of the build-to-suit arrangement, Alkermes signed a 15-year lease at the new property. The lease calls for base rent of $6.7 million in the initial year, increasing to $9.2 million in year 15, according to an SEC filing.