4. Property, Plant and Equipment, net

Property, plant and equipment, net consisted of the following (in thousands):

 

Manufacturing Facility

On July 31, 2018, the Company completed its purchase of a 135,000 square foot manufacturing facility located in Smithfield, Rhode Island for a purchase price of $8.0 million. In August 2018, the Company began renovations to customize this facility to manufacture clinical supply of its product candidates. Of the total purchase price, $1.3 million was allocated to the value of land acquired based on the value of comparable assets, and $6.7 million was allocated to construction in progress, as the building was not ready for its intended use. During the year ended December 31, 2018, the Company capitalized approximately $2.1 million in construction-in-progress for design and demolition costs related to the renovation project.

Construction-in-progress, as of December 31, 2018, also included $45.1 million capitalized in connection with the Company’s build-to-suit lease accounting (see Note 12), $1.0 million for the Company’s share of the costs of construction-in-progress for leasehold improvements related to the Company’s January 2018 lease for office and laboratory space in Cambridge, Massachusetts and $0.9 million of lab equipment received but not yet placed into service.

Depreciation and amortization expense was $1.3 million, $0.4 million and $0.1 million for the years ended December 31, 2018, 2017 and 2016, respectively.