Thermo Fisher Scientific plans to officially open a 300,000-square-foot manufacturing plant in Plainville on Wednesday that underscores the laboratory equipment supplier’s investment in the growing field of gene therapy.
Waltham-based Thermo Fisher, the largest Massachusetts company by stock market value, at more than $224 billion at Tuesday’s close, has built a two-story plant that will develop, test, and manufacture “viral vectors.” Those are viruses modified to carry a normal functioning gene into cells to replace a defective gene causing an inherited disease. Gene therapies are intended to be a one-time treatment.
Last Wednesday, the US Food and Drug Administration approved the latest gene therapy, Zynteglo, from Bluebird Bio, of Somerville. It delivers a potentially permanent genetic remedy to patients with beta thalassemia, a rare inherited blood disorder that causes a reduction of normal hemoglobin and red blood cells and leads to insufficient oxygen. Like the first two gene therapies approved in 2017 and 2019 for a rare form of vision loss and for a progressive neuromuscular disease, Zynteglo is breathtakingly expensive: $2.8 million per patient. But a Boston-based nonprofit drug-pricing watchdog, the Institute for Clinical and Economic Review, said the price is justified because of how much money the medicine will save the health care system. Patients with beta thalassemia need blood transfusions once or twice a month and other expensive treatments.
Among those expected to attend Wednesday’s official opening is Governor Charlie Baker and US Representative Jake Auchincloss.
“Thermo Fisher Scientific’s new manufacturing facility in Plainville will be one of the largest of its kind and will deepen the company’s ties and expand its employee footprint in Massachusetts,” Baker said in a statement before the event.
Marc N. Casper, who has been chief executive of Thermo Fisher since 2009, said the Plainville plant will help the pharmaceutical companies that are his firm’s customers discover, develop, and manufacture gene therapies faster. The company already had five sites in the US and Europe that can produce viral vectors.
The Plainville plant began operating recently and employs 125 people, according to a Thermo Fisher spokeswoman. It will add another 200 workers within two years.
Thermo Fisher employs more than 100,000 people worldwide. That includes at least 3,500 employees in Massachusetts at 15 sites in Cambridge, Waltham, Lexington, Franklin, and nine other cities and towns, said the company.
The firm made a significant commitment to gene therapy in 2019 when it bought Brammer Bio, a Cambridge manufacturer of viral vectors, for about $1.7 billion.
The construction project has not been without problems. On Feb. 2, about 200 people had to be evacuated because a frozen pipe cracked, leaking about 2,000 pounds of a refrigerant, according to state and local public safety officials.
Last year, COVID-19 diagnostic testing business made up nearly a third of Thermo Fisher’s first quarter revenues — $2.85 billion of the $9.91 billion total. In the first quarter of this year, COVID testing’s share of total revenue fell to less than 15 percent, but the firm has thrived because of other core businesses.
Vijay Kumar, an analyst at Evercore in New York, told investors in a note last month that Thermo Fisher was a “juggernaut” that had made shrewd acquisitions, including paying $17.4 billion for a North Carolina company that helps drugmakers run clinical trials.
Jonathan Saltzman can be reached at jonathan.saltzman@globe.com.
Work at Boston Globe Media