China's Shenzhen Hepalink Pharmaceutical signed a deal to acquire contract drugmaker Cytovance Biologics for $205.7 million in cash, buying into the U.S.'s burgeoning market for large-molecule treatments.

Under the deal, Hepalink plans to fold the Oklahoma City-headquartered Cytovance into its American operation, which also includes the biologics contractor Scientific Protein Laboratories, acquired for $337.5 million last year.

The buyout will also speed up Cytovance's already-planned expansion, Hepalink said. The company is in the process of building a 30,000-square-foot manufacturing facility in Oklahoma City, bringing in additional reactors, fermenters and process-development technologies. Under Hepalink, Cytovance figures it can accelerate that process, CEO Darren Head said.

"This will expand our ability to develop and grow both our domestic and international businesses and to secure our current expansion plans in our Oklahoma City facilities," Head said in a statement. "We do not anticipate any changes in how we currently do business. We will become part of a very successful company that shares our commitment to safety and quality."

Founded in 2003 by veterans of Novazyme, Cytovance specializes in developing and manufacturing biologics for pharma clients.