Plymouth-based medical device maker Entellus Medical, which went public in 2015 and has been growing sales by more than 40 percent per year, is set to be acquired in a $662 million deal by Michigan's Stryker Corp.

Stryker has agreed to pay $24 per share for Entellus, a premium of about 50 percent from Wednesday's closing price. The deal is subject to regulatory approval.

"I wouldn't call it a bargain, but I think it makes sense," said Mike Matson, an analyst with Needham & Co. who follows medical device companies. "They are paying a lot, but everything is expensive right now."

Founded in 2006, Entellus developed a cheaper, less invasive way to treat chronic sinus problems with its XprESS family of balloon catheters, which are used to drain infected sinus cavities and prevent recurring infections. The treatment, typically performed in a doctor's office, is an alternative to surgery.

While Entellus also makes surgical instruments and other medical equipment, its XprESS products account for about 80 percent of company revenue, which climbed from $17 million in 2012 to $75 million in 2016, according to its most recent annual report.

The company has yet to turn a profit. At the end of 2016, Entellus reported an accumulated deficit of $150.8 million. In its most recently quarterly report, Entellus said it lost $3.2 million on sales of $23.3 million, ­compared with a net loss of $9.5 million for the same period last year. In announcing the Entellus deal, Stryker said it does not expect the acquisition to become profitable for the company until 2019.

Stryker, by contrast, has a widely diversified product line, ranging from implants used in hip and knee replacements to an extensive line of surgical tools and basic medical equipment such as hospital beds and stretchers. The company, which has bought more than 40 medical companies in the past five years, earned $1.6 billion on revenue of $11.3 billion in 2016.

Analysts noted that Stryker already has a small but significant presence in the market catering to ear, nose and throat (ENT) doctors. The company offers about 15 ENT products in its instruments business, according to Matson.

"They typically buy companies that offer products that are complementary to what they already have," Matson said. "They can leverage the relationships they have with these doctors."

Analysts said the deal could have a big upside for Stryker, noting that Entellus believes the total market for its products tops $2 billion. So far, about 150,000 patients have been treated with Entellus' XprESS products since the line debuted in 2010, according to the company. Entellus estimates that 690,000 patients could use the balloon catheters annually.

"Entellus is a leader in the ENT segment and offers a comprehensive portfolio of products that enable physicians to conveniently and comfortably perform a broad range of ENT procedures," Stryker executive Timothy Scannell said in a written statement.

It's not clear how the deal would affect the 280 people who work for Entellus, which makes the majority of its products at its facility in Plymouth. Officials with Entellus and Stryker did not respond to questions about the future of those workers or the Plymouth plant.

"The combination of Stryker's established commitment to making health care better and Entellus' innovative products within the ENT segment will continue to provide our customers the tools they need for cost-effective solutions," Entellus chief executive Robert S. White said in a written statement.

The announcement comes less than a month after Entellus announced that Anthem, the largest member of the Blue Cross and Blue Shield Association, had agreed to cover balloon-sinus dilation for chronic and recurrent sinusitis. Following Anthem's coverage policy, Entellus estimated that 95 percent of insured patients in the U.S. had access to the procedure, when deemed medically appropriate.

Joe Carlson • 612-673-4779

Jeffrey Meitrodt • 612-673-4132