Groton — Founded in Brooklyn, N.Y., Pfizer Inc. was 110 years old when it consolidated its medical research laboratory operations here in 1959.

In the 60 years since, the Groton site has had a hand in the discovery and development of such medicines as Zoloft and Zithromax and, more recently, Xalkori and Xeljanz. Today, nearly everything Pfizer produces is developed at its 160-acre complex on Eastern Point Road, where more than 2,600 people work in 2.8 million square feet of space.

Pfizer Groton has been observing the anniversary amid little fanfare.

“We’re excited to be celebrating it,” John Burkhardt, senior vice president of drug safety R&D and head of the Pfizer Groton site, said in a phone interview. “It’s interesting to reflect on what has changed over time.”

Pfizer’s presence in Groton dates back to 1946, when the company bought the Navy-owned Victory shipyard where Electric Boat built submarines during World War II. In May 1948, Pfizer began manufacturing citric acid at the site and added production of gluconic acid, penicillin and caffeine and, in 1950, Terramycin, a blockbuster antibiotic.

In 1954, a Pfizer executive would declare Pfizer Groton “the largest antibiotic plant in the world.”

Now devoted almost entirely to research and development, the site is engaged in treating a variety of diseases by focusing on molecular structures. The approach and the equipment involved are highly sophisticated, the people who do the work highly trained. Scientists account for about half of the Pfizer Groton workforce, Burkhardt said. Thousands of contractors also work at the site, bringing the total number of jobs provided to more than 5,600.

“Their impact on the town can’t be overstated, in terms of the taxes they pay, the number of employees, the community grants they give out,” Groton Town Manager John Burt said. “There’s a culture of volunteerism among the people who work there.”

Pfizer, long the town's top taxpayer, paid the town $8.3 million in property taxes last year, while providing the third-most jobs of any employer in town, behind Electric Boat and the Naval Submarine Base. It paid another $1.3 million in taxes to the City of Groton.

Keith Hedrick, the city’s mayor, said the city has a positive relationship with Pfizer, citing the company’s contributions to infrastructure improvements and various beautification projects. He said he considers Pfizer Groton’s manufacturing past, which occasionally involved complaints about foul smells and problem discharges into New London Harbor, all but forgotten.

“That’s not what this site is about now,” Hedrick said. “They’re renovating buildings for more lab space and have a plan for power-plant (expansion) work in a year or two. Their footprint and their contribution to the tax base will increase over time. Their mode is slow, controlled growth. … My point is they’re here for the long term.”

Pfizer credits the quality of life that Groton and coastal Connecticut provide with helping it recruit and retain talent, according to Burkhardt. Within the company, he said, the Groton site is known for its campus-like setting and a collegial atmosphere that’s conducive to creativity.

It’s also part of “a strengthening triangle of startups, mature pharma, and academia extending from Groton to New Haven to the University of Connecticut,” Burkhardt said. “These are creating a vibrant biomedical research community further strengthened by nonprofit contributions from leading organizations like BioCT,” a nonprofit business incubator that provides space in a building Pfizer donated in 2014.

Still, attracting millennials to a state that lacks a major metropolitan area has its challenges.

“What we can offer is the fulfillment of the job itself. That’s something we can control as an employer,” Burkhardt said. “Millennials want their lives to matter, and (achieving) that can be difficult. But when you work here, you can make a difference.”

Increasingly, Pfizer and the pharmaceutical industry in general have been concentrating on the rapid development of drugs that target narrow "subpopulations." For example, Burkhardt said, while Xeljanz, a Pfizer drug that treats arthritis, was developed over 15 years and treats hundreds of thousands of patients, it took Pfizer less than five years to develop Lorbrena, a drug that treats “a single-digit percentage of lung cancer patients” whose tumors have a specific mutation.

Lorbrena, approved by the U.S. Food and Drug Administration in November, was one of four Pfizer anti-cancer drugs that won such approval in a three-month period last year.

Charles Santa Maria, Pfizer Groton's senior director of chemical research and development, heads a 40-member team that works on production of the “active pharmaceutical ingredient” in a medicine and ensures that enough can be made to supply clinical trials. Large amounts of ingredients are produced at Pfizer’s facility in Sandwich, England, and tablets and capsules containing the ingredients are ultimately manufactured in Ireland.

An East Lyme resident, Santa Maria has been at Pfizer Groton for more than 32 years, virtually his entire career. The son of a pharmacist, he knew early that he wanted to work in the pharmaceutical industry.

“So much of the work is done in teams, with people of very different backgrounds and skills coming together in a spirit of collaboration,” he said. “I’ve done a lot of hiring, including some young Ph.D.s who said they really like the environment. … I’m lucky to be working with some of the same people I started with in 1986.”

Tess Wilson, vice president of precision medicine in early clinical development, has been with Pfizer for 28 years, all of them in Groton. She came to the United States from Yorkshire, England, to do postdoctoral research and lives in Stonington. Her 45-member team analyzes samples from patients involved in clinical trials to determine whether a drug is having the desired effect. She said she and her colleagues are mindful of the urgency that surrounds their work.

“You’re always thinking about the patient,” she said. “It could be a relative someday.”

She added that among those who work at Pfizer Groton, “There’s definitely a sense of pride in how far we’ve come as a company.”

b.hallenbeck@theday.com