Pfizer Zoloft Co-Inventor Ken Koe Dies at 90 Years of Age

Pfizer Zoloft Co-Inventor Ken Koe Dies at 90 Years of Age
October 14, 2015
By Mark Terry, Breaking News Staff

The co-inventor of the antidepressant Zoloft (sertraline hydrochloride), Ken Koe, died on Oct. 7 at the age of 90.

Koe, with another Pfizer Inc. chemist, Willard Welch, began work on Zoloft in the 1970s. Zoloft, once the best-selling treatment for depression, had peak sales of $3.36 billion in 2004. Its patent expired in 2006. It is in a class of drugs known as selective serotonin reuptake inhibitors.

He received his B.A. in chemistry from Portland, Oregon’s Reed College in 1945 and would later receive the Vollum Award for Distinguished Accomplishment in Science and Technology in 2008 from Reed. Koe earned his Ph.D. from the California Institute of Technology and shortly afterward joined Pfizer as a research scientist in the Chemistry Department of Pfizer Research Laboratories in Brooklyn, NY.

“I always wanted to work in the pharmaceutical industry because of its strong emphasis on scientific research,” Koe said in a Pfizer Retirement Spotlight article. “Publications on the elucidation of the chemical structure of terramycin by Pfizer scientists led me to apply for a position at Pfizer.”

His initial work at Pfizer involved antibiotics and semi-synthetic penicillins. He later transferred to a team that worked on drugs to treat schizophrenia, depression and anxiety. Koe’s work focused on the biochemistry of serotonin in the brain, which was implicated in depression.

Koe, Welch and their other team members received an award from the American Chemical Society in March 2006 for “team innovation.”

In 1995, Koe retired as Research Advisor in the Neuroscience department of Pfizer Central Research in Groton, Conn. After retiring, he participated in the Ledyard Planning Commission and Ledyard, Conn.’s Democratic Town Committee. He sang in the Chancel Choir at his church, the United Methodist Church of Gales Ferry, and in the Eastern Connecticut Symphony Chorus. He also participated on the Board of Trustees of the Thames Valley Music School at Connecticut College.

Koe’s first paper about Zoloft was published in 1983, but the drug wasn’t approved for sale until 1991. After winning the Vollum Award, Koe described his early work, saying, “Two compounds with chlorine [atoms] in particular positions had very interesting properties. I tested every one of those isomers — one turned out to be a selective serotonin reuptake inhibitor [SSRI], and that compound became sertraline hydrochloride, which developed into Zoloft.”

Koe received a scholarship to Reed, which at that time cost $250 in tuition per semester. He worked his way through college washing dishes and waiting tables at Hung Far Low, a restaurant in Chinatown in Portland.

Speaking of his early career at Pfizer, Koe said, “It was pretty free and open. You had to look for certain things, but how to do that was pretty much unregimented. We had lots of chances to do things on our own. It was a different atmosphere in those days, it was a smaller company, and everyone knew that research was the only way to get to those big products.”

Koe’s parents were Benjamin and Monta Jean Koe, Chinese immigrants. Benjamin worked as an itinerate laborer in salmon canneries. Koe’s wife, Jo Ann Lew Koe, died in 1995. He is survived by two daughters, Kristin M. Koe and Karen E. Koe, and five grandchildren.

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