Gilead has announced that Kevin Young, its Chief Operating Officer, is set to retire from the company in early 2018. The market reacted to the news with apparent surprise, by ducking more than 4% lower on the announcement.

It should not really have come as much of a shock, given that Young had previously come out of semi-retirement to take on the role last year; it always seemed a temporary arrangement, with speculation that his main purpose was to ensure the smooth acquisition of Kite Pharma.

After the announcement that the deal would take place, late in August, it seems that Young’s duty has been fulfilled and he will now return to the advisory capacity he had formerly adopted after his previous retirement in 2014.

"Kevin has had an impact on Gilead – and by extension on the field of medicine and the lives of patients – that is seldom seen," said John Milligan, President and Chief Executive Officer. "Those who have had the opportunity to work alongside Kevin know that he possesses both a deep commitment to his work and unparalleled leadership abilities. I am delighted that he will be helping us manage through a period of change over the next several months and I am deeply grateful to Kevin for his contributions to Gilead and to the lives of millions of people around the world."

Young has worked with the company for 13 years and his previous retirement also arrived as a surprise to analysts, though now there appears to be pattern. In 2014, he retired shortly after the approval and launch of revolutionary hepatitis C treatment, Solvadi, and It seems that Young prefers to leave on a high.

Prior to working at Gilead, he had been Head of Business Operations at Amgen, a company he worked at for over 12 years. He also held the role of Director of Operations at ICI Pharmaceuticals, a company that later went on to become Zeneca.

Gilead has not yet revealed its timeframe on replacing Young but has stated that he will stay with the company to help in the transition period.