Spencer was CEO and board member of Kaleo, Inc from 2016 to 2021. While at Kaleo, Spencer led the growth of the company from a three-person start-up to a business with five FDA approved drug-device combination products. In 2021 Kaleo was acquired by Marathon Asset Management for $310M, including milestones.

Spencer has also on the board of Avenu Medical which developed a percutaneous AV fistula catheter product for chronic kidney disease patients. Avenu was acquired in 2020 by Medtronic.

Before Spencer’s private company experience, he held senior executive level positions with Guidant / Boston Scientific in the Cardiac Rhythm Management division.