Ellen serves as the CEO of the END Fund, working to see an end of the suffering caused by five neglected tropical diseases (NTDs) affecting 1.7 billion people. The END Fund has supported local partners across more than 30 countries to deliver over 740 million NTD treatments to hundreds of millions of people since its founding in 2012.

Agler has worked in global health and humanitarian response for over 20 years in more than 70 countries, for organizations including International Medical Corps and Operation Smile. She holds graduate degrees in International Health from the Harvard School of Public Health and in Development Studies from the London School of Economics. She currently serves on the boards of Global Institute for Disease Elimination, Uniting to Combat NTDs, Legatum Institute, the World Economic Forum's Global Health Security Advisory Board and Panorama Global.

Agler's book, Under the Big Tree: Extraordinary Stories from the Movement to End Neglected Tropical Diseases (with foreword by Bill Gates) was published in January 2019 by Johns Hopkins University Press. She was also recently named as one of Fortune magazine's "World's 50 Greatest Leaders" for 2019.