Heumber has long standing experience in public health issues including access to treatment, human rights, research and development, and pharmaceutical policy. She previously worked for Médecins Sans Frontières (known in English as Doctors Without Borders) and is a former Head of Policy for the Drugs for Neglected Diseases initiative. Heumber played a leading role in advocacy for the adoption of a resolution on the neglected inflammatory disease Mycetoma by the World Health Assembly (WHA).
As Executive Director of IAFME, Heumber hopes to raise awareness of ME at the highest political level, stating that "It is an ethical and public health scandal that M.E. has not been addressed more seriously at the highest level, and patients' voices are not being heard."