In the newly created role, McCusker will help push Isobar’s brand commerce capabilities across the EMEA markets it operates in, as well as leading the management and development of clients.
Based in London, she will report to Jean Lin, Isobar’s global chief executive.
Lin replaced Mark Cranmer, who had led the agency since 2009, last year. She was previously Isobar’s global chief strategy officer and Asia-Pacific chief executive.
McCusker worked as a general manager at Publicis and Publicis Modem between 2007 and 2012. Before that, she was a client service director and regional director for the Western Union account at Publicis for three years.
Lin said: "Her track record in leading agencies and stewarding best-in-class clients, combined with her world view, will be brought to bear in ensuring the best service is given to our EMEA clients.
"She will also be a key player in building our business within Dentsu Aegis Network and in attracting new clients."