Mallak joined MSD in 2002 and assumed his current role in 2021. In June 2024, the company signed an MoU with Abu Dhabi’s Department of Health to support clinical research into lung cancer. In 2024, Mallak was named Diversity, Equity & Inclusion Council Lead for EEMEA at MSD. He is also a member of the executive committee of PHARMAG and a board member of the American Chamber of Dubai.