Most recently, Ms Heller was head of strategic alliances at Novartis Institutes for Biomedical Research, the global research organization for Novartis.
Previously she had served as vice president of corporate development and legal affairs at Signature BioScience.
George Scangos, president and CEO of Exelixis, said: “Fran is an extraordinary individual with a great deal of expertise in all aspects of business development. Her demonstrated success in both biotechnology and pharmaceutical companies will be of significant value to Exelixis as we pursue new collaborations around key compounds or broader strategic partnerships.”