Both positions were newly created as the agency has grown over the past year.
Calman is joining the technology company as VP of comms for Watson Health.
She will also continue to serve as president of the Astellas U.S.A. Foundation.
Former Edelman executive Mary Corcoran replaces Annalise Coady, who becomes president of W2O EMEA.
The CEO of Huntsworth's biggest and fastest-growing unit Huntsworth Health, which includes Nitrogen and Tonic Life, has departed after eight years.