Isenberg replaces Kym White, who left the PR agency in March to join Vertex Pharmaceuticals.
He is joining the pharma company from Archer Daniels Midland.
Gillespie will report to W2O president Jennifer Gottlieb.
She will lead Nuvo Group's U.S. operations and head marketing globally.
Schirmer previously led McCann Global Health as president for nearly five years.
She was one of the firm's original staffers in 2013.
He was previously a managing partner at Ogilvy CommonHealth.
Mesara previously worked in communications for pharma companies AbbVie, Abbott, and Pfizer.
The firm recently brought on SVPs in its Washington and Boston offices.
The firm has named Oliver Caporn and Debra Polkes to new roles.
Daniel Carucci is joining the Interpublic Group firm full-time after serving as a consultant and in roles with the U.N. Foundation and the U.S. Navy.
The network also appointed her predecessor, Nick Colucci, as COO of Publicis Communications North America, effective immediately.
Burson-Marsteller has appointed MSLGroup's EMEA head of healthcare to lead its own health practice in the UK, PRWeek has learned.
FDA issues new policies for compounded drugs; U.S. doctors test CRISPR on cancer patients for the first time; Palio merged into GSW
Nick Law, the global chief creative officer of R/GA, is leaving the company after 17 years to take on the newly created role of chief creative officer across Publicis Groupe and president of Publicis Communications.
She is overseeing three of the network's agencies in the newly created role.
Sigurdsson is charged with leading the agency's digital offering to meet growing client demand.
Pharma looks to Spark for pricing blueprint; Ipsen hires Amgen exec as CEO of North America; FDA could improve social-media approach, study finds
Novartis Oncology taps Pfizer exec as CEO; healthcare jobs become the largest source of U.S. employment; HHS nominee wary about drug-pricing negotiations
WPP has named Karen Blackett as its first UK country manager, making her the most important agency leader in the British ad industry.
Celgene to buy Impact Biomedicines for up to $7 billion; Pfizer plans to cut 300 positions in neuroscience; Perrigo hires new CEO
The agency issue, people moves, and a series of restructures top the list.
VP of investor relations Teri Loxam will take over Ambrose's role in January.
Beiser previously held leadership roles at Edelman, Hilton, Discover, and Burson-Marsteller.
FDA approves first topical skin growth treatment; Teva to cut 14,000 jobs; Novartis Oncology CEO resigns
The drugmaker named William Huyett as COO and Gina Consylman as SVP and CFO.
GCI Health has confirmed new hire Kath Kerry and maternity leave returner Rikki Jones as co-MDs of its London operation, the network's second hub alongside its New York headquarters.
Cannes Lions' longtime leader, chief spokesman, and a figure many viewed as the heart and soul of the global creativity festival will be moving on after the 2018 event ends.
DeVine will oversee the agency's health IT and medical device work.
Botox-like wrinkle-reducer shows positive results in trials; investors double down on fertility; few websites transparent about pricing, study finds