People on the move: Havas, ​TalkTalk, 72andSunny, Publicis, Summit and more

This week has seen another wave of appointments and departures at brands, media owners and agencies. The Drum has rounded up the key moves from the EMEA, APAC and North America regions below.
EMEA
​TalkTalk 
TalkTalk chief executive Didio Harding has stepped down after seven years in the job.
The boss will be replaced by current managing director Tristia Harrison, while longtime employee Charles Blingh will take up the role of chief operating officer. Both have been on the TalkTa