The review was handled by Agency Assessments and the agency won out against LBi, Razorfish and EHS Brann.
The incumbent, Partners Andrews Aldridge, was involved during an earlier stage of the pitch process.
Rapp already works on Alli, the weight loss drug, in the US.
The appointment follows GSK’s move to shake up the advertising rosters for several of its consumer brands.
It appointed TBWA to look after Alli, Nicorette, NicoDerm, CQ and Commit. The accounts were previously held by Arnold and WCRS.
In April, GSK launched a pan-European retail campaign, created by Bezier group, to support the launch of Alli. It has run across 27 countries and includes point of sale and floor media.
NiQuitin, the nicotine replacement brand, currently runs a Click2Quit scheme which gives consumers the opportunity to seek advice on how to give up smoking.