The charity chose The Remarkable Group following a five-way pitch. A spokesperson for the incumbent agency, Ascot-based TC Communications, said it declined to repitch after several years managing the account.
The brief focuses on raising the charity's profile among corporate and fundraising groups and the promotion of a new partnership with Sir Jimmy Savile's TV show Jim'll Fix It Strikes Again, airing on UK Gold.
It will also publicise the UK tour of US pop band The Fray, which has chosen Dreams Come True as its charity partner.
The agency will work on maximizing coverage around the hundreds of sponsored runners undertaking the London Marathon for the charity.
Dreams Come True fundraising manager Philip Pride said: ‘Part of our objective is raising our national profile over the next three years. Every year in the UK 10,000 children are diagnosed with a terminal or serious illness and we want to be able to do something for all of them.'
Dreams Come True was founded 20 years ago. The account is led by Remarkable's PR director Chris Wotton who reports to fundraising manager Pride.