The Teenage Cancer Trust has been named the charity partner for next year’s London Marathon, with a fundraising target of £1.5m.
The charity said it hoped the partnership would play "a significant role" in helping the charity reach its goal of supporting every young person with cancer by 2020.
The partnership comes with an allocation of 250 places in the race itself, and part of the £1.5m total will come from the sponsorship money raised by the runners.
The marathon’s sponsor, Virgin Money, will also engage in fundraising for the charity.
In a tongue-in-cheek film that satirises how we think about charity in the social media age, the comedian Russell Brand will launch the partnership by encouraging people to "be a legend" and take part in the marathon so they can "look good whilst doing good" .
Kate Collins, director of fundraising and marketing at the Teenage Cancer Trust, said: "We’re delighted to be launching our important partnership with Virgin Money London Marathon 2018 with a film that has a cheeky tone but a serious message.
"We need hundreds of people to ‘be a legend’ and run or volunteer for the Teenage Cancer Trust in the London Marathon 2018, so we can make sure that no young person faces cancer alone."
Hugh Brasher, event director for the London Marathon, said the Teenage Cancer Trust was an amazing charity and the race was very excited to partner with it.
"Its team of legends will bring the party to marathon day and help raise much-needed funds so that more young people with cancer can access their expert support," he said.
The mental health campaign Heads Together, which is backed by charities including Mind, YoungMinds and Calm – The Campaign Against Living Miserably, was the official partner of this year’s London Marathon, which took place on Sunday.