A new campaign from U.K. charity Breast Cancer Now will play out on a messaging app in the form of a group chat between four female friends, after one of them receives a breast cancer diagnosis.

The content series, created by London agency BMB and featuring a quartet of well-known British TV actors (Rakie Ayola, Kate Ashfield, Claudie Blakley and Indira Varma) will unfold in real-time over the course of six weeks via voice notes, video messages, photos and text messages. The story will show how the group of women deal with the experience and support their friend, from her diagnosis to treatment and beyond.

It's claimed to be the first time a drama series has aired in this format. Initially, the charity will invite celebrities, journalists, breast cancer ambassadors and influencers to watch the series on their mobile phones via a private link. They will be invited to post content from the series to their social channels to tease it for the wider general public, and from March 6, a wider audience will be able to watch the story unfold via a dedicated microsite, with a user interface that reflects social media messaging.

BMB devised the format after being inspired by research showing that two thirds of people diagnosed with breast cancer want more honest conversations about their experience.

“Breast Cancer Now are the people to speak to if you want to talk more openly about breast cancer," said Matt Lever, chief creative officer at BMB, in a statement. "In creating the U.K.’s first group messaging drama series, we’re hoping to give the public an intimate and authentic portrayal of how a breast cancer diagnosis can affect all aspects of your life, via a medium that allows our characters to be completely honest with each other, and that’s completely relatable to anyone who’s in a group chat with their friends or loved ones.”

The campaign is being promoted via PR, with strategy and amplification led by W Communications, and organic social activity including a hero trailer that will appear on Breast Cancer Now’s social channels. A further media push will follow in April to build awareness.