A Walthamstow scientist is preparing to run the London Marathon for charity to show support for his brother currently battling cancer.

Tom Lerner is raising money for Leukaemia & Lymphoma Research.

Josh Lerner, 23, was diagnosed with blood cancer in October 2013.

During a year studying chemistry in Spain for his Master’s degree, Josh had severe pain in his arm, rapidly lost weight and suffered night sweats.

A week after his graduation, his cancer was diagnosed.

Mr Lerner immediately underwent chemotherapy, but scans showed residual cancer.

He is due to undergo a stem cell transplant in the next few weeks.

His brother Tom, 27, a tuberculosis research scientist at The Francis Crick Institute in London, said: “I realised soon after Josh was diagnosed that there was nothing I could actually do to help, except to support him and unfortunately I wasn’t a stem cell match.

“I felt terrible that he was suffering and there was nothing I could do. I then realised that there are indirect ways to help.

“I chose this charity because it funds scientific research into improving diagnosis and treatments for blood cancers. As a scientific researcher I know that although research is a very time consuming, difficult and expensive thing to do, it is the only way that cures will be found.”

Dr Lerner added: “I have all the inspiration I need to keep running once I hit the ‘wall’ knowing that the pain I will be in is nothing compared to what he has endured for so long. I’m sure it will be an emotional moment for us all.”

Tom has been fundraising and documenting his journey since his brother's diagnosis.

Josh has writes a regular blog called Living With Lymphoma.