Dear Prime Minister, please let me have my medicine (by the way it’s locked in a hospital cupboard where I am treated)

Abi Longfellow suffers from a one-in-a-million kidney disease called Dense Deposit Disease (DDD), which stops the kidneys from filtering waste from the blood.

A petition set up by her parents, Andy and Jo Longfellow, to get her the drugs she needs has been signed by more than 160,000 people.

And Abi wrote a heartfelt letter to Prime Minister David Cameron asking for his help.

But health bosses will not pay for the Eculizumab drug, which costs £393,000 a year, because her condition is too rare to be covered by the national funding policy, but not rare enough to qualify as an exceptional case.

Mr Longfellow, 45, said the family only want the NHS to fund five dosages to see if the drug works.

He said: “It could mean Abi could be a normal teenager again. She would be able go back to school and hang out with her friends. It could totally transform her life.

“We just want £60,000 for five doses of treatment to find out if it is effective, then we will look at our options.

“It is difficult when other children around the world use the drug and I have seen that it works but they won’t give us the trial. That’s all we want.”

Abi was diagnosed with the disease aged 10 when a trip to A&E for a throat infection revealed she was suffering from the kidney disease.

She now spends 10 hours a day at home on a dialysis machine and it means she cannot return to school full time.

And the drugs which could help change her life are kept under lock and key in Leeds General Infirmary where Abi is treated.

Mrs Longfellow said: “The disease had such a devastating effect on her health. In the first year Abi received really high dosages of chemotherapy and it took a toll on her.

“Her hair fell out, she could barely walk and became painfully thin. Her health was a real concern for the doctors but over time she has got better but the drugs could help change her life.”

Abi’s family, of Robin Hood, said they have been overwhelmed by the support from people who signed their petition.

Mr Longfellow said: “To have the nation behind you and to have their support is incredible. We never expected that. We are not asking the NHS for a miracle but to reconsider and give our daughter the medication she needs.”

To sign the petition log on www.change.org/p/david-cameron-mp-allow-the-nhs-to-give-abi-longfellow-her-life-saving-medicine.

A spokesperson for NHS England North said: “These are incredibly difficult situations, but in this case doctors and medical experts decided that it would not be right to fund a treatment that hasn’t been proven to work for patients in these circumstances.”