A terminally ill man's dream to see his baby daughter start school could become a reality after a mystery benefactor has offered to buy the drugs he needs to stay alive.

Last year, Jack Rosser, of Kingswood, South Gloucestershire, was diagnosed with cancer of the kidney three days after his daughter, Emma, was born.

The cancer had spread to his bones and Mr Rosser, was told he might live for only two years unless he was given Sutent, a drug that could extend his life for a further two years.

But the 57-year-old was told by NHS officials that the extra time it would give him did not justify the £3,000 cost of the six-week treatment.

Sutent does not have approval from the National Institute for Health and Clinical Excellence (Nice), so bosses are not obliged to prescribe it on the NHS.

Mr Rosser's wife, Jenny, 41, said the shocking decision was tantamount to a death sentence. In the months that followed, the couple have campaigned for South Gloucestershire Primary Care Trust (PCT) to grant Mr Rosser the drugs to enable him to live long enough to see his daughter walk on her own, talk and spend her first day at school.

Now his wish could come true after an anonymous New York hedge fund manager, who heard about the case, offered to fund Mr Rosser's treatment.

He contacted Kate Spall, a full-time activist who set up British cancer campaign group, the Pamela Northcott fund, and who relayed the offer to the Rossers.

Mr Rosser, who has had operations to remove a kidney, adrenal glands and tumours in his arm, spine and neck said he was "totally stunned" by the offer as he prepared to start private drug treatment on Monday.

He said: "All I want is to be there when Emma has her first day at school. That thought has kept me going.

"I got the news in a text message on my phone at 11.30pm one night.

"After I wiped away the tears, I thought how marvellous this man must be.

"We've never spoken, but I would love to thank him. Hopefully, he's added two years to my life – maybe more.

"I'm overjoyed and more determined than ever to see Emma start school."

By February next year, the Rossers hope Nice will have reversed its ruling on Sutent – as it is expected to do – and Mr Rosser will then be able to continue using the drug with NHS funding.

Even if Nice refuses to change its mind about Sutent's cost-effectiveness, the Rossers hope the drug will quickly prove clinically effective in treating Mr Rosser's cancer.

The hope is that it might persuade the PCT to pay for continued use of Sutent even without Nice backing.

The Rossers, who live in Middle Road, say the mystery benefactor in New York will keep in touch with Kate Spall.

"By February we should have evidence to show whether the drug is working," said Jenny, who is also a nurse.

"If we are not successful in our appeal to the PCT at that stage and Nice won't reverse its ruling on Sutent, it'll be up to our benefactor whether he is able to continue to help us.

"If Sutent doesn't prove to be working, we would look at other treatment options, such as clinical trials of other drugs."

Mr Rosser, who served in the Royal Navy for nine years, was diagnosed after he went to his doctor about what he believed was "a popped rib".

But when he went for a scan a tumour was discovered in his kidney and it was found that the pains he was suffering were the result of the cancer spreading to his bones.

He was originally told that he may have just months to live, but after having the kidney and corresponding adrenal gland removed he was told that he could live a few years longer.

He tried the drug Interferon but he suffered many side-effects and lost weight.

He said: "When I think how all my life I have always kept myself fit, running marathons for charity and have worked for 40 years and paid my national insurance, I would have thought I would be able to get the drugs I need now.

"I want some quality of life and longer to spend with my beautiful little girl and my wife."

As well as one-year-old Emma, Mr Rosser has a 26-year-old daughter, Carly, and is a stepfather to his wife Jenny's two teenage sons, Sam and Daniel.

Sutent, which stops cancer cells from dividing and chokes off a tumour's blood supply, was first approved for European use in July 2006. Kidney cancer sufferers taking the drug had an average survival rate of 26.4 months, according to a study presented at the American Society of Clinical Oncology.

Mr Rosser has twice appealed decisions by the PCT not to fund the drug.

In August, the PCT stood by its ruling for the second time, saying that neither Mr Rosser's medical condition nor personal circumstances were considered to be an "exceptional" reason to pay for Sutent.

On the same day Nice, published draft guidance saying the drug was not cost-effective. It was a decision that caused outraged and which the body is expected to reverse in its final ruling next month.

The PCT is now considering a new appeal.