LUNG cancer patients in Scotland are to have access for the first time to a new immunotherapy drug which proved so effective at boosting survival compared to chemotherapy that clinical trials were halted early.

The Scottish Medicines Consortium has approved Keytruda - also known as pembrolizumab - as a first-line treatment for patients with advanced non-small-cell lung cancer who have not previously received chemotherapy and whose tumour has tested positive for a particular protein, known as PD-L1. It is expected that around 150-160 patients a year in Scotland will benefit.

A clinical trial involving 305 lung cancer patients the US was cut short in 2016 after results showed that it cut the risk of death or tumours spreading by 50 per cent compared to chemotherapy. It was deemed unethical not to extend the therapy to everyone in the study. The drug also improved overall survival, with a 40 per cent reduction in death compared to chemotherapy.

Keytruda is already available to lung cancer patients in England via the Cancer Drugs Fund, and it was previously accepted by the SMC in 2015 as a treatment for some patients with advanced melanoma skin cancer. Former US President Jimmy Carter credited Keytruda with making his tumours "vanish" in 2016 after advanced melanoma spread to his brain, a condition which would usually be fatal.

Dr Marianne Nicolson, a consultant medical oncologist at NHS Grampian said: "Scotland has the third lowest survival rate for lung cancer in Europe so there is a clear need for new treatment options for our patients. This welcome positive SMC decision means that people are now able to access pembrolizumab when it is right for them, potentially leading to better patient outcomes."

Incidence of lung cancer in Scotland is among the highest in the world, and Scotland is the only nation in the UK where lung cancer remains the most common cancer in adults. Non-small cell lung cancer accounts for approximately 85 per cent of lung cancers and it is diagnosed at an advanced stage in approximately two-thirds of cases.

Keytruda is among a new wave of cancer drugs, known as immunotherapy, which fight cancer by supercharging the body's own natural defences against it. As well as Keytruda, the SMC has also recommended Opdivo - another immunotherapy drug - for routine use on the NHS to treat patients with a highly aggressive blood cancer.

Opdivo, also known as nivolumab, is already available to patients in Scotland with forms of lung cancer, kidney cancer, and advanced melanoma, and is currently being considered for head and neck cancer.

The latest approval will see it offered to adult patients with classical Hodgkin lymphoma whose cancer has progressed despite undergoing a stem cell transplant and drug treatment. Previously, patients in this position would have been considered terminally ill. However, in clinical trials Opdivo significantly reduced cancer in more than two thirds of patients and, in eight per cent of patients, the cancer disappeared.

It is expected that six patients in Scotland will be eligible for Opdivo in the first year, rising to 18 by year five.

Dr Pam McKay, consultant haematologist at the Beatson West of Scotland Cancer Centre, said the decision was "a significant step forward". She added: "In patients whose cancer has returned or worsened on current treatments, previously many would have faced palliative care. Now these patients have a much-needed treatment option which may help to improve survival.”

Dr Alan MacDonald, chairman of the SMC, said: “The committee heard how pembrolizumab can give patients meaningful extra time with their families, which we know will be welcomed.

“Nivolumab will be a valuable new treatment option for patients with Hodgkin lymphoma, particularly as it may help some towards a transplant which may be curative."