The National Institute for Health and Care Excellence is now recommending NHS use of Amgen's Imlygic to treat advanced melanoma that has spread and can't be surgically removed.

The Institute has published final draft guidelines endorsing the drug as an option for treating unresectable, regionally or distantly metastatic (Stage IIIB, IIIC or IVM1a) melanoma that has not spread to bone, brain, lung or other internal organs, but only if: treatment with systemic immunotherapies is not suitable and; the company provides it with the discount agreed in the patient access scheme.

The decision marks a change in position from initial guidelines rejecting Imlygic (talimogene laherparepvec) in this setting, because of uncertainty over its effect on survival compared with other treatments, which the company has since addressed.

The therapy, which is also known as T-Vec, is a modified form of the herpes simplex virus type-1 approved by European regulators last year as the first oncolytic immunotherapy to treat adults with unresectable melanoma that is regionally or distantly metastatic with no bone, brain, lung or other visceral disease.

Injected directly into tumour, the therapy has fewer side-effects than some other immunotherapies for treating melanoma, according to the Institute. On the efficacy front, data from one clinical trial showed a 50 percent or greater reduction in size in 64 percent of tumours injected with the drug.

Imlygic's NHS list price is £1,670 per 1 ml vial, and clinical experts suggest that it would be suitable for about 10 - 15 percent of those with advanced melanoma that has spread and can't be surgically removed.