The National Institute for Health and Care Excellence is not backing National Health Service use of Roche's Cotellic/Zelboraf as a treatment for melanoma.

The cost-watchdog has published preliminary guidelines rejecting Cotellic (cobimetinib) in combination with Zelboraf (vemurafenib) for treating unresectable or metastatic melanoma in adults with a BRAF V600 mutation.

Cotellic is an inhibitor of MEK 1 and MEK 2 kinases, while Zelboraf is an inhibitor of the BRAF protein. The BRAF protein and MEK 1 and 2 kinases are part of the same cell signalling pathway, and inhibiting these proteins stops proliferation and survival of melanoma cells.

According to NICE's appraisal consultation document, the combination extends survival by an average (median) of 4.9 months compared with Zelboraf alone, however, the Committee concluded that its likely incremental cost-effectiveness ratio would be over £100,000 per QALY gained, and thus well outside the realms of what is considered value for money for the NHS.

This is despite the drug being considered under 'end-of-life' conditions, and a Patient Access Scheme agreed between Roche and the Department of Health, under which both pills would be offered at an undisclosed discount.

This stage of the consultation is now open until July 7.