The UK Strategy for Rare Diseases was set out in 2013 with the aim of improving the understanding and care for patients with a rare disease. This aim is reflected in NICE’s Highly Specialised Technology (HST) appraisal process, which acknowledges the additional difficulties of generating clinical evidence in very rare disease patient populations, and of demonstrating cost-effectiveness; accordingly, the cost-effectiveness threshold is raised to £100-300 k/QALY. For a drug to be appraised via the HST process it must meet seven criteria, based on: a small and clinically distinct patient population, a limited number of specialist treatment centres for the indication in question, treatment price, and severity of the condition. Since the introduction of the HST process in 2013, only nine such drugs have been recommended.

The current NICE appraisal system means orphan drugs that do not meet HST criteria go through the standard technology appraisal (TA) process, with a cost-effectiveness threshold of £30 k/QALY, or £50 k/QALY when end-of-life criteria are met. Therefore, orphan medical products may be left in a ‘no man’s land’ between standard TA and HST routes, where any concessions made in HST to the acceptable evidence package and the application of cost-effectiveness methods are not applied.

It has been estimated that up to 3 million people in the UK experience a rare disease during their lifetime. NICE’s forthcoming methods review provides the opportunity to introduce QALY weightings, for factors such as disease rarity, as a way to bridge the gap between TA and HST.