OBJECTIVES: NICE defines ultra-orphan drugs as those treating life-threatening or seriously debilitating conditions affecting ≤1:50,000 people and developed the HST programme to assess these drugs, which are unlikely to meet standard HTA criteria. We compare outcomes of HST evaluations with assessment by HAS and the G-BA. METHODS: HST final evaluations published by June 2017 were identified (n=7). HAS and G-BA evaluations of the same drugs were then identified. RESULTS: The HST programme assessed unmet need, cost to NHS/personal social services, and value for money. NICE recommended six of the seven drugs, three outright, two with managed access agreements (MAAs) requiring additional data collection to account for uncertainty, and one for a subpopulation with an MAA. Despite acknowledgement of clinical need and likely benefit, sebelipase‑α was not recommended because of high costs. HAS consider additional benefit (ASMR) of orphan drugs with expected budget impact (BI) <€30 million/year to be proven at marketing authorisation. However, the drugs reviewed here were assessed through normal processes. HAS considered six drugs to provide additional benefit (two ASMR II, one ASMR III, three ASMR IV) but requested additional data for each, due to uncertainty. Eliglustat received ASMR V. Sebilipase-α (ASMR IV) was withdrawn by the manufacturer, suggesting that price agreement was not reached. The G-BA assume additional benefit for orphan drugs based on marketing authorisation. The remaining criterion was assessment of expected BI, with a threshold of €50 million/year in the first three years. All seven drugs were recommended, three with validation periods. CONCLUSIONS: While HTAs of ultra-orphan technologies were largely based on clinical benefit and BI, and all three bodies requested follow-up data to manage uncertainty, their recommendations varied. As further high-cost ultra-orphan drugs are introduced, additional criteria, such as the HST QALY threshold, may be considered to manage combined BI.