OBJECTIVES: This study compared number of patients included in pivotal clinical trials and assessed during NICE HST over time, to observe trends in the strictness of application of HST criterion with regards to the acceptable clinical evidence base.

METHODS: Drugs assessed via HST prior to June 2021 were included. The number of patients from whom data was considered during the HST was extracted, alongside the number of patients in the “pivotal” trial. This was analysed as a proportion of the estimated number of UK patients, to observe any trends in the rarity of indications being assessed over time. Data for the next 5 anticipated HSTs were also extracted and compared against the first 5 HST appraisals to observe any differences in future versus early appraisals.

RESULTS: There does not appear to be a change in the application of the population size criterion over time. When considering the evidence base supporting HST submissions in proportion to estimated number of patients in the UK, results varied from 26% to 187.2%. When using pivotal trial size, proportions ranged from 15% to 187.2%. Although there was no clear trend in this output, when the first 5 HSTs were compared with 5 proposed HSTs, there was a trend towards a reduced number of patients in the pivotal trial for HSTs proposed.

CONCLUSIONS: This analysis suggests that eligibility for HST based on number of patients enrolled in clinical trials as a proxy for target patient group size has been consistently applied for HST, with no obvious trend observed. However, when we consider pivotal trial population for the first 5 HST’s vs 5 HSTs currently proposed, there is a clear trend towards reduced pivotal trial population. This may suggest that as the HST process develops, eligibility via size of addressable population will become more stringent.