OBJECTIVES: Patient number estimates feature prominently in Commission de la Transparence (CT) assessments in France, reflecting the system’s emphasis on budget impact. So we set out to understand which other factors influence the correlation between price and prevalence and to what extent.

METHODS: This study analyses 22 non-oncology orphan drugs that received EMA approval after July 2012. Annual treatment cost (ATC) was calculated using publicly available launch list prices when available, or cohort Autorisation Temporaire d’Utilisation (ATUc) prices. Dosing assumptions followed EMA guidelines or a pragmatic approach based on Commission Évaluation Économique et de Santé Publique (CEESP) assumptions or ATUc dosing. Number of patients eligible for treatment (prevalence) and ASMR ratings were retrieved from CT (Avis) reports.

RESULTS: The results of this analysis demonstrate that there is an inverse relationship between ATC and prevalence, in which ATC decreases logarithmically as prevalence increases. Prices of products in ATUc or post-ATUc often sit above the trendline, highlighting manufacturer negotiating tactics. Neither ASMR rating nor use of ATUc patient data appears to influence the ATC relative to the trendline. ASMRs subject to the average-EU-price rule do not always attain superior prices, while mixed ratings can achieve high ATCs. Although ATUc patient data is also often leveraged in CT submissions, it does not always lead to higher ASMRs or ATCs; this may reflect the importance of other factors including medical unmet need and the existence of a clinical comparator. Finally, the majority of products analysed were granted ASMR 4 or 5, illustrating the challenges in providing methodologically robust, convincing evidence for HTAs in rare disease, even when supported by ATUc patient-level data.

CONCLUSIONS: Payers in France value low patient numbers and the relatively limited budget impact of orphan drugs, although clinical unmet need, competitive context and, importantly, the evidence package also influence price.