Evidence Quality and Health Technology Assessment Outcomes in Reappraisals of Drugs for Rare Diseases in Germany

Objectives: Evidence on reappraisals of health technologies in Germany is limited, and for rare disease treatments (RDTs), the Federal Joint Committee follows different processes (limited or regular), depending on whether an annual revenue threshold has been exceeded. Our objective is to better understand (re)appraisal processes and their outcomes for RDTs in Germany. Methods: We analyzed appraisal documents of 55 RDT indications for which an initial appraisal and a reappraisal were conducted between 2011 and 2023. We extracted information for the type of evidence, the risk of bias, the availability of additional evidence, and the change in the maturity of survival data as proxies for evidence quality. Specifically, we reviewed the reasons for conducting reappraisals, examined how evidence quality and the clinical benefit rating (CBR) differed between initial appraisals and reappraisals, and explored the association between evidence quality and (1) the CBR and (2) the change in the CBR after reappraisal. Results: Most reappraisals were conducted because the annual revenue threshold was exceeded or the initial appraisal resolution was time limited. Almost all initial appraisals used the limited process, whereas the majority of reappraisals used the regular process. The CBR increased in only 9 and decreased in 21 of 55 reappraisals. There was some evidence that reappraisals with an accepted randomized controlled trial were significantly more likely to achieve a higher CBR. Conclusions: Findings confirmed that reasons and processes for conducting reappraisals of RDTs in Germany differ. Further, high CBRs in reappraisals were not common and evidence quality in initial appraisals and reappraisals was limited.