Pivotal Studies for Drugs About to Be Launched for Rare Diseases: Will They Better Support Health Technology Assessment and Market Access than in the Past?

Abstract

The designs of clinical trials of drugs for rare diseases are challenged by health technology assessment organisations and payers. Phase II pivotal studies, single-arm or open-label designs, the extensive use of non-final endpoints, and the limited use of patient-reported outcomes (PROs) are the main points of contention. The evidence on the actual design of these trials is limited, but corroborates the concerns of the above. Our aim is to scrutinise whether the design of pivotal studies of drugs for rare diseases to be launched into the Italian market by 2026 present similar issues. The drugs and the relevant pivotal studies were retrieved from Biomedtracker and US and European clinical trial databases. We identified 154 new drugs for rare diseases. Single-arm designs account for 36% of trials. Almost 50% of randomised control trials (RCTs) are designed using an active comparator and 61% are double-blinded. Primary endpoints are mostly (82%) surrogate. A total of 59% of studies include PROs. Our findings were partially expected (e.g., extensive use of surrogate endpoints) and partially not (e.g., RCTs and an active comparator), considering previous studies on the same topic. Having more head-to-head studies may reduce uncertainty concerning evidence at market launch, but different issues persist, including the still limited role of PROs.