Joint Clinical Assessment in the EU HTA Regulation—Would Drugs Supported by Single-Arm Trials Fit Under Evaluation?

The Joint Clinical Assessment (JCA) evaluates the relative effectiveness (RE) of interventions over comparators. While randomised control trials (RCTs) are considered the gold standard, single-arm trials (SATs) require an external control for accurate RE estimation. This study reviewed Health Technology Assessment (HTA) outcomes for medicinal products supported by SATs in France, Germany, Poland, and Spain, and simulated the JCA for these products based on evidence submitted in France. Among HTA evaluations published in France in 2019–2024, 16% were SAT-driven, and 5.6% of them included external controls. SAT-supported drugs had a high reimbursement approval rate (74%) and showed better HTA outcomes when controls were used. In Germany, 64% of SAT-based HTA outcomes indicated no added benefit and 30% a non-quantifiable benefit. In Poland and Spain, 63% and 72% HTA evaluations recommend reimbursement, respectively. Despite wide acceptance by Member States, experts determined that 94% of SAT-supported products would not qualify for JCA review due to insufficient evidence. Only 6% would qualify for JCA for a likely limited number of PICOs (Population–Intervention–Comparator–Outcome), but the certainty rating would be low. These findings suggest that SATs, as primary evidence, may not be suitable for JCA, potentially undermining HTA in EU Member States.