Across 789 included European Phase III oncology trials, progression-free survival was the largest primary endpoint anchor, while overall survival remained highly visible but more often as a co-primary or secondary endpoint. The signal is not that OS has disappeared from pivotal oncology design, but that the dominant architecture has shifted toward earlier disease-control readouts backed by survival follow-up.
PFS was the dominant primary anchor, appearing in 270 of 789 trials (34.2%). OS was primary or co-primary in 194 trials (24.6%), split between OS-only primary designs and OS co-primary designs.
OS remains clinically central, but it is not the dominant primary endpoint anchor. The largest primary-endpoint bucket is PFS, which indicates a broad shift toward earlier disease-control readouts in European Phase III oncology trials.
OS appeared somewhere in the endpoint architecture of 628 of 789 trials (79.6%). However, its most common role was secondary-only, seen in 434 trials (55.0%).
The modern pattern is not OS abandonment. It is OS repositioning: survival is usually retained, but more often as a secondary or co-primary endpoint behind a faster disease-control primary.
The strongest PFS-led signal came from 2024, where PFS primary endpoints appeared in 206 of 545 trials (37.8%). In 2025 and 2026, OS primary exposure increased to 34.1% and 32.4%, largely through co-primary designs.
The year pattern suggests a hybridization of pivotal endpoint strategy: PFS remains the most common lead endpoint, while OS gains weight through co-primary structures rather than replacing PFS as the dominant anchor.
When trials led with non-OS primary endpoints, OS was often preserved as a secondary endpoint. This was especially common in PFS-primary trials, where 231 of 270 trials (85.6%) still tracked OS secondarily.
For many oncology programs, OS now functions as the survival validator behind earlier primary endpoints. This creates a two-speed evidence strategy: earlier PFS or disease-control readout first, survival confirmation later.
Taken together, OS primary/co-primary, PFS primary, and EFS/DFS-family primary endpoints accounted for 605 of 789 trials (76.7%). Response-based endpoints accounted for only 39 trials (4.9%) as the main primary anchor.
European Phase III oncology trial design is still built around time-to-event evidence. The key change is the hierarchy inside that family: PFS and disease-control endpoints are more common lead anchors than OS-only designs.
Across European Phase III oncology trials, OS is still strategically important but no longer the single dominant primary endpoint anchor. The dominant design logic is now PFS or another disease-control endpoint first, with OS frequently retained as the longer-horizon survival endpoint.
For sponsors, the endpoint strategy question is less whether OS matters and more where OS should sit in the evidence hierarchy. In this dataset, the common architecture is clear: use PFS or related disease-control endpoints to accelerate primary readout, while preserving OS to support confirmatory survival interpretation.