Clinical Trial Intelligence

When Do Kidney Cancer Phase III Trials Use OS Instead of PFS?

29 May 2026

Across 13 endpoint-informative Phase III renal cell carcinoma / kidney cancer trials authorized in 2024–2026, PFS remained the dominant primary efficacy anchor, while OS appeared more often as a secondary, confirmatory, or co-primary endpoint. The pattern suggests that kidney cancer Phase III trial design is still largely built around earlier readout endpoints, with OS reserved for selected high-stakes comparative or basket contexts.

13
Endpoint-informative trials
38.5%
Used PFS as a primary endpoint
15.4%
Used OS as a primary or co-primary endpoint
61.5%
Used OS somewhere in the endpoint hierarchy

Primary Endpoint Hierarchy

PFS appeared as a primary endpoint in 5 of 13 trials, while OS appeared as a primary or co-primary endpoint in 2 of 13 trials. Other primary endpoints included response, imaging detectability, disease-free/event-style survival, clinical benefit, or safety/observational endpoint structures.

Primary Endpoint Placement
PFS primary
38.5%
OS primary/co-primary
15.4%
Other primary endpoint
46.2%
OS and PFS in Kidney Cancer Phase III Trials
Interpretation

PFS is the more common primary efficacy anchor in kidney cancer Phase III trials. OS is not absent, but it is used more selectively as a primary endpoint, usually when the design needs a harder survival claim or when the trial spans broader high-risk advanced solid-tumor contexts.

OS as Confirmatory Endpoint

OS appeared somewhere in the endpoint hierarchy in 8 of 13 trials. In most cases, OS was not the sole primary endpoint; it appeared as a secondary, subgroup, duration, or co-primary endpoint behind PFS, response, imaging, or disease-control measures.

OS and PFS Endpoint Roles
OS anywhere
8/13
PFS anywhere
7/13
PFS + OS together
6/13
OS and PFS in Kidney Cancer Phase III Trials
Interpretation

The dominant pattern is not “OS versus PFS,” but “PFS first, OS preserved.” Kidney cancer Phase III trials frequently keep OS in the evidentiary package while relying on PFS or response-based endpoints to structure the primary readout.

Endpoint Bundles Beyond OS and PFS

Most survival-oriented trials layered OS/PFS with additional efficacy endpoints. ORR or response-based endpoints appeared in 6 of 13 trials, DOR or disease-control endpoints in 5 of 13 trials, and patient-reported outcome or deterioration endpoints in 3 of 13 trials.

Common Secondary Endpoint Families
ORR / response
46.2%
DOR / DCR
38.5%
Safety endpoints
46.2%
PRO / deterioration
23.1%
OS and PFS in Kidney Cancer Phase III Trials
Interpretation

Kidney cancer trials rarely rely on survival endpoints alone. PFS and OS are commonly embedded inside broader packages that also capture response, response durability, safety, and kidney cancer symptom burden.

Modality Context

Small-molecule-containing regimens were the dominant setting for survival endpoint architecture, appearing in 8 of 13 trials. Monoclonal antibody-containing regimens appeared in 4 of 13 trials, while radiopharmaceutical/imaging-oriented and peptide/protein/enzyme approaches were less frequent.

Drug Modality Context
Small molecule
61.5%
Monoclonal antibody
30.8%
Radiopharmaceutical
7.7%
Peptide / protein / enzyme
15.4%
OS and PFS in Kidney Cancer Phase III Trials
Interpretation

The survival endpoint pattern is most visible in targeted small-molecule and immunotherapy-containing kidney cancer trials. Imaging/radiopharmaceutical trials were more likely to use detection-oriented endpoints rather than OS or PFS as the primary objective.

Executive Interpretation

European Phase III kidney cancer trials show a layered survival strategy. PFS is usually the nearer-term efficacy endpoint, OS is retained as the harder confirmatory endpoint, and response, safety, and quality-of-life measures complete the evidentiary package.

Observed Pattern Summary
Primary anchor
PFS appeared as primary in 5/13 trials, compared with OS primary/co-primary in 2/13.
Confirmatory layer
OS appeared somewhere in the hierarchy in 8/13 trials, often secondary or co-primary.
Evidence package
Response, durability, safety, and PRO endpoints were commonly layered around OS/PFS.
Modality signal
Small-molecule-containing regimens appeared in 8/13 trials and dominated the survival-endpoint context.
Observed Pattern Summary
Interpretation

The observed pattern reflects a pragmatic endpoint hierarchy: PFS supports earlier comparative readout in advanced RCC, while OS remains important where survival differentiation, treatment sequencing, or broad advanced-disease positioning needs to be preserved. The most mature designs combine PFS, OS, response durability, safety, and PRO/deterioration measures rather than depending on a single survival metric.