Clinical Trial Intelligence
When Do Phase III Oncology–Haematology Trials Use PFS-Family Primary Endpoints?
1 June 2026
Across 1,054 combined Phase III oncology–haematology CTIS records authorized in 2024–2026, PFS-family endpoints were used as primary endpoints in 392 records (37.2%). The signal is concentrated in progression-driven cancer settings—especially CLL/SLL, multiple myeloma, ovarian/peritoneal cancer, lymphoma/DLBCL-type disease, and systemic targeted or antibody-based treatment programs. Standard PFS dominates; rPFS and bPFS remain niche variants, and PFS2 was not observed as a primary endpoint.
1,054
Combined Phase III records
96.7%
Standard PFS within family
PFS-Family Share of Primary Endpoint Architecture
PFS-family endpoints accounted for 392 of 1,054 combined Phase III records (37.2%). The remaining 662 records (62.8%) used other primary endpoint architectures, including OS-led, DFS/EFS/iDFS/RFS/MFS-led, response-led, safety, bleeding/event-rate, thrombotic-event, organ-failure, laboratory-response, transfusion/anaemia, and composite clinical endpoints.
PFS-family primary endpoint37.2%
Other primary endpoint architectures62.8%
Interpretation: In the combined disease area, PFS-family endpoints remain a major Phase III primary endpoint family, but they are not universal. The share is pulled toward progression-driven malignancy settings and diluted by trial types where the primary clinical question is bleeding prevention, thrombosis prevention, anaemia correction, organ failure, response, or safety.
Subtype Breakdown: PFS, rPFS, bPFS, PFS2
Among 392 PFS-family primary endpoint records, standard PFS was used in 379 records (96.7%). rPFS appeared in 7 records (1.8%), bPFS in 6 records (1.5%), and PFS2 was not observed as a primary endpoint.
Interpretation: The combined PFS-family signal is overwhelmingly conventional PFS. rPFS and bPFS are specialized variants tied to radiographic or biochemical progression logic, while PFS2 functions as a downstream sequencing endpoint rather than a primary endpoint anchor.
Disease Patterns
PFS-family primary endpoint use was most visible in diseases where progression is measurable and clinically meaningful before OS maturity. The strongest observed disease signals were CLL/SLL (91.7%), multiple myeloma (75.0%), ovarian/peritoneal cancer (69.2%), and lymphoma (61.6%). The additional haematology-only PFS-primary cases reinforced the malignant lymphoid pattern rather than creating a separate endpoint pattern.
Ovarian / peritoneal cancer69.2%
Lymphoma / DLBCL-type disease61.6%
Interpretation: The core disease pattern is progression-driven malignancy, not therapeutic-area labeling. PFS is most common when protocols can define progression using established disease-specific criteria such as Lugano, iwCLL, IMWG, RECIST, RANO, radiographic criteria, or PSA/biochemical progression rules.
Treatment-Line Pattern
In classifiable metastatic records, PFS-inclusive primary designs were common in both first-line and later-line disease: 138 of 228 first-line metastatic trials (60.5%) and 47 of 88 later-line metastatic trials (53.4%) used PFS-inclusive primary endpoint architectures.
First-line metastatic
60.5%
Later-line metastatic
53.4%
Interpretation: PFS is not restricted to refractory or salvage designs. It is also common in first-line metastatic settings, where disease-control separation can be measured before OS maturity and before downstream therapies dilute survival attribution.
Modality Pattern
PFS-family primary endpoints appeared across small molecules, monoclonal antibodies, bispecific antibodies, ADC-containing regimens, radiopharmaceuticals, and multi-modality combinations. The recurring pattern was not one drug class; it was systemic anti-malignancy treatment in measurable disease.
Antibody + small molecule
Observed in lymphoma/CLL-style PFS primary designs.
ADC-containing regimens
Observed in ovarian/peritoneal and breast-cancer endpoint architectures.
Radiopharmaceutical / prostate
Observed in PFS/bPFS-style prostate progression definitions.
Bispecific + antibody combinations
Observed in CLL/Richter and hematologic malignancy designs.
Interpretation: PFS-family endpoints are attached more to disease setting, measurability, and treatment-sequencing logic than to a single modality. Combination systemic regimens dominate the visible pattern because PFS can capture additive disease-control effects before survival outcomes mature.
Endpoint Definitions
PFS — progression-free survival: time from randomization or treatment start to first documented disease progression or death, commonly assessed by RECIST, Lugano, RANO, iwCLL, or IMWG depending on disease.
rPFS — radiographic progression-free survival: PFS variant where progression is defined radiographically, most commonly in prostate-cancer-style imaging assessments.
bPFS — biochemical progression-free survival: PFS variant where biochemical recurrence or PSA-defined progression contributes to the progression event definition, usually in prostate cancer.
PFS2 — second progression-free survival: time-to-event endpoint tracking progression or death after subsequent therapy; observed as a secondary follow-up endpoint rather than a primary endpoint anchor.
Executive Interpretation
Across the combined oncology–haematology Phase III dataset, PFS-family primary endpoints are common but disease-selective: 392 of 1,054 records (37.2%) used PFS-family primary endpoints, almost entirely standard PFS. The pattern is strongest in measurable progression-driven malignancies, especially CLL/SLL, multiple myeloma, ovarian/peritoneal cancer, and lymphoma/DLBCL-type disease. rPFS and bPFS are niche prostate-style variants, and PFS2 remains a sequencing endpoint rather than a primary endpoint. The endpoint strategy is therefore best understood as a disease-control readout in settings where progression can be defined earlier and more cleanly than mature OS.