Table 1.
Characteristics of PFS and OS Trials
| Trial Factor | PFS Trials (N=146) N (%) |
OS Trials (N=114) N (%) |
p-value* | |
|---|---|---|---|---|
| Total enrollment, median (IQR) | 495 patients (302 – 751) | 619 patients (416 – 896) | p=0.03 | |
| Time between accrual start and primary completion, median (IQR) | 36 months (27 – 58) | 39 months (32 – 54) | p=0.48 | |
| Industry funding of trial | Yes | 130 (89.0%) | 105 (92.1%) | p=0.41 |
| No | 16 (11.0%) | 9 (7.9%) | ||
| Cooperative group trial | Yes | 20 (13.7%) | 25 (21.9%) | p=0.08 |
| No | 126 (86.3%) | 89 (78.1%) | ||
| Disease site | Breast | 39 (26.7%) | 5 (4.4%) | p<0.0001 |
| Gastrointestinal | 24 (16.4%) | 30 (26.3%) | ||
| Genitourinary | 16 (11.0%) | 22 (19.3%) | ||
| Thoracic | 36 (24.7%) | 38 (33.3%) | ||
| Other | 31 (21.2%) | 19 (16.7%) | ||
| Molecular profile restrictiona | Yes | 22 (15.1%) | 5 (4.4%) | p=0.005 |
| No | 124 (84.9%) | 109 (95.6%) | ||
| Systemic therapyb | Targeted therapy | 117 (80.1%) | 77 (67.5%) | p=0.048 |
| Cytotoxic chemotherapy | 28 (19.2%) | 33 (28.9%) | ||
| Treatment order | First-line therapy | 77 (52.7%) | 57 (50.0%) | p=0.66 |
| Second-line or higher therapy | 69 (47.3%) | 57 (50.0%) | ||
| Single-agent or combinationc | Single-agent | 61 (41.8%) | 41 (36.0%) | p=0.44 |
| Combination | 84 (57.5%) | 69 (60.5%) | ||
| Trial success (PEP met)d | Yes | 89 (66.9%) | 34 (33.3%) | p<0.0001 |
| No | 44 (33.1%) | 68 (66.7%) | ||
p-value reflects Pearson’s Chi-squared test p-values comparing PFS and OS trials for all trial characteristics except total enrollment, for which the Mann-Whitney U-test p-value is provided, and time between accrual start and primary completion, for which binary logistic regression p-value is provided.
Molecular profile restriction refers to those trials that selected for patients with specific tumor-related mutations. This includes trials selecting for patients with EGFR mutation, ALK fusion, BRAF mutation, and similar.
Systemic therapy interventions were divided into targeted therapies (including monoclonal antibodies, small molecule inhibitors, and similar) and cytotoxic chemotherapy; 5 trials (1 PFS PEP and 4 OS PEP) investigated either a purely surgical or nuclear medicine question and were not included in this analysis.
Studies tested either a single-agent intervention (“Single-agent”) or in combination with other oncotherapeutics (“Combination”); 5 trials (1 PFS PEP and 4 OS PEP) investigated either purely surgical or nuclear medicine questions and were not included in this analysis.
Trial success based on earliest peer-reviewed publication of trial PEP results; 25 trials (13 PFS PEP and 12 OS PEP) were excluded because they either did not have peer-reviewed results published at the time of analysis, results were published as part of a pooled-analysis rather than the individual trial-level data, or the publication did not analyze the PEP.
Abbreviations: PFS, progression-free survival; OS, overall survival; N, number of trials; %, percentage of trials; IQR, interquartile range; PEP, primary endpoint.