Table 2.
Univariate Cox-regression on progression-free survival
| Covariate | HR | Lower 95% CI | Upper 95% CI | P value |
| Treatment arm | ||||
| SBRT+nivolumab+ipilimumab | 1 | |||
| SBRT+nivolumab | 2.86 | 1.34 | 6.10 | 0.007 |
| Age, years | ||||
| >66.5 years | 1 | |||
| ≤66.5 years | 1.123 | 0.545 | 2.314 | 0.754 |
| Sex | ||||
| Female | 1 | |||
| Male | 0.406 | 0.1815 | 0.911 | 0.029 |
| WHO performance status | ||||
| 0 | 1 | |||
| 1 | 1.3 | 0.62 | 2.73 | 0.486 |
| Weight loss >5% | ||||
| No | 1 | |||
| Yes | 1.316 | 0.6323 | 2.737 | 0.463 |
| Number of metastatic sites | ||||
| ≥2 | 1 | |||
| < 2 | 2.336 | 0.972 | 5.612 | 0.0579 |
| Whipple procedure | ||||
| No | 1 | |||
| Yes | 0.681 | 0.29 | 1.60 | 0.377 |
| Biliary stent | ||||
| No | 1 | |||
| Yes | 1.169 | 0.548 | 2.50 | 0.69 |
| Median CA19-9, kU/L | ||||
| ≤median | 1 | |||
| >median | 1.329 | 0.635 | 2.80 | 0.452 |
| NLR | ||||
| ≥5 | 1 | |||
| < 5 | 1.957 | 0.878 | 4.36 | 0.1 |
| Bilirubin, 25 µmol/L | ||||
| >25 | NA | NA | NA | NA |
| ≤25 | NA | NA | NA | NA |
| Albumin, 36 g/L | ||||
| ≤36 | 1 | |||
| >36 | 4.68 | 1.084 | 20.18 | 0.038 |
| CRP, 10 mg/L | ||||
| ≤10 | 1 | |||
| >10 | 0.8 | 0.387 | 1.66 | 0.547 |
| mGPS | ||||
| 0 | 1 | |||
| ≥1 | 0.8 | 0.387 | 1.66 | 0.547 |
| Prior lines of therapy | ||||
| <2 | 1 | |||
| ≥2 | 1 | 0.489 | 2.05 | 0.996 |
| Best optimal response to prior last therapy | ||||
| Clinical benefit | 1 | |||
| No benefit | 1 | 0.493 | 2.08 | 0.972 |
| ELISpot response to TGF-β-15 at baseline | ||||
| ≤median | 1 | |||
| >median | 0.227 | 0.091 | 0.566 | 0.0015 |
| Multivariate Cox-regression on progression-free survival | ||||
| Covariate | HR | Lower 95% CI | Upper 95% CI | P value |
| Treatment arm | ||||
| SBRT+nivolumab+ipilimumab | 1 | |||
| SBRT+nivolumab | 1.94 | 0.832 | 4.53 | 0.125 |
| Sex | ||||
| Female | 1 | |||
| Male | 0.446 | 0.192 | 1.034 | 0.061 |
| Albumin, 36 g/mL | ||||
| ≤36 | 1 | |||
| >36 | 2.60 | 0.55 | 12.31 | 0.229 |
| ELISpot response to TGF-β-15 at baseline | ||||
| ≤median | 1 | |||
| >median | 0.322 | 0.121 | 0.857 | 0.023 |
CRP, C-reactive protein; ELISpot, enzyme-linked immunospot assay; mGPS, modified Glasgow Prognostic Score; NLR, Neutrophil-to-lymphocyte ratio; SBRT, stereotactic body radiotherapy; TGF-β, transforming growth factor-β.