Table 1.
Baseline characteristics of patients with immune checkpoint inhibitor use
|
Clinical variables
|
All patients (n = 128)
|
Patients with IMC (n = 64)
|
Patients without IMC (n = 64)
|
P
value
|
|||
| Age, yr (mean ± SD)1 | 66.6 (± 11.5) | 67.4 (± 11.7) | 65.8 (± 11.3) | 0.420 | |||
| Sex1 | |||||||
| Male, n (%) | 74 | 57.81% | 37 | 57.81% | 37 | 57.81% | 1.000 |
| Female, n (%) | 54 | 42.19% | 27 | 42.19% | 27 | 42.19% | |
| Race | |||||||
| White, n (%) | 102 | 79.69% | 52 | 81.25% | 50 | 78.13% | 0.660 |
| Black, n (%) | 4 | 3.13% | 2 | 3.13% | 2 | 3.13% | 1.000 |
| Asian, n (%) | 9 | 7.03% | 4 | 6.25% | 5 | 7.81% | 0.730 |
| Type of malignancy1 | |||||||
| Melanoma, n (%) | 66 | 51.56% | 33 | 51.56% | 33 | 51.56% | 1.000 |
| RCC, n (%) | 15 | 11.72% | 8 | 12.50% | 7 | 10.94% | 0.783 |
| NSCLC, n (%) | 12 | 9.38% | 6 | 9.38% | 6 | 9.38% | 1.000 |
| Sarcoma, n (%) | 11 | 8.59% | 5 | 7.81% | 6 | 9.38% | 0.752 |
| Head and neck SCC, n (%) | 7 | 5.47% | 3 | 4.69% | 4 | 6.25% | 0.697 |
| Other, n (%) | 17 | 13.28% | 9 | 14.06% | 8 | 12.50% | 0.795 |
| Stage IV malignancy, n (%) | 114 | 89.07% | 56 | 87.50% | 58 | 90.63% | 0.778 |
| Type of immune checkpoint inhibitor1 | |||||||
| Ipilimumab plus nivolumab, n (%) | 48 | 37.50% | 24 | 37.50% | 24 | 37.50% | 1.000 |
| Ipilimumab, n (%) | 22 | 17.19% | 11 | 17.19% | 11 | 17.19% | 1.000 |
| Nivolumab, n (%) | 12 | 9.38% | 6 | 9.38% | 6 | 9.38% | 1.000 |
| Pembrolizumab, n (%) | 38 | 29.69% | 19 | 29.69% | 19 | 29.69% | 1.000 |
| Atezolizumab, n (%) | 8 | 6.25% | 4 | 6.25% | 4 | 6.25% | 1.000 |
| Number of Infusionsa (mean ± SD)1 | 6.91 (± 8.40) | 6.09 (± 7.20) | 7.73 (± 9.40) | 0.268 | |||
| Dose of ICI (mg/kg) (mean ± SD) | 2.47 (± 1.30) | 2.63 (± 1.60) | 2.31 (± 1.00) | 0.318 | |||
| Prior ICI use1 | 19 | 14.84% | 10 | 15.63% | 9 | 14.06% | 0.500 |
| Medical history, n (%) | |||||||
| Non-liver, non-upper GI diseaseb, n (%) | 28 | 21.88% | 18 | 28.13% | 10 | 15.63% | 0.087 |
| Personal history of autoimmune diseaseb, n (%) | 30 | 23.44% | 20 | 31.25% | 10 | 15.63% | 0.037 |
| Prior irAEb, n (%) | 8 | 12.50% | 7 | 10.90% | 1 | 1.56% | 0.062 |
| Family history of autoimmune diseaseb, n (%) | 10 | 7.81% | 8 | 12.50% | 2 | 3.13% | 0.048 |
| Prior immune-enhancing therapyb, n (%) | 11 | 8.59% | 2 | 3.13% | 9 | 14.06% | 0.027 |
| Prior interferon-γ therapy, n (%) | 7 | 5.47% | 1 | 1.56% | 6 | 9.38% | 0.115 |
| Vitamin D use, n (%) | 38 | 29.69% | 25 | 39.06% | 13 | 20.31% | 0.020 |
| Smoking (current or prior), n (%) | 61 | 47.66% | 33 | 51.56% | 28 | 43.75% | 0.376 |
| NSAID use, n (%) | 21 | 16.41% | 10 | 15.63% | 11 | 17.19% | 0.811 |
| Any vaccine, n (%) | 25 | 19.53% | 9 | 14.06% | 16 | 25.00% | 0.119 |
| Flu vaccine, n (%) | 19 | 14.84% | 7 | 10.94% | 12 | 18.75% | 0.214 |
| Pneumonia vaccine, n (%) | 11 | 8.59% | 4 | 6.25% | 7 | 10.94% | 0.344 |
| Other vaccine, n (%) | 2 | 1.56% | 1 | 1.56% | 1 | 1.56% | 1.000 |
| Weight at start of ICI (kg) (mean ± SD) | 78.1 (± 17.4) | 79.4 (± 16.9) | 76.8 (± 17.9) | 0.396 | |||
| Medications | |||||||
| Steroid at start of ICI, n (%) | 20 | 15.63% | 11 | 17.19% | 9 | 14.06% | 0.626 |
| Steroid duration (d) | N/A | 107.7 (± 164.2) | N/A | ||||
| Infliximab use, n (%) | N/A | 10 | 15.63% | N/A | |||
| Vedolizumab use, n (%) | N/A | 1 | 1.56% | N/A | |||
| Malignancy outcomes | |||||||
| Mean PFS (mo) | 12.8 (± 15.3) | 13.7 (± 14.9) | 11.9 (± 15.8) | 0.524 | |||
| PFS > 6 mo, n (%) | 63 | 49.22% | 35 | 54.69% | 28 | 43.75% | 0.216 |
| OS (mo) | 21.0 (± 18.9) | 24.3 (± 19.4) | 17.7 (± 18.0) | 0.050 | |||
| OS > 12 mo, n (%) | 72.0 | 56.25% | 42 | 65.63% | 30 | 46.88% | 0.025 |
| Death, n (%) | 20 | 15.63% | 6 | 9.38% | 14 | 21.88% | 0.051 |
1
Variable matched between cases and controls.
a
Number of infusions of immune checkpoint inhibitor prior to immune checkpoint inhibitor-mediated colitis diagnosis (cases) or total (controls).
b
IMC: Immune checkpoint inhibitor-mediated colitis; ICI: Immune checkpoint inhibitor; SD: Standard deviation; RCC: Renal cell carcinoma; NSCLC: Non-small cell lung cancer; SCC: Squamous cell carcinoma; PFS: Progression-Free Survival; irAE: Immune related adverse event; OS: Overall survival.