Table 2.
Patient clinical characteristics, n = 193
| Characteristic | Bortezomib n = 114 |
Carfilzomib n = 55 |
Ixazomib n = 24 |
|---|---|---|---|
| No. (%) | No. (%) | No. (%) | |
| Time from PI initiation to symptom onset, days, median (IQR) | 58.3 (17.1–148.4)a | 89 (31–193) | 312.5 (42.5–835.5)a |
| Other irAEs | 37 (32.5%) | 18 (32.7%) | 10 (41.7%) |
| Concurrent cancer medicationsb | 71 (49.3%) | 45 (81.8%) | 16 (66.7%) |
| Location of GI toxicity | |||
| Upper GI | 9 (7.9%) | 7 (12.7%) | 9 (37.5%)* |
| Lower GI | 109 (95.6%) | 50 (90.9%) | 16 (66.7%)* |
| Hepatobiliary | 1 (0.9%) | 1 (1.8%) | 1 (4.2%) |
| Pancreatic | – | – | – |
| Presenting symptoms | |||
| Nausea/vomiting | 7 (6.1%)a | 9 (16.4%) | 9 (37.5%)a |
| Diarrhea | 102 (89.5%)a | 50 (90.9%) | 17 (70.8%)a |
| Constipation | 8 (7.0%) | 1 (1.8%) | 0 (0%) |
| Blood in stool | 3 (2.6%) | 2 (3.6%) | 0 (0%) |
| Abdominal pain | 3 (2.6%) | 4 (7.3%) | 2 (8.3%) |
| Peak diarrhea CTCAE grade | |||
| 1 | 24 (45.3%) | 19 (51.4%) | 10 (58.8%) |
| 2 | 21 (39.6%) | 16 (43.2%) | 6 (35.3%) |
| 3 | 7 (13.2%) | 2 (5.4%) | 1 (5.9%) |
| 4 | 1 (1.9%) | 0 (0%) | 0 (0%) |
| Fecal lactoferrin positive, n = 7 tested | 2 (40.0%) | 1 (100%) | 1 (100%) |
| Peak fecal calprotectin values, mean ± SEM (n = 8) |
30.5 ± 8.9 (n = 6) |
57.3 (n = 1) |
31 (n = 1) |
CTCAE, Common Terminology Criteria for Adverse Events; GI, gastrointestinal; irAE, immune-related adverse event; IQR, interquartile range; PI, proteasome inhibitor; SEM, standard error of the mean
*This group differed significantly from the other two groups at the p < 0.05 level
aThese two groups differed significantly at the p < 0.05 level (p = 0.01)
bIncluded patients taking cyclophosphamide, daratumumab, isatuximab, lenalidomide, or pomalidomide. Only 1 (0.5%) patient developed GI Graft-versus-host disease prior to the diagnosis of PI-induced GI toxicity