Table 1.
Model parameters: baseline values, ranges, and distributions for the sensitivity analysis.
| Parameters | Baseline value | Range | Reference | Distribution | |
|---|---|---|---|---|---|
| Minimum | Maximum | ||||
| Weibull survival model for OS of serplulimab plus chemotherapy | |||||
| Overall population | Scale= 0.012874, Shape= 1.445565 | – | – | (9) | – |
| Chinese | Scale= 0.009574, Shape= 1.535633 | – | – | (9) | – |
| Weibull survival model for PFS of serplulimab plus chemotherapy | |||||
| Overall population | Scale= 0.14015, Shape= 0.92013 | (9) | – | ||
| Chinese | Scale= 0.09846, Shape= 1.08898 | (9) | – | ||
| Weibull survival model for OS of chemotherapy | |||||
| Overall population | Scale= 0.016452, Shape= 1.527988 | (9) | – | ||
| Chinese | Scale= 0.03359, Shape= 2.07247 | (9) | – | ||
| Weibull survival model for PFS of chemotherapy | |||||
| Overall population | Scale= 0.01472, Shape= 1.56003 | – | – | (9) | – |
| Chinese | Scale= 0.03309, Shape= 2.15174 | - | - | (9) | - |
| Rate of post-discontinuation therapy | |||||
| Chemotherapy group | 0.049 | 0.039 | 0.059 | (9) | Beta |
| Serplulimab plus chemotherapy group | 0.041 | 0.033 | 0.049 | (9) | Beta |
| Risk for main AEs in chemotherapy group | |||||
| Risk of anemia | 0.054 | 0.043 | 0.065 | (9) | Beta |
| Risk of thrombocytopenia | 0.062 | 0.050 | 0.074 | (9) | Beta |
| Risk of white blood cell decreased | 0.085 | 0.068 | 0.102 | (9) | Beta |
| Risk of decreased neutrophil count | 0.141 | 0.113 | 0.169 | (9) | Beta |
| Risk for main AEs in serplulimab plus chemotherapy group | |||||
| Risk of anemia | 0.056 | 0.045 | 0.067 | (9) | Beta |
| Risk of thrombocytopenia | 0.082 | 0.066 | 0.098 | (9) | Beta |
| Risk of white blood cell decreased | 0.087 | 0.070 | 0.104 | (9) | Beta |
| Risk of decreased neutrophil count | 0.138 | 0.110 | 0.166 | (9) | Beta |
| Utility | |||||
| Utility PFS | 0.673 | 0.538 | 0.808 | (17, 19) | Beta |
| Utility PD | 0.473 | 0.378 | 0.568 | (17, 19) | Beta |
| Disutility | |||||
| Anemia | 0.074 | 0.059 | 0.089 | (19) | Beta |
| Decreased neutrophil count | 0.090 | 0.072 | 0.108 | (19) | Beta |
| White blood cell decreased | 0.090 | 0.072 | 0.108 | (19) | Beta |
| Thrombocytopenia | 0.200 | 0.160 | 0.240 | (14) | Beta |
| Drug cost, $/per cycle | |||||
| Serplulimab | 605 | 484 | 726 | Local Charge | Gamma |
| Etoposide | 12 | 10 | 14 | Local Charge | Gamma |
| Carboplatin | 73 | 58 | 88 | Local Charge | Gamma |
| Topotecan | 317 | 254 | 380 | Local Charge | Gamma |
| Cost of AEs, $ | |||||
| Chemotherapy | 386 | 309 | 463 | (14, 19) | Gamma |
| Serplulimab plus chemotherapy | 309 | 247 | 371 | (14, 19) | Gamma |
| Administration per cycle | 36 | 29 | 43 | (19) | Gamma |
| Laboratory per cycle | 166 | 133 | 199 | (19) | Gamma |
| Tumor imaging per cycle | 507 | 406 | 608 | (19) | Gamma |
| Best supportive care per cycle | 221 | 177 | 265 | (19) | Gamma |
| Terminal care per patient | 2,221 | 1,777 | 2,665 | (17) | Gamma |
| Weight (Kg) | 65 | 52 | 78 | (12) | Normal |
| Body surface area (meters2) | 1.72 | 1.38 | 2.06 | (12) | Normal |
| Area under the curve (mg/mL/min) | 5 | – | – | (12) | Uniform |
| Serum creatinine (mg/dL) | 1 | – | – | (13) | Uniform |
| Discount rate | 0.03 | – | – | (14) | Uniform |
OS, overall survival; PFS, progression-free survival; PD, disease progressed; AEs, adverse events.