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Table 1 Model inputs

From: Cost-effectiveness analysis of pembrolizumab compared to standard of care as first line treatment for patients with advanced melanoma in Hong Kong

 InterventionBase case comparatorAdditional comparators tested in scenario analyses
PembrolizumabDTICIpilimumabTemozolomidePaclitaxel/carboplatin
Survival extrapolation for progression free survival (PFS) and overall survival (OS)
 PFS funtional formaWeibullConstant HR from NWMALog-normalAssumed the same as for DTICAssumed the same as for DTIC
 OS functional formbLognormal model for HRConstant HR from NWMA followed by registry dataKEYNOTE-006 ipilimumab arm, long-term ipilimumab data from Schadendorf et al. [4] and AJCC data.Assumed the same as for DTICAssumed the same as for DTIC
Utility: mean (95% confidence interval)
 Utility: ≥ 360 days till death0.82 (0.81, 0.83)
 Utility [270,360) days till death0.74 (0.69, 0.79)
 Utility [90, 270) days till death0.69 (0.65, 0.73)
 Utility [30,90) days till death0.60 (0.54, 0.66)
 Utility < 30 days till death0.42 (0.29, 0.56)
 Utility for PFS0.82 (0.81, 0.83)0.79 (0.77, 0.80)0.82 (0.81, 0.83)  
 Utility for post-progression0.72 (0.70, 0.74)   
Adverse events (AE)   
 Colitis, grade 3 and abovef1.8%0.0%6.3%0.0%0.0%
 Diarrhea (excl. colitis), grade 2 and above3.6%0.0%7.8%0.0%0.0%
 Endocrine disorders, any grade12.3%0.0%5.5%3.0%0.0%
 Neutropenia, grade 3 and above0.0%11.9%0.0%3.0%18.8%
 Thrombocytopenia0.0%5.1%0.0%7.0% 
 Hemorrhage (non-CNS/pulmonary)0.0%0.0%0.0% 5.8%
 Asthenia0.0%0.0%0.0%3.0%0.0%
 Headache0.0%0.0%0.0%6.0%0.0%
 Pain0.0%0.0%0.0%7.0%0.0%
 Constipation0.0%0.0%0.0%3.0%0.0%
 Nausea0.0%0.0%0.0%4.0%0.0%
 Vomiting0.0%0.0%0.0%5.0%0.0%
 # of treatment for endocrine disorders3.2303.0000
 Costs of AE management$863$92$1196$672$767
 Disutility of an AEe0.15 over 8 weeks
Drug costs
 Unit cost of drug$2564 per 100 mg vial$56 per 100 mg vial$ 5.897 per 50 mg vial$14.28 per 20 mg vialPaclitaxel: $25.77 per 100 mg
Carboplatin: $30.69 per 450 mg
 Dose per administration200 mg Q3W1000 mg/m23 mg/kg Q3W for a maximum of 4 doses1000 mg/m2Paclitaxel: 300 mg
Carboplatin: 525 mg
 Mean number of vials per 3 weeks (based on whole vials at the patient level)1.84 vials17.54,40 of 50 mg vials1750 mg (1000 mg/m2)Paclitaxel: 3 of 100 mg vials
Carboplatin: 1.17 of 450 mg vials
 Mean cost of drug administrationc$91.67 per administration$91.67 per administration$91.67 per administration$0 (oral drug)$91.67 per administration
 Total drug cost for each dose$4706$980$25.937$1.249,50Paclitaxel: $77.31
Carboplatin: $61.38
Total: $138.69
Disease management costsd
 Management during PFS$144/week
 Management during post progression$109/week
 Death related costs$24,089 (last 6 months of life)
  1. aFunctions selected based on Akaike Information Criterion and Bayesian Information Criterion for best fit in weeks 13 and beyond from the trial data
  2. bFunctions selected based on Akaike Information Criterion and Bayesian Information Criterion for best fit from the trial data
  3. cDrug administration costs are from local Hong Kong data. DTIC and pembrolizumab are given once in every 3 weeks until disease progression or 24 months and 41% of patients in PFS at the end of 2 years are projected to receive a second course for a maximum of 12 months
  4. dDisease management costs include oncology office visits, lab tests, scans and other resources which are enlisted in Appendix: Table 4 and the costs are based on Hospital Authority itemized charges as of July 2013
  5. eAE costs were based on frequencies of grade 3 or higher AEs that impacted at least 3% of patients in either arm and the costs were extracted from the Hospital Authority Ordinance [14]. AE disutility was measured by pooling utility scores in patients experiencing an AE versus patients in weeks without an AE and AEs were then modeled as lasting 8 weeks. Costs for managing colitis and diarrhea were $11,785 and $2892 respectively. A cost of $1379 was incurred for treating endocrine disorders every 6 months while Neutropenia of grade 3 or above was associated with a cost of $779 [14]. Even though thrombocytopenia was also a prominent adverse event, its management cost was in significant and hence assumed to be $0
  6. fAn exception to the 3% rule was applied for this AE since it had a 6.3% incidence with Ipilimumab and it was the grade 3–4 AE with the highest incidence in the pembrolizumab Q3W group