Cost-Effectiveness Analysis of Biomarker-Guided Treatment for Metastatic Gastric Cancer in the Second-Line Setting

Table 1

Summary of model inputs. Costs, probabilities, and utilities are per month unless otherwise specified.

Parameter type	Parameter	Base case estimate
All treatment arms
Probabilities	Cancer-specific mortality on 3L best supportive care	0.1476 [20]
	trAE-related hospitalization	0.0440 [4]
Costs	Cost of GP follow-up	$179.39 [22]
	Cost of oncology follow-up	$355.35 [22]
	Cost of radiology follow-up	$284.00 [22]
	One-time cost: PD-L1 testing (CPT 88342)	$118.51 [23]
	One-time cost: MSI-H testing (CPT 81301)	$348.56 [24]
Utilities	2L progression-free survival	0.622 [25, 26]
	3L best supportive care	0.362 [25, 26]
Best supportive care
Probabilities	Disease progression
	Months 0–3	0.414 [20]
	Months 4–10	0.347 [20]
	Months 11+	0.251 [20]
	Cancer-specific mortality	0.129 [20]
Costs	Average cost of routine home care Medicare rate (2018)	$5169.60 [27, 28]
Pembrolizumab
Probabilities	Disease progression: biomarker agnostic
	Months 0–1	0.31 [10]
	Months 2–9	0.122 [10]
	Months 10+	0.014 [10]
	Cancer-specific mortality	0.01857 [10]
	Disease progression: PDL1 + CPS > 1%
	Months 0–3	0.2940 [10]
	Months 4–10	0.0998 [10]
	Months 11+	0.0127 [10]
	Cancer-specific mortality	0.01179 [10]
	Disease progression: MSI-H
	Months 0–3	0.0835 [10, 29]
	Months 4–10	0.0249 [10, 29]
	Months 11+	0.0134 [10, 29]
	Cancer-specific mortality	0.0057 [10]
	Adverse events
	Grade 1/2	0.1035 [6, 7, 10, 30, 31]
	Grade 3/4	0.0237 [6, 7, 10, 30, 31]
	Discontinuation	0.0028 [6, 7, 10, 30, 31]
	Death	0.00098 [6, 7, 10, 30, 31]
Costs	Pembrolizumab	$12246.75 [32]
	Drug administration	$470 [33]
	trAEs (grade 3/4)	$19487 [34, 35]
Disutilities	trAEs (grade 1/2)	−0.086 [36]
	trAEs (grade 3/4)	−0.165 [36]
Paclitaxel
Probabilities	Disease progression
	Months 0–3	0.1870 [7]
	Months 4–10	0.1730 [7]
	Months 11+	0.1430 [7]
	Cancer-specific mortality	0.028 [7]
	Adverse events
	Grade 1/2	0.0864 [7, 10]
	Grade 3/4	0.0644 [7, 10]
	Discontinuation	0.0085 [7, 10]
	Death	0.0021 [7, 10]
Costs	Paclitaxel	$66.53 [32]
	Drug administration	$1412 [33]
	trAEs (grade 3/4)	$13198 [34, 35]
Disutilities	trAEs (grade 1/2)	−0.071 [36–39]
	trAEs (grade 3/4)	−0.180 [36–39]
Ramucirumab + paclitaxel
Probabilities	Disease progression
	Months 0–1	0.1176 [7]
	Months 2–11	0.1843 [7]
	Months 12+	0.03297 [7]
	Cancer-specific mortality	0.01235 [7]
	Adverse events
	Grade 1/2	0.0306 [7]
	Grade 3/4	0.1773 [7]
	Discontinuation	0.0210 [7]
	Death	0.0034 [7]
Costs	Ramucirumab + paclitaxel	$12974 [32]
	Drug administration	$2118 [33]
	trAEs (grade 3/4)	$20658 [34, 35]
Disutilities	trAEs (grade 1/2)	−0.110 [36]
	trAEs (grade 3/4)	−0.250 [36]