Cost- Effectiveness of Avatrombopag for the Treatment of Thrombocytopenia in Patients with Chronic Liver Disease

Figures & data

Figure 1 Cost-effectiveness model structure.

Notes: [+] Clone refers to a copy of the decision-tree branches directly above. Grey portions of the tree denote components that are used only during scenario analyses. *Included in the cost of each treatment is the expected cost of a thromboembolic event.

Table 1 Population and Subpopulations for Base-Case Analysis

	Parameter Value	Sources and Assumptions
Population selected for comparison	Overall population (all patients with a platelet count <50×10^9/L)
Platelet count cut-point
Avatrombopag
Lower platelet count population	<40×10^9/L	Doptelet prescribing information (2018)^Citation29
Higher platelet count population	≥40×10^9/L to <50×10^9/L	Doptelet prescribing information (2018)^Citation29
Lusutrombopag
Lower platelet count population	<35×10^9/L	Peck-Radosavljevic et al (2019)10
Higher platelet count population	≥35×10^9/L to <50×10^9/L	Peck-Radosavljevic et al (2019)10
Proportion of population with lower and higher platelet counts		Doptelet prescribing information (2018)^Citation29
Avatrombopag
Lower platelet count population	57.7%	Doptelet prescribing information (2018)^Citation29
Higher platelet count population	42.3%	Doptelet prescribing information (2018)^Citation29
Lusutrombopag
Lower platelet count population	35.3%	AASLD 2017^a^Citation13
Higher platelet count population	64.7%	AASLD 2017^a^Citation13

Note: ^aPresented at the AASLD 2017 Annual Meeting.

Abbreviation: AASLD, American Association for the Study of Liver Diseases.

Table 2 Model Inputs: Treatment Costs per Procedure for Avatrombopag and Lusutrombopag (2019 USD)

	Avatrombopag (40 mg)	Avatrombopag (60 mg)	Lusutrombopag (3 mg)	Source Notes
Dose per package/scheduled procedure (mg)	200	300	21	Doptelet prescribing information (2018);^Citation29 Mulpleta prescribing information (2018)^Citation12
WAC per package/scheduled procedure	$2970	$4455	$8500	Red Book Online (2019)^Citation14
Weighted average WAC per package/scheduled procedure for avatrombopag	$3827		Not applicable	Calculated the weighted average cost of avatrombopag per scheduled procedure based on the distribution by subpopulation

Abbreviations: USD, US dollar; WAC, wholesale acquisition cost.

Table 3 Base-Case Results: Overall Population (Platelet Count <50×10⁹/L)

Outcome	Avatrombopag	Prophylactic Platelet Transfusion	Lusutrombopag
Economic outcomes (per person)
Costs of drug treatment	$3827	$0	$8500
Costs of prophylactic platelet transfusion	$1475	$9271	$2552
Costs of thromboembolic events	$56	$200	$179
Costs of bleeding events requiring rescue procedure	$54	$191	$0
Total costs	$5412	$9662	$11,231
Health outcomes (per person)
Number of prophylactic platelet transfusions	0.2034	1.0000	0.3519
Number of thromboembolic events	0.0037	0.0130	0.0117
Number of bleeding events requiring rescue procedure	0.0113	0.0403	0.0000
Incremental outcomes (per person)		Avatrombopag vs prophylactic platelet transfusion	Avatrombopag vs lusutrombopag
Incremental costs		-$4250	-$5819
Number of prophylactic platelet transfusions avoided		0.7966	0.1485
Cost per prophylactic platelet transfusion avoided		-$5335^a	-$39199^a

Note: ^aAvatrombopag compared with both prophylactic platelet transfusion and lusutrombopag resulted in lower costs and fewer prophylactic platelet transfusions, yielding a negative cost per prophylactic platelet transfusion avoided, which suggests that avatrombopag is the dominant treatment.

Figure 2 One-way sensitivity analyses results. (A) Cost per prophylactic platelet transfusion avoided with avatrombopag in comparison with prophylactic platelet transfusion in the overall patient population. (B) One-way sensitivity analysis results: cost per prophylactic platelet transfusion avoided with avatrombopag in comparison with lusutrombopag in the overall population.

Note: Gray indicates the lower bound and black indicates the upper bound.

Figure 3 Probabilistic sensitivity analyses results. (A) Probabilistic sensitivity analysis results: cost per prophylactic platelet transfusion avoided with avatrombopag in comparison with prophylactic platelet transfusion in the overall population. (B) Probabilistic sensitivity analysis results: cost per prophylactic platelet transfusion avoided with avatrombopag in comparison with lusutrombopag in the overall population.

Table 4 Base-Case Results for Scenario Analysis Incorporating Long-Term Outcomes: Overall Population (Platelet Count <50×10⁹/L)

Outcome	Avatrombopag	Prophylactic Platelet Transfusion	Lusutrombopag
Economic outcomes (per person)
Costs of treatment	$3827	$0	$8500
Costs of prophylactic platelet transfusion	$1475	$9271	$2552
Costs of thromboembolic events	$56	$200	$179
Costs of bleeding events requiring surgical repair	$19	$68	$0
Costs of bleeding events requiring other rescue procedure	$52	$185	$0
Total costs	$5429	$9724	$11,231
Health outcomes (per person)
Number of prophylactic platelet transfusions	0.2034	1.0000	0.3519
Number of thromboembolic events	0.0037	0.0130	0.0117
Number of bleeding events requiring surgical repair	0.0004	0.0014	0.0000
Number of bleeding events requiring other rescue procedure	0.0109	0.0389	0.0000
Number of life-years (undiscounted)	24.2619	24.2543	24.2585
Number of life-years (discounted)	18.0606	18.0570	18.0590
Incremental outcomes		Avatrombopag vs prophylactic platelet transfusion	Avatrombopag vs lusutrombopag
Incremental costs		-$4294	-$5802
Number of prophylactic platelet transfusions avoided		0.7966	0.1485
Incremental life-years (undiscounted)		0.0076	0.0034
Incremental life-years (discounted)		0.0036	0.0016
Cost per prophylactic platelet transfusion avoided		-$5391^a	-$39,084^a

Note: ^aAvatrombopag compared with both prophylactic platelet transfusion and lusutrombopag resulted in lower costs and fewer prophylactic platelet transfusions, yielding a negative cost per prophylactic platelet transfusion avoided, which suggests that avatrombopag is the dominant treatment.

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