Economic evaluation of rituximab plus cyclophosphamide, vincristine and prednisolone for advanced follicular lymphoma

Figures & data

Figure 1. First-line R-CVP First R versus CVP.

Figure 2. (a) Observed survival based on the trial data and then predicted using hazard ratios. (b) Observed progression-free survival and then predicted using hazard ratios.

Table I.  Calculation of costs of CVP

	CVP			R-CVP
	CTX	Vincristine	Prednisolone	CTX	Vincristine	Prednisolone
Normalized dose given (divided by BSA)	4866	7.1	1323	5315	7.7	1471
Recommended dose	10,320	19.3	6880	10,320	19.3	6880
Actual dose given	8370	12.2	2276	9142	13.2	2530
Percent	81.1%	63.4%	82.7%	88.6%	68.8%	36.8%
Cost per cycle	$47.40	$13.37	$13.32	$46.60	$13.37	$13.32
Cost per course	$302.35	$67.81	$88.11	$330.25	$67.81	$88.11
			$458.27			$501.76

CTX, cyclophosphamide; BSA, body surface area.

Table II.  Rituximab cost calculation

Dosing information	Estimate
Intended number of cycles	8
Mean body surface area (m^2)	1.72
Prescribed dose (mg per m^2)	375
Dose per cycle (mg)	645
Dose purchased (mg)*	700
Cost per cycle	$3372
Percent of dose given	89.1%
Cost per course	$24,034

*One 500 mg vial (50 mL) and two 50 mg vials (10 mL).

Table III.  R-CVP arm administration costs

Administration costs	CPT Code	Fee	Amount
First cycle
Initial administration cost	96413	$172.81	1
Additional hour cost	96415	$39.03	4.4
Additional infusion cost	96417	$84.51	2
Total Cost		$513.56
Subsequent
Initial administration cost	96413	$172.81	1
Additional hour cost	96415	$39.03	3.4
Additional infusion cost	96417	$84.51	2
Total Cost		$474.53

Table IV.  Salvage therapy regimens and costs over 6 months

Regimen	Utilization (%)	Cost
Chlorambucil	6	$935
Cyclophosphamide	6	$1541
CHOP	6	$3829
Fludarabine	6	$9001
FMD	6	$22,084
Rituximab-containing regimens*	70	$29,084
Average		$23,206

*Includes R-CHOP, R-CVP, R-COP, R-F, R-FMD, with patients receiving at seven cycles of rituximab.

Table V.  Summary of base-case estimates, ranges for sensitivity analyses and quality of the evidence

Parameter	Base-case estimate		Range for sensitivity analyses	Quality of evidence
	R-CVP	CVP
Utilities
Follicular lymphoma pre-progression	0.805		0.70 to 90	B
Post-progression	0.618		0.52 to 0.72	B
Tariffs
Chemotherapy	−0.15		−0.3 to 0	C
Stem cell transplantation	−0.20		−0.4 to 0	C
End-of life (last 6 months)	−0.30		−0.6 to 0	C
Costs
Chemotherapy drugs
Rituximab	$24,034	–	±25%	A
CVP	$502	$458	±25%	A
Chemotherapy administration	$3,529	$1,702	±25%	A
Adverse events	$580	$95	±25%	A
After treatment
Follow-up tests and visits	Approximately $142 every 3 months		±25%	B
Follow-up treatment	$23,206		−25% to +100%	B
Stem cell transplantation	$75,352		±25%	B
End-of-life care	$21,463		±25%	B
Other variables
Societal time discount rate	3%		0% – 5%	A
Time horizon	Lifetime		5 years to lifetime	B

CVP, chemotherapy regimen containing cyclophosphamide; vincristine and prednisolone.

See Figure 3 for grading system.

Cost of laboratories per month; increase by $841 for periodic CT scans in first 2 years.

Figure 3. Quality of the evidence – grading system.

Table VI.  Base-case results

Endpoint	R-CVP	CVP	Difference
OS (yr)	13.68	12.17	1.51
PFS (yr)	3.78	1.84	1.93
QALY
Remission	6.40	5.51	0.89
Chemotherapy	−0.15	−0.15	0.00
Salvage treatment	−0.19	−0.22	0.03
End of life	−0.21	−0.22	0.01
Total	5.85	4.93	0.93
Costs
Chemotherapy drugs	$24,536	$458	$24,078
Chemotherapy administration	$3529	$1702	$1827
Adverse events	$580	$95	$485
Follow-up tests and visits	$13,348	$12,051	$1297
Stem cell transplantation	$5123	$4514	$609
Salvage treatment	$34,466	$36,610	−$2144
End of life	$24,025	$23,737	$287
Total	$105,607	$79,168	$26,439
Cost per life-year gained			$17,504
Cost per QALY gained			$28,565

OS, overall survival; PFS, progression-free survival; QALY, quality-adjusted life years; CVP, chemotherapy regimen containing cyclophosphamide, vincristine and prednisolone.

Figure 4. Sensitivity analyses.