Background: In an era of multiple effective treatment options for relapsed/refractory multiple myeloma (MM), a recent meta-analysis has shown that retreatment with bortezomib continues to be an effective option in previously treated patients who relapsed. As economic pressures rise in oncology, it is important to evaluate the cost-effectiveness of newer therapies relative to standards of care. Carfilzomib was recently approved by the US Food and Drug Administration for the treatment of relapsed/refractory MM.
Objective: This analysis estimates treatment-related costs for bortezomib retreatment versus carfilzomib in patients with relapsed MM previously treated with bortezomib.
Methods: A cost model was constructed from a US managed care payer’s perspective. Treatment-related costs included drug, medical (physician assessment and counseling, intravenous [IV] administration, hydration, laboratory tests), and adverse event (AE) costs. Drug costs were based on wholesale acquisition costs, and medical costs were based on Medicare published Current Procedural Terminology codes; AE costs were obtained from published literature. Pooled weighted average estimates from the 4 studies of IV bortezomib-dexamethasone retreatment were identified in the recent meta-analysis (0%-≥10% bortezomib-refractory patients) were used for treatment and efficacy inputs; the median duration of treatment (DOT) was 6.3 twenty one–day cycles; overall response rate (ORR) was 51.0%. Single-agent carfilzomib data were taken from the PX-171-003-A1 study (Siegel, et al. Blood. 2012; 100% bortezomib-exposed, 73% bortezomib-refractory patients; DOT, 3.2 28-day cycles; the ORR was 40.3% in bortezomib-exposed patients but not bortezomib-refractory patients). Because of a lack of information regarding carfilzomib’s DOT in bortezomib-exposed but not bortezomib-refractory patients in PX-171-003-A1, the DOT was also estimated based on the PX-171-004 trial (bortezomib-naïve patients; seven 28-day cycles). The results were calculated as monthly costs and per course of treatment (ie, per median DOT).
Results: For bortezomib-dexamethasone retreatment, the monthly treatment-related cost was $11,919, including a drug cost of $8643, a medical cost of $1173, and an AE cost (including anemia, neutropenia, and thrombocytopenia) of $2103. The treatment-related cost per course was $52,311. For carfilzomib (DOT, 3.2 cycles for PX-171-003-A1), the monthly treatment-related cost was $21,899; including a drug cost of $10,659; a medical cost of $1295; and an AE cost (including anemia, neutropenia, and acute renal failure) of $9945. The treatment-related cost per course was $65,499. Using a carfilzomib DOT of 7 cycles (PX-171-004), the monthly treatment-related cost with carfilzomib was $16,511 and $107,578 per course. Progression-free and overall survival cannot yet be fully evaluated because of a lack of comparable data.
Conclusions: With a similar ORR and lower treatment-related costs, bortezomib-dexamethasone is a cost-saving treatment option compared with carfilzomib in bortezomib-relapsed patients.
