Imatinib Versus Interferon-alpha (IFN) for Patients with Newly Diagnosed Chronic-Phase (CP) Chronic Myeloid Leukemia (CML) from the Chinese Public Healthcare System Perspective: 12 Months Cost and Cost Per Responder Analyses.

Background: Imatinib, a break-through oral molecular targeted therapy, has demonstrated impressive and durable responses as well as survival advantage over IFN based therapy in CML (1, 2). Reed et al. estimated the survival for a newly diagnosed CP CML patient treated with imatinib was 19.07 years vs. 9.09 years with IFN plus low dose cytarabine (LDAC) (3). However, imatinib has not been registered on the Chinese National Reimbursement Drug List (RDL) whereas IFN has. Although studies have shown IFN plus Ara-C is more effective than IFN alone, IFN is normally used alone in China in CP CML. Therefore, this study compared imatinib with IFN alone. Complete cytogenetic response (CCyR) at 12 months has been established as an effective measure for treatment efficacy in CML (4). The 12 months cost and cost per responder in CCyR analyses were conducted to compare imatinib with IFN alone from the Chinese public healthcare systems perspective.

Methods: The cost per responder at 12 months for a newly diagnosed CP CML patient was calculated as dividing the total 1-year cost of treatment by the CCyR rate at 12 months. The 1-year cost of treatment consists of the following occurred during one year: drug cost, office visits, and blood tests. The cost of managing adverse events was excluded as local China data were unavailable at the time of the analyses. The CCyR at 12 months for imatinib was obtained from the International Randomized Infereron vs. STI571 Study (IRIS) (1). The CCyR at 12 months for IFN was from the Baccarani et al. study (6). Price information on drugs was obtained from the listed retail price in China. The price for imported IFN was used as the cytogenetic response data were unavailable for domestic made IFN. Unit cost on office visit and blood test was estimated based on the average fees charged by tier 3 hospitals. Dosages for imatinib and IFN were based on the approved product labels in China.

Results: The 12-month CCyR rate for imatinib was 69% vs. 3% for IFN. The 1-year cost of treatment associated with imatinib was RMB77,700, lower than that with IFN (RMB79,200). The cost to achieve 1 CCyR at 12 month was RMB112,609 with imatinib vs. RMB2,640,000 with IFN.

Conclusion: In newly diagnosed CP CML, patients treated with imatinib achieved a significantly higher CCyR at a lower cost than those treated with IFN at 12 months. Based on the 1 year analysis, imatinib is a dominant treatment option in comparison to IFN in newly diagnosed CP CML treatment from the Chinese public healthcare system’s perspective.