PCN92 Cost Effectiveness of Obinutuzumab PLUS Chemotherapy Followed By Obinutuzumab Maintenance for Patient with Previously Untreated Advanced-STAGE Follicular Lymphoma in French Setting

Abstract

Obinutuzumab with chemotherapy plus obinutuzumab maintenance ( G-chemo+G) is reimbursed in France for the treatment of patient with previously untreated advanced-stage follicular lymphoma. Here, we evaluate the cost effectiveness of G-chemo+G over rituximab with chemotherapy plus R maintenance (R-chemo+R). A Markov model was developed over a 30 years time horizon including four health state: ‘PFS (on/off treatment)’, ‘Early progression within 24 months, ‘Late progressive disease in subsequent months’ and ‘Death’. Patient characteristics and clinical data were retrieved from GALLIUM study, except for death probabilities in late progressive diseases state which was based on PRIMA study. We adopted a payer perspective for costs. Frequency of resources used were based on expert opinion. We estimated the benefit in quality-adjusted life years (QALYs) according to age-adjusted EQ-5D-3L utility scores from GALLIUM and to disutilities for grade 3-4 AEs. Costs and outcomes were discounted at 2,5%. Sensitivity analysis were performed. Compared R-chemo+R, G-chemo+G was associated with a gain of 0.622 (11.999 versus 11.377) (QALYs) and an incremental cost of €28,367 mostly driven by treatment costs. The incremental cost-utility ratio (ICUR) was €45,610/QALY. Progression cost (including follow-up cost and 2nd line treatment cost) were lower in the G-chemo plus G arm with a difference of - 7,350€ (€39,175 versus €46,525) due the reduced number of patients progressing within 24 months. We demonstrate that G-chemo plus G maintenance is a cost effective option compared to R-chemo plus R maintenance. The PFS gain with G-chemo+G in patient with previously untreated advanced-stage follicular lymphoma bring a substantial health benefit to the patients at an acceptable additional cost in France.