PCN73 COST-EFFECTIVENESS OF BLINATUMOMAB VERSUS STANDARD OF CARE IN ADULT PATIENTS WITH PHILADELPHIA-CHROMOSOME-POSITIVE RELAPSED OR REFRACTORY B-CELL PRECURSOR ACUTE LYMPHOBLASTIC LEUKEMIA FROM A CANADIAN HEALTHCARE SECTOR PERSPECTIVE

Abstract

To evaluate the cost-effectiveness of blinatumomab vs. standard of care (SOC) therapy in patients with Philadelphia-chromosome-positive (Ph+) relapsed or refractory (R/R) B-cell precursor acute lymphoblastic leukemia (BCP-ALL) from a Canadian healthcare perspective. A partitioned survival model was used to estimate the incremental cost-effectiveness ratio (ICER) of blinatumomab vs. SOC. Where available, model estimates were informed by the ALCANTARA study and a historical comparator (HC) study. The HC population was matched to patients in ALCANTARA using inverse probability of treatment weights (IPTW). Parametric distributions were fit to individual patient data from the studies to estimate relapse-free and overall survival. Since utility data were not available in ALCANTARA, utilities were informed by the TOWER study in patients with R/R ALL. Cost estimates were from published sources. A lifetime (30-year) time horizon was used. The model assumed patients surviving to 3 years would be cured and no longer at risk of ALL-related death. Alternative cure definitions and model assumptions were tested in probabilistic and deterministic sensitivity analyses. Probabilistic analyses projected a 1.24 life year gain and 1.00 additional quality-adjusted life years (QALYs) for blinatumomab vs SOC. While blinatumomab medication costs were CAD 127,543 higher vs. SOC, they were partially offset by lower incremental administration (CAD -51,070), transplant (CAD -4,162), and post-relapse (CAD -4,331) costs. The mean probabilistic ICER for blinatumomab vs. SOC was CAD 68,185/QALY and blinatumomab was cost-effective in 70% of simulations at an ICER threshold of CAD 100,000/QALY. Along with the cure assumptions, key drivers for the ICER were the duration of blinatumomab therapy and model time horizon. Compared with SOC, blinatumomab is a cost-effective treatment option for adults with Ph+ R/R BCP-ALL from a Canadian healthcare perspective. Blinatumomab provides a valuable alternative to systemic agents, as demonstrated by the improvement in survival and quality of life.