OBJECTIVES: Approximately 7,000 Canadians have multiple myeloma (MM). Without effective treatment, patients can suffer from a constellation of disease-related symptoms that significantly reduce quality of life and survival. Management of stem cell transplant (SCT) ineligible MM patients is complex and varied. Maintenance therapies (MTs) after various induction regimens have been shown to improve response rate and progression-free survival.  We sought to compare Canadian costs between two common approaches to MT, either bortezomib or lenalidomide, in MM patients ineligible for SCT. METHODS: The total annual drug cost of the two MT options were calculated and compared. Costs were based on 1.3mg/m of bortezomib on days 1, 4, 8, 11 every three months, plus 50 mg of prednisone every other day, or 10 mg of lenalidomide on days 1 through 21 of each 28-day cycle. Administration costs including oncology nursing time and pharmacist workload, and pharmacy costs including a 10% markup and dispensing fees were added to the acquisition cost of bortezomib and lenalidomide, respectively. Unit and labour costs were obtained from public Canadian sources. Additional analyses were conducted to consider the impact of several variables including the management of adverse events, treatment duration and alternate costing assumptions. RESULTS: The total annual costs of treatment per patient were $20,106, and $108,741 for bortezomib and lenalidomide, respectively. The incremental differences were robust to changes in inputs and assumptions (to be presented in poster). CONCLUSIONS: The results of this analysis suggest that substantial savings were associated with bortezomib MT when compared with lenalidomide MT. As drug costs represent an increasing proportion of public spending in Canada, it is important to consider both efficacy and cost of treatment. Further studies are required to determine the complete cost-benefit of available MTs.