OBJECTIVES: The exclusive selling rights of several very expensive medicines are coming to an end and they are entering to the reference price system (RPS) and towards more competitive market. One of these medicines is the blockbuster cancer medicine lenalidomide, which has been among the ten best-selling medicines in Finland in terms of medicine reimbursement expenditure. The saving potential in the reimbursement expenditure of lenalidomide was evaluated before lenalidomide entered RPS in April 2022. The accuracy of our estimate was checked after lenalidomide had remained in RPS for almost one year, in the spring 2023.

METHODS: Statistics of the Social Insurance Institution of Finland on the sales of lenalidomide in 2021–2023 were used. The saving potential was estimated by calculating the difference between the reference prices and the prices of the reference product before and after the transition to RPS, assuming that all lenalidomide sold in 2021 were the sales of the reference product.

RESULTS: Before lenalidomide entered RPS, the saving potential in Finland was estimated to be around EUR 40 million. After, the reimbursement expenditure of lenalidomide were EUR 42.7 million in 2021 and EUR 12.2 million in 2022, even though the number of users had slightly increased. Thus, the costs of the medicine decreased by EUR 30.5 million (-71%). Considering that lenalidomide was included in the reference price system for nine months from April to December in 2022, our estimate appeared accurate.

CONCLUSIONS: Transition to RPS dramatically increased competition and lowered the prices of lenalidomide. Evaluating the saving potential of expensive medicines of which exclusive selling rights are about to expire, is important in order to forecast the future burden of the reimbursement scheme. The Finnish case can be a useful example to evaluate the saving potential of blockbuster medicines.