Background: In 2013, eribulin was reimbursed under a coverage with evidence development (CED) as third or later chemotherapy line for advanced breast cancer (ABC) patients in the Netherlands because of uncertain cost effectiveness. In 2016, the final decision of reimbursing eribulin was taken without considering the evidence collected during CED research. We analysed the cost effectiveness of eribulin versus non-eribulin chemotherapy, using real-world data. Methods: A three health states (progression-free, progressed disease, dead) partitioned survival model was developed. The SOuth East Netherlands Advanced BREast Cancer (SONABRE) registry informed the effectiveness and costs inputs. Health state utility values were obtained from the literature. Incremental cost-effectiveness ratio (ICER) between the eribulin and matched non-eribulin chemotherapy was estimated. Deterministic and probabilistic sensitivity analyses and scenario analyses were performed. The financial risk (i.e., the expected value of perfect ...