Outcome data from >10 000 multiple myeloma patients in the Danish and Swedish national registries.

Objective: We describe real-world evidence (RWE) from the nationwide Swedish and Danish registries that provide important information on incidence and outcome in multiple myeloma (MM).

Method: First line treatment data on more than 10.000 MM patients from Denmark and Sweden between 2005-2018 are presented. Key results from research conducted within the Swedish and Danish myeloma registries are summarized, describing subgroups of patients with comorbidity, myeloma complications, and early relapse.

Results: We show that national guidelines, generated on results from randomized clinical trials (RCTs) are rapidly implemented and improve overall survival (OS). We find that both the incidence of MM and the median age at diagnosis is higher in national registries compared to results from referral centres, indicating a more complete coverage. This highlights the need of validation of prognostic scoring systems and indices in e.g., SMM and high-risk MM in a real- world-population. We show that these subgroups are unlikely to be captured in RCTs with narrow inclusion and exclusion criteria, that they have worse survival, and are in need of new treatment approaches.

Conclusion: National registries that include all MM patients are an important source of knowledge on epidemiology, treatment and outcome with implications for the planning of MM care. Despite the introduction of new and better treatments, rapidly implemented in our countries, our registries uncover subgroups of patients that still have inferior outcome. Our RWE can help to identify important research questions to be studied in further clinical trials also in patients currently not included in RCTs.