New Zealand Multiple Myeloma Patients Demonstrate Inferior Outcomes When Compared to Australian Counterparts - A Retrospective Cohort Study from the Myeloma and Related Diseases Registry (MRDR).

OBJECTIVES

This study compared patient and disease-related demographics, access to treatment, and the OS of Australian and New Zealand (ANZ) patients with multiple myeloma.

STUDY

DESIGN

A retrospective cohort study of ANZ patients with a new diagnosis of (MM) enrolled between 2012 and 2023 onto the bi-national Myeloma and Related Diseases Registry (MRDR). Baseline characteristics (age, gender, country), clinical data (ISS Stage, comorbidities, high-risk cytogenetics, performance status), and OS from date of diagnosis to all-cause mortality were used to compare the two cohorts. The Cox proportional hazard model was applied to covariates to analyse the association with survival. All data analysis was performed with R.

RESULTS

A total of 5031 patients were included in this study (3871 from Australia and 1160 from New Zealand). Patients in New Zealand demonstrated an older median age, more cardiac disease and poorer performance status (ECOG 2-4) at diagnosis, but the two cohorts were otherwise similar. New Zealand patients had a significantly inferior median OS when compared to Australian patients, 65.3 vs. 79.8 months, respectively. Adjusted for demographic and clinical characteristics, utilization of autologous stem cell transplant (ASCT, HR 0.59, 95% CI, 0.51-0.68), frontline combination therapy with a proteasome inhibitor and an IMID combination (HR 0.63, 95% CI, 0.55-0.72), and receiving anti-CD38 monoclonal antibody therapy at first relapse compared with VTD regimen (HR 0.61, 95% CI, 0.44-0.83) were associated with improved survivals. New Zealand patients were less frequently transplanted across all age groups after adjusting for cofounders.

CONCLUSION

Despite both countries having access to publicly funded health care, the survival for patients with newly diagnosed MM in New Zealand is significantly inferior when compared to Australian counterparts.