Multiple Myeloma in Italy: An Epidemiological Model by Treatment Line and Refractoriness Status.

Background: Multiple myeloma (MM) clinical management is challenging owing to its relapse and refractoriness to treatment. Understanding the treatment patterns and refractory dynamics is crucial for optimizing patient care. This study aimed to estimate the evolution of MM according to the treatment line and refractoriness status in Italy.

Materials And Methods: A new epidemiological model was developed using epidemiological and clinical data from literature. Prevalent MM patients were characterized by calibrating the model inputs. Incident patients were included starting in 2021, when antiCD38-containing regimens were reimbursed as first-line treatments in Italy. The model employed a 1-year cycle Markov structure to simulate patient flow through the treatment lines, accounting for the development of lenalidomide and anti-CD38 monoclonal antibody (mAb) refractoriness.

Results: In 2020, Italy had an estimated 33,734 prevalent MM patients. By 2027, treated patients were projected to increase from 28,499 to 35,074. The introduction of lenalidomide and mAb therapies in earlier lines has resulted in a higher accumulation of patients in the early lines, with a corresponding decrease in the proportion of patients requiring subsequent lines of therapy. Furthermore, the proportion of patients refractory to both lenalidomide and mAbs in the second to fourth lines of treatment is estimated to increase from 1.6% in 2021 to 29.7% by 2027.

Conclusion: Our model revealed a rising prevalence of patients receiving first-line treatment owing to more effective treatments. The marked increase in the number of refractory patients in subsequent lines underscores the urgent need for innovative therapies to address treatment resistance.