OBJECTIVES : Daratumumab administered via an intravenous infusion (dara-IV) is currently approved for the treatment of patients with multiple myeloma, both newly diagnosed (NDMM) and relapsed/refractory (RRMM). A daratumumab formulation for subcutaneous administration (dara-SC) was developed with the goal of shortening treatment duration without compromising safety and efficacy. Dara-SC was licensed in 2020 and is expected to be reimbursed in the Italian setting for the same indications as dara-IV. A cost-minimization model (CMM) was developed to evaluate the economic implications of using dara-SC instead of dara-IV in Italy.

METHODS : The analysis included all currently reimbursed indications: DVMP and DRd for transplant-ineligible NDMM; DVTd for transplant-eligible NDMM; DRd and DVd for RRMM; daratumumab monotherapy for patients who have received at least three prior lines of therapy. The analysis was conducted from the Italian societal perspective and accounted for daratumumab administration cost, adverse events cost, and productivity loss. Unit costs were collected from published literature and institutional Italian data. Adverse events rates and treatment duration were taken from clinical trials. Drug acquisition costs were assumed to be equivalent for dara-IV and dara-SC and therefore not considered. In line with clinical trials results, we assumed that dara-SC and dara-IV regimens are equally effective. A lifetime horizon was considered. Costs and outcomes were discounted at an annual 3% rate. Sensitivity analyses were used to test the results.

RESULTS : Over 30 years, treatment with dara-SC was associated to lower costs compared with dara-IV in every regimen. Savings were observed in every cost category and ranged from € 5.562 for daratumumab monotherapy to € 23.822 for DRd in RRMM patients. Daratumumab administration cost was the main driver of the results. The probabilistic sensitivity analysis confirmed dara-SC was cost-saving in most of the replications.

CONCLUSIONS : Results suggest that, switching dara-IV patients to the subcutaneous formulation could save resources in the Italian setting.