Aim: The POLARIX trial showed that Pola + R-CHP (polatuzumab vedotin plus rituximab, cyclophosphamide, doxorubicin, and prednisolone) prolongs progression-free survival (PFS) in patients with previously untreated diffuse large B-cell lymphoma (DLBCL) compared with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone), the conventional standard of care, with a similar safety profile. However, Pola + R-CHP has not been evaluated from the viewpoint of health economics in Japan. This study evaluates the cost-effectiveness of Pola + R-CHP for previously untreated DLBCL from a Japanese public healthcare payer's perspective.
Methods: A partitioned survival analysis model was constructed to estimate lifetime costs and effectiveness of Pola + R-CHP and R-CHOP in previously untreated DLBCL who had an International Prognostic Index score (IPI) score of ≥2. A parametric survival model was applied to data analyzed in the POLARIX trial to estimate the lifetime overall survival (OS) and PFS for each treatment. The parameters required for the model were based on the results of a literature search and expert opinion.
Results: The incremental cost-effectiveness ratio (ICER) of Pola + R-CHP vs. R-CHOP was JPY2,710,238 per quality-adjusted life year (QALY), less than the ICER of JPY7.5 million per QALY that is considered to be cost-effective based on the threshold of the Japanese cost-effectiveness evaluation system. One-way sensitivity analysis showed that the parameters influencing the results of the analysis were median PFS and the total cost per regimen of salvage chemotherapy, patient weight, and patient age. Probabilistic sensitivity analysis showed that the probability of Pola + R-CHP having superior cost-effectiveness was 99.2% when the reference value was JPY7.5 million. The results of scenario analysis suggested that prolongation of PFS was an important factor in the evaluation of cost-effectiveness in previously untreated DLBCL with or without prolongation of OS.
Conclusions: This study suggests that Pola + R-CHP is a cost-effective treatment for previously untreated DLBCL in Japan under the public health insurance system.
Keywords: Cost-effectiveness; I; I1; I10; I18; diffuse large B-cell lymphoma; first-line therapy; incremental cost-effectiveness ratio; partitioned survival model; polatuzumab vedotin.