OBJECTIVES : To evaluate the cost-effectiveness of obinutuzumab in combination with bendamustine (G-Benda), cyclophosphamide-vincristine-prednisone (G-CVP) and cyclophosphamide-doxorubicin-vincristine-prednisone (G-CHOP), followed by obinutuzumab maintenance, compared to rituximab in combination with bendamustine (R-Benda), cyclophosphamide-vincristine-prednisone (R-CVP) and cyclophosphamide-doxorubicin-vincristine-prednisone (R-CHOP), followed by rituximab maintenance. This analysis takes place at the public Chilean health system for the treatment advanced Non-Hodgkin Follicular Lymphoma (NHFL).

METHODS : A 4-state Markov model was used to mimic the lifetime progression of NHFL patients. The states included were, Progression-Free-Survival (PFS), early-Post-Progression-Survival (ePPS), late-Post-Progression-Survival (lPPS) and death. The transition probabilities were estimated by the parameterise of PFS and Overall-survival (OS) data. The expected direct cost measured as chilean Pesos ($1USD= CLP$640) and utilities for the health states were obtained from the literature. Deterministic and Probabilistic sensitive analysis were performed to account for second order uncertainty of the model. Also, a scenario analysis was conducted to asses the impact of varying structural and methodological assumptions implemented in the model.

RESULTS : Obinutuzumab-chemotherapy followed by obinutuzumab maintenance was the most effective alternative, generating 0,565 QALYs more than rituximab-chemotherapy followed by rituximab maintenance. The incremental cost-effectiveness ratio (ICER) estimated was $24,571 USD per QALY gained, which is above the reference threshold for Chile ($15,618 USD). One-way-sensibility-analysis inform that obinutuzumab is cost-effective under a price discount of 25%. From the scenario analysis, it was observed that the ICER of obinutuzumab varies according with the parametric model used for the extrapolation of PFS data, ranging between $18,625 to $28,886 USD per additional QALY.

CONCLUSIONS : Although obinutuzumab-chemotherapy followed by Obinutuzumab maintenance is associated with an increase of QALY expectancy, in the light of Chilean threshold, cannot be considered a cost-effective strategy. Under a price discount of 25% Obinutuzumab is a cost-effective alternative.