OBJECTIVES

Pertuzumab(P), trastuzumab and chemotherapy(HT) for the adjuvant treatment of HER2+ early breast cancer(eBC) significantly improved invasive disease-free survival(iDFS) versus HT in the intention-to-treat population(ITT) and, particularly, in lymph node-positive(N+) and/or hormone receptor-negative(HR-) patients.

We performed a study aimed at determining the cost-utility of PHT versus HT as adjuvant treatment in HER2+ eBC for Spain.

METHODS

A six-state Markov model (iDFS, local recurrence, iDFS after local recurrence, metastatic-relapse[1L], metastatic-relapse[2L], and death) was adapted considering the Spanish National Healthcare System perspective, over a lifetime horizon. APHINITY 4 year-iDFS data were fitted with a log-logistic distribution for ITT and N+ populations and with an exponential distribution for HR- patients. Transition probabilities and costs (€ 2019 and list prices of medicines considered) were obtained from national databases/ literature. Utilities were derived from the APHINITY trial. Model inputs were validated by an expert panel. A 3% annual discount rate was applied to effects and costs. Deterministic and probabilistic sensitivity analyses(SA) were performed to explore uncertainties.

RESULTS

PHT provided 0.637 additional quality-adjusted life-years(QALYs) and €27,733 cost versus HT in the N+ subgroup (incremental cost-utility ratio[ICUR] of €43,530/QALY). In this subgroup, ICUR were between €19,000 and €27,000 when applying a 20%-30% reduction in pertuzumab and trastuzumab treatment price. In the HR- subgroup, PHT provided 0.405 QALYs and €39,159 cost (ICUR of €96,630/QALY). ICUR were between €58,000 and €71,000 when applying a 20%-30% reduction in treatment price. The ICUR of PHT versus HT was €102,581/QALY in the ITT population, and between €60,000 and €74,000 when considering a 20%-30% treatment price decrease. SA confirmed the robustness of the model.

CONCLUSIONS

Great controversy currently surrounds cost-effectiveness thresholds. Eighteen cycles of PHT would be an efficient therapeutic alternative in HER2+ N+ eBC with a threshold of €43,530/QALY and in HR- patients with a threshold of €96,630/QALY.