Threshold cost-effectiveness analysis for a therapeutic vaccine against HPV-16/18-positive cervical intraepithelial neoplasia in the Netherlands

In this study, the potential price for a therapeutic vaccine against Human Papilloma Virus (HPV)-16 & 18 (pre)-malignant cervical lesions is examined. A decision tree model was built in the context of the new Dutch cervical cancer-screening program and includes a primary test for the presence of HPV. Based on data of cervical cancer screening and HPV prevalence in the Netherlands, cohorts were created with HPV-16 or 18 positive women with cervical intraepithelial neoplasia (CIN) 2 or 3 or cervical cancer stage 1A (FIGO 1A). In the base case, the vaccine price was based on equal numbers of effective treatments in the vaccine branch and the current treatments branch of the model, and parity in cost, i.e. total cost in both branches are the same. The vaccine price is calculated by subtracting the cost of the vaccine branch from cost in the standard treatment branch and divided by the total number of women in the cohort, thereby equalizing costs in both strategies. Scenario analyses were performed taking quality adjusted life years (QALYs) into account with €20,000/QALY, €50,000/QALY and €80,000/QALY as corresponding thresholds. Sensitivity analyses were specifically targeted at the characteristics of the type-specific HPV test in the screening practice and vaccine efficacy. A probabilistic sensitivity analysis (PSA) was performed to quantify the level of uncertainty of the results found in the base case. In the base case, break-even vaccine prices of €381, €568 and €1697 were found for CIN 2, CIN 3 and FIGO 1A, respectively. The PSA showed vaccine pricing below €310, €490 and €1660 will be cost saving with a likelihood of 95% for CIN 2, CIN 3 and FIGO 1A, respectively. The vaccine price proved to be very sensitive for inclusion of QALY gains, including the HPV-type specific test into the Dutch screening practice and vaccine efficacy.