Analysis of nivolumab and ipilimumab for mesothelioma, February 2024
Page last updated: 19 July 2024
Drug utilisation sub-committee (DUSC)
February 2024
Abstract
Purpose
Analysis of the predicted versus actual utilisation of nivolumab and ipilimumab 24 months following its addition to the Pharmaceutical Benefits Scheme (PBS) for unresectable malignant mesothelioma on 1 July 2021.
Data Source / methodology
PBS dispensing data was extracted from the PBS data maintained by the Department of Health and Aged Care, processed by Services Australia.
Key Findings
- In the first year of listing there was 748 prevalent patients using nivolumab and ipilimumab at a cost to the PBS/RPBS of $58 million. In the second year of listing there were 742 prevalent patients at a cost of $59 million.
- Although there was a lower patient number and lower script count in the second year of listing, the high cost is likely associated with the movement towards three-weekly flat-dosing of nivolumab at 360mg resulting in higher doses being used compared to two-weekly doses at 3mg/kg.
- Approximately 15-20 patients per quarter have no dispensing history of ipilimumab and appear to be undergoing nivolumab monotherapy.
- There were 1,429 unique patients by 2023Q4 and the majority were classified as males (1,122) with a median age of 75 years. The remaining 307 patients were classified as female and had a median age of 71 years.
- The median time to resupply for nivolumab for mesothelioma was 16 days and for ipilimumab it was 42 days. A Kaplan-Meier analysis was undertaken was undertaken to establish time on treatment. Approximately 23-28% of patients were censored and the median time on treatment for the remaining patients was 132 and 120 days for nivolumab and ipilimumab respectively.
- There may be a small number of patients exceeding the 24 month stopping criteria that forms part of the PBS criteria.
