Atezolizumab for extensive-stage small cell lung cancer: analysis of predicted versus actual utilisation, September 2022
Page last updated: 31 March 2023
Drug utilisation sub-committee (DUSC)
September 2022
Abstract
Purpose
To compare the predicted and actual utilisation of atezolizumab for extensive-stage small cell lung cancer since its listing on the Pharmaceutical Benefits Scheme (PBS).
Date of listing on the Pharmaceutical Benefits Scheme (PBS)
Atezolizumab was first listed for extensive-stage (ES) small cell lung cancer (ES-SCLC) on the PBS on 1 March 2020. On 1 July 2020 the listing was extended to include an additional flat dosing regimen of 1680 mg every four weeks (Q4W) using a new 840 mg in 14mL formulation.
Data Source / methodology
Data extracted from the PBS database maintained by Department of Health and Aged Care, processed by Services Australia were used for the analyses.
Key Findings
- The number of patients using atezolizumab has been more than predicted, but the number of scripts and benefits paid is lower than anticipated.
- In the first year of listing there were 961 prevalent patients supplied atezolizumab and in the second year of listing there were 1,209.
- The estimated number of grandfathered patients (n=|) was uncertain as the patient access program had not commenced at the time of the submission. The actual count of grandfathered patients in Year 1 was 113. The underestimation may also have contributed to more patients being supplied treatment in Year 2.
- The mean time on treatment with breaks in supply was 170 days. This is less than the sponsor’s estimate of a treatment duration of | days based on the IMpower133 trial. The mean time on treatment without breaks was 188 days, which is close to the sponsor’s estimate of | days.
- The PBAC noted in the March 2020 submission that there was uncertainty around the estimated 100% uptake of the 1680 mg four weekly (Q4W) dosing regimen for continuing treatment. However, it was considered likely that most patients would be prescribed this new dosing regimen once it became available. This review demonstrates that most patients were still being prescribed the three weekly regimen (Q3W).
