Analysis of omalizumab for chronic spontaneous urticaria, June 2023
Page last updated: 14 November 2023
Drug utilisation sub-committee (DUSC)
June 2023
Abstract
Purpose
The PBAC requested an update of the June 2020 DUSC predicted versus actual analysis of omalizumab for chronic spontaneous urticaria (CSU), including additional analyses on the trend in prescribing a higher dose (600 mg) of omalizumab for CSU and the age distribution of PBS patients.
Date of listing on the Pharmaceutical Benefits Scheme (PBS)
Omalizimuab was first listed on the PBS for severe CSU on 1 September 2017.
Data Source / methodology
Authorities data and prescriptions data was extracted from the prescription database and Authorities database maintained by the Department of Health and Aged Care, processed by Services Australia from between 28 March 2023 and 5 April 2023, respectively. Data were extracted based on the date of supply.
Key Findings
- The number of patients supplied omalizumab for CSU was different than predicted over the first five years of listing.
- For both initial and continuing treatment, the majority of prescriptions supplied were for 300 mg. The number of cases where first initiating or continuing prescriptions for 150 mg was negligible.
- Only a small proportion of patients were found to down titrate from 300 mg to 150 mg.
- While median, mode, and minimum dosing supplied for both initial and continuous treatment have remained stable since listing, the mean and maximum doses have increased over time.
- The median time on treatment including breaks was estimated to be 863 days and excluding breaks was estimated to be 697 days.
- Most prescriptions dispensed were prescribed by an immunologist, allergist or dermatologist.
- Approximately one third of prescriptions were provided by specialities outside of those listed in the restriction.
- The most common sequence of treatment is omalizumab without any prior PBS-listed therapy identified.
