Individual Abstract within a Delegate Designed Symposium Clinical Oncology Society of Australia Annual Scientific Meeting 2023

Uptake of recently PBS-listed cancer medicines (#131)

Benjamin Daniels 1 , Fanny Franchini 2 , Jennifer Soon 3 , Marliese Alexander 4 , Yat Hang To 5 , Maarten IJzerman 2 , Sallie-Anne Pearson 1
  1. Medicines Intelligence Research Program, School of Population Health, University of New South Wales Sydney, Kensington, NSW, Australia
  2. Centre for Cancer Research, Cancer Health Services Research, University of Melbourne, Melbourne, VIC, Australia
  3. Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, VIC, Australia
  4. Pharmacy Department, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne, VIC, Australia
  5. Walter and Eliza Hall Research Institute, Melbourne, VIC, Australia

Aims
New systemic cancer therapies offer hope for improved survival and quality of life, however, uptake of novel treatments in the real-world clinic is not well known. We described uptake patterns of cancer medicines post-Pharmaceutical Benefits Scheme (PBS) listing with the aim of informing future uptake based on horizon scanning for new non-small cell lung cancer (NSCLC) treatments.

Methods
We examined alectinib (PBS-listed January 2018) and crizotinib (PBS-listed July 2015) as they aligned with the horizon scanned medicine lorlatinib. We used Victorian Cancer Registry data (2010-2019) linked with PBS dispensing records (2008-2021) to estimate patient eligibility and medicine use. Monthly initiation rates were calculated as the number of new users (numerator) over the medicine’s eligible population (denominator), expressed per 10,000. When eligibility was contingent on gene mutations, we used epidemiological prevalence estimates and bootstrap sampling to estimate the eligible population. We summarised the monthly rates over time for each medicine and used negative binomial regressions to quantify the monthly rate of uptake.

Results
Uptake of alectinib was highest during the first month of subsidy (29/10,000/month); thereafter decreasing by 5%/month to average 5 initiations/10,000/month between February 2018 and December 2020. Uptake of crizotinib was highest during the first month of subsidy (18/10,000/month); thereafter decreasing by 4%/month to average 3 initiations/10,000/month between August 2015 and December 2020.  

Conclusion
Uptake was highest immediately following subsidy, reflecting the population of patients who may not have responded to existing treatments as well as prevalent users previously accessing treatments through compassionate access schemes. Pathology data would help improve estimates of populations eligible for these medicines, however, our findings suggest that uptake has been steady, if low, following initial month of PBS availability. These results can inform uptake expectations for similar, newly-subsidised treatments.