Poster Presentation Clinical Oncology Society of Australia 2014 Annual Scientific Meeting

Cetuximab use in metastatic colorectal cancer at five large Queensland public hospitals: comparison to key clinical trials (#277)

Suzannah Chapman 1 , Daniel McKavanagh 2 , Matthew Burge 3 , Paul Klages 3 , Jeremy Long 4 , Jasotha Sanmugarajah 5 , Ian McPherson 6 , Julia Hasker 4 , Anita Connor 5 , Guranjan Grewal 6 , Euan Walpole 2 , Samantha Hollingworth 1
  1. School of Pharmacy, The University of Queensland, Brisbane, QLD, Australia
  2. Princess Alexandra Hospital, Woolloongabba, QLD, Australia
  3. Royal Brisbane & Women’s Hospital, Brisbane, QLD, Australia
  4. Nambour General Hospital, Nambour, QLD, Australia
  5. Gold Coast University Hospital, Southport, QLD, Australia
  6. Toowoomba Health Service, Toowoomba, QLD, Australia

Aims
Cetuximab is a novel monoclonal antibody used in the treatment of metastatic colorectal cancer (mCRC). Randomised clinical trials (RCTs) demonstrate that, in KRAS wild type patients, cetuximab improves survival after failure of first-line mCRC chemotherapy1-4. In Australia, cetuximab cost was government reimbursed from 2011, but there is little evidence that these trial results translate into real world improvements in patient outcomes. This project aimed to summarise data from the electronic prescribing system (Charm®) on cetuximab use in mCRC patients at five large metropolitan and regional Queensland public hospitals and to compare this data to published RCT results.


Methods
Data was extracted from the central Charm® database for mCRC patients assigned to cetuximab therapy during the period 01/09/2009-31/08/2013. Descriptive statistical analyses including Kaplan-Meier curves were calculated.


Results
There were 208 cetuximab-containing protocols for mCRC planned, 2199 cetuximab doses ordered, and 134 patients received at least one cetuximab dose. 95 patients were deceased at the time of data extraction. Median patient age was 64yrs, and 60% were male. Patients were distributed into seven cetuximab-containing protocol groups, with most (72%) prescribed weekly cetuximab with or without irinotecan based chemotherapy. Median cetuximab maintenance dose was 458mg (weekly) and 975mg (biweekly). Median time on treatment was 174 days for the whole cohort. Median overall survival was 9.1 months from first cetuximab dose.


Conclusions
Cetuximab use in this cohort of mCRC patients was similar to trial results, based on patient and treatment characteristics. The median survival was similar to that published in larger RCTs (6.9 to 9.2 months)1-4, providing reassurance that the local outcomes for patients treated at the Queensland sites studied is similar to the evidence.

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  2. Jonker DJ, O'Callaghan CJ, Karapetis CS, et al. Cetuximab for the treatment of colorectal cancer. The New England Journal of Medicine. 2007;357(20):2040-2048.
  3. Karapetis CS, Khambata-Ford S, Jonker DJ, et al. K-ras mutations and benefit from cetuximab in advanced colorectal cancer. The New England Journal of Medicine. 2008;359(17):1757-1765.
  4. Wilke H, Glynne-Jones R, Thaler J, et al. Cetuximab PLUS Irinotecan in heavily pretreated metastatic colorectal cancer progressing on irinotecan: MABEL study. American Society of Clinical Oncology. 2008;26(33):5335-5343.