Best of Best Poster Oral Clinical Oncology Society of Australia Annual Scientific Meeting 2019

Beyond Cabazitaxel: Late Line Treatments in Metastatic Castration Resistant Prostate Cancer (mCRPC): A Retrospective Multi-Centre Analysis (#182)

Grace Chazan 1 , Angelyn Anton 2 , Shirley Wong 3 , Julia Shapiro 4 , Andrew Weickhardt 5 , Arun Azad 1 4 , Edmond Kwan 4 6 , Lavinia Spain 4 7 , Arun Muthusamy 5 , Javier Torres 8 , Phillip Parente 4 7 , Francis Parnis 9 10 , Jeffrey Goh 11 12 , Anthony Joshua 13 , David Pook 4 6 , Peter Gibbs 2 3 , Ben Tran 1 2
  1. Peter MacCallum Cancer Center, Melbourne, VIC, Australia
  2. Walter and Eliza Hall Institute, Melbourne, Victoria, Australia
  3. Western Health, Melbourne, Australia
  4. Department of Medicine, School of Clinical Sciences, Monash University, Melbourne, Australia
  5. Olivia Newton John Cancer Wellness and Research Centre, Melbourne, Australia
  6. Department of Medical Oncology, Monash Health, Melbourne, Australia
  7. Eastern Health, Melbourne, Australia
  8. Goulburn Valley Health, Shepparton, Victoria , Australia
  9. Adelaide Cancer Center, Adelaide, South Australia, Australia
  10. University of Adelaide, Adelaide, Australia
  11. Royal Brisbane and Women’s Hospital, Brisbane, Queensland, Australia
  12. University of Queensland, St Lucia , Australia
  13. St Vincent’s Hospital, Sydney, Australia

Purpose:

Multiple life-prolonging systemic therapies are now approved for patients with metastatic castrate resistant prostate cancer (mCRPC). However the optimal treatment strategy following progression through standard treatment lines, including docetaxel, novel anti-androgens abiraterone or enzalutamide and cabazitaxel, remains unclear. We aimed to describe treatment patterns in men with mCRPC following progression on cabazitaxel.

 

Patients and Methods:

Patients with mCRPC, who had received treatment with cabazitaxel were identified from the ePAD database (a multicenter mCRPC registry). Clinicopathologic information, treatment and outcome data were extracted. Descriptive statistics were used to report prior and subsequent systemic therapies. T-tests and chi square analyses compared characteristics between those who did and did not receive further therapies.

 

Results:

Search of the ePAD database identified 106 eligible patients. The median age at commencement of cabazitaxel was 70.8 years. Cabazitaxel was most frequently given as third line treatment (n= 56, 53%). Seventy-nine patients (75%) had previously received both docetaxel and a novel anti-androgen. The median duration of cabazitaxel treatment was 4.1 months, with most patients stopping due to disease progression (n=61, 58%) or toxicity (n=14, 13%). Following cabazitaxel, 47 patients (44%) received further systemic therapy. Eighteen patients received a novel anti-androgen, 11 entered a clinical trial and 10 received carboplatin. Other agents included docetaxel (n=8), cyclophosphamide (n=6) and mitoxantone (n=5). Patients who received further systemic therapy were more likely to have better ECOG performance status (p=0.0013) but had no difference in median age or comorbidities compared to those who received no further systemic therapy. There was no significant difference in the duration on subsequent systemic therapy.

 

Conclusion:

This retrospective analysis demonstrates the wide variety of prescribing patterns with regards to sequencing of standard treatments and later lines of systemic therapy. Greater numbers are required to assess the impact of post-cabazitaxel treatment choice on survival outcomes.