662P - Genomic/genetic testing (GT) patterns for patients with metastatic castrate-resistant prostate cancer (mCRPC): Interim results from a real-world study in Europe (EU5)

Background

Homologous recombination repair gene alternations (HRRm) are potential clinical biomarkers to identify mCRPC pts likely to benefit from Poly (ADP-ribose) polymerase inhibitors (PARPis). This study examined real-world GT patterns for mCRPC pts in France, Germany, Italy, Spain, the UK (EU5).

Methods

Data were drawn from the Adelphi Prostate Cancer Disease Specific Programme^TM; a cross-sectional survey administered to oncologists (onc) and urologists (uro) in EU5 countries. Physicians (phys) completed an attitudinal survey and a patient record form (PRF) for the next four mCRPC pts seen, plus optional PRFs for 2L mCRPC patients. Study variables included patient demographics, clinical factors and GT patterns. HRRm testers were defined as phys who tested for HRRm. Pts were identified as positive, negative or unknown depending on the outcome of the HRRm test.

Results

A total of 171 phys (85% onc/14% uro) reported on 730 mCRPC pts. 135 phys (79%) reported having access to GT; of these 7% identified as having access to germline tests only, 4% somatic tumour tests only and 89% both. Challenges to conducting GT were ‘cost per test’ (42%), ‘access to latest GT’ (34%), ‘not reimbursed’ (33%) and ‘turnaround time’ (29%). GT typically done at identification of castrate-resistance (54%) and metastases (50%). 65% of total phys conducting GTs were HRRm testers; drivers of HRRm testing include family history, young diagnosis age and hormone therapy failure (72%, 53% and 52% respectively). 78% of all phys more likely to test for HRRm if a PARPi becomes available. 141 (19% of 730) mCRPC pts were HRRm tested; 39% were identified with HRRm. Common HRRm tested were BRCA1 (87%), BRCA2 (84%) and ATM (45%), with variation between countries. Of pts tested for HRRm, 21% had BRCA1, 17% BRCA2 (of these 69% and 67% germline respectively) and 11% ATM.

Conclusions

Many European physicians have access to GT, however HRRm testing is low. Biggest driver to testing was family history. Most pts were assessed for BRCA1 or BRCA2; which were primarily germline in nature. Broader GT usage depends on addressing barriers to testing including reimbursement and access.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Adelphi Real World.

Funding

Merck & Co, Inc.

Disclosure

A. Leith: Full/Part-time employment, AL is an employee of Adelphi Real World, who received funding from Merck & Co, Inc for this analysis: Adelphi Real World. A. Ribbands: Full/Part-time employment, AR is an employee of Adelphi Real World, who received funding from Merck & Co, Inc for this analysis: Adelphi Real World. A. Gayle: Full/Part-time employment: AstraZeneca UK Ltd. S. Payne: Leadership role, Shareholder/Stockholder/Stock options, Full/Part-time employment, Non-remunerated activity/ies: AstraZeneca UK Ltd. C. McCrea: Shareholder/Stockholder/Stock options, Full/Part-time employment: AstraZeneca UK Ltd. L. Yang: Shareholder/Stockholder/Stock options, Full/Part-time employment: Merck Sharpe & Dohme. J. Burgents: Shareholder/Stockholder/Stock options, Full/Part-time employment: Merck Sharpe & Dohme. S. Ghate: Shareholder/Stockholder/Stock options, Full/Part-time employment: Merck Sharpe & Dohme.