- Olaparib shows activity against metastatic castration-resistant prostate cancer with DNA damage response (DDR) gene aberrations.
Why this matters
- Findings, if confirmed in registration studies, would support the implementation of tumor genomic testing in clinical practice for treatment stratification in advanced disease.
- 98 patients with progressing metastatic castration-resistant prostate cancer and with DDR gene aberrations previously treated with 1/2 taxane-based chemotherapy regimens were randomly assigned to 300 or 400 mg olaparib.
- Funding: Cancer Research UK; AstraZeneca.
- Median follow-up, 24.8 months.
- In patients who received 400 vs 300 mg olaparib:
- Confirmed composite response rate: 54.3% vs 39.1% (P=.14).
- Radiological objective response rate: 24.2% vs 16.2%.
- At least 50% decrease in PSA: 37.0% vs 30.2%.
- Circulating tumor cell count conversion rate: 53.6% vs 48.1%.
- Median radiographic PFS was 5.5 (95% CI, 4.4-8.3) vs 5.6 (95% CI, 3.7-7.7) months.
- The most common grade 3-4 adverse events were anemia (37% vs 31%).
- 19 serious adverse reactions were reported in 13 patients.
- 1 treatment-related death was reported with the 300-mg dose.
- Open-label design.