For platinum-resistant ovarian cancer patients with BRCA wild-type tumors, olaparib does not show consistent or frequent clinical benefit. This study aimed to evaluate the combination of olaparib with the DNA-damaging chemotherapy agent pegylated liposomal doxorubicin (PLD) for these patients.
Patients of any BRCA status with high-grade serous or endometrioid and 1 previous platinum-resistant ovarian cancer (between 28 days and 6 months after last platinum) were enrolled in this study. These patients had received ≤4 previous lines, unless they were BRCA-mutated patients, in which case ≤5 previous lines were permitted, and primary platinum-resistant ovarian cancer was only allowed in the presence of BRCA mutation. For all others, patients had experienced at least 1 platinum-sensitive relapse. The treatment regimen consisted of 6 cycles of olaparib 300 mg twice daily and PLD 40 mg/m2 (PLD40) intravenously every 28 days. Patients were then given olaparib 300 mg twice daily until progression or toxicity. The treatment protocol was amended during the study due to high toxicity with reduction in the dose of PLD to 30 mg/m2 (PLD30). The primary end point of the study was progression-free survival (PFS) at 6 months by RECIST 1.1. The threshold for futility was 40% PFS at 6 months.
The intention-to-treat (ITT) population consisted of 31 patients receiving at least 1 cycle; however, only 20 patients were treated per protocol. For the ITT population, the median age was 58.03 years, 32.3% of patients were Eastern Cooperative Oncology Group (ECOG) grade 0 and 67.7% were ECOG grade 1, and 87.1% were serous subtype. For the per protocol cohort, median age was 59.75 years, 25% were ECOG grade 0 and 75% were ECOG grade 1, and 85% were serous subtype. BRCA status for the per protocol population was wild-type for 80% of patients, mutated for 15% of patients, and unknown for 5% of patients. The median number of prior lines was 2 (range, 1-4). The median follow-up time was 10.18 months (range, 2.18-25.22 months). For the ITT population, 6-month PFS was 46.59% (95% confidence interval [CI], 31.71-68.47) and median PFS was 5.82 months (95% CI, 4.4-9.72) at median follow-up. Overall survival at 6 months was 86.67% estimated as a cumulative survival ratio, and median overall survival was 14.48 months (95% CI, 9.95-NA). For the per protocol cohort, results at median follow-up were similar, with 6-month PFS being 46.1% (95% CI, 27.2-78.3) and a median PFS of 5.42 months (95% CI, 4-12). The rates of partial response, stable disease, and overall disease control were 25%, 65%, and 90%, respectively. Quality of life was not significantly decreased during the first 32 weeks of treatment.
The most common grade ≥3 adverse events for the ITT population were neutropenia (38.7%), anemia (22.6%), and febrile neutropenia (9.7%). In total, 74.2% of patients in the ITT population experienced at least 1 grade ≥3 adverse event. PLD30 (n = 14) was associated with fewer related serious adverse events at 7.1% than PLD40 (n = 17) at 17.6%. PLD dosing delays occurred in 45% of those taking PLD40 versus 30% of those taking PLD30. Dose reductions occurred in 25% of those taking PLD40 versus 10% of those taking PLD30.
Authors concluded that the combination of olaparib and PLD resulted in a 46.59% 6-month PFS rate, demonstrating activity in treating patients with platinum-resistant ovarian cancer. In addition, of the 2 doses of PLD used in the study, PLD30 was better tolerated, and the combination of olaparib and PLD does not significantly impair quality of life.
Abstract and Poster 832P. ESMO 2020. September 19-21, 2020. GEICO1601-ROLANDO trial: a multicentric single arm phase II clinical trial to evaluate the combination of olaparib and pegylated liposomal doxorubicin for platinum-resistant ovarian cancer.