Real-world safety and effectiveness of olaparib maintenance after first-relapse platinum-sensitive ovarian cancer in Japan: a multicenter historical cohort (JGOG3026)

ObjectiveThe primary objective of the study was to evaluate the safety and effectiveness of olaparib maintenance therapy in Japanese patients with platinum-sensitive first-relapsed ovarian cancer. The secondary objective was to survey the treatment given after the olaparib maintenance therapy. MethodsThe JGOG3026 study was a nationwide, multicenter historical cohort study across 43 sites. Patients receiving olaparib maintenance therapy after platinum-based chemotherapy between Jan 2018 and Jul 2020 were included as modified intention-to-treat (mITT1). Those who received any post-olaparib therapy were extracted as mITT2. The primary endpoint was adverse events; secondary endpoints included progression-free survival (PFS), the time to first subsequent therapy (TFST), progression-free survival to the second progression (PFS2), and overall survival (OS). ResultsIn the mITT1 (n = 413), any adverse event occurred in 41.6%; anemia was the most common (28.8%). MDS occurred in 1.0% and no AML was observed during a mean follow-up of 34.1 months. The 24-month PFS and OS rates were 31.7% and 70.1%, respectively. Median PFS and OS were 12 months (95% confidence interval [CI]: 9.9-13) and 39 months (95% CI, 33-45). The 24-month TFST and PFS2 rates were 33.3% and 34.3%. In the mITT2 (n=284), chemotherapy after olaparib therapy was used in 97.2%, with an overall response rate of 22.5%. ConclusionOlaparib maintenance therapy showed acceptable safety and effectiveness in Japanese clinical practice. Monitoring for secondary hematologic malignancies is needed after the start of olaparib maintenance therapy. SynopsisOur multicenter collaborative historical cohort study confirmed acceptable safety and effectiveness of olaparib maintenance therapy in Japanese patients with platinum-sensitive first-relapsed ovarian cancer; the incidence of AML/MDS was comparable to reports from Western cohorts.