For patients with platinum-sensitive, relapsed ovarian cancer with germline BRCA1/2 mutations, maintenance therapy with olaparib, a potent oral inhibitor of poly(ADP-ribose) polymerase (PARP), may prolong the period of time before significant symptoms of toxicity (TWiST) appear and improve quality-adjusted progression-free survival (QAPFS) without negatively affecting health-related quality of life (HRQoL), according to research published in The Lancet Oncology.
An international group of investigators conducted a randomized, double-blind, multicenter, phase 3 study, SOLO2/ENGOT-Ov21 (ClinicalTrials.gov Identifier: NCT01874353) to assess potential adverse effects associated with olaparib treatment, including the drug’s impact on HRQoL measures and progression-free survival (PFS) compared with placebo.
A prespecified primary analysis was conducted using the Trial Outcome Index score to determine changes in HRQoL during the first 12 months of the study. A secondary analysis was conducted to measure the durations of TWiST and QAPFS.
Patients aged 18 years or older with relapsed, high-grade serous ovarian cancer or endometrioid cancer with a germline BRCA 1/2 mutation who underwent at least 2 previous lines of platinum-based chemotherapy were eligible for participation.
A total of 294 patients were randomly assigned (2:1) to receive either 300 mg twice-daily olaparib tablets (195 participants) or the dose-equivalent placebo (99 participants). The median duration of treatment for the olaparib and placebo groups were 19.4 months and 5.6 months, respectively.
Measuring for adjusted average change over the first 12 months, the investigators reported Trial Outcome Index scores of -2.90 for olaparib-treated patients and -2.87 for placebo-treated patients. Average QAPFS for the olaparib and placebo groups were 13.96 and 7.28 months, respectively; average duration of TWiST for the olaparib and placebo groups were 15.03 and 7.70 months, respectively.
“To our knowledge, SOLO2 is the first trial to report the impact of maintenance therapy with a [poly(ADP-ribose) polymerase] inhibitor on predefined HRQOL and patient-centered endpoints to help interpret the benefits to patients with platinum-sensitive, relapsed ovarian cancer of prolongation of progression-free survival,” the authors wrote.
“Olaparib did not have a detrimental effect on HRQoL compared with placebo and there were additional significant patient-centered benefits in terms of TWiST and QAPFS, as well as in [time to first subsequent therapy or death] and [time to second subsequent therapy or death]. All these predefined end points support the benefit to patients of a prolongation of progression-free survival, which is the primary end point in maintenance trials in ovarian cancer, and should be routinely included in future trials,” concluded the investigators.
Disclosure: This study was funded by AstraZeneca.
- Friedlander M, Gebski V, Gibbs E, et al. Health-related quality of life and patient-centered outcomes with olaparib maintenance after chemotherapy in patients with platinum-sensitive, relapsed ovarian cancer and a BRCA1/2 mutation (SOLO2/ENGOT Ov-21): a placebo-controlled, phase 3 randomised trial. Lancet Oncol. 2018;19(8):1126-1134.