Dr Elias on Efficacy Data With Olaparib in BRCA-Mutated Ovarian Cancer

“[In SOLO-1] the primary outcome was progression-free survival (PFS), and for women randomized to olaparib, the chances of progression or death were reduced by 70%... In SOLO-2, PFS in the olaparib group was 19 months vs 5.5 months in the placebo group.”

Kevin Elias, MD, a gynecologic oncologist at the Cleveland Clinic, discussed pivotal efficacy findings from the phase 3 SOLO-1 (NCT01844986) and SOLO-2 (NCT01874353) trials, which evaluated the use of olaparib (Lynparza) as maintenance therapy in patients with BRCA-mutated ovarian cancer. These landmark studies collectively established the role of PARP inhibition in extending progression-free survival (PFS) across both frontline and recurrent disease settings.

SOLO-1 enrolled patients with newly diagnosed, high-grade serous or endometrioid ovarian cancer who had achieved a complete or partial response following first-line platinum-based chemotherapy. Eligible patients carried either a germline or somatic BRCA1 or BRCA2 mutation. Patients were randomly assigned 2:1 to receive olaparib at 300 mg twice daily or placebo for up to 2 years or until disease progression. The trial’s primary end point was PFS.

Elias highlighted that at the time of analysis, 67.0% of patients treated with olaparib vs 46.5% of patients treated with a placebo were alive. The magnitude and durability of benefit observed in SOLO-1 firmly positioned olaparib as a standard-of-care option for eligible patients following completion of platinum-based chemotherapy.

In contrast, SOLO-2 evaluated olaparib in patients with platinum-sensitive, relapsed ovarian cancer harboring germline BRCA mutations. All enrolled patients had received at least 2 prior lines of platinum-based chemotherapy and were required to have achieved a response to their most recent regimen. Similar to SOLO-1, patients were randomized to olaparib at 300 mg twice daily or placebo, with PFS as the primary end point. In SOLO-2 at 5 years, 28.3% of patients in the olaparib arm vs 12.8% of patients in the placebo arm were alive and had still not received subsequent treatment. In total, 42.1% of olaparib patients vs 33.2% of placebo patients were alive at the study’s conclusion.

Elias emphasized that both SOLO trials provided consistent evidence supporting olaparib as an effective maintenance strategy for patients with BRCA-mutated ovarian cancer, whether in the newly diagnosed or recurrent setting. Together, these studies established the clinical rationale for early incorporation of PARP inhibition into treatment paradigms and underscored the durable disease control achievable through targeted maintenance therapy.