Progression-free survival (PFS) and second PFS (PFS2) by disease stage in patients (pts) with homologous recombination deficiency (HRD)-positive newly diagnosed advanced ovarian cancer receiving bevacizumab (bev) with olaparib/placebo maintenance in the phase III PAOLA-1/ENGOT-ov25 trial. View Full Abstract


Background:In the Phase III PAOLA-1/ENGOT-ov25 trial (NCT02477644), the addition of maintenance olaparib to bev in pts with newly diagnosed advanced high-grade ovarian cancer (HGOC) resulted in a significant PFS benefit, particularly in HRD-positive (HRD+) pts (hazard ratio [HR] 0.33; 95% CI 0.25–0.45) (Ray-Coquard et al.NEJM 2019). We explored efficacy in HRD+ pts by disease stage.

 

Methods:Pts with newly diagnosed, FIGO stage III–IV HGOC in response after platinum-based chemotherapy + bev received bev (15 mg/kg q3w for 15 months [mo]) + either olaparib (300 mg bid for 24 mo) or placebo (pbo). This exploratory analysis evaluated PFS (data cut-off [DCO]: Mar 22 2019) and PFS2 (DCO: Mar 22 2020) in HRD+ pts (tumor BRCA1/BRCA2 mutation [tBRCAm] or genomic instability score [Myriad myChoice HRD Plus] ≥42) by FIGO stage.  

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Results:387/806 randomized pts (48%) were HRD+; 272/387 (70%) had stage III disease and 115/387 (30%) had stage IV disease. 153 (56%) HRD+ stage III pts and 61 (53%) HRD+ stage IV pts had a tBRCAm. Among HRD+ stage III pts, 172 (63%) had upfront surgery (51/172 [30%] had residual disease) and 90 (33%) had interval surgery (19/90 [21%] had residual disease); 52 (45%) HRD+ stage IV pts had upfront surgery (34/52 [65%] had residual disease) and 55 (48%) had interval surgery (18/55 [33%] had residual disease). Median follow-up for PFS and PFS2 was respectively 24.8 and 37.2 mo in HRD+ stage III pts and 24.0 and 37.0 mo in HRD+ stage IV pts. Median PFS, PFS2 and HRs are in the Table. Among HRD+ stage III pts, 36-mo PFS2 (olaparib + bev vs pbo + bev) was 74% vs 60%; among HRD+ stage IV pts, 53% vs 30%. Among HRD+ stage III pts with no residual disease after upfront surgery, HR (95% CI) for PFS was 0.15 (0.07–0.30) and for PFS2 was 0.22 (0.06–0.67). Among HRD+ stage III pts with residual disease after upfront surgery or who received neoadjuvant chemotherapy, or HRD+ stage IV pts, HR (95% CI) for PFS was 0.38 (0.27–0.53) and PFS2 was 0.68 (0.46–1.03).

 

Conclusions:In the PAOLA-1 study, maintenance olaparib + bev provided a PFS and PFS2 benefit over pbo + bev in HRD+ pts, irrespective of FIGO stage and residual disease after upfront surgery. Clinical trial information: NCT02477644