NOVA was a randomized Phase 3 trial assessing the efficacy of niraparib maintenance for patients (pts) with platinum-sensitive recurrent ovarian cancer (OC); overall survival (OS) was the secondary endpoint. The aim of this real-world (RW) study was to compare OS in BRCA wild-type (BRCAwt) pts with recurrent OC receiving second-line maintenance (2Lm) niraparib monotherapy or active surveillance (AS) to complement NOVA trial results.
This study used the US nationwide Flatiron Health de-identified electronic health record-derived database. Pts diagnosed with epithelial OC from 1 Jan 2011–31 May 2021 and completed 2L therapy from 1 Jan 2017–2 Mar 2022 were eligible for inclusion. Pts were assigned to niraparib 2Lm or AS cohorts according to their treatment scenario after end of 2L therapy (≤120 days). Follow-up was measured from index date (end of 2L non-maintenance therapy) until end of study (31 May 2022), last activity or death, whichever came first. A target trial emulation cloned inverse probability of censoring weighting (IPCW) methodology was selected a priori to minimize bias. IPCW median OS and hazard ratios (HR) for 2Lm vs AS were estimated with Kaplan-Meier curves and Cox regression models.
Overall, 199 and 707 BRCAwt pts received niraparib 2Lm or were under AS, respectively. Most pt characteristics were similar across cohorts (Table). Median follow-up was 15.6 and 9.3 months, and median OS was 24.1 (95% confidence interval [CI]: 20.9, 29.5) and 18.4 (95% CI: 15.1, 22.8) months for niraparib 2Lm and AS cohorts, respectively (HR: 0.77 [95% CI: 0.66, 0.89]).
Table. Patient characteristics and follow-up before adjustment
| 2Lm (N=199) | 2L AS (N=707) | |
| Characteristics, n (%) | ||
| Age | ||
| 18–74 | 146 (73) | 498 (70) |
| ≥75 | 53 (27) | 209 (30) |
| Race | ||
| White | 132 (66) | 508 (72) |
| Black | 9 (5) | 42 (6) |
| Other | 52 (26) | 115 (16) |
| NR | 6 (3) | 42 (6) |
| Practice type | ||
| Community | 168 (84) | 574 (81) |
| Academic | 18 (9) | 118 (17) |
| Both | 13 (7) | 15 (2) |
| Histology | ||
| Serous | 156 (78) | 545 (77) |
| Other | 20 (10) | 68 (10) |
| NR | 23 (12) | 94 (13) |
| ECOG | ||
| 0–1 | 167 (84) | 505 (71) |
| 2–4 | 18 (9) | 93 (13) |
| NR | 14 (7) | 109 (15) |
| Stage | ||
| I–II | 21 (11) | 77 (11) |
| III | 103 (52) | 353 (50) |
| IV | 56 (28) | 203 (29) |
| NR | 19 (10) | 74 (10) |
| HRD | ||
| HRd | 10 (5) | 38 (5) |
| HRp | 7 (4) | 56 (8) |
| NR | 182 (91) | 613 (87) |
| Median follow-up, months (quartile 1, quartile 2) | 15.6 (9.1, 27.1) | 9.3 (3.2, 21.0) |
HRp, HR proficient; NR, not reported
This RW study provides supportive evidence of niraparib's OS benefit in BRCAwt pts in the 2Lm setting. Homologous recombination deficiency (HRD) testing in the RW is limited and prevented examination of BRCAwt + HR deficient (HRd) subgroup.
Editorial support provided by Claire Kelly, Fishawack Health, funded by GSK.