Effect of testing for BRCA1/2 on outcomes in patients with ovarian cancer treated with PARPi in 1st line maintenance (1LM).

Abstract

e17576 Background: The treatment of ovarian cancer (OC) has expanded with the approval of PARPi in 1LM. Guidelines recommend that all women with OC get tested for BRCA1/2 and HRD status, given the therapeutic implication. Methods: This retrospective observational study used de-identified records from the Integra Connect PrecisionQ database enriched with information obtained by curation. Adult patients (>18 yrs) with OC who had initiated treatment between 01/01/2019 and 12/31/2021 were included. Categorical variables were reported as proportions and continuous variables as median (interquartile range, IQR), as appropriate. Results: In the 1,093 patients studied, the median age was 69 yrs and 75% had high grade carcinomas. Patients were predominantly White (74%); 9% were African American. 65% were ECOG 0-1 and 8% were ECOG 2. The first line (1L) treatment included platinum (Pl) chemotherapy alone in 60% (678) and Pl + bevacizumab (bev) in 37% (401), with 86% of patients being Pl-sensitive (929/1079). Most patients (84%, 782/929) received a BRCA test, of which 415 were tested for BRCA only and 367 were BRCA/HRD. The median turnaround time was 11 days (IQR=9) for BRCA tests and 15 days (IQR=35) for HRD tests. Of 929 patients who were Pl-sensitive, 503 (54%) received 1LM and 426 (46%) did not receive 1LM. Of 503 patients who received 1LM, 86% (435) had BRCA test results and 41% (208) had HRD results before maintenance initiation. In 48 patients who received 1LM, BRCA/HRD test results were not reported before initiation of maintenance. Patients who received Pl-only induction received bev (24), niraparib (94), olaparib (O) (78), rucaparib (5), O+bev (2), or nira+bev (6) in 1LM. Patients who had Pl+bev induction received bev (134), niraparib (28), O (29), and O+bev (57), or nira+bev (18) in 1LM. The median time to discontinuation (TTD) in all patient groups regardless of BRCA/HRD testing and results, was 24 mo. (13.8-NR) with O+bev and 22 mo. (17-NR) with O alone, compared to 7.8 mo. (6.9-10.1) with bev, and 8.2 mo. with niraparib (6.7-9.9). The probability of remaining on treatment at 3 mo. for O, niraparib, or O+bev was >90% compared to 80% with bev alone and remained high at 6 mo. (>80% for O or O+bev). The benefit was sustained for O and O+bev-treated groups, with an 18-mo. prob. of remaining on treatment of 57% (45-67) for O and 52% (36-65) for O+bev compared to 16% (10-24) for bev. Ongoing analyses will evaluate the TTD in patient subgroups by BRCA/HRD mutation status. Conclusions: Patients who had a test result and started a PARPi in 1LM had a longer TTD compared to bev-only treated groups, underscoring the importance of genetic testing for the initiation of 1LM and outcome improvement. [Table: see text]