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

person Lucio N. Gordan Florida Cancer Specialist, Gainesville, FL info_outline Lucio N. Gordan, Anupama Vasudevan, Sandy English, Alison Roos, Marielle Fares, Lindsay Aton, Brandon Wang, Simon Blanc

Authors person Lucio N. Gordan Florida Cancer Specialist, Gainesville, FL info_outline Lucio N. Gordan, Anupama Vasudevan, Sandy English, Alison Roos, Marielle Fares, Lindsay Aton, Brandon Wang, Simon Blanc Organizations Florida Cancer Specialist, Gainesville, FL, Integra Connect PrecisionQ, West Palm Beach, FL, Illumina, Inc., Foster City, CA, Integra Connect, West Palm Beach, FL Abstract Disclosures Research Funding No funding received None. 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. BRCA test results and 1LM treatment received. Bev Niraparib O Rucaparib O + bev Niraparib + bev Total 122 102 96 5 53 21 BRCA+ 3 2 37 1 7 0 BRCA wt/HRD 12 12 23 0 15 5 BRCA wt/HRP 40 34 7 1 12 7 BRCA wt/HRD Not reported 60 44 29 2 18 8 BRCA wt/HRD unknown 7 10 0 1 1 1