Primary treatment approaches in advanced HRD-positive (BRCAm and BRCAwt) ovarian cancer in the Russian non-interventional OVARD study.

e17561 Background: Homologous recombination deficiency (HRD) positive status is a clinically meaningful biomarker in ovarian cancer (OC), associated with improved progression-free survival with the addition of olaparib (ola) to bevacizumab (bev) as maintenance after first-line therapy in PAOLA-1 study. The OVARD study evaluated real-world primary treatment patterns in HRD+BRCAm and HRD+BRCAwt high-grade OC (HGOC). Methods: This non-interventional study analyzed demographics, clinical characteristics, surgery and systemic treatment in HRD+BRCAm and HRD+BRCAwt HGOC using descriptive statistics; multivariable analysis explored factors associated with treatment choice. Results: A total of 400 patients (pts) with newly diagnosed HRD-positive HGOC (FIGO IC–IV) who completed surgery and first-line carboplatin/paclitaxel with or without bev at 29 Russian sites were analyzed: 234 BRCAm and 160 BRCAwt pts. HRD+BRCAm pts were younger (median 52 vs 61 years, p=0.000001) and more frequently had family (44.5% vs 7.5%) and personal (breast cancer 13.3% vs 1.3%) cancer history. HRD status results became available at median 83 days after diagnosis with primary cytoreduction and 105.5 days with interval cytoreduction from routine HRD-testing. Bev was added to first-line chemotherapy in 14.1% (33/234) of BRCAm vs 29.4% (47/160) of BRCAwt pts (p=0.00021), with subsequent ola+bev maintenance in 5.6% vs 17.5% (p=0.00014). Ola maintenance monotherapy was used more often in BRCAm (62.8% vs 35.6%, p=0.000001), while bev monotherapy was more frequent in BRCAwt (14.4% vs 5.1%, p=0.00153). Among pts with residual disease after cytoreduction, response rates to first-line therapy were comparable between BRCAm and BRCAwt (Table). Conclusions: HRD-positive status has become a routine biomarker at HGOC diagnosis and substantially influences first-line and maintenance treatment selection, with bev-containing regimens more often chosen in BRCAwt and ola-based maintenance widely used in both subgroups in real-world practice. Clinical trial information: NCT05918042 . Response on 1 st line therapy in pts with residual disease after cytoreduction. Type of objective response BRCAmn/N BRCAm% BRCAwtn/N BRCAwt% P value Complete response 19/43 44.19 13/36 36.11 0.46653 Partial response 7/43 16.28 10/36 27.78 0.21550