Real-world biomarker testing, treatment patterns and outcomes in a US cohort of patients with advanced ovarian cancer.

Dan Steven Veljovich Gynecologic Oncology and Pelvic Surgery, Swedish Medical Center, Seattle, WA info_outline Dan Steven Veljovich, Richard T. Penson, Michael J. Birrer, Linlin Luo, Nick Pyrih, Simon Pack, Crystal Iu, Manila Hada

Authors Dan Steven Veljovich Gynecologic Oncology and Pelvic Surgery, Swedish Medical Center, Seattle, WA info_outline Dan Steven Veljovich, Richard T. Penson, Michael J. Birrer, Linlin Luo, Nick Pyrih, Simon Pack, Crystal Iu, Manila Hada Organizations Gynecologic Oncology and Pelvic Surgery, Swedish Medical Center, Seattle, WA, Harvard Medical School, Massachusetts General Hospital, Boston, MA, University of Arkansas for Medical Sciences, Little Rock, AR, Oncology Outcomes Research, Global Medical Affairs, Oncology R&D, AstraZeneca Pharmaceuticals LP, Gaithersburg, MD, Oncology Outcomes Research, Global Medical Affairs, Oncology R&D, AstraZeneca Pharmaceuticals LP, Cambridge, United Kingdom Abstract Disclosures Research Funding AstraZeneca Pharmaceuticals LP Background: Olaparib, a poly(ADP-ribose) polymerase inhibitor (PARPi), has shown efficacy as monotherapy for the treatment of BRCA mutated (BRCAm) advanced ovarian cancer (AOC) and in combination with bevacizumab for Homologous Recombination Deficient (HRD+) AOC. This study describes real-world (RW) characteristics, testing and treatment patterns in patients (pts) with AOC, including outcomes with olaparib first-line maintenance (1LM) therapy. Methods: A retrospective observational study utilizing the electronic health record-derived de-identified US-based Flatiron Health database was performed including women aged ≥18 y at AOC diagnosis (Jul 2018–Dec 2022) with ≥1 clinical visit. Pts were followed from diagnosis until Aug 31, 2023, cessation of dataset coverage, or death, whichever occurred first. Biomarker testing was defined as evidence of a test for BRCAm or HRD (inclusive of BRCAm). Estimated RW time to first subsequent therapy or death (TFST) and time to treatment discontinuation or death (TTD) are reported. Results: Demographic and clinical characteristics are shown in the Table. Of 1503 pts included, 80.8% (n=1214) were BRCAm tested and 36.3% (n=546) were HRD (inclusive of BRCAm) tested. Among pts who were either BRCAm or HRD tested (n=1220), 58.0% (n=708) were tested between AOC diagnosis and initiation of 1LM therapy. No 1LM therapy was recorded in 61.9% (n=931/1503) of pts. In both BRCAm and HRD+ pts, olaparib, either as monotherapy (44.5% [n=69/155] and 33.6% [n=100/298], respectively) or in addition to bevacizumab (7.1% [n=11/155] and 9.4% [n=28/298], respectively), was the most frequently used PARPi for 1LM therapy (Table). Median (95% CI) TFST and TTD was 44.7 (27.0, NA) and 22.7 (17.0, 47.0) mos, respectively in BRCAm pts receiving olaparib 1LM (n=69), and 29.1 (22.1, NA) and 22.1 (13.1, NA) mos, respectively in HRD+ pts receiving olaparib + bevacizumab 1LM (n=28). Conclusions: While most pts received BRCAm testing, a majority did not receive HRD (inclusive of BRCAm) testing. A sizeable proportion of pts with actionable biomarker results did not receive PARPi as 1LM therapy highlighting the need for education on the importance of genetic testing to guide AOC treatment. Time-to-event outcomes were comparable with those from the SOLO1 and PAOLA-1 clinical trials, thus supporting the real-world effectiveness of olaparib. BRCAm n=155 HRD+ n=298 All N=1503 Age at AOC diagnosis in y, median (IQR) 60.0 (53.0, 67.0) 63.5 (55.0, 71.0) 67.0 (59.0, 75.0) Stage III at index 96 (61.9) 185 (62.1) 877 (58.3) Optimal debulking 98 (63.2) 190 (63.8) 741 (49.3) Bevacizumab monotherapy a 5 (3.2) 14 (4.7) 180 (12.0) Olaparib monotherapy a 69 (44.5) 100 (33.6) 141 (9.4) Olaparib + bevacizumab a 11 (7.1) 28 (9.4) 50 (3.3) Other PARPi monotherapy a 8 (5.2) 37 (12.4) 148 (9.8) No recorded 1LM 56 (36.1) 104 (34.9) 931 (61.9) All data are n (%) unless otherwise stated. a 1LM.