Moore, Kathleen N.

Abstract Purpose: Our goal was to determine if the HRDefine biomarker combining methylation and mutation assessment of key homologous recombination repair genes identifies BRCA wildtype (BRCAwt) ovarian cancer (OC) with outcomes similar to BRCA mutated (BRCAm) OC within the context of a frontline PARP inhibitor trial for advanced ovarian cancer. Methods: We performed an exploratory biomarker analysis of blood and neoplastic samples from the VELIA trial, a phase 3 study evaluating the PARP inhibitor veliparib as frontline maintenance therapy in OC. We developed a highly sensitive droplet digital PCR assay for quantitative BRCA1 and RAD51C promoter methylation and assessed germline/somatic mutations using the BROCA next generation sequencing platform. Cases were grouped into: BRCAm, HRDefine positive (BRCAwt HRDefine+), and HRDefine negative (BRCAwt HRDefine-). Carcinomas were considered HRDefine+ if quantitative BRCA1 or RAD51C promoter methylation was >/= 60% or if a germline or somatic pathogenic variant (PV) was identified in the following non-BRCA HRR repair genes: RAD51C, RAD51D, PALB2, BARD1. For this analysis, the control group included the two study arms with placebo maintenance compared to the investigational arm of veliparib with chemotherapy and continued as maintenance (veliparib throughout group). HRDefine was compared to the Myriad genomic instability score (GIS) used as HRD assessment in the trial. Progression free survival (PFS) was compared using log rank tests. Results: Among 1140 VELIA participants, biomarker analysis could be performed for 487 cases. Of these, 255 (52%) were BRCAm, 60 (12%) were BRCAwt HRDefine+, and 172 (35%) were BRCAwt HRDefine-. BRCAwt HRDefine+ was driven by promoter methylation (57%), germline (40%), or somatic (3%) PVs. Median PFS (months, all arms combined) was 26 months (BRCAm), 27 months (BRCAwt HRDefine+), and 15 months (BRCAwt HRDefine-), with corresponding hazard ratios (HR) of 0.50 (95% CI: 0.39-0.65) and 0.50 (0.34-0.73) versus HRDefine-. All HRDefine+ molecular subgroups were associated with longer PFS, including RAD51C/D mutations (HR 0.44, 0.25-0.77) and promoter methylation (HR 0.60, 0.36-0.97). HRDefine positivity was significantly associated with improved PFS compared to HRDefine-/GIS low (n=60 vs n=111, median PFS 27 versus 14 months, HR 0.44, 0.30-0.65), while the HRDefine- cases with high GIS demonstrated a trend toward an intermediate PFS (n=56, median 18 months, HR 0.67, 0.45-1.01). When compared by treatment arm, median PFS was significantly longer in the veliparib throughout arm compared to control only for the BRCAm group (32 months vs 23 months, HR 0.61, 0.42-0.87), though the analysis was underpowered for the BRCAwt HRDefine+ sub-group (30 months vs 25 months, HR 0.79, 0.4-1.57). Conclusions: HRDefine identifies BRCAwt OC associated with a PFS that is like that of BRCAm cases and may improve stratification for PARP inhibitor therapy beyond current HRD assays. GIS may have some, albeit reduced, prognostic implication that is independent of HRDefine. Citation Format: Isabel V. Rodriguez, Marc Radke, Ronit Katz, Persephone Miller, Paula Ladd, Nithisha Khasnavis, Jennifer Ochoa, Melanie Dillon, Heather Lankes, Peter Ansell, Carol Aghajanian, Gini Fleming, Michael Birrer, Scott Kaufmann, Charles Leath, Kathleen Moore, Theresa Werner, Linda Van Le, Robert L. Coleman, Elizabeth M. Swisher. Application of HRDefine: a biomarker for identifying root causes of homologous recombination deficiency to a phase 3, randomized, placebo-controlled trial of veliparib in front-line treatment of advanced ovarian cancer (VELIA/GOG-3005) [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Ovarian Cancer Research; 2025 Sep 19-21; Denver, CO. Philadelphia (PA): AACR; Cancer Res 2025;85(18_Suppl):Abstract nr A044.

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual . ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines . Clinical Practice Guidelines and other guidance (“Guidance”) provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases or stages of diseases. Guidance is based on review and analysis of relevant literature and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and 2 (online only) for more . PURPOSE To provide updated guidance regarding neoadjuvant chemotherapy (NACT) and primary cytoreductive surgery (PCS) among patients with stage III-IV epithelial ovarian, fallopian tube, or primary peritoneal cancer (epithelial ovarian cancer [EOC]). METHODS A multidisciplinary Expert Panel convened and updated the systematic review. RESULTS Sixty-one studies form the evidence base. RECOMMENDATIONS Patients with suspected stage III-IV EOC should be evaluated by a gynecologic oncologist, with cancer antigen 125, computed tomography of the abdomen and pelvis, and chest imaging included. All patients with EOC should be offered germline genetic and somatic testing at diagnosis. For patients with newly diagnosed advanced EOC who are fit for surgery and have a high likelihood of achieving complete cytoreduction, PCS is recommended. For patients fit for PCS but deemed unlikely to have complete cytoreduction, NACT is recommended. Patients with newly diagnosed advanced EOC and a high perioperative risk profile should receive NACT. Before NACT, patients should have histologic confirmation of invasive ovarian cancer. For NACT, a platinum-taxane doublet is recommended. Interval cytoreductive surgery (ICS) should be performed after ≤four cycles of NACT for patients with a response to chemotherapy or stable disease. For patients with stage III disease, good performance status, and adequate renal function treated with NACT, hyperthermic intraperitoneal chemotherapy may be offered during ICS. After ICS, chemotherapy should continue to complete a six-cycle treatment plan with the optional addition of bevacizumab. Patients with EOC should be offered US Food and Drug Administration–approved maintenance treatments. Patients with progressive disease on NACT should have diagnosis reconfirmed via tissue biopsy. Patients without previous comprehensive genetic or molecular profiling should be offered testing. Treatment options include alternative chemotherapy regimens, clinical trials, and/or initiation of end-of-life care. Additional information is available at www.asco.org/gynecologic-cancer-guidelines . This guideline has been endorsed by the Society of Gynecologic Oncology.

3084 Background: Homologous recombination (HR) is an essential, high-fidelity mechanism to repair DNA double strand breaks (DSBs) in cancer cells. CYT-0851 inhibits HR leading to an accumulation of unrepaired DSBs and tumor cell death. We are reporting the completed Phase 1 dose-escalation results and RP2D selection to support ongoing development of CYT-0851. Methods: Patients (pts) with advanced hematologic and solid tumors were treated with continuous 28-day cycles of increasing doses of CYT-0851 following a 3+3 design. The primary objective was determining the maximum tolerated dose. Secondary objectives included safety, pharmacokinetics, and anti-tumor activity. Results: As of a 15 Nov 2021 data cutoff (DCO), 73 pts with advanced cancers (NHL n = 18; Sarcoma n = 16; Pancreas n = 11; Breast n = 8; HNSCC n = 6; Ovarian n = 4; SCLC n = 4; Other n = 4; Myeloma n = 2) were treated in 12 cohorts (total daily doses: 30 mg to 1200 mg). One pt experienced a dose-limiting toxicity (DLT) of reversible metabolic acidosis at 1200 mg. Two of 3 pts at 800 mg experienced reversible DLT-like events in Cycle 2 of Gr3 dry skin and Gr3 myalgia and polyarthritis, respectively. Three of 10 pts treated at 600 mg experienced DLT-like events in Cycle 1: 1 pt experienced an SAE of Gr3 anorexia with Gr3 stomatitis, vomiting, and dehydration and 2 pts had Gr3 fatigue. No DLTs occurred at 400 mg daily which was selected as the RP2D. 42 pts (57.5%) experienced a CYT-0851-related adverse event (AE), including 12 (16.4%) with a Gr3/4 AE. There were no treatment-related deaths. AE leading to CYT-0851 withdrawal were reported in 2 pts (2.7%) treated with 600 and 800 mg. The most common CYT-0851-related AEs were primarily Gr1/2 and included fatigue (20.5%), hyperuricemia (11%), nausea (11%), alopecia (9.6%), constipation (8.2%) and headache (8.2%). CYT-0851 exposure was approximately dose-proportional across the evaluated doses with an effective half-life of ̃3 days. Exposure at 400 mg daily was consistent with efficacy in preclinical models. 46 pts were evaluable for response at the DCO. 12 pts with NHL were evaluable by Lugano and included 1 CR in FL and 1 PR in DLBCL treated for 393+ and 244 days respectively. 34 pts with solid tumors were evaluable by RECIST v1.1 with 1 PR in a pt with myxofibrosarcoma treated for 313 days and 16 pts with stable disease. Fifteen pts were treated for 100+ days and 5 for 180+ days. Conclusions: CYT-0851 has demonstrated promising and broad clinical activity in a Ph 1 population of pts with advanced cancers. The safety profile is favorable as characterized by events that were infrequent, primarily Gr1/2, and reversible. Six expansion cohorts (DLBCL, Follicular Lymphoma, Myeloma, Pancreatic, Ovarian and Sarcoma) are enrolling to characterize activity at the RP2D. Ph 1 evaluation of CYT-0851 in combination with 3 chemotherapy backbones is also ongoing. Clinical trial information: NCT03997968.

PURPOSEAn ASCO provisional clinical opinion offers timely clinical direction to ASCO's membership following publication or presentation of potentially practice-changing data from major studies. This provisional clinical opinion addresses the appropriate use of tumor genomic testing in patients with metastatic or advanced solid tumors.CLINICAL CONTEXTAn increasing number of therapies are approved to treat cancers harboring specific genomic biomarkers. However, there is a lack of clarity as to when tumor genomic sequencing should be ordered, what type of assays should be performed, and how to interpret the results for treatment selection.PROVISIONAL CLINICAL OPINIONPatients with metastatic or advanced cancer should undergo genomic sequencing in a certified laboratory if the presence of one or more specific genomic alterations has regulatory approval as biomarkers to guide the use of or exclusion from certain treatments for their disease. Multigene panel–based assays should be used if more than one biomarker-linked therapy is approved for the patient's disease. Site-agnostic approvals for any cancer with a high tumor mutation burden, mismatch repair deficiency, or neurotrophic tyrosine receptor kinase ( NTRK) fusions provide a rationale for genomic testing for all solid tumors. Multigene testing may also assist in treatment selection by identifying additional targets when there are few or no genotype-based therapy approvals for the patient's disease. For treatment planning, the clinician should consider the functional impact of the targeted alteration and expected efficacy of genomic biomarker–linked options relative to other approved or investigational treatments. Additional information is available at www.asco.org/assays-and-predictive-markers-guidelines .

Abstract BACKGROUND: Patients with ROC have limited treatment options in later lines of therapy, as many become platinum-resistant or -ineligible. Poly(ADP-ribose) polymerase inhibitor (PARPi) treatment is one option, however these agents are currently not approved for BRCAwt patients in the treatment setting. Niraparib, a PARPi, has demonstrated increased progression-free survival vs placebo as maintenance therapy for platinum-responsive ROC. Niraparib was effective regardless of BRCAmut or homologous recombination deficiency (HRD) status, although an increased treatment effect was observed in the HRDpos population. QUADRA (NCT02354586) evaluated niraparib treatment in heavily pretreated ROC patients, regardless of BRCAmut or HRD status, platinum sensitivity, or prior PARPi use. METHODS: Eligible patients had grade 2-3 serous ROC, ≥3 prior chemotherapy lines, and measurable disease. Patients were evaluated for BRCAmut and HRD status (MyChoice HRD Test). Patients received niraparib 300 mg once daily until progression; dose could be lowered to 200 mg or 100 mg due to treatment-emergent adverse events (TEAEs). The primary endpoint was objective response rate (ORR) per RECIST v1.1 in patients treated in 4th or 5th line who were HRDpos, platinum sensitive, and PARPi naïve. RESULTS: 463 patients were treated. Of these, 161 were platinum refractory, 151 platinum resistant, and 120 platinum sensitive to their last line of platinum therapy. Of note, 83 patients were primary platinum resistant or refractory (42 and 41, respectively). Median number of prior lines of therapy was 4 (range 2-16), and 27% of patients were treated in 6th or later line. 100% of patients received prior platinum, 99.6% received prior taxane, 81% received prior doxorubicin, 63% received prior bevacizumab, and 59% received prior gemcitabine. In the primary efficacy population (N=45), ORR was 29% (95% CI: 16-44, P=0.0003), disease control rate (DCR) was 71% (95% CI: 56-84), and duration of response (DOR) was 9.2 months (95% CI: 5.9-NE); overall survival (OS) was not reached (95% CI: 18.5-NE). The efficacy outcomes in all 456 patients with measurable disease at baseline treated in 4th or later line demonstrated a DCR of 49% with 2 complete responses (CR), 36 partial responses (PR), and 187 patients with stable disease (SD). The responses were durable with a median DOR of 9.4 months, a clinical benefit rate (CR+PR+SD) at 16 weeks of 29%, and median OS of 17.2 months (95% CI: 14.9-19.8) among all patients treated in 4th or later line. 266 (57.5%) patients had grade ≥3 treatment-related TEAEs. Grade ≥3 thrombocytopenia event (thrombocytopenia or decreased platelet count) by dose at onset of the event was 27.5% at 300 mg, 4.7% at 200 mg, and 2.7% at 100 mg. The other most common grade ≥3 TEAEs were anemia (26.3%) and neutropenia (8.2%). Hematologic TEAEs were most frequent in the first month and decreased in frequency and severity after dose reduction during months 2-3. CONCLUSIONS: Niraparib demonstrated durable anticancer activity in this heavily treated (≥3 lines) ROC population, including platinum-resistant or BRCAwt patients. Toxicities were consistent with previous niraparib studies. DISCLOSURE Funded by TESARO, Inc. Citation Format: Kathleen Moore, Angeles Secord, Melissa Geller, David Miller, Noelle Cloven, Gini Fleming, Andrea E. Wahner Hendrickson, Masoud Azodi, Paul Disilvestro, Amit Oza, Mihaela Cristea, Jonathan S. Berek, John Chan, Yong Li, Kaiming Sun, Katarina Luptakova, Ursula A. Matulonis, Bradley J. Monk. QUADRA: A PHASE 2, OPEN-LABEL, SINGLE-ARM STUDY TO EVALUATE SINGLE-AGENT NIRAPARIB TREATMENT IN PATIENTS WITH RELAPSED OVARIAN CANCER (ROC) WHO HAVE RECEIVED ≥3 PRIOR CHEMOTHERAPY REGIMENS [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr NT-101.

2549 Background: BDC-1001 is a novel ISAC consisting of an investigational trastuzumab biosimilar chemically conjugated to a TLR 7/8 agonist with a non-cleavable linker. BDC-1001 was designed to activate the innate immune system, eliciting antibody-mediated effector functions (eg, antibody-dependent cellular phagocytosis) and a durable adaptive immune response. In preclinical tumor models resistant to anti-HER2 treatments, BDC-1001 demonstrated potent and durable immune-mediated antitumor efficacy. Methods: A 4-part, phase 1/2 dose-escalation/expansion study was initiated to evaluate BDC-1001 ± PD1 inhibitor pembrolizumab in pts with HER2-expressing solid tumors who had progressive disease on standard of care (NCT04278144). Preliminary results of the monotherapy dose escalation (Part 1) are reported. Pts with advanced metastatic HER2-expressing (IHC2/3+) or amplified solid tumors received BDC-1001 IV q3w in a 3+3 design w/ 12 pts/cohort backfill allowed. Primary objectives were to evaluate safety, tolerability, dose-limiting toxicities (DLTs) and determine a phase 2 dose; secondary objectives were to assess pharmacokinetics (PK), pharmacodynamics and preliminary anti-tumor activity. Results: As of Jan 29, 2021, 20 pts w/ a median age of 65 (46-85) have enrolled in 4 dose levels (0.15mg/kg to 5 mg/kg). Cancer types include breast, biliary, cervical, colorectal (CRC), lung, gastroesophageal, salivary, urinary tract and endometrial. Pts had received a median of 4 (1-7) prior therapies; 65% received >1 prior anti-HER2 therapy. All pts completed the 21-day DLT period; no DLTs or drug-related serious adverse events (AEs) have been observed. AEs deemed related to BDC-1001 have been mild to moderate including infusion-related reactions. The MTD has not been reached (treatment duration 5-17+wk); enrollment is ongoing. PK evaluations showed Cmax levels consistent with predicted modeling based on non-human primates (NHP). One pt with microsatellite stable (MSS) HER2+ CRC with lung metastases had a confirmed partial response after 4 cycles and remains on study; 2 additional pts with metastatic MSS HER2+ CRC had stable disease (SD) and a pt with heavily pretreated MSS endometrial cancer with lung metastases had confirmed SD and remains on treatment 17+ wk; 3 of these pts had received 2 prior anti-HER2 therapies. Conclusions: In this first-in-human study, BDC-1001 appears to be well-tolerated up to the dose tested to date (5 mg/kg), with Cmax levels achieved as predicted by NHP modeling. Evidence of clinical activity have been observed, including in pts previously treated with anti-HER2 therapy. Dose escalation is ongoing and will be followed by combination dosing with CPI and the phase 2 component in selected tumors. Clinical trial information: NCT04278144.

5012 Background: VEGF receptor-mediated-signaling contributes to ovarian cancer pathogenesis. Elevated VEGF expression and serum levels are associated with poor clinical outcomes. We investigated RAM, a fully human VEGFR-2 antagonist antibody, in patients (pts) with persistent or recurrent EOC/FTC/PPC. Methods: Adult women with EOC/FTC/PPC who had completed ≥1 platinum (P)-based chemotherapeutic (ct) regimen and had a P-free interval (PFI) of <12 months (m), progression on, or persistent disease after P-based therapy were eligible. Any number of prior ct regimens was allowed. ECOG PS 0-1 and adequate organ function were required. Pts received 8 mg/kg RAM IV every 2 weeks. Primary endpoints were progression-free survival at 6m (PFS-6) and confirmed objective response rate (ORR) by RECIST 1.0. Results: 60 pts were treated; 1 remains on study as of Dec 2011. Median age was 62 years (range 27-80). Median number of prior regimens was 3 (range 1– 14). 51 pts (85%) received ≥ 2 prior regimens; 25 pts (42%) received >3 prior regimens. 45 pts (75%) were P resistant or refractory, with 65% (39 pts) serous tumors. PFS-6: 34.2% (95% CI: 21.7% – 47%). Best overall response: 3 PR (5%), 34 SD (57%), 20 PD (33%) and 3 not evaluable (5%). Median duration of PR: 5.6m (3.7, 5.6, 17.5); median PFS: 3.5m (95% CI: 2.3 – 5.3). Median OS: 11.1m (95% CI: 8.3 – 17.0). No unexpected toxicities were observed. Grade (G) 3 adverse events (AEs) observed in >5% of pts were: headache (10%) and fatigue (8%). No G4 AEs were observed in >5% of pts. 5 deaths occurred on RAM or within 30 days of discontinuation; 4 due to PD, and 1 due to intestinal perforation. 1 G4 bowel perforation and one G4 colo-vaginal fistula were noted. All 3 cases of perforation/fistula occurred in the setting of progressive, large-volume disease. Correlative biomarker studies are ongoing to identify patients most likely to benefit. Conclusions: Ramucirumab was reasonably tolerated and demonstrated single-agent activity in persistent or recurrent ovarian carcinoma, with approximately one-third of patients progression free at 6 months.

5565 Background: The goal of this study was to determine the recurrence rates (R) of patients with grade 1 and 2 stage 1A and IB ovarian tumors treated with and without chemotherapy. Methods: We conducted a five-center retrospective study of patients with Stage 1A/B grade 1 and 2 ovarian carcinoma. All women underwent comprehensive staging including a minimum of unilateral salpingo-ophorectomy, unilateral pelvic and para-aortic lymphadenectomy, and omentectomy. Clear cell histologies were classified as grade 3 and excluded. The minimum cancer-free survivor follow-up was 3 years. Results: We identified 82 patients with Stage 1A/B grade 1 and 2 who met criteria for the study. The median age was 58 yrs (range 29 to 83) and the median follow-up was 5.3 yrs (range 3 to 11 yrs). The majority were of endometrioid histology (51), followed by mucinous (19), papillary serous (11), and mixed (1). Recurrences were of endometrioid (4), mucinous (1), or papillary serous (1) histology. For Stage 1A, overall recurrence rate was 9% (6/67). The overall recurrence rates for Stage 1A, grade1 tumors was 6% and among grade 2 tumors 12% (p=0.40). Among Stage 1A patients not treated with chemotherapy, there was a 7% (2/29) and 9.5% (2/21) recurrence rate for grade 1 and grade 2 tumors, respectively. For the grade 1 tumors, both patients are alive with disease at 3 and 5 yrs. For the grade 2 tumors, one is alive without evidence of disease at 7 yrs and the other died from disease at 4 yrs. Time to recurrence (TTR) was 2.3 yrs for grade 1 tumors and 2.6 yrs for grade 2 tumors. For Stage 1A patients treated with a platinum chemotherapy regimen, there were no recurrences (0/5) for grade 1 tumors and a 16% (2/12) recurrence rate for grade 2 tumors. Of the recurrences, one patient died from disease at 1.4 yrs and the other is alive with stable disease at 6 yrs. Time to recurrence was 2.85 yrs for grade 2 tumors. For grade 1 or 2, Stage 1A tumors, recurrence rates and time to recurrence were not effected by chemotherapy administration (R, p=0.55 and p=0.54, respectively; TTR, grade 2, p=0.85). No recurrences were observed in the 15 patients with Stage IB, grade 1 and 2 tumors. Conclusions: In comprehensively staged patients with Stage 1A/B, grade 1 and 2, low recurrence rates suggest adjuvant chemotherapy may not be indicated. No significant financial relationships to disclose.