Coleman, Robert L.

PURPOSE Low-grade serous carcinoma (LGSOC) of the ovary, fallopian tube, or peritoneum is a hormonally driven, relatively chemoresistant malignancy with limited treatment options in the recurrent setting. Given frequent estrogen receptor (ER) expression and dysregulation of the cyclin-dependent kinases 4 and 6 (CDK4/6)–p16–Rb pathway, features shared with hormone receptor–positive breast cancer, dual endocrine, and CDK4/6 inhibition is a biologically rational strategy. This phase II trial evaluated ribociclib plus letrozole in recurrent LGSOC. METHODS This open-label, single-arm, multicenter phase II study enrolled women with measurable, recurrent LGSOC. Patients received ribociclib (600 mg orally, once daily, days 1-21 of a 28-day cycle) and letrozole (2.5 mg orally, once daily). The primary end point was investigator-assessed objective response rate (ORR) per RECIST 1.1. Secondary end points included clinical benefit rate (CBR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS Of 74 patients screened, 51 were enrolled and 49 treated. The confirmed ORR was 30.6% (90% CI, 19.9 to 43.2), including one complete and 14 partial responses. Among responders, the median duration of response was 21.2 months. The CBR was 84% (90% CI, 72.5 to 91.6). The median PFS was 14.5 months (90% CI, 10.1 to 28.8), and the median OS was 44.5 months (90% CI, 31.8 to not reached). The most common grade ≥3 adverse event (AE) was neutropenia (47%), managed with dose modifications. Three grade 5 events (6%) occurred but were unrelated to treatment. Treatment discontinuation because of AEs occurred in 4%. No dose-limiting toxicities were observed. CONCLUSION Ribociclib plus letrozole met the primary end point, achieving meaningful response rates and durable disease control in recurrent LGSOC. The safety profile was consistent with prior CDK4/6 inhibitor studies. This combination represents a therapeutic option in this rare and genomically distinct subtype.

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.

Abstract Background: The benefit of adjuvant regional nodal irradiation including the chest wall after mastectomy (CWI+RNI) and with whole breast irradiation (WBI+RNI) after breast conserving surgery (BCS) is well established in pts with pathologically positive axillary nodes (pN+). Pts who present with axillary node involvement (cN+), receive neoadjuvant chemotherapy (NC), and are found to be pathologically node-negative at surgery (ypN0), have lower loco-regional recurrence (LRR) rates compared to those who remain pathologically node-positive (ypN+). This phase III, randomized trial aimed to evaluate whether CWI+RNI after mastectomy or addition of RNI to WBI after BCS significantly improves invasive breast cancer recurrence-free interval (IBC-RFI) in cN+ pts found to be ypN0 after NC. Methods: Eligible pts had clinical cT1-3, N1, M0 invasive breast cancer (biopsy-proven N+ by FNA/core needle bx), completed ≥8 wks of NC (and anti-HER2 therapy if HER2+), and were ypN0 after mastectomy or BCS and sentinel node biopsy (SLNB, ≥2 nodes), axillary lymph node dissection (ALND), or both. Pts were randomized to “No RNI” (i.e., observation after mastectomy or WBI after BCS) vs. “RNI” (i.e., CWI+RNI after mastectomy or WBI+RNI after BCS). Primary endpoint was IBC-RFI. Secondary endpoints reported here: LRR-free interval (LRRFI), distant recurrence-free interval (DRFI), disease-free survival (DFS), and overall survival (OS). Study was designed to have 80% power to detect 35% reduction in annual rate of IBC-RFI for an absolute risk reduction of 4.6% (5-yr cumulative rate). Per protocol, final analysis was to occur after 172 events or 10 yrs after study initiation.Here we report the time-driven analysis prespecified in the protocol. Results: From 9/13-12/20, 1,641 pts were enrolled; 1,556 pts were available for primary event analysis; median f/u time 59.5 mos (IQR 40.7-74.1). Pt/tumor characteristics were well balanced between groups. Median age 52 yrs (range 21-84); 31% non-white; 21% cT1, 60% cT2, 19% cT3; 23% triple-negative, 21% HR+/HER2-, 56% HER2+; 58% BCS; 55% SLNB, 45% ALND+/-SLNB; and 78% had breast pathologic complete response. At the time of the analysis, 109 IBC-RFI events (63% of the planned 172) were confirmed (“No RNI”: 59, “RNI”: 50). There was no statistically significant difference between groups for IBC-RFI (HR=0.88, 95%CI 0.60-1.29; p=0.51), 5-yr point estimates: 91.8% for “No RNI” and 92.7% for “RNI.” There were no statistically significant differences between the treatment groups for secondary endpoints. There were no study-related deaths and no unexpected toxicities.Grade 4 toxicity was rare (0.1% with “No RNI”, 0.5% with “RNI”); 6.5% of pts developed grade 3 toxicity in “No RNI” and 10% in “RNI” group. Most common grade 3 toxicity was radiation dermatitis (3.3% in “No RNI,” 5.7% in “RNI”). Conclusion: In pts who present with biopsy-proven axillary node involvement and convert their axillary nodes to ypN0 after NC, CWI+RNI after mastectomy, or WBI+RNI after BCS, did not significantly improve IBC-RFI, LRRFI, DRFI, DFS, or OS. These findings suggest that downstaging involved axillary nodes with NC can result in optimization of adjuvant radiotherapy without adversely affecting oncologic outcomes. Follow-up of pts for long-term outcomes continues. NCT01872975 *EPM and JW are co-first authors. Table 1 Citation Format: Eleftherios Mamounas, Hanna Bandos, Julia White, Thomas Julian, Atif Khan, Simona Shaitelman, Mylin Torres, Frank Vicini, Patricia Ganz, Susan McCloskey, Nilendu Gupta, X. Allen Li, Peter Lucas, Nadeem Abu-Rustum, Saumil Gandhi, Rahul Tendulkar, Robert Coleman, Keiichi Fujiwara, Samantha Seaward, William Irvin, Kristin Higgins, Robert Mutter, Jean-Francois Boileau, Andrew Muskovitz, Reshma Jagsi, Anna Weiss, Curran Walter Jr., Norman Wolmark. Loco-Regional Irradiation in Patients with Biopsy-proven Axillary Node Involvement at Presentation Who Become Pathologically Node-negative After Neoadjuvant Chemotherapy: Primary Outcomes of NRG Oncology/NSABP B-51/RTOG 1304 [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr GS02-07.

PURPOSE In patients with high-grade ovarian cancer, predictors of bevacizumab efficacy in first-line setting are needed. In the ICON-7 trial, a poor tumor intrinsic chemosensitivity (defined by unfavorable modeled cancer antigen-125 [CA-125] ELIMination rate constant K [KELIM] score) was a predictive biomarker. Only the patients with high-risk disease (suboptimally resected stage III, or stage IV) exhibiting unfavorable KELIM score < 1.0 had overall survival (OS) benefit from bevacizumab (median: 29.7 v 20.6 months; hazard ratio [HR], 0.78). An external validation study in the GOG-0218 trial was performed. METHODS In GOG-0218, 1,873 patients were treated with carboplatin-paclitaxel ± concurrent-maintenance bevacizumab/placebo. Patient KELIM values were calculated with CA-125 kinetics during the first 100 chemotherapy days by the Lyon University team. The association between KELIM score (favorable ≥ 1.0, or unfavorable < 1.0) and bevacizumab benefit for progression-free survival (PFS)/OS was independently assessed by NGR-GOG using univariate/multivariate analyses. RESULTS KELIM was assessable in 1,662 patients with ≥ 3 CA-125 available values. An unfavorable KELIM score was associated with bevacizumab benefit compared with placebo (PFS: HR, 0.70; 95% CI, 0.59 to 0.82; OS: HR, 0.87; 95% CI, 0.73 to 1.03), whereas a favorable KELIM was not (PFS: HR, 0.96; 95% CI, 0.79 to 1.17; OS: HR, 1.11; 95% CI, 0.89 to 1.39). The highest benefit was observed in patients with a high-risk disease exhibiting unfavorable KELIM, for PFS (median: 9.1 v 5.6 months; HR, 0.64; 95% CI, 0.53 to 0.78), and for OS (median: 35.1 v 29.1 months; HR, 0.79; 95% CI, 0.65 to 0.97). CONCLUSION This GOG-0218 trial investigation validates ICON-7 findings about the association between poor tumor chemosensitivity and benefit from concurrent-maintenance bevacizumab, suggesting that bevacizumab may mainly be effective in patients with poorly chemosensitive disease. Bevacizumab may be prioritized in patients with a high-risk and poorly chemosensitive disease to improve their PFS/OS (patient KELIM score calculator available on the Biomarker Kinetics website).

5553 Background: In patients with high-grade ovarian cancer in first-line setting, predictive factors of bevacizumab efficacy are needed, for selecting patients. In ICON-7 trial, a poor tumor intrisic chemosensitivity (defined by unfavorable modeled CA-125 kinetic ELIMination rate constant KELIM) was a predictive biomarker. Among patients with high-risk diseases, only those with unfavorable KELIM had survival benefit from bevacizumab (mOS: 29.7 vs 20.6 months, HR = 0.78)(Colomban. JNCI CS 2020). The objective was to perform an external validation in GOG-0218 trial (NCT00262847). Methods: In GOG-0218, 1,873 patients were treated with carboplatin-paclitaxel +/- concurrent bevacizumab/placebo followed by a 15 month maintenance. Patient KELIM values were estimated with longitudinal CA-125 kinetics during the first 100 chemotherapy days. The association between KELIM score (categorized as favorable ≥ 1, or unfavorable < 1) and efficacy of bevacizumab (bevacizumab-concurrent + maintenance, vs placebo) for PFS and OS was assessed using univariate/multivariate analyses, in a Training set with 2/3 patients managed the investigators, and then a Validation set with all patients, managed by NGR-GOG. Results: KELIM was assessable in 1,662 patients with ≥ 3 CA-125 available values. In both sets, the patients with unfavorable KELIM derived benefit from bevacizumab compared to placebo (Training: PFS, HR = 0.65 [0.54-0.80]; OS, HR = 0.80 [0.65-0.99]; Validation: PFS, HR = 0.69 [0.59-0.82]; OS, HR = 0.87 [0.73-1.03]), whilst those with favorable KELIM had no benefit from bevacizumab (Training: PFS, HR = 0.96 [0.75-1.23]; OS, HR = 1.05 [0.80-1.37]; Validation, PFS, HR = 0.96 [0.79-1.17]; OS HR = 1.11 [0.89-1.84]). The highest benefit was observed in patients with high-risk diseases (stage IV or sub-optimally resected stage III) characterized by unfavorable KELIM, for PFS (Learning (n = 276): mPFS: 9.0 vs 5.2 months, HR = 0.61 [0.48-0.78]; Validation (n = 433): mPFS: 9.1 vs 5.6 months, HR = 0.64 [0.53-0.78]), and for OS (Learning (n = 278): mOS: 38.9 vs 27.9 months, HR = 0.72 [0.56-0.93], Validation set (n = 438): mOS: 35.1 vs 29.1 months, HR = 0.79 [0.65-0.97]). Conclusions: This validation analysis of GOG-0218 trial confirms the outcomes of ICON-7 trial about the association between poor tumor chemosensitivity and benefit from concurrent + maintenance bevacizumab, suggesting that bevacizumab is mainly effective in patients with poorly chemosensitive diseases. No benefit was found in patients with favorable KELIM. The patients who derived the highest benefit from bevacizumab in PFS and OS (OS absolute benefit ̃ 6 to 9 months) were those with high-risk diseases (stage IV, or incompletely resected stage III) associated with an unfavorable KELIM score (calculator on https://www.biomarker-kinetics.org/CA-125).

Abstract A key resistance mechanism to platinum-based chemotherapies and PARP inhibitors in BRCA-mutant cancers is the acquisition of BRCA reversion mutations that restore protein function. To estimate the prevalence of BRCA reversion mutations in high-grade ovarian carcinoma (HGOC), we performed targeted next-generation sequencing of circulating cell-free DNA (cfDNA) extracted from pretreatment and postprogression plasma in patients with deleterious germline or somatic BRCA mutations treated with the PARP inhibitor rucaparib. BRCA reversion mutations were identified in pretreatment cfDNA from 18% (2/11) of platinum-refractory and 13% (5/38) of platinum-resistant cancers, compared with 2% (1/48) of platinum-sensitive cancers (P = 0.049). Patients without BRCA reversion mutations detected in pretreatment cfDNA had significantly longer rucaparib progression-free survival than those with reversion mutations (median, 9.0 vs. 1.8 months; HR, 0.12; P &lt; 0.0001). To study acquired resistance, we sequenced 78 postprogression cfDNA, identifying eight additional patients with BRCA reversion mutations not found in pretreatment cfDNA. Significance: BRCA reversion mutations are detected in cfDNA from platinum-resistant or platinum-refractory HGOC and are associated with decreased clinical benefit from rucaparib treatment. Sequencing of cfDNA can detect multiple BRCA reversion mutations, highlighting the ability to capture multiclonal heterogeneity. This article is highlighted in the In This Issue feature, p. 151

Abstract Germline and somatic mutations in BRCA1 and BRCA2 (BRCA) confer PARP inhibitor sensitivity. Promoter hypermethylation is an alternate mechanism of gene down-regulation, and BRCA1 promoter methylation is relatively common in sporadic ovarian cancer. The clinical significance of BRCA1 methylation is less clear than for mutations, as the Cancer Genome Atlas (TCGA) and others have failed to show improved survival in ovarian carcinomas with BRCA1 methylation. No one has previously tested whether BRCA1 methylation confers in vivo sensitivity to PARP inhibitors in patients with ovarian cancer. ARIEL2 is a phase 2 study of the PARP inhibitor rucaparib in patients with recurrent platinum sensitive high-grade ovarian, peritoneal or fallopian tube carcinoma. At enrollment, ARIEL2 required pre-treatment tumor biopsies with the goal of developing tissue predictors of PARP inhibitor sensitivity other than BRCA mutations. The number of women with known germline mutations was capped at 15 patients in order to predominantly enroll BRCA wildtype cases. As presented at ASCO 2016, in cases with no BRCA mutations, a high fraction of genomic loss of heterozygosity (LOH) significantly predicted a better progression-free survival (the primary endpoint), longer duration of response, and a higher fraction of responders compared to cases with low LOH. We assessed BRCA1 and RAD51C promoter hypermethylation using methylation-sensitive polymerase chain reaction in paired archival and pre-treatment biopsies from patients on ARIEL2. Of 165 cases for which methylation analyses were completed, 21 (12.7%) were methylated at the BRCA1 promoter and four (2.4%) at the RAD51C promoter. Methylation of BRCA1 and RAD51C was mutually exclusive with mutation in BRCA or other homologous recombination genes. All four cases with RAD51C methylation and 15/19 (78.9%) with BRCA1 methylation were associated with high LOH. In 90 paired samples archival and pre-treatment tissues, RAD51C methylation was 100% concordant and BRCA1 methylation was highly concordant (p&lt;0·001). For 13 cases with BRCA1 methylation in the archival specimen, 4 (30·8%) were unmethylated in the paired pretreatment tumor, but for 77 unmethylated archival specimens, gain of methylation in the pretreatment biopsy was observed just once. Confirmed RECIST responses were seen in 52.4% (11/21) BRCA1 methylated and 75.0% (3/4) RAD51C methylated cases. In conclusion, BRCA1 and RAD51C methylation in ovarian carcinomas correlates with a high response rate to PARP inhibitors. If methylation was to be used as a predictor of PARP inhibitor sensitivity, it would need to be assessed in a pre-treatment (not archival) specimen. The loss of BRCA1 methylation in recurrent ovarian carcinoma, which was common even in these platinum sensitive cases, could explain why BRCA1 methylation is associated with similar survival to methylated cases, despite initial improved therapeutic sensitivity. Citation Format: Elizabeth Swisher, Maria Harrell, Kevin K. Lin, Clare Scott, Sandra Goble, Amit Oza, Robert L. Coleman, Gottfried Konecny, Anna V. Tinker, David M. O'Malley, Rebecca Kristeleit, Ling Ma, James Brenton, Katherine Bell-McGuinn, Ana Oaknin, Alexandra Leary, Elaina Mann, Heidi Giordano, Mitch Rapon, Iain McNeish, Scott H. Kaufmann. BRCA1 and RAD51C Promoter Hypermethylation Confer Sensitivity to PARP Inhibitors in Patients with Platinum Sensitive Ovarian Carcinoma [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP28.