Ursula A Matulonis

Usability, Acceptability, and Barriers to Implementation of a Collaborative Agenda-Setting Intervention (CASI) to Promote Person-Centered Ovarian Cancer Care: Development Study

Abstract Background People with advanced ovarian cancer and their caregivers report unmet supportive care needs. We developed a Collaborative Agenda-Setting Intervention (CASI) to elicit patients’ and caregivers’ needs through the patient portal before a clinic visit and to communicate these needs to clinicians using the electronic health record. Objective We aimed to assess the usability and acceptability of the CASI and identify barriers to and facilitators of its implementation. Methods We recruited English- and Spanish-speaking patients, caregivers, and clinicians from the gynecologic oncology program at a comprehensive cancer center. Participants used the CASI prototype and then completed individual cognitive interviews and surveys. We assessed usability with the System Usability Scale (scores range 0‐100, scores ≥70 indicate acceptable usability) and acceptability with the Acceptability of Intervention Measure and Intervention Appropriateness Measure (scores for both measures range from 1 to 5, higher scores indicate greater acceptability). Interviews were audio recorded, transcribed, and analyzed using directed content analysis. Domains and constructs from the Consolidated Framework for Implementation Research comprised the initial codebook. We analyzed survey data using descriptive statistics and compared usability and acceptability scores across patients, caregivers, and clinicians using analyses of variance. Results We enrolled 15 participants (5 patients, 5 caregivers, and 5 clinicians). The mean System Usability Scale score was 72 (SD 16). The mean Acceptability of Intervention Measure and Intervention Appropriateness Measure scores were 3.9 (SD 1.0) and 4.1 (SD 0.8), respectively. Participants viewed the CASI content and format positively overall. Several participants appreciated the CASI’s integration into the clinical workflow and its potential to increase attention to psychosocial concerns. Suggestions to refine the CASI included removing redundant items, simplifying item language, and adding options to request a conversation or opt out of supportive care referrals. Key barriers to implementing the CASI include its complexity and limited resources available to address patients’ and caregivers’ needs. Conclusions The CASI is usable and acceptable to patients with advanced ovarian cancer, caregivers, and clinicians. We identified several barriers to and facilitators of implementing the CASI. In future research, we will apply these insights to a pilot randomized controlled trial to assess the feasibility of comparing the CASI to usual care in a parallel group-randomized efficacy trial.

Mirvetuximab soravtansine in folate receptor alpha (FRα)–high platinum-resistant ovarian cancer: final overall survival and post hoc sequence of therapy subgroup results from the SORAYA trial

Objective The single-arm, phase II SORAYA trial ( NCT04296890 ) of mirvetuximab soravtansine-gynx in folate receptor alpha (FRα)–high platinum-resistant ovarian cancer (n=105 (efficacy-evaluable)) met its primary endpoint with an objective response rate of 32.4% (95% CI, 23.6 to 42.2). Here we report final SORAYA trial results for overall survival and post hoc objective response rates in subgroups by sequence and number of prior therapies. Methods Eligible patients had high-grade serous platinum-resistant ovarian cancer with high FRα expression and one to three prior therapies (prior bevacizumab required). Enrolled participants received 6 mg/kg mirvetuximab soravtansine-gynx adjusted ideal body weight intravenously once every 3 weeks until progressive disease, unacceptable toxicity, withdrawal of consent, or death. Final overall survival and post hoc objective response rates were assessed in efficacy-evaluable participants. The safety population included all patients who received ≥1 dose of mirvetuximab soravtansine-gynx. Results At data cut-off (December 22, 2022; n=105), final median overall survival was 15.0 months (95% CI, 11.5 to 18.7). Median overall survival in participants with one to two prior therapy lines was 18.7 months (95% CI, 13.8 to not estimable (NE)) and 11.6 months (95% CI, 7.1 to 16.7) with three prior therapy lines. Median overall survival was 15.0 months (95% CI, 11.5 to NE) in participants with prior poly (ADP-ribose) polymerase inhibitor (PARPi) treatment versus 14.0 months (95% CI, 7.1 to NE) in those without. Objective response rate (data cut-off: November 17, 2021) differed among participants who received mirvetuximab soravtansine-gynx as their first treatment in the platinum-resistant setting (34.8%; 95% CI, 23.5 to 47.6) versus a different first treatment (28.2%; 95% CI, 15.0 to 44.9) or had received prior bevacizumab in a platinum-sensitive (34.0%; 95% CI, 24.6 to 44.5) versus platinum-resistant setting (17.6%; 95% CI, 3.8 to 43.4). No new safety signals were observed. Conclusion These results support the clinically meaningful efficacy of mirvetuximab soravtansine-gynx in FRα-expressing platinum-resistant ovarian cancer, irrespective of prior treatment or sequence.

Poor Concordance Between Cancer Antigen-125 and RECIST Assessment for Progression in Patients With Platinum-Sensitive Relapsed Ovarian Cancer on Maintenance Therapy With a Poly(ADP-ribose) Polymerase Inhibitor

PURPOSE Cancer antigen-125 (CA-125) is recommended by treatment guidelines and widely used to diagnose ovarian cancer recurrence. The value of CA-125 as a surrogate for disease progression (PD) and its concordance with radiologic progression are unclear, particularly for women with platinum-sensitive relapsed ovarian cancer (PSROC) who have responded to chemotherapy and treated with maintenance poly(ADP-ribose) polymerase inhibitor (PARPi). METHODS In this pooled analysis of four randomized trials of maintenance PARPi or placebo (Study 19, SOLO2, ARIEL3, and NOVA), we extracted data on CA-125 PD as defined by Gynecologic Cancer InterGroup criteria and RECIST v1.1. We evaluated the concordance between CA-125 and RECIST PD and reported on the negative predictive value (NPV) and positive predictive value (PPV). RESULTS Of 1,262 participants (n = 818 PARPi, n = 444 placebo), 403 (32%) had CA-125 PD, and of these, 366 had concordant RECIST PD (PPV, 91% [95% CI, 88 to 93]). However, of 859 (68%) without CA-125 PD, 382 also did not have RECIST PD (NPV, 44% [95% CI, 41 to 48]). Within the treatment arms, PPV remained high (PARPi, 91% [95% CI, 86 to 94]; placebo, 91% [95% CI, 86 to 95]) but NPV was lower on placebo (PARPi, 53% [95% CI, 49 to 57]; placebo, 25% [95% CI, 20 to 31]). Of 477 with RECIST-only PD, most (95%) had a normal CA-125 at the start of maintenance therapy and the majority (n = 304, 64%) had CA-125 that remained within normal range. Solid organ recurrence without peritoneal disease was more common in those with RECIST-only PD than in those with CA-125 and RECIST PD (36% v 24%; P < .001). CONCLUSION In patients with PSROC treated with maintenance PARPi, almost half with RECIST PD did not have CA-125 PD, challenging current guidelines. Periodic computed tomography imaging should be considered as part of surveillance, particularly in those with a normal CA-125 at the start of maintenance therapy and on treatment.

A Phase II, Two-Stage Study of Letrozole and Abemaciclib in Estrogen Receptor–Positive Recurrent Endometrial Cancer

PURPOSE Estrogen receptor (ER)–positive endometrial cancers (ECs) are characterized by phosphatidylinositol 3-kinase (PI3K) and receptor tyrosine kinase (RTK)/RAS/β-catenin (CTNNB1) pathway alterations in approximately 90% and 80% of cases, respectively. Extensive cross-talk between ER, PI3K, and RTK/RAS/CTNNB1 pathways leads to both ligand-dependent and ligand-independent ER transcriptional activity as well as upregulation of cyclin D1 which, in complex with cyclin-dependent kinases 4 and 6 (CDK4 and CDK6), is a critical regulator of cell cycle progression and a key mediator of resistance to hormonal therapy. We hypothesized that the combination of the aromatase inhibitor letrozole and CDK4/6 inhibitor abemaciclib would demonstrate promising activity in this setting. METHODS We conducted a phase II, two-stage study of letrozole/abemaciclib in recurrent ER-positive EC. Eligibility criteria included measurable disease, no limit on prior therapies, and all EC histologies; prior hormonal therapy was allowed. Primary end points were objective response rate by RECIST 1.1 and progression-free survival (PFS) rate at 6 months. RESULTS At the data cutoff date (December 03, 2021), 30 patients (28 with endometrioid EC) initiated protocol therapy; 15 (50%) patients had prior hormonal therapy. There were nine total responses (eight confirmed), for an objective response rate of 30% (95% CI, 14.7 to 49.4), all in endometrioid adenocarcinomas. Median PFS was 9.1 months, PFS at 6 months was 55.6% (95% CI, 35.1 to 72), and median duration of response was 7.4 months. Most common ≥ grade 3 treatment-related adverse events were neutropenia (20%) and anemia (17%). Responses were observed regardless of grade, prior hormonal therapy, mismatch repair, and progesterone receptor status. Exploratory tumor profiling revealed several mechanistically relevant candidate predictors of response ( CTNNB1, KRAS, and CDKN2A mutations) or absence of response ( TP53 mutations), which require independent validation. CONCLUSION Letrozole/abemaciclib demonstrated encouraging and durable evidence of activity in recurrent ER positive endometrioid EC.

Safety and management of niraparib monotherapy in ovarian cancer clinical trials

Niraparib is a poly (ADP-ribose) polymerase inhibitor that has shown a significant improvement in progression-free survival irrespective of biomarker status in patients with advanced epithelial ovarian cancer. This review focuses on the adverse events associated with niraparib and their management to maintain efficacy of niraparib treatment and improve quality of life for patients. In five trials assessing efficacy of niraparib in patients with advanced epithelial ovarian cancer (PRIMA, NOVA, NORA, QUADRA, and PRIME), treatment-emergent adverse events of any grade were reported in nearly all patients (≥99%) receiving niraparib; the events were grade ≥3 in 51-74% of patients. Across all lines of therapy, treatment-emergent adverse events led to dose interruptions in 62-80% of patients receiving niraparib and dose reductions in 47-71%. Hematologic events were most frequently reported, including thrombocytopenia, anemia, and neutropenia. Common non-hematologic events included gastrointestinal events, which were generally low grade (<5% were grade ≥3). Clinical strategies to manage these and other events, such as fatigue and insomnia, cognitive behavioral therapy and pharmacologic agents, are summarized. Once-daily niraparib dosing may be advantageous for some patients for many reasons, including night-time dosing which may help alleviate gastrointestinal symptoms. An individualized starting dose (determined by baseline body weight and platelet count) of niraparib demonstrated an improved safety profile while maintaining efficacy. Patients receiving the niraparib individualized starting dose had fewer grade ≥3 adverse events, dose interruptions, and dose reductions than patients receiving a fixed starting dose. The safety profile of niraparib across five pivotal studies in advanced epithelial ovarian cancer was consistent across multiple lines of treatment, including as maintenance therapy in first-line and recurrent settings and as treatment in heavily pre-treated patients. Long-term safety data from the NOVA trial confirmed that, with appropriate and early dose modifications, niraparib is well tolerated.

Mirvetuximab soravtansine-gynx: first antibody/antigen-drug conjugate (ADC) in advanced or recurrent ovarian cancer

Mirvetuximab soravtansine-gynx (MIRV) is a conjugate of a folate receptor alpha (FRα)-directed antibody and the maytansinoid microtubule inhibitor, DM4. Accumulating pre-clinical and clinical data supported the safety and anti-tumor activity of MIRV in tumors expressing FRα. In 2017, a phase I expansion study reported the first experience of MIRV in FRα-positive platinum-resistant ovarian cancer with promising results. However, the phase III FORWARD I study failed to demonstrate a significant benefit of MIRV in FRα-positive tumors. On the basis of the data reported from this latter study, MIRV was then explored in the FRα-high population only and using a different folate receptor assay. The phase II SORAYA trial supported the adoption of MIRV in this setting. Hence, the US Food and Drug Administration granted accelerated approval of MIRV for patients with FRα-positive platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer who have received 1-3 prior systemic treatment regimens. Moreover, the results of the MIRASOL trial showed a significant reduction in the risk of tumor progression or death among patients treated with MIRV versus chemotherapy. VENTANA FOLR1 (FOLR-2.1) was approved as a companion diagnostic test to identify FRα patients. MIRV appears to be a significant asset in managing advanced or recurrent ovarian cancer. Further trials are needed to confirm these promising results, even in the neoadjuvant, adjuvant, and maintenance settings.

Ultrasensitive Detection of Circulating LINE-1 ORF1p as a Specific Multicancer Biomarker

Abstract Improved biomarkers are needed for early cancer detection, risk stratification, treatment selection, and monitoring treatment response. Although proteins can be useful blood-based biomarkers, many have limited sensitivity or specificity for these applications. Long INterspersed Element-1 (LINE-1) open reading frame 1 protein (ORF1p) is a transposable element protein overexpressed in carcinomas and high-risk precursors during carcinogenesis with negligible expression in normal tissues, suggesting ORF1p could be a highly specific cancer biomarker. To explore ORF1p as a blood-based biomarker, we engineered ultrasensitive digital immunoassays that detect mid-attomolar (10−17 mol/L) ORF1p concentrations in plasma across multiple cancers with high specificity. Plasma ORF1p shows promise for early detection of ovarian cancer, improves diagnostic performance in a multianalyte panel, provides early therapeutic response monitoring in gastroesophageal cancers, and is prognostic for overall survival in gastroesophageal and colorectal cancers. Together, these observations nominate ORF1p as a multicancer biomarker with potential utility for disease detection and monitoring. Significance: The LINE-1 ORF1p transposon protein is pervasively expressed in many cancers and is a highly specific biomarker of multiple common, lethal carcinomas and their high-risk precursors in tissue and blood. Ultrasensitive ORF1p assays from as little as 25 μL plasma are novel, rapid, cost-effective tools in cancer detection and monitoring. See related commentary by Doucet and Cristofari, p. 2502. This article is featured in Selected Articles from This Issue, p. 2489

Relacorilant + Nab-Paclitaxel in Patients With Recurrent, Platinum-Resistant Ovarian Cancer: A Three-Arm, Randomized, Controlled, Open-Label Phase II Study

PURPOSE Despite therapeutic advances, outcomes for patients with platinum-resistant/refractory ovarian cancer remain poor. Selective glucocorticoid receptor modulation with relacorilant may restore chemosensitivity and enhance chemotherapy efficacy. METHODS This three-arm, randomized, controlled, open-label phase II study (ClinicalTrials.gov identifier: NCT03776812 ) enrolled women with recurrent, platinum-resistant/refractory, high-grade serous or endometrioid epithelial ovarian, primary peritoneal, or fallopian tube cancer, or ovarian carcinosarcoma treated with ≤4 prior chemotherapeutic regimens. Patients were randomly assigned 1:1:1 to (1) nab-paclitaxel (80 mg/m2) + intermittent relacorilant (150 mg the day before, of, and after nab-paclitaxel); (2) nab-paclitaxel (80 mg/m2) + continuous relacorilant (100 mg once daily); or (3) nab-paclitaxel monotherapy (100 mg/m2). Nab-paclitaxel was administered on days 1, 8, and 15 of each 28-day cycle. The primary end point was progression-free survival (PFS) by investigator assessment; objective response rate (ORR), duration of response (DOR), overall survival (OS), and safety were secondary end points. RESULTS A total of 178 women were randomly assigned. Intermittent relacorilant + nab-paclitaxel improved PFS (hazard ratio [HR], 0.66; log-rank test P = .038; median follow-up, 11.1 months) and DOR (HR, 0.36; P = .006) versus nab-paclitaxel monotherapy, while ORR was similar across arms. At the preplanned OS analysis (median follow-up, 22.5 months), the OS HR was 0.67 ( P = .066) for the intermittent arm versus nab-paclitaxel monotherapy. Continuous relacorilant + nab-paclitaxel showed numerically improved median PFS but did not result in significant improvement over nab-paclitaxel monotherapy. Adverse events were comparable across study arms, with neutropenia, anemia, peripheral neuropathy, and fatigue/asthenia being the most common grade ≥3 adverse events. CONCLUSION Intermittent relacorilant + nab-paclitaxel improved PFS, DOR, and OS compared with nab-paclitaxel monotherapy. On the basis of protocol-prespecified Hochberg step-up multiplicity adjustment, the primary end point did not reach statistical significance ( P &lt; .025). A phase III evaluation of this regimen is underway (ClinicalTrials.gov identifier: NCT05257408 ).

Checkpoint Blockade: Not Yet NINJA Status in Ovarian Cancer

EPIK-O/ENGOT-OV61: Alpelisib Plus Olaparib vs Cytotoxic Chemotherapy in High-Grade Serous Ovarian Cancer (Phase III Study)

Patients with platinum-resistant or -refractory high-grade serous ovarian cancer (HGSOC) have a poor prognosis, and their management represents a substantial unmet medical need. Preclinical data and results from a phase Ib trial demonstrated the efficacy and tolerability of the combination of the α-specific phosphatidylinositol-3-kinase (PI3K) inhibitor alpelisib plus the poly(adenosine diphosphate-ribose) polymerase (PARP) inhibitor olaparib in platinum-resistant, non-

Mutational Signature 3 Detected from Clinical Panel Sequencing is Associated with Responses to Olaparib in Breast and Ovarian Cancers

Abstract Purpose: The identification of patients with homologous recombination deficiency (HRD) beyond BRCA1/2 mutations is an urgent task, as they may benefit from PARP inhibitors. We have previously developed a method to detect mutational signature 3 (Sig3), termed SigMA, associated with HRD from clinical panel sequencing data, that is able to reliably detect HRD from the limited sequencing data derived from gene-focused panel sequencing. Experimental Design: We apply this method to patients from two independent datasets: (i) high-grade serous ovarian cancer and triple-negative breast cancer (TNBC) from a phase Ib trial of the PARP inhibitor olaparib in combination with the PI3K inhibitor buparlisib (BKM120; NCT01623349), and (ii) TNBC patients who received neoadjuvant olaparib in the phase II PETREMAC trial (NCT02624973). Results: We find that Sig3 as detected by SigMA is positively associated with improved progression-free survival and objective responses. In addition, comparison of Sig3 detection in panel and exome-sequencing data from the same patient samples demonstrated highly concordant results and superior performance in comparison with the genomic instability score. Conclusions: Our analyses demonstrate that HRD can be detected reliably from panel-sequencing data that are obtained as part of routine clinical care, and that this approach can identify patients beyond those with germline BRCA1/2mut who might benefit from PARP inhibitors. Prospective clinical utility testing is warranted.

Improved T-cell Immunity Following Neoadjuvant Chemotherapy in Ovarian Cancer

Abstract Purpose: Although local tissue-based immune responses are critical for elucidating direct tumor–immune cell interactions, peripheral immune responses are increasingly recognized as occupying an important role in anticancer immunity. We evaluated serial blood samples from patients with advanced epithelial ovarian cancer (EOC) undergoing standard-of-care neoadjuvant carboplatin and paclitaxel chemotherapy (including dexamethasone for prophylaxis of paclitaxel-associated hypersensitivity reactions) to characterize the evolution of the peripheral immune cell function and composition across the course of therapy. Experimental Design: Serial blood samples from 10 patients with advanced high-grade serous ovarian cancer treated with neoadjuvant chemotherapy (NACT) were collected before the initiation of chemotherapy, after the third and sixth cycles, and approximately 2 months after completion of chemotherapy. T-cell function was evaluated using ex vivo IFNγ ELISpot assays, and the dynamics of T-cell repertoire and immune cell composition were assessed using bulk and single-cell RNA sequencing (RNAseq). Results: T cells exhibited an improved response to viral antigens after NACT, which paralleled the decrease in CA125 levels. Single-cell analysis revealed increased numbers of memory T-cell receptor (TCR) clonotypes and increased central memory CD8+ and regulatory T cells throughout chemotherapy. Finally, administration of NACT was associated with increased monocyte frequency and expression of HLA class II and antigen presentation genes; single-cell RNAseq analyses showed that although driven largely by classical monocytes, increased class II gene expression was a feature observed across monocyte subpopulations after chemotherapy. Conclusions: NACT may alleviate tumor-associated immunosuppression by reducing tumor burden and may enhance antigen processing and presentation. These findings have implications for the successful combinatorial applications of immune checkpoint blockade and therapeutic vaccine approaches in EOC.

Randomized Phase II Study of Gemcitabine With or Without ATR Inhibitor Berzosertib in Platinum-Resistant Ovarian Cancer: Final Overall Survival and Biomarker Analyses

PURPOSE The multicenter, open-label, randomized phase 2 NCI-9944 study ( NCT02595892 ) demonstrated that addition of ATR inhibitor (ATRi) berzosertib to gemcitabine increased progression-free survival (PFS) compared to gemcitabine alone (hazard ratio [HR]=0.57, one-sided log-rank P = .044, which met the one-sided significance level of 0.1 used for sample size calculation). METHODS We report here the final overall survival (OS) analysis and biomarker correlations (ATM expression by immunohistochemistry, mutational signature 3 and a genomic biomarker of replication stress) along with post-hoc exploratory analyses to adjust for crossover from gemcitabine to gemcitabine/berzosertib. RESULTS At the data cutoff of January 27, 2023 (&gt;30 months of additional follow-up from the primary analysis), median OS was 59.4 weeks with gemcitabine/berzosertib versus 43.0 weeks with gemcitabine alone (HR 0.79, 90% CI 0.52 to 1.2, one-sided log-rank P = .18). An OS benefit with addition of berzosertib to gemcitabine was suggested in patients stratified into the platinum-free interval ≤3 months (N = 26) subgroup (HR, 0.48, 90% CI 0.22 to 1.01, one-sided log-rank P =.04) and in patients with ATM-negative/low (N = 24) tumors (HR, 0.50, 90% CI 0.23 to 1.08, one-sided log-rank P = .06). CONCLUSION The results of this follow-up analysis continue to support the promise of combined gemcitabine/ATRi therapy in platinum resistant ovarian cancer, an active area of investigation with several ongoing clinical trials.

Primary Analysis of EPIK-O/ENGOT-ov61: Alpelisib Plus Olaparib Versus Chemotherapy in Platinum-Resistant or Platinum-Refractory High-Grade Serous Ovarian Cancer Without BRCA Mutation

PURPOSE Patients with platinum-resistant/platinum-refractory high-grade serous ovarian cancer (HGSOC) without a BRCA mutation have poor prognosis and limited treatment options. We report efficacy and biomarker data from EPIK-O, which investigated alpelisib + olaparib versus single-agent chemotherapy in these patients. PATIENTS AND METHODS EPIK-O was an open-label, phase III trial that randomly assigned patients with platinum-resistant/platinum-refractory HGSOC with no germline or known somatic BRCA mutation 1:1 to alpelisib 200 mg once daily + olaparib 200 mg twice daily or treatment of physician's choice (TPC; paclitaxel 80 mg/m 2 once weekly or pegylated liposomal doxorubicin 40-50 mg/m 2 once every 28 days). Patients had 1-3 previous systemic therapies. Previous bevacizumab was required (unless contraindicated); previous poly(adenosine diphosphate-ribose) polymerase inhibitors were allowed. Primary end point was progression-free survival (PFS) per RECIST 1.1 (blinded independent review committee [BIRC]). Secondary efficacy end points included overall response rate (ORR; per BIRC), duration of response (per BIRC), and overall survival (OS; key secondary end point). RESULTS A total of 358 patients (alpelisib + olaparib [n = 180], TPC [n = 178]) were included. The median follow-up time was 9.3 months. At data cutoff (April 21, 2023), 33 (18.3%) and 30 (16.9%) patients remained on treatment with alpelisib + olaparib and TPC, respectively. The median PFS (BIRC) was 3.6 versus 3.9 months (hazard ratio [HR], 1.14 [95% CI, 0.88 to 1.48]; one-sided P = .84) for alpelisib + olaparib versus TPC. The ORR was 15.6% (95% CI, 10.6% to 21.7%) versus 13.5% (95% CI, 8.8% to 19.4%). The median OS was 10.0 versus 10.6 months (HR, 1.22; 95% CI, 0.87 to 1.71). The safety profile of alpelisib + olaparib was consistent with that observed for the individual agents. CONCLUSION The primary objective, PFS improvement, was not met in EPIK-O. No new or unexpected adverse events were observed. Biomarker analyses provided new insights for responders to alpelisib + olaparib.

Serial Circulating Tumor DNA Sequencing to Monitor Response and Define Acquired Resistance to Letrozole/Abemaciclib in Endometrial Cancer

PURPOSE In a phase II study, letrozole/abemaciclib demonstrated an objective response rate of 30% and a median progression-free survival (PFS) of 9.1 months in recurrent estrogen receptor–positive endometrial cancer (EC). While tissue-based tumor profiling revealed several mechanistically relevant candidate baseline genomic predictors of response, circulating tumor DNA (ctDNA) is a less invasive alternative to monitor therapeutic efficacy and define acquired resistance. METHODS Serial plasma specimens were obtained at baseline, C2D1, C3D1, C8D1, the time of objective response, and the time of progression. Samples were analyzed using the Guardant Reveal assay to assess methylation-based tumor fraction (TF), with the Guardant360 assay providing genotyping of &gt;700 genes in samples with detectable ctDNA. Treatment response was assessed using a measure of the relative change in TF pre- versus on-treatment. RESULTS A total of 99 of 102 (97%) samples from 28 patients were successfully analyzed. Patients with above median baseline TF exhibited worse median PFS (2.0 months v 16.5 months, P &lt; .005, hazard ratio [HR], 24.1) and worse overall survival (OS) (10.7 months v not yet reached, P &lt; .005, HR, 14.8). Patients with molecular response (MR) after the first or second cycle of letrozole/abemaciclib therapy had significantly better median PFS and OS regardless of the cutoff used for definition of MR. ctDNA analysis of postprogression specimens identified several acquired genomic alterations associated with resistance to letrozole/abemaciclib therapy in more than half of the patients, including PI3K pathway, receptor tyrosine kinase ( FGFR1 , 2 and ERBB2 alterations), cell cycle pathway ( RB1 and CCNE1 alterations), and ESR1 and MAPK pathway alterations. Two of the three patients with mismatch repair–deficient ECs acquired ESR1 mutations at the time of progression. CONCLUSION Baseline and on-treatment ctDNA dynamics may provide an early indication of benefit from letrozole/abemaciclib in EC. ctDNA at the time of progression may identify resistance alterations that may inform subsequent therapy.

Functional Profiling of p53 and RB Cell Cycle Regulatory Proficiency Suggests Mechanism-Driven Molecular Stratification in Endometrial Carcinoma

Abstract In the United States, Endometrial carcinoma (EC) is the most frequently occurring gynecologic cancer. Many ECs harbor mutations in cell cycle regulatory genes including TP53 and RB1, amongst others. RB and p53 both regulate the G1/S transition while p53 also regulates the G2/M transition and mitotic progression, all of which rely on targetable regulatory kinases. It is likely that many ECs harbor targetable defects in some aspect of cell cycle regulation, but there has been no profiling of p53- or RB- linked cell cycle functional capacity and corresponding therapeutic vulnerabilities in EC cells. Here, we utilize functional and transcriptomic assays on a panel of EC cell lines and patient-derived organoids to characterize the p53 and RB cell cycle regulatory proficiency and linked therapeutic vulnerabilities in EC. We show that TP53 genomic and functional status has poor predictive capacity for EC therapeutic response. Rather, proper RB regulation correlates with response to G1/S targeting CDK4/6 inhibitors, and dysfunction in regulation of mitotic progression correlates with response to Aurora kinase B inhibitors. A subset of TP53 mutant ECs are RB1 wild type, express RB protein, have intact RB regulation, and are sensitive to CDK4/6 inhibitors, suggesting that excluding patients from emerging CDK4/6 inhibitor trials based on aggressive histology or TP53 status should be reconsidered. These findings were validated in vivo in xenograft models. These results can expand current EC molecular stratification to include mechanism-driven subtypes and suggest clinical trials of novel targeted therapies based on biologic understanding for advanced or recurrent EC patients. Significance: We show novel cell cycle regulatory molecular classifications and therapeutic targets for endometrial carcinoma. Intact RB regulation and mitotic progression regulatory defects correlate with CDK4/6 and Aurora kinase B inhibitor sensitivity respectively.

Telmisartan in Combination With Cytotoxic Regimens in Platinum-Resistant Ovarian Cancer

The primary study objective is to assess progression-free survival in patients with ovarian cancer receiving telmisartan plus selected standard of care chemotherapy regimens versus historical controls.

Relacorilant in Combination With Nab-Paclitaxel in Advanced, Platinum-Resistant, High-Grade Epithelial Ovarian, Primary Peritoneal, or Fallopian-Tube Cancer

The primary objectives of this study are to evaluate progression-free survival (PFS) by blinded independent central review (BICR) and overall survival (OS) (evaluated independently, as dual primary endpoints) in patients treated with intermittent regimen of Relacorilant in combination with nab-paclitaxel compared with patients treated with nab-paclitaxel monotherapy.

Alpelisib Plus Olaparib in Platinum-resistant/Refractory, High-grade Serous Ovarian Cancer, With no Germline BRCA Mutation Detected

The objective of this study is to assess the efficacy and safety of the combination of alpelisib and olaparib compared with single agent cytotoxic chemotherapy in patients with platinum resistant or refractory high-grade serous ovarian cancer, with no germline BRCA mutation detected.

A Study of Mirvetuximab Soravtansine in Platinum-Resistant, Advanced High-Grade Epithelial Ovarian, Primary Peritoneal, or Fallopian Tube Cancers With High Folate Receptor-Alpha Expression

This study is designed to evaluate the efficacy and safety of mirvetuximab soravtansine (MIRV) in participants with platinum-resistant high-grade serous epithelial ovarian cancer, primary peritoneal, or fallopian tube cancer, whose tumors express a high-level of Folate Receptor-Alpha (FRα). Participants will be, in the opinion of the Investigator, appropriate for single-agent therapy for their next line of therapy. All participants will receive single-agent MIRV at 6 mg/kg adjusted ideal body weight administered on Day 1 of every 3-week cycle.

Study of Relacorilant in Combination With Nab-Paclitaxel for Patients With Recurrent Platinum-Resistant Ovarian, Fallopian Tube, or Primary Peritoneal Cancer

This is a Phase 2, open-label, randomized, 3-arm study to evaluate progression-free survival (PFS) in patients with recurrent platinum-resistant ovarian, fallopian tube, or primary peritoneal cancer treated with intermittent or continuous regimens of relacorilant in combination with nab-paclitaxel compared with patients treated with nab-paclitaxel alone.

RESOLVE: Abemaciclib + Letrozole +/- Metformin, Zotatifin, or Gedatolisib in Endometrial or Low-Grade Serous Ovarian Cancer

This research study is studying a combination of targeted therapies as a possible treatment for estrogen-receptor positive (ER+) endometrial cancer and low-grade serous ovarian cancer. The drugs involved in this study are: * Abemaciclib (also known as Verzenio™) * Letrozole (also known as Femara®) * Metformin (also known as Glucophage®) * Zotatifin (also known as eFT226) * Gedatolisib (also known as PF-05212384)