Diagnosing and staging epithelial ovarian cancer by serum glycoproteomic profiling

BACKGROUND

There is a need for diagnostic tests for screening, triaging and staging of epithelial ovarian cancer (EOC). Glycoproteomics of blood samples has shown promise for biomarker discovery.

METHODS

We applied glycoproteomics to serum of people with EOC or benign pelvic masses and healthy controls. A total of 653 analytes were quantified and assessed in multivariable models, which were tested in an independent cohort. Additionally, we analyzed glycosylation patterns in serum markers and in tissues.

RESULTS

We identified a biomarker panel that distinguished benign lesions from EOC with sensitivity and specificity of 83.5% and 90.1% in the training set, and of 86.7 and 86.7% in the test set, respectively. ROC analysis demonstrated strong performance across a range of cutoffs. Fucosylated multi-antennary glycopeptide markers were higher in late-stage than in early-stage EOC. A comparable pattern was found in late-stage EOC tissues.

CONCLUSIONS

Blood glycopeptide biomarkers have the potential to distinguish benign from malignant pelvic masses, and early- from late-stage EOC. Glycosylation of circulating and tumor tissue proteins may be related. This study supports the hypothesis that blood glycoproteomic profiling can be used for EOC diagnosis and staging and it warrants further clinical evaluation.

Molecular profiling of gestational trophoblastic neoplasia: Identifying therapeutic targets

OBJECTIVE

The treatment for high risk or recurrent gestational trophoblastic neoplasia (GTN) is a highly toxic multi-agent chemotherapy. For patients with progressive or recurrent GTN, checkpoint inhibitors have demonstrated anti-tumor activity; however, identification of novel therapies for GTN remain an unmet need. Therefore, we sought to characterize the molecular landscape of GTN to identify potential therapeutic targets.

METHODS

GTN samples were analyzed using a combination of molecular - next-generation sequencing (NGS) or whole exome sequencing (WES)- and protein- Immunohistochemistry (IHC) analyses. GTN samples encompassed complete moles, choriocarcinoma, epithelioid trophoblastic tumors (ETT), and placental site trophoblastic tumors (PSTT).

RESULTS

We analyzed 30 cases of GTN including 15 choriocarcinoma, 7 ETT, 5 PSTT, 1 invasive mole and 2 mixed histologies. The median age was 41.5. GTN samples were found to be PD-L1 positive (92.3%), tumor mutational burden (TMB) low (92.8%), and microsatellite stable (MSS) (100%). Forty-six percent of choriocarcinoma specimens contained a genomic alteration including TP53 (33%) and homologous recombination repair (HRR) (13%) genes. Alterations in RTK-RAS pathway signaling was present in 40% of ETT cases.

CONCLUSIONS

The high rate of PD-L1 positivity in this real-world database and reported in prior literature support continued clinical trial development evaluating immunotherapy for treatment of GTN. Other potential targeted treatments identified include Wee1, PARP and MEK inhibitors based on molecular alterations in TP53, HRR genes, and RTK-RAS pathways respectively.

Ofranergene Obadenovec (Ofra-Vec, VB-111) With Weekly Paclitaxel for Platinum-Resistant Ovarian Cancer: Randomized Controlled Phase III Trial (OVAL Study/GOG 3018)

PURPOSE

To evaluate the addition of ofranergene obadenovec (ofra-vec, VB-111), a novel gene-based anticancer targeted therapy, to once a week paclitaxel in patients with recurrent platinum-resistant ovarian cancer (PROC).

METHODS

This placebo-controlled, double-blind, phase III trial (ClinicalTrials.gov identifier: NCT03398655) randomly assigned patients with PROC 1:1 to receive intravenous ofra-vec every 8 weeks with once a week IV paclitaxel or placebo with paclitaxel until disease progression. The dual primary end points were overall survival (OS) and progression-free survival (PFS) as assessed by Blinded Independent Central Review.

RESULTS

Between December 2017 and March 2022, 409 patients were randomly assigned. The median PFS was 5.29 months in the ofra-vec arm and 5.36 months in the control arm, hazard ratio (HR) 1.03 (CI, 0.83 to 1.29; P = .7823). The median OS with ofra-vec was 13.37 months versus 13.14 months, HR 0.97 (CI, 0.75 to 1.27; P = .8440). Objective response rates (ORRs) per RECIST 1.1 were similar in both arms: 28.9% with ofra-vec versus 29.6% with control. In both treatment arms, response to CA-125 was a substantial prognostic factor for both PFS and OS. In the ofra-vec arm, the HR in CA-125 responders compared with that in nonresponders for PFS was 0.2428 (CI, 0.1642 to 0.3588), and for OS, the HR was 0.3343 (CI, 0.2134 to 0.5238). Safety profile was characterized by common transient flu-like symptoms such as fever and chills.

CONCLUSION

The addition of ofra-vec to paclitaxel did not improve PFS or OS. The PFS and ORR in the control arm exceeded the results that were anticipated on the basis of the AURELIA chemotherapy control arm. CA-125 response was a substantial prognostic biomarker for PFS and OS in patients with PROC treated with paclitaxel.

Optimizing disease progression assessment using blinded central independent review and comparing it with investigator assessment in the PRIMA/ENGOT-ov26/GOG-3012 trial: challenges and solutions

OBJECTIVE

Progression-free survival is an established clinically meaningful endpoint in ovarian cancer trials, but it may be susceptible to bias; therefore, blinded independent centralized radiological review is often included in trial designs. We compared blinded independent centralized review and investigator-assessed progressive disease performance in the PRIMA/ENGOT-ov26/GOG-3012 trial examining niraparib monotherapy.

METHODS

PRIMA/ENGOT-ov26/GOG-3012 was a randomized, double-blind phase 3 trial; patients with newly diagnosed stage III/IV ovarian cancer received niraparib or placebo. The primary endpoint was progression-free survival (per Response Evaluation Criteria in Solid Tumors [RECIST] v1.1), determined by two independent radiologists, an arbiter if required, and by blinded central clinician review. Discordance rates between blinded independent centralized review and investigator assessment of progressive disease and non-progressive disease were routinely assessed. To optimize disease assessment, a training intervention was developed for blinded independent centralized radiological reviewers, and RECIST refresher training was provided for investigators. Discordance rates were determined post-intervention.

RESULTS

There was a 39% discordance rate between blinded independent centralized review and investigator-assessed progressive disease/non-progressive disease in an initial patient subset (n=80); peritoneal carcinomatosis was the most common source of discordance. All reviewers underwent training, and as a result, changes were implemented, including removal of two original reviewers and identification of 10 best practices for reading imaging data. Post-hoc analysis indicated final discordance rates between blinded independent centralized review and investigator improved to 12% in the overall population. Median progression-free survival and hazard ratios were similar between blinded independent centralized review and investigators in the overall population and across subgroups.

CONCLUSION

PRIMA/ENGOT-ov26/GOG-3012 highlights the need to optimize blinded independent centralized review and investigator concordance using early, specialized, ovarian-cancer-specific radiology training to maximize validity of outcome data.

TP53 mutation and abnormal p53 expression in endometrial cancer: Associations with race and outcomes

OBJECTIVE

This multi-center cohort study assessed associations between race, TP53 mutations, p53 expression, and histology to investigate racial survival disparities in endometrial cancer (EC).

METHODS

Black and White patients with advanced or recurrent EC with Next Generation Sequencing data in the Endometrial Cancer Molecularly Targeted Therapy Consortium database were identified. Clinicopathologic and treatment variables were summarized by race and compared. Overall survival (OS) and progression-free survival (PFS) among all patients were estimated by the Kaplan-Meier method. Cox proportional hazards models estimated the association between race, TP53 status, p53 expression, histology, and survival outcomes.

RESULTS

Black patients were more likely than White patients to have TP53-mutated (N = 727, 71.7% vs 49.7%, p < 0.001) and p53-abnormal (N = 362, 71.1% vs 53.2%, p = 0.003) EC. Patients with TP53-mutated EC had worse PFS (HR 2.73 (95% CI 1.88-3.97)) and OS (HR 2.20 (95% CI 1.77-2.74)) compared to those with TP53-wildtype EC. Patients with p53-abnormal EC had worse PFS (HR 2.01 (95% CI 1.22-3.32)) and OS (HR 1.61 (95% CI 1.18-2.19)) compared to those with p53-wildtype EC. After adjusting for TP53 mutation and p53 expression, race was not associated with survival outcomes. The most frequent TP53 variants were at nucleotide positions R273 (n = 54), R248 (n = 38), and R175 (n = 23), rates of which did not differ by race.

CONCLUSIONS

Black patients are more likely to have TP53-mutated and p53-abnormal EC, which are associated with worse survival outcomes than TP53- and p53-wildtype EC. The higher frequency of these subtypes among Black patients may contribute to survival disparities.

Overcoming the challenges of drug development in platinum-resistant ovarian cancer

The definition of "platinum-resistant ovarian cancer" has evolved; it now also reflects cancers for which platinum treatment is no longer an option. Standard of care for platinum-resistant ovarian cancer is single-agent, non-platinum chemotherapy with or without bevacizumab, which produces modest response rates, with the greatest benefits achieved using weekly paclitaxel. Several recent phase 3 trials of pretreated patients with prior bevacizumab exposure failed to meet their primary efficacy endpoints, highlighting the challenge in improving clinical outcomes among these patients. Combination treatment with antiangiogenics has improved outcomes, whereas combination strategies with immune checkpoint inhibitors have yielded modest results. Despite extensive translational research, there has been a lack of reliable and established biomarkers that predict treatment response in platinum-resistant ovarian cancer. Additionally, in the platinum-resistant setting, implications for the time between the penultimate dose of platinum therapy and platinum retreatment remain an area of debate. Addressing the unmet need for an effective treatment in the platinum-resistant setting requires thoughtful clinical trial design based on a growing understanding of the disease. Recent cancer drug approvals highlight the value of incorporating molecular phenotypes to better define patients who are more likely to respond to novel therapies. Clinical trials designed per the Gynecologic Cancer InterGroup recommendations-which advocate against relying solely upon the platinum-free interval-will help advance our understanding of recurrent ovarian cancer response where platinum rechallenge in the platinum-resistant setting may be considered. The inclusion of biomarkers in clinical trials will improve patient stratification and potentially demonstrate correlations with biomarker expression and duration of response. With the efficacy of antibody-drug conjugates shown for the treatment of some solid and hematologic cancers, current trials are evaluating the use of various novel conjugates in the setting of platinum-resistant ovarian cancer. Emerging novel treatments coupled with combination trials and biomarker explorations offer encouraging results for potential strategies to improve response rates and prolong progression-free survival in this population with high unmet need. This review outlines existing data from contemporary clinical trials of patients with platinum-resistant ovarian cancer and suggests historical synthetic benchmarks for non-randomized trials.

Sulforaphane Bioavailability in Healthy Subjects Fed a Single Serving of Fresh Broccoli Microgreens

Cruciferous vegetable consumption is associated with numerous health benefits attributed to the phytochemical sulforaphane (SFN) that exerts antioxidant and chemopreventive properties, among other bioactive compounds. Broccoli sprouts, rich in SFN precursor glucoraphanin (GRN), have been investigated in numerous clinical trials. Broccoli microgreens are similarly rich in GRN but have remained largely unexplored. The goal of this study was to examine SFN bioavailability and the microbiome profile in subjects fed a single serving of fresh broccoli microgreens. Eleven subjects participated in a broccoli microgreens feeding study. Broccoli microgreens GRN and SFN contents and stability were measured. Urine and stool SFN metabolite profiles and microbiome composition were examined. Broccoli microgreens had similar GRN content to values previously reported for broccoli sprouts, which was stable over time. Urine SFN metabolite profiles in broccoli microgreens-fed subjects were similar to those reported previously in broccoli sprouts-fed subjects, including the detection of SFN-nitriles. We also reported the detection of SFN metabolites in stool samples for the first time. A single serving of broccoli microgreens did not significantly alter microbiome composition. We showed in this study that broccoli microgreens are a significant source of SFN. Our work provides the foundation for future studies to establish the health benefits of broccoli microgreens consumption.

Differential outcomes and immune checkpoint inhibitor response among endometrial cancer patients with MLH1 hypermethylation versus MLH1 "Lynch-like" mismatch repair gene mutation

OBJECTIVES

To identify differential survival outcomes and immune checkpoint inhibitor (ICI) response in MLH1 hypermethylated versus MLH1 mutated ("Lynch-like") endometrial tumors and determine whether their molecular profiles can elucidate the differential outcomes.

METHODS

1673 mismatch repair deficient endometrial tumors were analyzed by next-generation sequencing and whole transcriptome sequencing (Caris Life Sciences, Phoenix, AZ). PD-L1, ER, and PR were tested by immunohistochemistry and immune cell infiltrates were calculated using MCP-counter. Significance was determined using Chi-square and Mann-Whitney U tests and adjusted for multiple comparisons. Overall survival (OS) was depicted using Kaplan-Meier survival curves.

RESULTS

The endometrial cancer cohort comprised 89.2% patients with MLH1 hypermethylated tumors and 10.8% with MLH1 mutated tumors, with median ages of 67 and 60 years, respectively (p < 0.01). Patients with MLH1 hypermethylated tumors had significantly worse OS and trended toward worse OS following ICI treatment than patients with MLH1 mutated tumors. The immune microenvironment of MLH1 hypermethylated relative to MLH1 mutated was characterized by decreased PD-L1 positivity, immune checkpoint gene expression, immune cell infiltration, T cell inflamed scores, and interferon gamma (IFNγ) scores. MLH1 hypermethylation was also associated with decreased mutation rates in TP53 and DNA damage repair genes, but increased rates of JAK1, FGFR2, CCND1, and PTEN mutations, as well as increased ER and PR positivity.

CONCLUSIONS

Endometrial cancer patients with MLH1 hypermethylation display significantly decreased survival and discrepant immunotherapy responses compared to patients with MLH1 mutated tumors, which was associated with differential mutational profiles, a more immune cold phenotype, and increased ER/PR expression in MLH1 hypermethylated tumors. Providers may consider early transition from single agent ICI to a multi-agent regimen or hormonal therapy for patients with MLH1 hypermethylated tumors.

The Genomic Landscape of Vulvar Squamous Cell Carcinoma

Vulvar squamous cell cancer (VSC) accounts for 90% of vulvar cancers. Next-generation sequencing studies of VSC imply human papillomavirus (HPV) and p53 status play separate roles in carcinogenesis and prognosis. We sought to describe the genomic landscape and analyze the immunologic profiles of VSC with respect to HPV and p53 status. A total of 443 VSC tumors underwent tumor profiling. Next-generation sequencing was performed on genomic DNA isolated from formalin-fixed paraffin-embedded tumor samples. PD-L1, microsatellite instability were tested by fragment analysis, IHC, and next-generation sequencing. Tumor mutational burden-high was defined as >10 mutations per MB. HPV 16/18 positive (HPV+) status was determined using whole exome sequencing on 105 samples. Three cohorts were identified from 105 samples with known HPV: HPV+, HPV-/p53wt, and HPV-/p53mt. Where HPV and p53 status were examined, TP53 mutations were exclusive of HPV+ tumors. In all, 37% of samples were HPV+. Among the 66 HPV- tumors, 52 (78.8%) were HPV-/p53mt and 14 (21.2%) were HPV-/p53wt. The HPV-/p53wt cohort had a higher rate of mutations in the PI3KCA gene (42.9% HPV-/p53wt vs 26.3% HPV+ vs. 5.8% HPV-/p53mt, q =0.028) and alterations in the PI3K/AkT/mTOR pathway (57.1% HPV-/p53wt vs. 34.2% HPV+ vs. 7.7% HPV-/p53mt, q =0.0386) than the other 2 cohorts. Ninety-eight VSC tumors with HPV16/18 information underwent transcriptomic analysis and immune deconvolution method. No differences were observed in immune profiles. The HPV-/p53wt VSC tumors had significantly higher rates of mutations in the PI3KCA gene and alterations in the PI3K/AkT/mTOR pathway, a potential target that merits further investigation in this subgroup.

Acute pulmonary complications in the setting of high risk gestational trophoblastic neoplasia and induction of chemotherapy

Gestational trophoblastic neoplasia (GTN) consists of rare malignancies of the placenta with a known propensity to metastasize to the lungs. GTN is treated with chemotherapeutic agents known to cause lung injury, further placing patients at risk for serious pulmonary events. In the literature, only a few reports of these complications and their management have been described. Here, we present two cases of GTN with pulmonary complications in the hopes of providing guidance in management. Management of these acute complications had to be balanced between continuation of life-saving therapy to reduce disease burden versus further exacerbation existing pulmonary disease. A review of the English language literature on pulmonary complications in GTN and chemotherapy was performed. In these two cases, we identified key steps that were critical in management: inpatient chemotherapy, early intervention and transfer to an intensive unit when needed, multidisciplinary teams, and altering regimens to reduce lung toxicity. Sequelae of pulmonary injury secondary to chemotherapy can be similar to those secondary to metastases. Because consistent criteria for chemotherapy-induced lung injury has not been established, the true incidence of lung injury that is directly related to chemotherapy versus metastatic disease cannot always be parsed out, making management of these complications difficult. There is also a lack of centralized care for a rare disease like GTN and regional differences in incidence, which can lead to inconsistent treatment decisions. It therefore remains important to illuminate rarely seen complications and their management in the hopes of providing guidance to future clinicians.

ARTISTRY-7: phase III trial of nemvaleukin alfa plus pembrolizumab vs chemotherapy for platinum-resistant ovarian cancer

Standard single-agent nonplatinum chemotherapy provides only modest benefit in a small proportion of patients with platinum-resistant/-refractory ovarian cancer, with objective response rates of 6-20% and progression-free survival of ≈3-4 months. Nemvaleukin alfa (nemvaleukin, ALKS 4230) is a novel cytokine designed to capture and expand the therapeutic potential of high-dose interleukin-2 (IL-2) while mitigating its associated toxicity issues. Nemvaleukin preferentially activates cytotoxic CD8+ T cells and natural killer cells with minimal, non-dose-dependent effects on CD4+ regulatory T cells. The global, randomized, open-label, phase III ARTISTRY-7 trial will compare efficacy and safety of nemvaleukin plus pembrolizumab with chemotherapy in patients with platinum-resistant ovarian cancer. The primary end point is investigator-assessed progression-free survival. Clinical Trial Registration: GOG-3063; ENGOT-OV68; NCT05092360 (ClinicalTrials.gov).

Dostarlimab for Primary Advanced or Recurrent Endometrial Cancer

BACKGROUND

Dostarlimab is an immune-checkpoint inhibitor that targets the programmed cell death 1 receptor. The combination of chemotherapy and immunotherapy may have synergistic effects in the treatment of endometrial cancer.

METHODS

We conducted a phase 3, global, double-blind, randomized, placebo-controlled trial. Eligible patients with primary advanced stage III or IV or first recurrent endometrial cancer were randomly assigned in a 1:1 ratio to receive either dostarlimab (500 mg) or placebo, plus carboplatin (area under the concentration-time curve, 5 mg per milliliter per minute) and paclitaxel (175 mg per square meter of body-surface area), every 3 weeks (six cycles), followed by dostarlimab (1000 mg) or placebo every 6 weeks for up to 3 years. The primary end points were progression-free survival as assessed by the investigator according to Response Evaluation Criteria in Solid Tumors (RECIST), version 1.1, and overall survival. Safety was also assessed.

RESULTS

Of the 494 patients who underwent randomization, 118 (23.9%) had mismatch repair-deficient (dMMR), microsatellite instability-high (MSI-H) tumors. In the dMMR-MSI-H population, estimated progression-free survival at 24 months was 61.4% (95% confidence interval [CI], 46.3 to 73.4) in the dostarlimab group and 15.7% (95% CI, 7.2 to 27.0) in the placebo group (hazard ratio for progression or death, 0.28; 95% CI, 0.16 to 0.50; P<0.001). In the overall population, progression-free survival at 24 months was 36.1% (95% CI, 29.3 to 42.9) in the dostarlimab group and 18.1% (95% CI, 13.0 to 23.9) in the placebo group (hazard ratio, 0.64; 95% CI, 0.51 to 0.80; P<0.001). Overall survival at 24 months was 71.3% (95% CI, 64.5 to 77.1) with dostarlimab and 56.0% (95% CI, 48.9 to 62.5) with placebo (hazard ratio for death, 0.64; 95% CI, 0.46 to 0.87). The most common adverse events that occurred or worsened during treatment were nausea (53.9% of the patients in the dostarlimab group and 45.9% of those in the placebo group), alopecia (53.5% and 50.0%), and fatigue (51.9% and 54.5%). Severe and serious adverse events were more frequent in the dostarlimab group than in the placebo group.

CONCLUSIONS

Dostarlimab plus carboplatin-paclitaxel significantly increased progression-free survival among patients with primary advanced or recurrent endometrial cancer, with a substantial benefit in the dMMR-MSI-H population. (Funded by GSK; RUBY ClinicalTrials.gov number, NCT03981796.).

Single cell transcriptomic analysis of HPV16-infected epithelium identifies a keratinocyte subpopulation implicated in cancer

Persistent HPV16 infection is a major cause of the global cancer burden. The viral life cycle is dependent on the differentiation program of stratified squamous epithelium, but the landscape of keratinocyte subpopulations which support distinct phases of the viral life cycle has yet to be elucidated. Here, single cell RNA sequencing of HPV16 infected compared to uninfected organoids identifies twelve distinct keratinocyte populations, with a subset mapped to reconstruct their respective 3D geography in stratified squamous epithelium. Instead of conventional terminally differentiated cells, an HPV-reprogrammed keratinocyte subpopulation (HIDDEN cells) forms the surface compartment and requires overexpression of the ELF3/ESE-1 transcription factor. HIDDEN cells are detected throughout stages of human carcinogenesis including primary human cervical intraepithelial neoplasias and HPV positive head and neck cancers, and a possible role in promoting viral carcinogenesis is supported by TCGA analyses. Single cell transcriptome information on HPV-infected versus uninfected epithelium will enable broader studies of the role of individual keratinocyte subpopulations in tumor virus infection and cancer evolution.

Safety and activity of anti-mesothelin antibody-drug conjugate anetumab ravtansine in combination with pegylated-liposomal doxorubicin in platinum-resistant ovarian cancer: multicenter, phase Ib dose escalation and expansion study

OBJECTIVES

Anetumab ravtansine is an antibody-drug conjugate consisting of a fully human anti-mesothelin monoclonal antibody conjugated to cytotoxic maytansinoid tubulin inhibitor DM4. Mesothelin is highly expressed in ovarian cancer. This phase Ib study determines the safety, pharmacokinetics, and anti-tumor activity of anetumab ravtansine and pegylated liposomal doxorubicin in mesothelin-expressing platinum-resistant ovarian cancer.

METHODS

Anetumab ravtansine (5.5 or 6.5 mg/kg) and pegylated liposomal doxorubicin (30 mg/m2) were administered intravenously every 3 weeks to 65 patients with platinum-resistant epithelial ovarian cancer. Mesothelin expression was assessed by central immunohistochemistry. Adverse events, tumor response (RECIST 1.1), and progression-free survival were determined. Biomarker samples were assessed by ELISA and next-generation sequencing.

RESULTS

In dose escalation, nine patients received anetumab ravtansine across two doses (5.5 or 6.5 mg/kg). The maximum tolerated dose of anetumab ravtansine was 6.5 mg/kg every 3 weeks and no dose-limiting toxicities were observed. In dose expansion, 56 patients were treated at the maximum tolerated dose. The most common treatment-emergent adverse events of any grade were nausea (47.7%), decreased appetite (43.1%), fatigue (38.5%), diarrhea (32.3%), and corneal disorder (29.2%). In all treated patients the objective response rate was 27.7% (95% CI 17.3% to 40.2%), including one complete (1.5%) and 17 partial responses (26.2%), with median duration of response of 7.6 (95% CI 3.3 to 10.2) months and median progression-free survival of 5.0 (95% CI 3.2 to 6.0) months. In an exploratory analysis of a sub-set of patients (n=19) with high mesothelin expression who received ≤3 prior lines of systemic therapy, the objective response rate was 42.1% (95% CI 20.3% to 66.5%) with a median duration of response of 8.3 (95% CI 4.1 to 12.0) months and median progression-free survival of 8.5 (95% CI 4.0 to 11.4) months.

CONCLUSIONS

Anetumab ravtansine and pegylated liposomal doxorubicin showed tolerability and promising clinical activity. These results established the dose schedule and the mesothelin-positive target population of this combination for a phase III study in platinum-resistant ovarian cancer.

TRIAL REGISTRATION NUMBER

NCT02751918.

Randomized phase II trial of farletuzumab plus chemotherapy versus placebo plus chemotherapy in low CA-125 platinum-sensitive ovarian cancer

OBJECTIVE

The primary purpose of this study was to determine if farletuzumab, an antifolate receptor-α monoclonal antibody, improved progression-free survival (PFS) versus placebo when added to standard chemotherapy regimens in patients with platinum-sensitive recurrent ovarian cancer (OC) in first relapse (platinum-free interval: 6-36 months) with low cancer antigen 125 (CA-125) levels.

METHODS

Eligibility included CA-125 ≤ 3 x upper limit of normal (ULN, 105 U/mL), high-grade serous, platinum-sensitive recurrent OC, previous treatment with debulking surgery, and first-line platinum-based chemotherapy with 1st recurrence between 6 and 36 months since frontline platinum-based treatment. Patients received investigator's choice of either carboplatin (CARBO)/paclitaxel (PTX) every 3 weeks or CARBO/pegylated liposomal doxorubicin (PLD) every 4 weeks x6 cycles in combination with either farletuzumab [5 mg/kg weekly] or placebo randomized in a 2:1 ratio. Maintenance treatment with farletuzumab (5 mg/kg weekly) or placebo was given until disease progression or intolerance.

RESULTS

214 patients were randomly assigned to farletuzumab+chemotherapy (142 patients) versus placebo+chemotherapy (72 patients). The primary efficacy endpoint, PFS, was not significantly different between treatment groups (1-sided α = 0.10; p-value = 0.25; hazard ratio [HR] = 0.89, 80% confidence interval [CI]: 0.71, 1.11), a median of 11.7 months (95% CI: 10.2, 13.6) versus 10.8 months (95% CI: 9.5, 13.2) for farletuzumab+chemotherapy and placebo+chemotherapy, respectively. No new safety concerns were identified with the combination of farletuzumab+chemotherapy.

CONCLUSIONS

Adding farletuzumab to standard chemotherapy does not improve PFS in patients with OC who were platinum-sensitive in first relapse with low CA-125 levels. Folate receptor-α expression was not measured in this study. (Clinical Trial Registry NCT02289950).

Systematic mapping review of guidelines for BRCA1/2 genetic testing globally: investigating geographic and regional disparities in health equity for women and families at risk for hereditary ovarian cancer

OBJECTIVE

Identification of persons at risk for hereditary syndromes through genetic testing prior to cancer diagnosis may proactively reduce the cancer burden morbidity and mortality. Using a framework of health equity, this study characterizes the global landscape of publication and reference to BRCA1/2 genetic testing guidelines (GTG).

METHODS

This study used a systematic literature search supplemented by an International Gynecologic Cancer Society (IGCS) informal survey and cross referenced with Myriad Genetics records, to identify published GTG, their country of origin, and countries referencing them.

RESULTS

Of 1011 identified publications, 166 met the inclusion criteria, from which 46 unique guidelines were identified, published by 18 countries and two regions (Europe and the UK). Authorship from the USA accounted for 63% of publications on GTG. Systematic mapping reviews revealed 34 countries with published and/or referenced guidelines, the IGCS survey revealed 22 additional countries, and coordination with Myriad Genetics revealed additional information for two countries and primary information for one country. Of the 57 countries evaluated, 33% published their own guidelines and reference guidelines from another country/region, 5% published their own guidelines without referencing another country/region, and 61% only referenced a guideline from another country/region. No data were available for 138 of 195 countries, disproportionately from Africa, the Middle East, Eastern Europe, and Southeast Asia.

CONCLUSIONS

Global geographic disparities in the publication and referencing of GTG exist, with a large emphasis on North American and European guidelines in the published literature. These disparities highlight a need for uniform BRCA GTG to improve global health equity.

Analysis of concordance between microsatellite instability by next generation sequencing (NGS-MSI) and mismatch repair deficiency by immunohistochemistry (IHC-MMR) in >28,000 colorectal tumors

30

Background: The use of immune checkpoint inhibitors (ICI) in MSI-H/MMRd CRC patients has profoundly changed the treatment landscape in the metastatic setting; the most recent NICHE-2 trial showed 100% response rate in MSI-H/MMRd locally advanced CRC patients treated with neoadjuvant ICI, further highlighting the importance of identifying these patients accurately to enhance patient care. Here we report the concordance of NGS-MSI and IHC-MMR from a very large cohort of CRC tumors and study the molecular characteristics and clinical outcomes of these patients. Methods: A total of 28,105 CRC tumors were analyzed by NGS (592 genes, NextSeq or WES, NovaSeq) and IHC. MMRd was defined as complete loss of ≥1 IHC stains (MLH1, MSH2, MSH6, or PMS2) and proficient (MMRp) as any positive staining for all four proteins. MSI status was determined from over 7,000 target microsatellite loci covered by NGS. Central pathology review (CPR) of MMR IHC was done on 73 cases with discordant MMR/MSI results. Real-world overall survival was obtained from insurance claims and calculated from either tissue collection or treatment start to last contact; Kaplan-Meier estimates were calculated for molecularly defined patients. Results: For CRC tumors with NGS and IHC, 28031/28105 were concordant (99.74%), 0.09% were MMRd/MSS, and 0.2% were MMRp/MSI-H. After CPR, 23/24 (96%) of MMRd/MSS cases and 46/49 (94%) of MMRp/MSI-H were confirmed. Of the 46 post-CPR MMRp/MSI-H CRC samples, 52% had ≥1 pathogenic missense mutation in including MLH1/PMS2/MSH2/6 or MLH3, MSH3, PMS1 or POLE. Of the 23 post-CPR MMRd/MSS CRC samples, 38% had MLH1 loss, 91% PMS2 loss, no MSH2 loss and 9% MSH6 loss. When comparing clinical outcomes with concordant MSS/MMRp tumors, concordant MSI-H/MMRd patients had significantly longer OS (HR=1.131 [95% CI: 1.02-1.254], p<0.001) and post-ICI survival (HR= 2.695 [95% CI: 1.932-3.76], p<0.001). Compared to MSS/MMRd tumors (N=21), MSI-H/MMRp (N=29) trends to have longer OS (HR=2.163, [95% CI: 0.939-4.983], p=0.064) and insufficient ICI-treated patients were available for analysis. Conclusions: Here we report from >28,000 CRC tumors that the concordance of IHC-MMR/NGS-MSI is 99.74%. Clinical outcome from a large cohort of patients show NGS is not inferior compared to IHC in identifying patients with MSI-H/MMRd. The additional lens that NGS-MSI offers is of value in identifying CRC patients who may benefit from ICI therapy. [Table: see text]

Testing for homologous recombination repair or homologous recombination deficiency for poly (ADP-ribose) polymerase inhibitors: A current perspective

Poly (ADP-ribose) polymerase inhibitors (PARPis) have demonstrated clinical activity in patients with BRCA1 and/or BRCA2 mutated breast, ovarian, prostate, and pancreatic cancers. Notably, BRCA mutations are associated with defects in the homologous recombination repair (HRR) pathway. This homologous recombination deficiency (HRD) phenotype can also be observed as genomic instability in tumour cells. Accordingly, PARPi sensitivity has been observed in various tumours with HRD, independent of BRCA mutations. Currently, four PARPis are approved by regulatory agencies for the treatment of cancer across multiple tumour types. Most indications are specific to tumours with a confirmed BRCA mutation, mutations in other HRR-related genes, HRD evidenced by genomic instability, or evidence of platinum sensitivity. Regulatory agencies have also approved companion and complementary diagnostics to facilitate patient selection for each PARPi indication. This review aims to summarise the biological basis, clinical validation, and clinical relevance of the available diagnostic methods and assays to assess HRD.

Is there a "low-risk" patient population in advanced epithelial ovarian cancer?: a critical analysis

Ovarian cancer is the leading cause of gynecologic cancer-related death in the United States. Historically, studies have demonstrated that ovarian cancer is a heterogeneous disease with several patient and oncologic characteristics, including BRCA status and residual disease at surgery, known to be predictive of clinical outcomes. However, during the last decade, the discovery and approval of bevacizumab and poly(adenosine diphosphate-ribose) polymerase inhibitors have moved the frontline treatment paradigm beyond platinum-doublet therapy for women with advanced ovarian cancer. Subsequently, investigators have sought to assess the therapeutic efficacy of these agents in women who are considered "high" risk and "low" risk to determine which patients may benefit the most from aggressive therapy and in whom additional treatment may be avoided. We reviewed historic and contemporary definitions of "high-risk" and "low-risk" ovarian cancer and how this has been incorporated into the subset analyses of randomized, clinical trials of therapeutic agents, including bevacizumab and poly(adenosine diphosphate-ribose) polymerase inhibitors. Next, we provided an in-depth discussion of landmark trials for frontline maintenance therapy with bevacizumab and/or poly(adenosine diphosphate-ribose) polymerase inhibitors, focusing on the impact of treatment efficacy according to a "high-risk" and "low-risk" paradigm. Furthermore, we highlighted that recent data have challenged this dichotomous classification, notably from the Gynecologic Oncology Group-0218, ICON7, SOLO-1, and PAOLA-1 trials. Although some studies have suggested that certain populations of women with advanced ovarian cancer may have a more favorable prognosis and be considered "low risk," the risk of progression and death remains unacceptably high in all women. Furthermore, in many cases, those considered the lowest risk have the most treatment benefit from maintenance therapy with poly(adenosine diphosphate-ribose) polymerase inhibitors and/or bevacizumab. From these data, we have advocated that virtually all women with advanced ovarian cancer are high risk and that the use of our most effective therapies in the frontline setting holds promise for potentially curing more patients. Lastly, we critically discuss the practice of using subanalyses in clinical trials, with emphasis that although this practice is important for hypothesis generation, caution must be taken before accepting findings from subanalyses as actual treatment effects.

HER2 in Uterine Serous Carcinoma: Testing platforms and implications for targeted therapy

OBJECTIVE

HER2 is an important prognostic and therapeutic target in uterine serous carcinoma (USC). Optimal HER2 testing platforms have not been defined and guidelines for testing have changed over time. Our objective is to assess the concordance of HER2 positivity based on chromogenic in situ hybridization (CISH), immunohistochemistry (IHC), and next generation sequencing (NGS) and to determine the rate of downstream mutations that may affect response to HER2 directed therapy.

METHODS

Utilizing the Caris tumor registry, 2192 USC tumors were identified and analyzed using NGS (NextSeq, 592 Genes and WES, NovaSEQ), IHC, and CISH. PD-L1 expression was tested by IHC. Microsatellite instability was tested by fragment analysis, IHC, and NGS. Tumor mutational burden (TMB) was measured by totaling somatic mutations per tumor. HER2 positivity through IHC and CISH was determined based on 2007 and 2018 ASCO/CAP HER2 breast cancer guidelines.

RESULTS

There was a higher rate of HER2 positivity by IHC when using the 2018 guidelines compared to the 2007 guidelines (16.3% vs 12.3%). Concordance between IHC and CISH was 98.9%. ERBB2 amplification was identified by NGS in 10.5% of tumors. Compared to CISH results, this corresponds to a concordance rate of 91.6% and a positive predictive value (PPV) of 60.3%. Single gene alterations in HER2 amplified tumors that may implicate HER2 therapy resistance included PI3K (33.1%), KRAS (2.5%), and PTEN (1.3%).

CONCLUSIONS

There was high concordance between HER2 positivity based on CISH and IHC. Rate of HER2 positivity is the lowest by NGS. Ultimately these testing platforms need to be validated by response to targeted therapy.

Genomic profiling in low grade serous ovarian cancer: Identification of novel markers for disease diagnosis and therapy

OBJECTIVES

Low grade serous ovarian cancer (LGSOC) differs from high grade serous in terms of pathogenesis, molecular, genetic, and clinical features. Molecular studies have been hampered by small sample sizes, heterogenous histology, and lack of comprehensive testing. We sought to molecularly profile LGSOC in a homogenously tested, histologically confirmed cohort.

METHODS

Using hot-spot and whole exome next generation sequencing (NGS), fusion gene analysis interrogating RNA, fragment analysis, in situ hybridization and/or immunohistochemistry, 179 specimens were evaluated by Caris Life Sciences (Phoenix, AZ). A second independent histologic review confirmed histology in 153 specimens.

RESULTS

Most frequently mutated genes (5% or greater) were members of the mitogen-activated protein kinase (MAPK) pathway: KRAS (23.7%, n = 36), NRAS (11.2%, n = 19), NF1 (7.9%, n = 5), and BRAF (6.6%, n = 10). Class III mutations were seen in 3 of 10 BRAF mutations while 7 were Class I V600E. Overall, estrogen and progesterone receptor expression was 80.2% (n = 130) and 27.8% (n = 45), respectively. Of those that were hormone negative, nearly 50% contained KRAS or NF1 mutations. None were NRAS mutated. Markers of response to immunotherapy were low to absent.

CONCLUSION

BRAF mutations were seen to be lower than those traditionally reported. With increased MAPK activation resulting in ligand independent activation of ERα, a role of combination therapy with hormonal and targeted therapy should be considered as 49.2% of hormone negative specimens were KRAS or NF1 mutated. Absence of immunotherapy biomarkers suggest limited benefit to immunotherapeutic agents.

ARTISTRY-7: A phase 3, multicenter study of nemvaleukin alfa in combination with pembrolizumab versus chemotherapy in patients (pts) with platinum-resistant epithelial ovarian, fallopian tube, or primary peritoneal cancer

TPS5609

Background: ARTISTRY-7 will evaluate the novel engineered cytokine nemvaleukin alfa (nemvaleukin, ALKS 4230) in pts with gynecologic cancers. Epithelial ovarian cancer (OC) is the 7th most common cause of cancer mortality in women. OC is an area of high unmet need, as many pts become resistant or refractory to frontline platinum-based chemotherapy. Nemvaleukin was designed to selectively bind to the intermediate-affinity interleukin-2 (IL-2) receptor, preferentially activating and expanding antitumor CD8+ T and NK cells with minimal expansion of Tregs. This selectivity may provide enhanced tumor killing and improved safety/tolerability compared with high-dose IL-2. In clinical studies, nemvaleukin, as monotherapy and in combination with pembrolizumab, has shown evidence of clinical benefit in multiple tumor types, including OC. In ARTISTRY-1, 4 responses were observed in pts with OC, including 2 complete responses, 1 in a pt with platinum-resistant OC and 5 prior lines of therapy, and 2 partial responses. Methods: ARTISTRY-7 is a phase 3, multicenter, open-label randomized study of nemvaleukin and/or pembrolizumab vs chemotherapy. Eligible pts are women (≥18 y) with histologically confirmed epithelial OC (high-grade serous, endometrioid, clear cell), fallopian tube cancer, or primary peritoneal cancer. Pts must have received ≥1 prior line of systemic therapy in the platinum-sensitive setting, ≤5 prior lines in the platinum-resistant setting, and prior bevacizumab, with radiographic progression on most recent therapy. Primary platinum-refractory disease (progression on first-line platinum therapy) or primary platinum resistance (progression < 3 months after completion of first-line platinum therapy) is exclusionary. Pts must have ECOG performance status of 0 or 1, estimated life expectancy of ≥3 months, and adequate hematologic reserve and hepatic and renal function. Approximately 376 pts will be randomized (3:1:1:3) to receive nemvaleukin 6 μg/kg IV on days 1-5 and pembrolizumab 200 mg IV on day 1 of each 21-day cycle, pembrolizumab monotherapy, nemvaleukin monotherapy, or chemotherapy (pegylated liposomal doxorubicin, paclitaxel, topotecan, or gemcitabine) and stratified according to PD-L1 status, histologic subtype (high-grade vs non–high-grade serous), and chemotherapy (paclitaxel vs other). Pts will continue treatment until disease progression or intolerable toxicity (maximum 35 cycles for pembrolizumab; nemvaleukin can be continued). The primary endpoint is investigator-assessed PFS (RECIST v1.1) in the nemvaleukin/pembrolizumab vs chemotherapy group. Secondary/exploratory endpoints include overall survival, other antitumor measures, safety, health-related quality of life, and pharmacokinetic/pharmacodynamic effects. Clinical trial information: NCT05092360.

Exploring the nuances between BRCA1 and 2: A multiomic analysis

5580

Background: Emerging data suggests that key differences exist between BRCA1 and BRCA2 associated OC, including response to therapy and survival. The purpose of this study was to identify the gene expression profiles, interacting pathways and immune microenvironment of BRCA1 mutant (BRCA1mut), BRCA2 mutant (BRCA2mut) and homologous recombination wild-type (HRwt) associated high grade serous OC (HGSOC). Methods: Next-generation sequencing (592, NextSeq; WES, NovaSeq) and Whole Transcriptome Sequencing (NovaSeq) (Caris Life Sciences, Phoenix, AZ) were performed in 8196 OC tumors classified into 3 groups: BRCA1mt; BRCA2mt; and HRwt. BRCA mutations were defined as variants that result in loss-of-function of the BRCA protein and HRwt was defined as samples negative for aberrations in both BRCA1 and BRCA2, as well as for 28 other homologous recombination genes Microsatellite instability (MSI) was tested by fragment analysis, IHC and NGS. Tumor mutational burden (TMB) was measured by totaling somatic mutations (TMB-H: >10 mutations/MB). LOH cut-off >16%. Immune cell infiltrates were calculated by XCell. Differential gene expression was calculated using Limma. Significance was determined using chi-square and Wilcoxon rank sum test and adjusted for multiple comparisons (q-value < 0.05). Results: We identified 677 BRCA1mt, 439 BRCA2mt, and 7080 HRwt OC tumors. HGSOC made up the largest portion of BRCA1mt (523; 77%), BRCA2mt (306; 70%), and HRwt (4281; 60%) tumors. TP53 was most commonly mutated gene in all three groups. LOH (>16%) was highest in BRCA1mt (86.8%) compared to BRCA2mt (74.8%) and HRwt (38.4%). TMB-H was highest in BRCA2mt (6.29%) than in BRCA1mt (1.35%) and HRwt (0.91%) HGSOC (all q < 0.05). Expression of immune checkpoint genes CD80, CD86, CD274, CTLA4, HAVCR2/TIM3, IFNG, IDO1, LAG3, PDCD1 and PDCD1LG2 were significantly higher in BRCA1 and BRCA2 mt compared to HRwt HGSOC (FC: 1.12-1.59, q < 0.05). HRwt tumors had decreased infiltration of Activated Dendritic cells compared to BRCA1mt, and lower Macrophage M1 compared to both BRCA1mt and BRCA2mt (all q < 0.05). Additionally, T-inflamed score was higher in BRCA1mt compared to HRwt, while IFN score was higher in BRCA1mt compared to both BRCA2mt and HRwt (all q < 0.05). From 17,408 genes with measured expression. 522 (3.0%) differentially expressed genes (DEG) were found between BRCA2mt vs BRCA1mt; 1487 (8.54%) between BRCA2mt vs HRwt; and 9297 (53.4%) between BRCA1mt and HRwt HGSOC. Pathway analysis identified Fatty Acid Metabolism, Myc targets, ROS pathway, Oxidative Phosphorylation, and Wnt B-catenin signaling pathways as differentially regulated between the 3 groups. Conclusions: We describe the genomic, pathway and immunologic analyses in the largest cohort of BRCA1 and 2 mutated HGSOC to date. Both metabolic and immune response pathways are differentially regulated between the groups. Results can potentially inform targeted therapeutic studies based on unique BRCA genotype.

Pivotal study of ofra-vec (VB-111) combined with paclitaxel versus paclitaxel for treatment of platinum-resistant ovarian cancer (OVAL, VB-111-701/GOG-3018)

TPS5606

Background: Ofranergene obadenovec (Ofra-vec, VB-111) is an anti-cancer gene based immune activator and targeted vascular disruptor. The dual mechanism of action triggers a broad antiangiogenic effect and induces of a tumor directed immune response. A phase II trial in patients with platinum resistant ovarian cancer (PROC) demonstrated that ofra-vec in combination with weekly paclitaxel was well tolerated and associated with a CA-125 Objective Response Rate (ORR) of 58%, a trend for improved survival and induction of an immunotherapeutic effect of tumor infiltration with CD-8 T cells. Based on these observations, a pivotal phase III study was initiated in collaboration with the GOG Foundation, Inc. Methods: Study NCT03398655 is an international, randomized, double-blind, placebo-controlled, phase III study. Eligible patients have recurrent PROC and may have been previously treated with up to 5 prior lines of therapy (but not >2 for PROC). Patient are randomized 1:1 to receive ofra-vec (1x1013 Viral Particles) with weekly paclitaxel (80mg/m2), or weekly paclitaxel with placebo. Randomization is stratified by number of prior treatment lines, prior antiangiogenic therapy and platinum refractory disease status. The dual primary endpoints are OS and PFS. A pre-planned interim analysis of CA-125 response (GCIG) performed by the DSMC met the pre-defined criteria showing that CA-125 ORR in the treatment arm was at least 10% higher than in the control arm. Study is enrolling in the US, EU, Japan and Israel, with 90% enrollment to date. Completion of accrual is anticipated in Q1 2022. Clinical trial information: NCT03398655.

ROSELLA: A phase 3 study of relacorilant in combination with nab-paclitaxel versus investigator’s choice in advanced, platinum-resistant, high-grade epithelial ovarian, primary peritoneal, or fallopian-tube cancer

TPS5620

Background: Chemotherapy resistance is a major concern in the treatment of advanced platinum-resistant and platinum-refractory ovarian cancer. One mechanism of resistance is driven by cortisol, which can suppress the apoptotic pathways that chemotherapy agents rely upon, eg, suppression of BCL2 and FOXO3a pathways. Preclinical and clinical data indicate that glucocorticoid receptor (GR) antagonism may reverse the anti-apoptotic effects of cortisol, thereby restoring the efficacy of cytotoxic agents. Relacorilant is a selective GR modulator that has shown promise in overcoming resistance when combined with taxanes (particularly nab-paclitaxel) in preclinical models (Greenstein & Hunt 2021) and early-phase clinical studies (Munster et al. 2019) in various solid tumors. A randomized, controlled phase 2 study of relacorilant + nab-paclitaxel found clinically meaningful improvements in progression-free survival (PFS) and duration of response (DOR) without increased side effect burden in patients with recurrent, platinum-refractory and platinum-resistant ovarian cancer (Colombo et al. 2021). The aim of this phase 3 study is to confirm these phase 2 findings in a larger patient population. Methods: ROSELLA (EudraCT 2022-000662-18, NCT pending) is a phase 3, randomized, 2-arm, open-label, multicenter study of relacorilant + nab-paclitaxel compared to investigator’s choice of chemotherapy agents in patients with confirmed high-grade serous epithelial ovarian, primary peritoneal, or fallopian tube cancer. The trial is being conducted at multiple sites in North America and Europe and has a planned enrollment of 360 patients. Patients are randomized 1:1 to either relacorilant (150 mg the day before, day of, and day after nab-paclitaxel infusion) + nab-paclitaxel (80 mg/m2 on days 1, 8, and 15 of each 28-day cycle) or investigator’s choice of chemotherapy (liposomal doxorubicin, paclitaxel, topotecan, or nab-paclitaxel). Randomization is stratified by prior lines of therapy (1 vs > 1), region of world (North America vs Europe), and prior bevacizumab (yes/no). Adult female patients with platinum-resistant disease (progression within 6 months of completion of platinum-containing therapy), excluding patients with primary platinum refractory disease, who have received 1–3 lines of prior systemic anticancer therapy and at least 1 prior line of platinum therapy are being enrolled. Life expectancy ≥3 months, adequate organ function, and ECOG performance status of 0 or 1 are required. The primary study endpoint is PFS by blinded independent central review. Key secondary endpoints include overall survival, PFS by investigator, overall response rate, best overall response, DOR, clinical benefit rate, safety, quality of life, CA-125, pharmacodynamics, and pharmacokinetics. Clinical trial information: 2022-000662-18.

HER2 in uterine carcinosarcoma: Testing platforms and implications for targeted therapy

5590

Background: Uterine carcinosarcomas (UCS) are rare, aggressive tumors accounting for 5% of all uterine cancers. Recurrence rates are high and 5-year survival is only 18-39%. HER2 is an emerging prognostic and therapeutic target in uterine cancer including UCS. Testing algorithms and platforms in breast and gastric cancers are well studied and validated, but optimal HER2 testing in uterine cancer is not yet established. We aimed to determine HER2 prevalence in UCS and the concordance of chromogenic in situ hybridization (CISH), immunohistochemistry (IHC), and next generation sequencing (NGS) platforms to aid in the development of UCS specific testing guidelines. We also evaluated the rate of downstream mutations and immune biomarkers that may affect response to HER2 directed therapy. Methods: Eight hundred and seventy-five UCS tumor samples (primary 81.4%; metastatic 17.1%; unknown 1.5%) were analyzed using NGS (592, NextSeq; WES, NovaSeq, Caris Life Sciences, Phoenix, AZ). A subset of tumors with HER2 positivity were tested with IHC (4B5, Ventana) and/or CISH (INFORM DUAL HER2 ISH Assay, Ventana) based on 2018 ASCO/CAP HER2 Breast Cancer guidelines. Amplification of ERBB2/HER2 by NGS used a copy number cut-off >6. PD-L1 expression was analyzed by IHC (SP142, positive cut-off ≥1%, Ventana). Tumor mutational burden (TMB) was measured by counting all somatic mutations found per tumor (TMB high cut-off > 10 mutations per Mb). Microsatellite instability (MSI) was tested by fragment analysis (FA), IHC and NGS. Results: Rates of HER2 positivity were 3.4% (28/820) by NGS. Among the IHC/CISH-tested cohort, 7.2% was positive (10/139) by IHC, and 19.5% (27/133) by CISH. In the 105 samples tested with both IHC and CISH, the concordance was 100%. Specifically, 9/105 patients (8.6%) were IHC+/CISH+ and 96 patients (91.4%) were IHC-/CISH-. The concordance between CISH and NGS (N = 127) was 90.6% (sensitivity 100% and specificity 89.3%). Common gene alterations in CISH HER2+ UCS tumors that may implicate resistance to HER2 targeted therapy included mutations in TP53 (100%), FBXW7 (22.2%), PIK3CA (33.3%), PIK3R1 (18.5%), PTEN (3.7%) and KRAS (3.7%) and gene amplification of KRAS (11.1%). CISH+ HER2+ UCS tumors had low immunotherapy biomarker prevalence (0% MSI-H, 0% TMB high, 7.7% PD-L1+). Conclusions: Increased HER2 positivity was detected via CISH testing compared to IHC and NGS, which may reflect the heterogeneity of HER2 amplification due to mixed histology between the sarcoma and carcinoma portion of the tumor. High concordance rates were observed between CISH and IHC. These testing platforms need to be validated by response to HER2 targeted therapies in order to develop UCS specific testing guidelines.

Development of a Clinical Decision Support System to Predict Unplanned Cancer Readmissions

Unplanned 30-day cancer readmissions are an important outcome of cancer hospitalization and can significantly raise mortality rates and costs for both the patient and the hospital. This paper aimed to develop a predictive model using machine learning and electronic health records to predict unplanned 30-day cancer readmissions and further develop it as a clinical decision support system. The three-stage study design followed the 2022 AMIA Artificial Intelligence Evaluation Showcase. In the first stage, the technical performance of the model was determined (81% of AUROC) and contributing factors were identified. In the second stage, the technical feasibility and workflow considerations of using such a predictive model were explored through semi-structured interviews. In the third stage, a decision tree analysis and a cost estimation showed that the model can reduce unplanned readmissions significantly if timely action is taken and that preventing a single readmission may significantly reduce costs.

Gemogenovatucel-T (Vigil) maintenance immunotherapy: 3-year survival benefit in homologous recombination proficient (HRP) ovarian cancer

OBJECTIVE

Previously, Vigil demonstrated clinical benefit to prolong relapse free and overall survival in the BRCA wild-type (BRCA-wt), homologous recombination proficient (HRP) patient population. Here we provide long term follow up of 3 years in the HRP patient population enrolled in the Phase 2b VITAL study.

METHODS

HRP patients treated with Vigil (n = 25) or placebo (n = 20) who were enrolled in the Phase 2b, double-blind, placebo-controlled (VITAL study, NCT02346747) were followed for safety, OS and RFS. OS and RFS from time of randomization (immediately prior to maintenance therapy) and from debulking tissue procurement time points were analyzed by Kaplan-Meier (KM) and restricted mean survival time (RMST) analysis.

RESULTS

OS for Vigil treated patients at 3 years has not yet reached median OS time point (95% CI 41.6 months to not achieved) compared to 26.9 (95% CI 17.4 months to not achieved) in placebo treated patients (HR 0.417 p = 0.020). Three year RFS also showed benefit to Vigil (stratified HR 0.405, p = 0.011) and no long term toxicity to Vigil was observed. Three year OS for Vigil of 70% vs. 40% for placebo from time of randomization was observed (p = 0.019). RMST analysis was also significant for OS (45.7 vs. 32.8 months, p = 0.008) and RFS (p = 0.025).

CONCLUSION

In conclusion, results suggest durable activity of Vigil on RFS and OS and support further evaluation of Vigil in HRP ovarian cancer.

The impact of opportunistic salpingectomy on ovarian cancer mortality and healthcare costs: a call for universal insurance coverage

BACKGROUND

Opportunistic salpingectomy at the time of hysterectomy or as an alternative to bilateral tubal ligation may reduce the incidence of ovarian cancer, because it has been demonstrated that most serous ovarian cancers begin in the fallopian tubes. However, salpingectomy at the time of sterilization is not always financially covered by third-party payers, and this represents a barrier to adoption. Routine salpingectomy has become more common but is not always practiced at the time of hysterectomy.

OBJECTIVE

This study aimed to determine the impact of opportunistic salpingectomy as an alternative tubal ligation and routine salpingectomy at the time of hysterectomy on ovarian cancer mortality and overall cost.

STUDY DESIGN

An 8-state Markov state transition model was constructed, including hysterectomy, tubal ligation, and ovarian cancer. Transition probabilities were informed by previously reported population data and include age-adjusted rates of elective sterilization and hysterectomy. This model was used to predict ovarian cancer incidence and the cost effectiveness of opportunistic salpingectomy. Testing of this model suggested that it accurately predicted overall life expectancy and closely predicted the rate of hysterectomy in the population. The model may underestimate the rate of tubal sterilization, making it conservative with respect to the benefits of salpingectomy.

RESULTS

The recursive Markov model was run from ages 20 to 85 years in 1-year intervals with a half step correction and included age-adjusted rates of tubal ligation, hysterectomy (with and without oophorectomy), and ovarian cancer. The model predicts that opportunistic salpingectomy at the time of tubal ligation will reduce ovarian cancer mortality by 8.13%. Opportunistic salpingectomy at the time of hysterectomy will reduce ovarian cancer mortality by 6.34% for a combined decrease of 14.5%. Both strategies are cost effective when considering only the cost of the opportunistic salpingectomy. The excess cost of opportunistic salpingectomy at the time of tubal ligation was $433.91 with an incremental cost-effective ratio of $6401 per life-year and $5469 per quality-adjusted life year gained when adjusting for ovarian cancer with a utility of 0.64. The incremental cost-effective ratio for opportunistic salpingectomy during hysterectomy at a cost of $124.70 was $2006 per life-year and $1667 per quality-adjusted life year. When considering the impact of ovarian cancer prevention with respect to the cost of ovarian cancer treatment, opportunistic salpingectomy may produce a substantial healthcare savings. Utilizing a 3% discount rate, it is estimated that the total savings for universal salpingectomy could be as high as $445 million annually in the United States. A sensitivity analysis around the benefit of opportunistic salpingectomy suggests that this procedure will be cost effective even if salpingectomy provides only a modest reduction in the risk of ovarian cancer.

CONCLUSION

It is estimated that universal opportunistic salpingectomy may prevent 1854 deaths per year from ovarian cancer and may reduce healthcare costs. Given these data, universal opportunistic salpingectomy should be considered at the time of tubal ligation and hysterectomy and covered by third-party payers.

ATHENA (GOG-3020/ENGOT-ov45): a randomized, phase III trial to evaluate rucaparib as monotherapy (ATHENA-MONO) and rucaparib in combination with nivolumab (ATHENA-COMBO) as maintenance treatment following frontline platinum-based chemotherapy in ovarian cancer

Background

The optimal treatment strategy for women with newly diagnosed ovarian cancer has yet to be determined. Poly(ADP-ribose) polymerase (PARP) inhibitors have demonstrated substantial improvement in progression-free survival as monotherapy maintenance treatment in the frontline setting versus active surveillance. Furthermore, preclinical and early clinical studies have shown that PARP inhibitors and immune checkpoint inhibitors have synergistic antitumor activity and may provide an additional therapeutic option for patients in this population.

Primary Objectives

In women with newly diagnosed ovarian, fallopian tube, or peritoneal cancer, we wish to assess the efficacy of frontline maintenance treatment with the PARP inhibitor rucaparib versus placebo following response to platinum-based chemotherapy (ATHENA–MONO), and to assess the combination of rucaparib plus nivolumab (a programmed death receptor 1 (PD-1)–blocking monoclonal antibody) versus rucaparib alone (ATHENA–COMBO).

Study Hypothesis

(1) Maintenance therapy with rucaparib monotherapy may extend progression-free survival following standard treatment for ovarian cancer in the frontline setting. (2) The combination of nivolumab plus rucaparib may extend progression-free survival following standard treatment for ovarian cancer in the frontline setting compared with rucaparib alone.

Trial Design

ATHENA is an international, randomized, double-blind, phase III trial consisting of two independent comparisons (ATHENA–MONO and ATHENA–COMBO) in patients with newly diagnosed platinum-sensitive ovarian cancer. Patients are randomized 4:4:1:1 to the following: oral rucaparib+ intravenous nivolumab (arm A); oral rucaparib + intravenous placebo (arm B); oral placebo+ intravenous nivolumab (arm C); and oral placebo + intravenous placebo (arm D). The starting dose of rucaparib is 600 mg orally twice a day and nivolumab 480 mg intravenously every 4 weeks. ATHENA–MONO compares arm B with arm D to evaluate rucaparib monotherapy versus placebo, and ATHENA–COMBO evaluates arm A versus arm B to investigate the effects of rucaparib and nivolumab in combination versus rucaparib monotherapy. ATHENA–MONO and ATHENA–COMBO share a common treatment arm (arm B) but each comparison is independently powered.

Major Inclusion/Exclusion Criteria

Patients ≥18 years of age with newly diagnosed advanced, high-grade epithelial ovarian, primary peritoneal, or fallopian tube cancer who have achieved a response after completion of cytoreductive surgery and initial platinum-based chemotherapy are enrolled. No other prior treatment for ovarian cancer, other than the frontline platinum regimen, is permitted.

Primary Endpoint

The primary endpoint is investigator-assessed progression-free survival by Response Evaluation Criteria in Solid Tumors v1.1.

Sample Size

Approximately 1000 patients have been enrolled and randomized.

Estimated Dates for Completing Accrual and Presenting Results

The trial completed accrual in 2020. While dependent on event rates, primary results of ATHENA–MONO are anticipated in early 2022 and results of ATHENA–COMBO are anticipated to mature at a later date.

Trial Registration

This trial is registered at clinicaltrials.gov (NCT03522246).

Assessment of immune biomarkers and establishing a triple negative phenotype in gynecologic cancers

OBJECTIVE

Immuno-oncology (IO) has rapidly evolved, with many IO therapies either approved or under investigation for multiple malignancies. Biomarkers exist that can predict response to IO therapies including PD-L1 expression, microsatellite instability (MSI), and total mutation burden (TMB). This paper serves to analyze the presence of these biomarkers across gynecologic cancers.

METHODS

A total of 16,300 gynecologic cancer specimens submitted for molecular profiling to Caris Life Sciences were reviewed. Immunohistochemistry was performed using the SP142 anti-PD-L1 clone and assessed for intensity. Next-generation sequencing, immunohistochemistry, and fragment analysis were used to determine MSI status. TMB was measured by counting all non-synonymous missense mutations found per tumor not previously described as germline alterations. Chi-Square, Fisher Exact, and the Kruskal-Wallis test were used to compare cohorts.

RESULTS

Of 16,300 specimens, 54.1% were ovarian, 37.2% uterine, 7.2% cervical, 0.3% vulvar, 1.2% vaginal, with 0.1% unspecified. MSI-H was most frequent in uterine cancer (17.7%) and only 1% of ovarian cancers. PD-L1 expression was present in 38.3% of cervical and 62.5% of vulvar cancers, but less than 8% of ovarian and uterine cancers. TMB-H was present in 21.1% cervical, 19.7% uterine, and 5% ovarian cancers. Few specimens exhibited a "triple positive" phenotype - 0.3% ovarian, 1.5% uterine, and 1.5% cervical. Associations were seen between MSI, TMB, and PD-L1 across all cancer types.

CONCLUSIONS

The frequency of individual biomarkers pertinent to IO therapy varies by cancer type. HPV-driven genital tract cancers have higher frequencies of PD-L1 expression, MSI-H, and TMBH. Endometrial cancers are characterized by MSI-H and TMB, whereas ovarian cancers have a low frequency of MSI-H and modest PD-L1 or TMBH. The incidence of 'triple positive" cases was less than 2%.

Phase 1b study of AVB-500 in combination with paclitaxel or pegylated liposomal doxorubicin platinum-resistant recurrent ovarian cancer

OBJECTIVE

GAS6 and AXL are expressed in high-grade serous ovarian cancer but not in normal ovarian tissue. AVB-500, a novel high affinity Fc-sAXL fusion protein, binds GAS6 preventing AXL signaling. This Phase 1b study (NCT03639246) evaluated safety, efficacy, and exploratory predictive markers of AVB-500 combined with paclitaxel (PAC) or pegylated liposomal doxorubicin (PLD) in patients with platinum-resistant ovarian cancer (PROC), and used a model informed drug development (MIDD) approach for identification of the recommended phase 2 dose (RP2D).

METHODS

Eligible patients received AVB-500 at 10, 15, or 20 mg/kg IV q2wk combined with PAC (n = 23) or PLD (n = 30). Patients were treated until progression or unacceptable toxicity. All were followed for survival.

RESULTS

No dose limiting toxicities were observed and serum GAS6 was completely suppressed across the three dose levels evaluated. AVB-500 + PAC yielded better clinical activity than AVB-500 + PLD with an ORR of 34.8% (8/23, 2 complete responses) and median DoR, PFS, and OS of 7.0, 3.1, and 10.3 months, respectively. Subgroup analyses showed AVB-500 + PAC patients who had no prior bevacizumab or whose AVB-500 trough levels were >13.8 mg/L exhibited the best clinical response. The ORR and median PFS and OS in patients with these characteristics were ≥50%, ≥7.5 months, and ≥19 months, respectively. Given AVB-500 nor the combination with chemotherapy was expected to cause DLTs, the RP2D of AVB-500 was 15 mg/kg identified using an MIDD approach.

CONCLUSION

AVB-500 was well-tolerated in combination with PAC or PLD and contributed to the clinical activity of PAC in PROC patients. Subgroup analyses identified a population of PROC patients who may benefit the most from AVB-500 treatment, which will be further assessed in an ongoing Phase 3 PROC trial.

Clinical trial in progress: Pivotal study of VB-111 combined with paclitaxel versus paclitaxel for treatment of platinum-resistant ovarian cancer (OVAL, VB-111-701/GOG-3018)

TPS5599

Background: Ofranergene obadenovec (VB-111) is a targeted anti-cancer gene therapy with a dual mechanism of action that includes a broad antiangiogenic effect and induction of a tumor directed immune response. A phase II trial in patients with platinum resistant ovarian cancer showed that VB-111 in combination with weekly paclitaxel was well tolerated and associated with a CA-125 Objective Response Rate (ORR) of 58% with a trend for improved survival. The favorable outcomes were associated with induction of an immunotherapeutic effect of tumor infiltration with CD-8 T cells. Based on these observations, a phase III study was initiated in collaboration with the GOG Foundation, Inc. Methods: Study NCT03398655 is an international, randomized, double-blind, placebo-controlled, phase III study. Eligible patients have recurrent platinum-resistant epithelial ovarian cancer with measurable disease (RECIST 1.1), and may have been previously treated with up to 5 prior lines of therapy. Patient are randomized 1:1 to receive VB-111 (1x1013 VPs) with weekly paclitaxel (80mg/m2), or weekly paclitaxel with placebo. Randomization is stratified by number of prior treatment lines, prior antiangiogenic therapy and platinum refractory disease status. The efficacy endpoints are OS, PFS and ORR by RECIST 1.1 and by CA-125 (GCIG criteria). A pre-planned interim analysis was performed by the DSMC in the first 60 patients evaluable for CA-125 response. The analysis met the pre-defined criteria of a CA-125 ORR (GCIG) in the treatment arm at least 10% higher than in the control arm. Study enrolment is ongoing and over 220 patients were enrolled in the US, EU, and Israel. Enrolment of the full sample size of 400 patients is expected to complete by the end of 2021. Clinical trial information: NCT03398655.

HER2 in uterine serous carcinoma: Testing platforms and implications for targeted therapy

5580

Background: HER2 is an emerging prognostic and therapeutic target in uterine serous carcinoma (USC). Testing algorithms and platforms in breast and gastric cancers are well studied and validated, but optimal HER2 testing in uterine cancer is not yet established. We aimed to assess the concordance of chromogenic in situ hybridization (CISH), immunohistochemistry (IHC), and next generation sequencing (NGS) platforms to aid in the development of USC specific testing guidelines. We also evaluated the rate of downstream mutations that may affect response to HER2 directed therapy. Methods: A total of 2,192 USC tumors were analyzed using NGS (NextSeq, 592 Genes and WES, NovaSEQ), a subset of 1,423 tumors were also tested by IHC and CISH (Caris Life Sciences, Phoenix, AZ). HER2 positivity through IHC (4B5, Ventana) and CISH (INFORM DUAL HER2 ISH Assay, Ventana) was determined based on 2007 and 2018 ASCO/CAP HER2 breast cancer guidelines. PD-L1 expression was tested by IHC using SP142 (Spring Biosciences) (positive cut-off >1%). Microsatellite instability (MSI) was tested by fragment analysis (FA), IHC and NGS. Tumor mutational burden (TMB) was measured by totaling somatic mutations per tumor (TMB-high cut-off > 10 mutations per Mb). Statistical significance was determined using chi-square. Results: Rates of HER2 positivity were comparable using the 2018 and 2007 breast cancer guidelines (19.5% vs 17.5%; p=0.25). Based on 2018 guidelines, the concordance between IHC and CISH was 98.9%. Specifically, 229/1423 patients (16%) were IHC+/CISH+, 5 patients (0.4%) were IHC+/CISH- and 11 patients (0.8%) were IHC-/CISH+ (Table). Common pathway alterations in HER2+ USC include TP53, RTK RAS, PI3K, NOTCH, chromatin remodeling and cell cycle genes. Single gene alterations in HER2+ tumors that may implicate HER2 therapy resistance (based on pathway analyses in other tumor types) included PI3K (36%), KRAS (2.6%), and PTEN (2.1%). HER2+ tumors had low immunotherapy biomarker profiles (0.3% MSI-H, 0.8% TMB, 17.1% PD-L1). Conclusions: High concordance rates were observed between CISH and IHC. Ultimately these testing platforms need to be validated by response to HER2 targeted therapies in order to develop USC specific HER2 testing guidelines.[Table: see text]

A phase 3, randomized, double-blind, adaptive, placebo/paclitaxel-controlled study of AVB-S6-500 in combination with paclitaxel in patients with platinum-resistant recurrent ovarian cancer (GOG-3059/ENGOT OV-66/AVB500-OC-004)

TPS5605

Background: The AXL receptor and its activating ligand, GAS6, are important drivers of metastasis and therapeutic resistance in human cancers. This signaling axis represents an attractive target for therapeutic intervention, but the strong picomolar binding affinity between endogenous GAS6 and AXL and the promiscuity of small molecule AXL inhibitors have presented a barrier to specific and potent inhibition of AXL. AVB-S6-500 is a highly sensitive and specific inhibitor of AXL, with ̃200-fold higher affinity than wild-type (WT) AXL. AVB-S6-500 binds GAS6, the sole ligand of AXL, inhibiting its interaction with AXL thereby dramatically reducing AXL signaled invasion and migration of highly metastatic cells in vitro and inhibiting metastatic disease in nonclinical models of aggressive human cancers. A Phase 1b study in platinum resistant ovarian cancer showed no dose limiting toxicities and established a recommended Phase 2 dose of 15mg/kg administered every 2 weeks. Longer progression free survival (PFS) and overall survival (OS) times were observed in patients who had not been previously treated with bevacizumab. Furthermore, retrospective analyses demonstrated that serum soluble AXL to GAS6 ratio may identify patients more likely to respond to this therapy. Methods: Patients with high grade serous, platinum resistant ovarian cancer, who have received no more than 4 prior therapy regimens will be randomized 1:1 to AVB-500 + PAC or PAC + placebo. Patients will be stratified by recurrence after last platinum regimen (<3, 3-6 months), prior lines (1-2, 3-4), and prior bevacizumab (yes, no). The primary endpoint is PFS by RECIST v 1.1 as assessed by the investigator, with OS a key secondary endpoint. The study design is adaptive; with two interim analyses addressing conditional power in the bevacizumab treated subset, and in a serum soluble AXL, GAS6 biomarker subset, respectively, with interim results used to define the final target population. Simulations confirm a nominal one-sided type 1 error below 0.025, and show >90% statistical power for PFS under the following assumptions of PFS medians. Study recruitment began in Q1. Clinical trial information: NCT04729608.

Molecular determinants of response to immune-oncology therapy in uterine carcinosarcoma

5582

Background: Uterine carcinosarcoma (UCS) is subtype of endometrial cancer (EC) with aggressive behavior and poor prognosis. UCS has not traditionally been included in EC clinical trials and treatment options are limited. Immune-oncology (IO) therapy has shown promise UCS, but it is unknown which patients benefit most. We sought to identify immunogenic markers in UCS and explore treatment response to IO therapy. Methods: Tumor samples were analyzed using Nex-Gen sequencing of the DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ).PD-L1 IHC used SP-142 (cut-off >1%). MSI was tested by FA, IHC and NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank sum test and p values adjusted for multiple comparisons (q) to be <0.05. Results: A total of 1,144 UCS tumors underwent comprehensive tumor profiling. 68.4% of samples were obtained from primary tumors and 31.6% from metastatic sites. 21.6% of tumors expressed PD-L1, 8.5% were TMB-H and 6.8% were MSI-H/MMRd. UCS patients treated with IO had longer median overall survival than those not treated with IO (months: 31.2 vs 19.4; HR(95% CI): 0.39 (0.17-0.76) p=0.005). Median OS was also increased for dMMR/MSI-H (OS not yet reached vs 18.9 months); HR(95% CI): 0.56 (0.36-0.92) p=0.019) and TMB-H (OS not yet reached vs 18.9 months); HR(95% CI): 0.62 (0.38-0.99) p=0.047). More patients are needed to determine if these markers predict response to IO therapy. The most common mutations in UCS led to pathway dysregulation in the PI3K, RAS, chromatin remodeling, HR, and WNT pathways. dMMR/MSI-H tumors have distinct molecular profiles compared to MSS tumors (table). Additionally, dMMR/MSI-H tumors had higher TMB (96.9% vs 2.2%, q<0.01) and increased frequency of PDL-1 (23.6% vs 13.8%; q=0.04). Immune checkpoint genes were more often expressed in MSI-H tumors, though this was non-significant except for IFNG (4.66-fold increase; q=0.01). Conclusions: IO therapy is associated with improved survival in USC. MSI and TMB are markers of improved OS in patients with UCS. MSI tumors have a distinct molecular profile compared to MSS tumors, and they appear to be more immunogenic, which could contribute to the improved survival seen in patients who received IO therapy.[Table: see text]

Maintenance vigil immunotherapy in newly diagnosed advanced ovarian cancer: Efficacy assessment of homologous recombination proficient (HRP) patients in the phase IIb VITAL trial

5502

Background: In the VITAL (NCT02346747) trial, maintenance therapy with Vigil, an autologous tumor cell vaccine transfected with a DNA plasmid encoding GMCSF and bi-shRNA-furin for TGFβ expression control, following frontline platinum-based chemotherapy led to a recurrence-free survival (RFS) benefit in patients with advanced high-grade ovarian cancer (HR=0.69, 90% CI 0.44–1.07, p=0.078) and significantly in BRCA-wt patients (HR=0.51, 90% CI 0.30-0.88, p=0.020) ( Rocconi et al. Lancet Oncol. 2020). Here we report post-hoc HR deficiency (HRD) subgroup analysis and identification of an additional molecular subgroup sensitive to Vigil therapy involving STRING analysis. Methods: This double-blind, placebo-controlled, Phase 2b study randomized 92 patients with newly diagnosed stage III/IV ovarian cancer with a complete clinical response (CR) to frontline surgery and chemotherapy. Patients received 1 x 10e7 cells/ml of Vigil or placebo intradermally once a month for up to 12 doses or disease progression. RFS was the primary endpoint assessed by blinded independent central review. HRD status was determined according to the Myriad Genetics myChoice CDx assay (HRD score < 42 for proficient). Using tumor annotated DNA polymorphism data, a protein-protein interaction network was constructed using the STRING database. Properties of this network including topological distance and the identification of hub genes were used to predict a target molecular population sensitive to Vigil. Results: In the per-protocol population (PP, n=91), 62 BRCA-wt patients were tested for HRD status. Forty-five patients were HR proficient (HRP) and 17 patients were HR deficient (HRD). No HRP patients in the Vigil group reported treatment related Grade 3 or higher adverse events. From the time of study randomization median RFS was improved with Vigil (n=25) in HRP patients compared to placebo (n=20) (Table 1). Similarly, overall survival (OS) benefit was observed in the Vigil group compared to placebo (Table 1). Improved RFS was demonstrated for a subset of patients with STRING predicted molecular profile. Conclusions: Vigil immunotherapy as frontline maintenance in Stage III/IV ovarian cancer is well tolerated and showed clinical benefit in both BRCA-wt and HRP molecular profile patients. Results suggest a unique molecular network that enhances sensitivity to Vigil therapy. Clinical trial information: NCT02346747. [Table: see text]

Exploring molecular profiles of uterine carcinosarcoma with alterations in the chromatin remodeling pathway

5587

Background: In a preliminary data analysis to identify prognostic molecular biomarkers in uterine carcinosarcoma (UCS), we found that alterations in KMT2C, a gene involved in the chromatin remodeling pathway, correlated with improved survival. We sought to explore relevant biomarkers of KMT2C-mutated (KMT2C-mut) tumors compared to wildtype (KMT2C-wt) tumors. Methods: Tumor samples were analyzed using next generation sequencing (NGS) of the DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ).PD-L1 IHC used SP-142 (cut-off >1%). Microsatelite instability (MSI) was tested by FA, IHC and NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank sum test and p values adjusted for multiple comparisons (q) to be <0.05. Results: Molecular analysis was performed on 1,144 UCS tumors. 7.7% were found to be KMT2C-mut. Patients with pathogenic alterations in KMT2C had longer median OS than patients without (OS not yet reached vs 19.0 months HR(95% CI): 0.37(0.19-0.72) p< 0.01). The most common mutations in KMT2C-mut tumors are shown in Table and resulted in more frequent dysregulation in the following pathways compared to KMT2C-wt tumors: chromatin remodeling (100% vs 28%; q<0.01), WNT (39% vs 12%; q=0.01), base/nucleotide excision repair (29% vs 5%; q<0.01), homologous recombination (26% vs 6%; q=0.02), DNA damage sensors (23% vs 4%; q=0.02) and Fanconi anemia (13% vs 1%; q=0.04). KMT2C-mut tumors were more frequently MSI-H (32% vs 6%; q<0.01) and TMB-H (42% vs 5%; q<0.01). Among MSS tumors, KMT2C-mut tumors had increased mutations in JAK1 and POLE (q<0.01) and higher frequency of TMB-H (24% vs 1%; q<0.01) than KMT2C-wt tumors. Additionally, MSS patients with KMT2C-mut had longer OS than patients with KMT2C-wt tumors (OS not yet reached vs 18.9 months; HR(95% CI): 0.33(0.15-0.75) p< 0.01). Conclusions: Mutations in KMT2C correlate with improved OS in UCS. KMT2C-mut tumors have distinct molecular profiles from wild type tumors. They exhibit greater immunogenicity, including more frequent MSI-H and TMB-H. This suggests a potential role for Immune-oncology (IO) therapy. Further study of the impact of IO therapies in the cohort is warranted as this may contribute to the improved survival of these patients.[Table: see text]

Immune-response markers and actual response to immune-oncology therapy in uterine serous carcinoma

5590

Background: Uterine serous carcinoma (USC) is an aggressive subtype of endometrial cancer with poor prognosis and limited treatment options. Immune-oncology (IO) agents have shown promise USC, however data is limited regarding which patients benefit most from IO therapy. In other malignancies, PD-L1, MSI-H status and high TMB have been predictive of IO response. We sought to characterize the immune profiles of USC and investigate treatment response to IO therapy. Methods: Tumor samples were analyzed using Nex-Gen sequencing of the DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) (Caris Life Sciences, Phoenix, AZ).PD-L1 IHC used SP-142 (cut-off >1%). MSI was tested by FA, IHC and NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Real-world overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined patient cohorts. Statistical significance was determined using chi-square and Wilcoxon rank sum test and p values adjusted for multiple comparisons (q) to be < 0.05. Results: Molecular analysis was performed on 2,806 USC tumors. The median age was 67 years. 65.3% were from primary tumors, 34.7% from metastatic sites. In total, 92 patients were treated with IO therapy and had a significantly longer median survival than those not treated with IO (months: 59.6 vs 31.2; HR(95% CI): 0.38(0.24-0.61) p < 0.001), resulting in a survival advantage of 867 days. PD-L1 expression was present in 19.1% of cases, but only 2.3% of tumors were MSI-H and 4.2% were TMB-H. Patients with these markers trended toward a better median survival, but this was not significant; PD-L1 (months: 34.4 vs 31.2; HR(95% CI): 0.90 (0.74-1.1), MSI-H (OS not yet reached vs 31.6 months; HR(95% CI): 0.69(0.38-1.25) and TMB-H (months: 36.4 vs 31.6; HR(95% CI): 0.84(0.50-1.39). Regarding the immune microenvironment, the most common infiltrating immune cells were M2 Macrophages (5.35%), B cells (4.71%), myeloid dendritic cells (3.45%), NK cells (2.94%) and regulatory T cells (1.59%). There were few CD8 T cells and non-regulatory CD4 T cells. Conclusions: IO therapy was associated with a median survival benefit of more than 2 years in USC. We did not identify any prognostic markers of IO-therapy response. MSI-H and TMB-H are rare in USC, but PD-L1 is present in nearly 20% of cases. Notably these markers did predict a significant survival benefit, which has important clinical implications. Further study is warranted.

Phase 1b study of GAS6/AXL inhibitor (AVB-500) in recurrent, platinum-resistant ovarian carcinoma

5566

Background: AVB-500 is a first-in-class Fc fusion protein that binds the GAS6 ligand thereby inhibiting AXL signaling. Both GAS6 and AXL are highly expressed in high-grade serous ovarian cancer (HSGOC). This study evaluated safety, tolerability, and preliminary efficacy of AVB-500 in combination with pegylated liposomal doxorubicin (PLD) and paclitaxel (Pac) and determine the recommended Phase 2 dose (RP2D). Methods: Patients were enrolled in escalating dose cohorts of AVB-500 10mg/kg to 20mg/kg q2 weeks in combination with weekly Pac 80mg/m2 D1, 8, 15 q28 days or PLD 40mg/m2 D1 q28 days and assess for safety, pharmacokinetics, pharmacodynamics, and response by investigator, via RECIST v1.1. Results: A total of 53 patients with platinum-resistant HGSOC (PROC) were enrolled. A total of 23 patients received Pac + AVB-500 and 30 patients received PLD + AVB-500. Grade 3 or 4 treatment-related adverse events were observed in 4/23 (17%) and 2/30 (7%) PAC and PLD, respectively. No patients discontinued therapy due to an adverse event. Most events were related to known chemotherapy side effects. RP2D was identified as 15mg/kg. Confirmed overall response rate (ORR) with Pac+AVB-500 was 35% (8/23) including 2 CRs and 11% (3/28) in the PLD+AVB-500 subgroup. ORR was 19% (3/16) in patients with platinum free interval (PFI) of < 3 months versus (vs) 23% (8/35) in patients with PFI of 3-6 months. ORR was 11% (2/18) in patients with 1 prior treatment vs 27% (9/33) in patients with 2-3 prior lines of therapy. ORR in patients without prior bevacizumab was 33% (9/27) vs 8% (2/24) in those with prior bevacizumab. Patients treated with Pac combination and whose AVB-500 trough levels were above the minimal efficacious concentration (MEC) of 13.8mg/L achieved the greatest benefit with ORR, median PFS, and median OS of 43% (6/14), 3.9 months, and 17.8 months vs 22% (2/9), 2.8 months, and 8.7 months observed in those whose trough was below the MEC. Among the Pac treated subgroup, the ORR was 47% (13% CR) vs 0% for those with sAXL/GAS6 ratios > 0.773 compared to ratios <0.773. 67% of patients had baseline sAXL/GAS6 > 0.773. Conclusions: AVB-500 is a novel Fc fusion protein that binds the GAS6 ligand and inhibits AXL signaling. AVB-500 was well-tolerated in combination with Pac or PLD. This Ph1b trial suggested a higher ORR in the Pac treated subgroup, with C1D15 trough levels > 13.8mg/L (most consistently achieved at the 15mg/kg dose level). Exploratory analyses suggested that improved ORR may be observed in patients who have not been exposed to bevacizumab. The serum sAXL/GAS6 ratio may be a potential biomarker of pathway activation and identify patients who most benefit from Pac+AVB-500. The ORR in patients with PFI < 3 months or who had > 1 line of prior therapy were similar to those with 3-6 months PFI or ≤1 lines of therapy. Further development of AVB-500 15 mg/kg q2 weeks in combination with Pac is warranted in PROC. Clinical trial information: NCT03639246.

Association of the presence of estrogen and progesterone receptors in uterine carcinosarcoma with improved survival and increased immunogenicity

5588

Background: Recent data has shed light on molecular profiles of uterine carcinosarcoma (UCS), but few have correlated molecular profiles with prognosis. In a preliminary data analysis, we found that hormone receptors (HR)—estrogen receptor (ER) and progesterone receptor (PR)—expression was associated with improved OS. Here, we investigate the molecular profile differences between ER+/- and PR +/- tumors. Methods: Tumor samples were analyzed using Next-Generation sequencing of DNA (NextSeq, 592 genes or NovaSeq, whole exome sequencing) and RNA (NovaSeq, whole transcriptome sequencing) and immunohistochemistry (IHC) at the Caris Life Sciences Laboratory (Phoenix, AZ).ER and PR tested by IHC on whole tumor (cut-off: +1, 10%). PD-L1 IHC used SP-142 (cut-off >1%). MSI was tested by FA, IHC an NGS. TMB was measured by totaling somatic mutations per tumor (high > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq. Overall survival (OS) information was obtained from insurance claims data and Kaplan-Meier estimates were calculated for molecularly defined cohorts. Statistical significance was determined by chi-square and Wilcoxon rank sum test and p-values adjusted for multiple comparisons (q) to be <0.05. Results: 1,144 UCS tumors were included. (ER+, n=261; PR+, n=197; HR+ (ER+ and PR+), n=168). Median OS for patients with hormone receptor (HR)+ tumors was significantly longer than for patients with HR- tumors (months: 34.8 vs 17.4; HR(95% CI): 0.67 (0.53-0.84), p<0.01). This remained significant for ER (29.4 vs 17.3) and PR (25.3 vs 18.7) individually. ER+ tumors had fewer alterations in the TP53 pathway (71.4% vs 82.1%) in the WNT (19.5% vs 5.8%) pathway than ER- tumors (q<0.05). PR+ tumors had similar findings in the TP53 and WNT pathways, and also more alterations in the DNA damage sensor pathway. Both ER+ and PR+ UCS tumors had significantly increased MSI-H (ER: 10.9% vs 5.5%, PR: 12.9% vs 5.5%) and TMB-H (ER: 16.8% vs 6.0%; PR: 19.5% vs 6.1%) (all q<0.05) compared to ER- and PR- tumors. They also had increased T-reg cells in their immune micro-environment and increased expression of the immune checkpoint gene IDO1 (q<0.05; Table). Conclusions: HR+ tumors have distinct molecular profiles from HR- tumors. ER+ and PR+ UCS tumors appear more immunogenic with more frequent MSI-H status, TMB-H, increased infiltrating regulatory T-cells and IDO1 expression, suggesting possible benefit with immune-oncology (IO) therapy. This may contribute to the observed improved OS, but more data are needed to determine if HR status is a marker of response to IO therapy.[Table: see text]

A comprehensive landscape of BRCA1 versus BRCA2 associated molecular alterations and survival outcome across 35 cancer types

3120

Background: Poly (ADP-ribose) polymerase inhibitors (PARPi) are effective therapies for some patients with both germline and somatic BRCA1/2 mutations (MTs) or with homologous recombination repair deficiency (HRD). We aimed to characterize molecular differences between BRCA1 and BRCA2 MTs and their prognostic and/or predictive impact on PARPi outcomes in various cancer subtypes using real world data (RWD). Methods: Tumor samples obtained from patients with 35 types of cancer were analyzed by whole exome sequencing (WES, Novaseq) at Caris Life Sciences (Phoenix, AZ). High genomic loss of heterozygosity (gLOH-H) was defined as LOH-H in ≥16% of tested loci. MSI/MMR was tested by fragment analysis, IHC, and WES. Overall survival (OS) extracted from insurance claims was calculated from start of treatment or tissue collection until last contact or death using Kaplan-Meier curves. P-values adjusted for multiple comparisons (q-value of < 0.05 was considered to be significant). Results: In total, 17,640 tumors were included, of which 776 (4.3%) had tumor-based BRCA1/2 MTs. BRCA1/2 MTs were most commonly seen in ovarian (N = 221/2187, 10.1%), breast (138/2506, 5.5%), prostate (61/1131, 5.4%), pancreatic (48/1430, 3.4%), and non-small cell lung (100/4046, 2.5%) cancers. BRCA2 MTs were more frequent than BRCA1 except in ovarian cancers. BRCA1 MTs were more common in younger pts (median age, 61 vs 65 years, p <.001). When compared to BRCA2 MTs, BRCA1 MTs were more often associated with gLOH-H (64% vs 51%, p <.001) and TP53 MT (80% vs 53%, p <.001) in all tumor types. In NSCLC, EGFR mutations were exclusively seen in BRCA2 compared to BRCA1 (10.3 vs. 0%, P = 0.038). The EGFR mutations that co-occurred with BRCA2 mutations were L858R (N = 1), Exon19del (N = 4), and L861Q (N = 1). KRAS was more frequently mutated in BRCA1-mutated NSCLC ( BRCA1: 32% vs. BRCA2: 16%, p =.056). In univariate analyses, overall BRCA1/2 MTs were associated with improved OS compared to wild type (HR 1.38, 95% CI [1.31-1.45], P <.0001). This effect was seen in ovarian (1.42 [1.29-1.57], p < 0.0001) and triple-negative breast cancers (TNBC) (1.18, [1.09-1.28], p <.001); but was not observed in prostate, pancreatic, or non-TNBC breast cancer subtypes. In all breast cancers, BRCA2 MTs had a superior OS (0.68, [0.51-0.89], p =.005) compared to BRCA1, while no differences were seen in other cancers. Using RWD, PARPi treated-patients with BRCA2 MTs had worse OS than BRCA1 MTs (HR 1.4, [1.09-1.80], p = 0.009); but this was not significant when individual cancers were considered. Conclusions: BRCA1 and BRCA2 MTs had variable power to be prognostic and predictive for PARPi efficacy among different cancer types using RWD. About 2.5% of NSCLCs harbor BRCA1/2 MT. Additional genomic exploration may refine biomarkers predictive of response to PARPi and may highlight features within the tumor microenvironment of importance in the setting of HRD.

Cardiac safety of trabectedin monotherapy or in combination with pegylated liposomal doxorubicin in patients with sarcomas and ovarian cancer

Background

As with other alkylating agents, cardiac dysfunction can occur with trabectedin therapy for advanced soft tissue sarcomas (STS) or recurrent ovarian cancer (ROC) where treatment options for advanced disease are still limited. Cardiac safety for trabectedin monotherapy (T) for STS or in combination with pegylated liposomal doxorubicin (T+PLD) for ROC was evaluated in this retrospective postmarketing regulatory commitment.

Methods

Patient data for multiple cardiac‐related treatment‐emergent adverse events (cTEAEs) were evaluated in pooled analyses of ten phase 2 trials, one phase 3 trial in STS (n = 982), and two phase 3 trials in ROC (n = 1231).

Results

Multivariate analyses on pooled trabectedin data revealed that cardiovascular medical history (risk ratio [RR (95% CI)]: 1.90 [1.24‐2.91]; p = 0.003) and age ≥65 years (RR [95% CI]: 1.78 [1.12‐2.83]; p = 0.014) were associated with increased risk for cTEAEs. Multivariate analyses showed increased risk of experiencing cTEAEs with T+PLD compared to PLD monotherapy (RR [95% CI]: 2.70 [1.75‐4.17]; p < 0.0001) and with history of prior cardiac medication (RR [95% CI]: 1.88 [1.16‐3.05]; p = 0.010).

Conclusions

For patients with STS or ROC who still have limited treatment options, trabectedin may be initiated after carefully considering benefit versus risk.

Trial Registration (ClinicalTrials.gov): NCT01343277; NCT00113607; NCT01846611.

The GOG partners: A program for industry sponsored clinical trials in gynecologic oncology within the GOG foundation

The GOG Foundation, Inc. (GOG-F) is a non-profit 501(c)(3) organization with the purpose of promoting excellence in the quality and integrity of clinical and basic scientific research in the field of gynecologic malignancies. GOG Partners (GOG-P) is a program of the GOG-F and is positioned alongside NRG Oncology under the GOG-F organizational umbrella. GOG-P operates outside of the federally funded NCI NRG Oncology, a key distinguishing feature. By functioning as a site management organization (SMO), GOG-P provides an additional platform for clinical trial development, mentorship opportunities, patient accrual, and site infrastructure support yielding an expanded gynecologic oncology clinical trials infrastructure in the US. GOG-P has a consistent track record of conducting high quality clinical trials that lead to bringing novel FDA approved treatments for gynecologic cancer. This manuscript summarizes the history and organizational structure of the GOG-P. In addition, we outline the other key supportive programs within the GOG-F that help support the GOG-P effort to perform transformative gynecologic cancer research.