Overall survival and patient-reported outcome results from the placebo-controlled randomized phase III IMagyn050/GOG 3015/ENGOT-OV39 trial of atezolizumab for newly diagnosed stage III/IV ovarian cancer

OBJECTIVE

To determine the impact on overall survival (OS) and patient-reported outcomes (PROs) of combining atezolizumab with standard therapy for newly diagnosed stage III/IV ovarian cancer.

METHODS

The placebo-controlled double-blind randomized phase III IMagyn050/GOG 3015/ENGOT-OV39 trial (NCT03038100) assigned eligible patients to 3-weekly atezolizumab 1200 mg or placebo for 22 cycles with platinum-based chemotherapy and bevacizumab. Coprimary endpoints were progression-free survival (already reported) and OS in the PD-L1-positive and intent-to-treat (ITT) populations, tested hierarchically. Prespecified PRO analyses focused on disease-related abdominal pain and bloating symptoms (European Organisation for Research and Treatment of Cancer QLQ-OV28), functioning, and health-related quality of life (HRQoL) (QLQ-C30).

RESULTS

After 38 months' median follow-up, the OS hazard ratio in the PD-L1-positive population was 0.83 (95% CI, 0.66-1.06; p = 0.13); median OS was not estimable with atezolizumab versus 49.2 months with placebo. The hazard ratio for OS in the ITT population was 0.92 (95% CI, 0.78-1.09; median 50.5 versus 46.6 months, respectively). At week 9, similar proportions of patients in both arms of the neoadjuvant cohort showed ≥10-point improvement from baseline in abdominal pain and bloating, functioning, and HRQoL. In the primary surgery cohort, similar proportions of patients in each arm had improved, stable, or worsened physical and role function and HRQoL from baseline over time. Neither cohort showed differences between arms in treatment-related symptoms or overall side-effect bother.

CONCLUSIONS

Incorporation of atezolizumab into standard therapy for newly diagnosed ovarian cancer does not significantly improve efficacy or impose additional treatment burden for patients.

CLINICALTRIALS

gov registration: NCT03038100.

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.).

Endometrial Cancer Surgery With or Without Concomitant Stress Urinary Incontinence Surgery

OBJECTIVE

To compare quality of life (QOL) among patients with endometrial intraepithelial neoplasia or early-stage endometrial cancer and stress urinary incontinence (SUI) who chose to have concomitant surgery with cancer surgery alone.

METHODS

A multicenter, prospective cohort study was conducted across eight U.S. sites. Potentially eligible patients were screened for SUI symptoms. Those who screened positive were offered referral to urogynecology and incontinence treatment, including concomitant surgery. Participants were categorized into two groups: 1) concomitant cancer and SUI surgery or 2) cancer surgery alone. The primary outcome was cancer-related QOL as measured by the FACT-En (Functional Assessment of Cancer Therapy-Endometrial) (range 0-100; higher score indicates better QOL). The FACT-En and questionnaires assessing urinary symptom-specific severity and effects were assessed before surgery and 6 weeks, 6 months, and 12 months after surgery. Adjusted median regression accounting for clustering was used to examine the relationship between SUI treatment group and FACT-En scores.

RESULTS

Of 1,322 (53.1%) patients, 702 screened positive for SUI with 532 analyzed; 110 (21%) chose concomitant cancer and SUI surgery, and 422 (79%) chose cancer surgery alone. FACT-En scores increased for both the concomitant SUI surgery and cancer surgery-only groups from the preoperative to the postoperative period. After adjustment for timepoint and preoperative covariates, the median change in FACT-En score (postoperative-preoperative) was 1.2 points higher (95% CI -1.3 to 3.6) for the concomitant SUI surgery group compared with the cancer surgery-only group across the postoperative period. Median time until surgery (22 days vs 16 days; P <.001), estimated blood loss (150 mL vs 72.5 mL; P <.001), and operative time (185.5 minutes vs 152 minutes; P <.001) were all greater for the concomitant cancer and SUI surgery group compared with the cancer-only group, respectively.

CONCLUSION

Concomitant surgery did not result in improved QOL compared with cancer surgery alone for endometrial intraepithelial neoplasia and patients with early-stage endometrial cancer with SUI. However, FACT-En scores were improved in both groups.

Molecular testing for endometrial cancer: An SGO clinical practice statement

The Cancer Genome Atlas publication first described the genomic landscape of endometrial cancer and characterized these cancers into four molecular subtypes with different prognoses. The Proactive Molecular Classifier for Endometrial Cancer was developed to more easily and inexpensively classify endometrial cancers into four similar molecular subtypes which are termed POLE, mismatch repair deficient, p53 abnormal and no specific molecular profile. Beyond these four subtypes, other molecular biomarkers may influence clinical behavior and response to targeted therapies and include beta-catenin, Her2 amplification, PI3K/mTOR/AKT alterations, L1CAM, hormone receptor expression, tumor mutational burden, and ARID1A. There are numerous clinical trials exploring treatment escalation and de-escalation within the four molecular subtypes as well as matching targeted therapies to specific mutational or biomarker profiles. All endometrial cancers should undergo basic molecular classification that includes assessment of mismatch repair status. POLE and p53 status are prognostic and may become actionable in the future. Clinicians who treat patients with endometrial cancer should understand the role of molecular classification in guiding treatment. The goal of this practice statement is to guide appropriate testing, interpretation, and application of molecular information in endometrial cancer.

Translational randomized phase II trial of cabozantinib in combination with nivolumab in advanced, recurrent, or metastatic endometrial cancer

BACKGROUND

Combining immunotherapy and antiangiogenic agents is a promising treatment strategy in endometrial cancer. To date, no biomarkers for response have been identified and data on post-immunotherapy progression are lacking. We explored the combination of a checkpoint inhibitor (nivolumab) and an antiangiogenic agent (cabozantinib) in immunotherapy-naïve endometrial cancer and in patients whose disease progressed on previous immunotherapy with baseline biopsy for immune profiling.

PATIENTS AND METHODS

In this phase II trial (ClinicalTrials.gov NCT03367741, registered December 11, 2017), women with recurrent endometrial cancer were randomized 2:1 to nivolumab with cabozantinib (Arm A) or nivolumab alone (Arm B). The primary endpoint was Response Evaluation Criteria in Solid Tumors-defined progression-free survival (PFS). Patients with carcinosarcoma or prior immune checkpoint inhibitor received combination treatment (Arm C). Baseline biopsy and serial peripheral blood mononuclear cell (PBMC) samples were analyzed and associations between patient outcome and immune data from cytometry by time of flight (CyTOF) and PBMCs were explored.

RESULTS

Median PFS was 5.3 (90% CI 3.5 to 9.2) months in Arm A (n=36) and 1.9 (90% CI 1.6 to 3.4) months in Arm B (n=18) (HR=0.59, 90% CI 0.35 to 0.98; log-rank p=0.09, meeting the prespecified statistical significance criteria). The most common treatment-related adverse events in Arm A were diarrhea (50%) and elevated liver enzymes (aspartate aminotransferase 47%, alanine aminotransferase 42%). In-depth baseline CyTOF analysis across treatment arms (n=40) identified 35 immune-cell subsets. Among immunotherapy-pretreated patients in Arm C, non-progressors had significantly higher proportions of activated tissue-resident (CD103+CD69+) ɣδ T cells than progressors (adjusted p=0.009).

CONCLUSIONS

Adding cabozantinib to nivolumab significantly improved outcomes in heavily pretreated endometrial cancer. A subgroup of immunotherapy-pretreated patients identified by baseline immune profile and potentially benefiting from combination with antiangiogenics requires further investigation.

Phase I Trial of Stereotactic MRI-Guided Online Adaptive Radiation Therapy (SMART) for the Treatment of Oligometastatic Ovarian Cancer

PURPOSE

Stereotactic body radiation therapy is increasingly used to treat a variety of oligometastatic histologies, but few data exist for ovarian cancer. Ablative stereotactic body radiation therapy dosing is challenging in sites like the abdomen, pelvis, and central thorax due to proximity and motion of organs at risk. A novel radiation delivery method, stereotactic magnetic-resonance-guided online-adaptive radiation therapy (SMART), may improve the therapeutic index of stereotactic body radiation therapy through enhanced soft-tissue visualization, real-time nonionizing imaging, and ability to adapt to the anatomy-of-the-day, with the goal of producing systemic-therapy-free intervals. This phase I trial assessed feasibility, safety, and dosimetric advantage of SMART to treat ovarian oligometastases.

METHODS AND MATERIALS

Ten patients with recurrent oligometastatic ovarian cancer underwent SMART for oligometastasis ablation. Initial plans prescribed 35 Gy/5 fractions with goal 95% planning target volume coverage by 95% of prescription, with dose escalation permitted, subject to strict organ-at-risk dose constraints. Daily adaptive planning was used to protect organs-at-risk and/or increase target dose. Feasibility (successful delivery of >80% of fractions in the first on-table attempt) and safety of this approach was evaluated, in addition to efficacy, survival metrics, quality-of-life, prospective timing and dosimetric outcomes.

RESULTS

Ten women with seventeen ovarian oligometastases were treated with SMART, and 100% of treatment fractions were successfully delivered. Online adaptive plans were selected at time of treatment for 58% of fractions, due to initial plan violation of organs-at-risk constraints (84% of adapted fractions) or observed opportunity for planning target volume dose escalation (16% of adapted fractions), with a median on-table time of 64 minutes. A single Grade ≥3 acute (within 6 months of SMART) treatment-related toxicity (duodenal ulcer) was observed. Local control at 3 months was 94%; median progression-free survival was 10.9 months. Median Kaplan-Meier estimated systemic-therapy-free survival after radiation completion was 11.5 months, with concomitant quality-of-life improvements.

CONCLUSIONS

SMART is feasible and safe for high-dose radiation therapy ablation of ovarian oligometastases of the abdomen, pelvis, and central thorax with minimal toxicity, high rates of local control, and prolonged systemic-therapy-free survival translating into improved quality-of-life.

British Association of Dermatologists guidelines for the management of people with cutaneous lupus erythematosus (CLE) 2021

The overall objective of the guideline is to provide up-to-date, evidence-based recommendations for the management of cutaneous lupus erythematosus (CLE) in the presence or absence of systemic lupus erythematosus (SLE) in adults, young people and children. The document aims to: offer an appraisal of all relevant literature up to December 2020, focusing on any key developments address important, practical clinical questions relating to the primary guideline objective. provide guideline recommendations and if appropriate research recommendations.

Induction of labour during the COVID-19 pandemic: a national survey of impact on practice in the UK

BACKGROUND

Induction of labour (IOL) is one of the most commonly performed interventions in maternity care, with outpatient cervical ripening increasingly offered as an option for women undergoing IOL. The COVID-19 pandemic has changed the context of practice and the option of returning home for cervical ripening may now assume greater significance. This work aimed to examine whether and how the COVID-19 pandemic has changed practice around IOL in the UK.

METHOD

We used an online questionnaire to survey senior obstetricians and midwives at all 156 UK NHS Trusts and Boards that currently offer maternity services. Responses were analysed to produce descriptive statistics, with free text responses analysed using a conventional content analysis approach.

FINDINGS

Responses were received from 92 of 156 UK Trusts and Boards, a 59% response rate. Many Trusts and Boards reported no change to their IOL practice, however 23% reported change in methods used for cervical ripening; 28% a change in criteria for home cervical ripening; 28% stated that more women were returning home during cervical ripening; and 24% noted changes to women's response to recommendations for IOL. Much of the change was reported as happening in response to attempts to minimise hospital attendance and restrictions on birth partners accompanying women.

CONCLUSIONS

The pandemic has changed practice around induction of labour, although this varied significantly between NHS Trusts and Boards. There is a lack of formal evidence to support decision-making around outpatient cervical ripening: the basis on which changes were implemented and what evidence was used to inform decisions is not clear.

Abstract PO045: Inhibition of GAS6/AXL improves efficacy of HER2 inhibitor trastuzumab in uterine serous cancer

Objectives: To determine whether inhibition of GAS6/AXL can improve efficacy to the humanized anti-HER2 monoclonal antibody trastuzumab by decreasing uterine serous cancer cell invasion and cell survival in vitro and tumor burden in vivo. Methods: We treated AXL-expressing and HER2-expressing uterine serous cancer cell lines (ARK1, ARK2) with trastuzumab, AVB-500, or trastuzumab plus AVB-500. Clonogenic cell survival assays were performed. Matrigel invasion assays were used to assess the invasive capacity of ARK2 cells after 24 hours of treatment with vehicle, AVB-500, trastuzumab, or trastuzumab plus AVB-500. A proximity ligation assay was used to examine colocalization of HER2/neu and AXL. Western blots were performed to assess the effects of the individual drugs and combination on phosphorylation of HER2/neu and AXL. An intraperitoneal tumor model with 10 million ARK1 cells was treated with vehicle, AVB-500, trastuzumab, or trastuzumab plus AVB-500 for 35 days. The number, size, and volume of tumor nodules were measured. GraphPad Prism was used for statistical analysis. Results: We found decreased cell survival by clonogenic assays in ARK1 and ARK2 cells treated with trastuzumab plus AVB-500 compared to trastuzumab alone (relative absorbance 0.155 nm vs 0.202 nm, P=0.015). There was significantly less invasion from treatment with trastuzumab plus AVB-500 than with trastuzumab alone (3.2 vs 17.8 invading tumor cells/hpf, P=0.0004). Western blot showed that cells treated with trastuzumab plus AVB-500 had reduced phospho-AXL compared to cells treated with AVB-500 or trastuzumab alone. Furthermore, the proximity ligation assay demonstrated co-localization of the AXL and HER2 receptors in both ARK1 and ARK2 cells indicating a physical closeness that could account for this co-regulation. We found that mice treated with trastuzumab plus AVB-500 developed significantly less tumor burden than mice treated with trastuzumab alone (0.03205 g vs 0.08316 g, P= 0.024), AVB-500 alone (0.0320 g vs 0.1638 g, P&lt;0.0001), and vehicle alone (0.03205 g vs 0.1154 g, P= 0.0395). Conclusions: The GAS6/AXL inhibitor AVB-500 potentiated the effect of trastuzumab to decrease uterine serous cancer cell proliferation and invasion in vitro and tumor burden in vivo likely through AXL and HER2 complexes.

Citation Format: Joan Tankou, Michael Toboni, Hollie Noia, Alyssa Oplt, Daniel Wilke, Dineo Khabele, Lindsay Kuroki, Andrea Hagemann, Carolyn McCourt, Premal Thaker, David Mutch, Matthew Powell, Katherine Fuh. Inhibition of GAS6/AXL improves efficacy of HER2 inhibitor trastuzumab in uterine serous cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO045.

Abstract PO047: AVB-500, a receptor tyrosine kinase AXL inhibitor, improves response to olaparib in uterine serous cancer

Objectives: We determined whether inhibition of GAS6/AXL with AVB-500 in combination with olaparib could improve response in HR-proficient (HRP) uterine serous cancer (USC). Methods: Two USC cell lines (ARK1 & ARK4) were radiated with 10Gy, and RAD51 foci were identified by immunofluorescence (IF). These were treated with AVB-500 (Aravive Biologics, Houston, TX) in combination with the poly ADP ribose polymerase (PARP) inhibitor, olaparib. Colony forming assays were assessed after 4 days of treatment with either AVB-500 alone, olaparib alone or combination treatment (olaparib + AVB-500). Colonies were stained and absorbance was obtained to calculate relative cell survival using Graph Pad Prism. In vivo studies were performed using NOD-SCID mice injected with 1 × 107 ARK1 cells intraperitoneally followed by treatment q3 days for 14-day treatment period. Treatment groups were vehicle control, AVB-500 alone, olaparib alone and olaparib with AVB-500. Results: ARK1 and ARK4 cells were found to have an increase in gamma-H2AX and RAD51 foci after radiation that was consistent with HRP. In clonogenic assays, colonies were stained and absorbance was obtained for each experimental arm. Olaparib + AVB-500 had significantly less absorbance than the olaparib only group for ARK1s (0.417nm vs 0.756nm, p=0.001) as well as in ARK4s (0.186nm vs 0.641nm, p=0.003). In an intraperitoneal model with ARK1 tumors, the olaparib + AVB-500 treated group had less tumor weight than those treated with olaparib alone (0.008g vs 0.138g, p=0.002) and AVB-500 alone (0.008g vs 0.145g, p=0.0006) after a 14-day treatment period. Conclusions: AVB-500 in combination with olaparib demonstrates an improved response than olaparib alone with a greater decrease in tumor burden. This was demonstrated in two HRP cell lines. Additional therapeutic and mechanistic experiments are ongoing.

Citation Format: Michael D. Toboni, Mary Mullen, Jo'an Tankou, Hollie Noia, Alyssa Oplt, Daniel Wilke, Dineo Khabele, Lindsay Kuroki, Andrea Hagemann, Carolyn McCourt, Premal Thaker, David Mutch, Matthew Powell, Katherine Fuh. AVB-500, a receptor tyrosine kinase AXL inhibitor, improves response to olaparib in uterine serous cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PO047.

Abstract PR004: Multi-dimensional biomarker analyses identify pembrolizumab responders in advanced stage, high grade endometrial cancer

Objectives: The recent FDA approval of pembrolizumab for the treatment of recurrent, tissue agnostic cancers with Microsatellite Instability-High (MSI-H) or Mismatch Repair Deficient (dMMR) has led to the treatment of a selected cohort of endometrial cancer (EC) patients. Methods: We designed a study to ascertain tumor immune modulatory effects of pembrolizumab in the front-line setting for advanced stage III/IV surgically-resectable endometrial cancers regardless of MSI-H or dMMR status. The primary objectives were to determine the safety of treatment with pembrolizumab by radiographic imaging and to determine progression-free survival at 6 months. Exploratory objective was to compare the immune response before and after treatment. In an open label, single-arm Phase I trial, 8 EC patients were treated with 2 doses of preoperative pembrolizumab IV prior to surgery followed by carboplatin and paclitaxel and 4 doses of pembrolizumab 200mg/kg q3 weeks IV. Peripheral blood was collected from EC patients at baseline level before treatment and post 2 doses of pembrolizumab treatment. Blood from healthy controls (HC) was also collected. Both were processed for high-dimensional single-cell mass cytometry (CyTOF) using an optimized lymphoid and myeloid panel. Results: Patients who responded to therapy showed lower frequency of circulating CD8+ naïve T cells but higher frequency of CD8+ effector T cells after the treatment than the poor responders. We observed post-therapy expansion of populations of CD8+ and CD4+ T cells expressing co-stimulatory receptor ICOS in responders but not in poor responders. Granzyme+CD8+ and Granzyme+CD4+ T cell populations were expanded after pembrolizumab treatment in responders but were decreased in poor responders. Higher frequency of CD27+Fas- CD4+ T cells at baseline and increased frequency of CD27-Fas+CD4+ T cells post-treatment were observed in responders but not in the poor responders. Furthermore, we identified that circulating MDSCs were reduced after pembrolizumab treatment in responders. Conclusions: Our results suggest that peripheral blood analysis may provide valuable insights into responses to anti-PD-1-targeted therapies in patients with endometrial cancers.

Citation Format: Katherine Fuh, Elena Lomonosova, Russell Pachynski, Olga Malkova, Stephen Oh, Andrea Hagemann, Carolyn McCourt, Matthew Powell, Wendy Fantl, Premal Thaker. Multi-dimensional biomarker analyses identify pembrolizumab responders in advanced stage, high grade endometrial cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference: Endometrial Cancer: New Biology Driving Research and Treatment; 2020 Nov 9-10. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(3_Suppl):Abstract nr PR004.

Use of the Cutaneous Lupus Disease Area and Severity Index as an outcome measure in clinical trials: a descriptive study

This study summarizes the use, since its inception, of the Cutaneous Lupus Disease Area and Severity Index (CLASI) as an outcome measure in clinical studies. We systematically searched the MEDLINE, PubMed, EMBASE and Cochrane databases for papers including the term 'cutaneous lupus disease area and severity index' and its abbreviations up to August 2017, identifying 205 abstracts. Following shortlisting, two independent physicians critically reviewed 71 papers for data extraction. We found that a limited number of high-quality studies used the CLASI scoring as an outcome measure. We concluded that further validation is necessary to identify the effectiveness of the CLASI in the assessment of cutaneous lupus erythematosus subtypes. The use of standardized core patient- and physician-reported outcome measures may reduce heterogeneity and allow comparisons between patients enrolled in clinical trials. This would improve the relevance within clinical practice, where the use of CLASI is currently limited.

Abstract A13: Therapeutic AXL inhibition with AVB-S6-500 improves response to chemotherapy and induces a homologous recombination deficiency in ovarian cancer

Background: Over 80% of patients with advanced ovarian cancer will develop chemoresistance and die within 5 years. Biomarkers to predict chemoresponse and novel therapies to target chemoresistance would be practice changing. We aim to establish serum and tissue GAS6 as predictive biomarkers of chemoresponse and to determine if AXL inhibition through sequestration of its ligand, GAS6, with AVB-S6-500 (AVB) can improve chemoresponse. Further, we desired to understand the affect AVB has on DNA damage response (DDR).

Methods: AVB was supplied by Aravive Biologics. High-grade serous ovarian cancer (HGSOC) tumor samples were obtained pre- and post-neoadjuvant chemotherapy. AXL and GAS6 expression were evaluated by immunohistochemistry and serum concentration. In vitro viability and clonogenic assays were performed on chemoresistant tumor cells (OVCAR8, OVCAR5, COV62, and POV71-hTERT) treated with chemotherapy +/- AVB. Mouse models (OVCAR8, PDX, OVCAR5) were used to determine if the combination of chemotherapy + AVB reduced tumor burden. Immunofluorescent (IF) assays targeting γH2AX were used to evaluate DNA damage and additional assays targeting 53BP1, RAD51, BRCA1, and BRCA2 were used to evaluate DNA damage response in cells treated with AVB, carboplatin, and/or AVB+carboplatin. Flow cytometry was used to evaluate RPA binding and cell cycle.

Results: Patients with high pretreatment tumor GAS6 expression (&gt;85%, n=7) or serum GAS6 concentrations (&gt;25ng/mL, n=13) were more likely to be resistant to neoadjuvant chemotherapy than those with low tumor GAS6 expression (&lt;45%, n=4) (P=0.010) or low serum GAS6 concentrations (&lt;15ng/mL, n=5) (P=0.002). Carboplatin plus AVB (2μM, 5μM) and paclitaxel plus AVB (1μM) resulted in decreased cell viability and clonogenic growth compared to chemotherapy alone (p&lt;0.05) in all tumor cell lines. In vivo tumor mouse models treated with chemotherapy+AVB had significantly smaller subcutaneous and intraperitoneal (IP) tumors than those treated with chemotherapy alone (P&lt;0.001). Increased DNA damage occurred in tumor cells treated with AVB than controls and in tumor cells treated with carboplatin+AVB than carboplatin alone (OVCAR8, COV362, CAOV3, OVCAR3-TPMES P&lt;0.001). Cells treated with AVB either alone or in combination with carboplatin demonstrated decreased binding of protein involved in homologous recombination including RPA, RAD51, BRCA1, and BRCA2 (P&lt;0.05). Conversely, these same cells demonstrated increased binding of the nonhomologous end joining protein 53BP1 (P&lt;0.05). There were no differences in cell cycle among the treatment groups.

Conclusions: High GAS6 is associated with poor neoadjuvant chemoresponse in HGSOC patients. The combination of chemotherapy with AVB decreases tumor cell viability and tumor growth. AVB imparts a homologous recombination deficiency through downregulation of homology-directed DNA repair with an associated upregulation of nonhomologous end joining.

Citation Format: Mary Margaret Mullen, Elena Lomonosova, Hollie Noia, Daniel Wilke, Alyssa Oplt, Lei Guo, Lindsay Kuroki, Andrea Hagemann, Carolyn McCourt, Premal Thaker, David Mutch, Matthew Powell, Katherine Fuh. Therapeutic AXL inhibition with AVB-S6-500 improves response to chemotherapy and induces a homologous recombination deficiency in ovarian cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Ovarian Cancer Research; 2019 Sep 13-16, 2019; Atlanta, GA. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(13_Suppl):Abstract nr A13.

Histogram analysis of en face scattering coefficient map predicts malignancy in human ovarian tissue

Ovarian cancer is a heterogeneous disease at the molecular and histologic level. Optical coherence tomography (OCT) is able to map ovarian tissue optical properties and heterogeneity, which has been proposed as a feature to aid in diagnosis of ovarian cancer. In this manuscript, depth-resolved en face scattering maps of malignant ovaries, benign ovaries, and benign fallopian tubes obtained from 20 patients are provided to visualize the heterogeneity of ovarian tissues. Six features are extracted from histograms of scattering maps. All features are able to statistically distinguish benign from malignant ovaries. Two prediction models were constructed based on these features: a logistic regression model (LR) and a support vector machine (SVM). The optimal set of features is mean scattering coefficient and scattering map entropy. The LR achieved a sensitivity and specificity of 97.0% and 97.8%, and SVM demonstrated a sensitivity and specificity of 99.6% and 96.4%. Our initial results demonstrate the feasibility of using OCT as an "optical biopsy tool" for detecting the microscopic scattering changes associated with neoplasia in human ovarian tissue.

Effects of oral probiotic supplements on vaginal microbiota during pregnancy: a randomised, double-blind, placebo-controlled trial with microbiome analysis

Objective

To determine the effects on the vaginal microbiota of an oral probiotic preparation administered from early pregnancy.

Design

Randomised, double blind, placebo‐controlled trial.

Setting

Four maternity units in the UK.

Population

Women aged 16 years or older recruited at 9–14 weeks' gestation.

Methods

Participants were randomly allocated to receive oral capsules of probiotic containing Lactobacillus rhamnosus GR‐1 and Lactobacillus reuteri RC‐14 each at 2.5 × 10⁹ colony‐forming units (CFUs) or placebo once daily from recruitment until the end of pregnancy.

Main outcome measure

Rates of bacterial vaginosis (BV, defined as Nugent score ≥7) at 18–20 weeks' gestation compared by logistic regression adjusted for possible confounders.

Results

The primary analysis included 78% (238/304) of participants who initially consented (probiotic group 123, placebo group 115). Of these participants, 95% (227/238) reported an intake of 93% or more of the required number of capsules. The rates of BV did not differ between groups at 18–20 weeks' gestation (15% (19/123) in the probiotic group vs. 9% (10/115) in the placebo group, adjusted odds ratio 1.82, 95% confidence interval 0.64–5.19). There were also no differences between the groups in the proportion of women colonised with the probiotic strains, Escherichia coli, group B streptococci or other vaginal microbiota. There were no differences in the alpha diversity or composition of the bacterial communities between or within the probiotic and placebo groups at 9–14 and 18–20 weeks’ gestation.

Conclusions

Oral probiotics taken from early pregnancy did not modify the vaginal microbiota.

Tweetable abstract

The oral probiotic preparation used in this study does not prevent BV in pregnant women.

The oral probiotic preparation used in this study does not prevent BV in pregnant women.

SQ1274, a novel microtubule inhibitor, inhibits ovarian and uterine cancer cell growth

OBJECTIVE

Paclitaxel, a microtubule inhibitor, is subject to tumor resistance while treating high-grade serous ovarian and uterine cancer. This study aims to directly compare the effects of SQ1274, a novel microtubule inhibitor that binds to the colchicine-binding site on tubulin, and paclitaxel in high-grade serous ovarian and uterine cancer cell lines both in vitro and in vivo.

METHODS

We assessed the sensitivity of ovarian (OVCAR8) and uterine (ARK1) cancer cell lines to SQ1274 and paclitaxel using XTT assays. We used western blot and quantitative real-time PCR to analyze changes in AXL RNA and protein expression by SQ1274 and paclitaxel. Differences in cell-cycle arrest and apoptosis were investigated using flow cytometry. Finally, we treated ovarian and uterine xenograft models with vehicle, paclitaxel, or SQ1274.

RESULTS

First, we demonstrate that SQ1274 has a much lower IC₅₀ than paclitaxel in both ARK1 (1.26 nM vs. 15.34 nM, respectively) and OVCAR8 (1.34 nM vs. 10.29 nM, respectively) cancer cell lines. Second, we show SQ1274 decreases both RNA and protein expression of AXL. Third, we show that SQ1274 causes increased cell-cycle arrest and apoptosis compared to paclitaxel. Finally, we report that SQ1274 more effectively inhibits tumor growth in vivo compared to paclitaxel.

CONCLUSIONS

SQ1274 presents as a viable alternative to paclitaxel for treating ovarian and uterine cancer. This study supports the development of SQ1274 as a chemotherapeutic to treat ovarian and uterine cancer.

Abstract 4034: Inhibition of AXL improves response to platinum and taxane in chemotherapy-resistant uterine and ovarian cancers

AXL expression has been associated with decreased survival in uterine serous cancer (USC) and high-grade ovarian serous cancer (HGSOC). We determined whether therapeutic inhibition of AXL with BGB324, which is in Phase I/II clinical trials for solid tumors, would improve chemotherapy response in chemotherapy resistant uterine and ovarian cancers.

Taxane and platinum resistant ovarian and uterine cancer cell lines were used for in vitro cell viability (XTT) assays. Selective small molecule inhibition of AXL was achieved using BGB324. Western blotting was used to detect protein expression and activation. Tritium-labeled paclitaxel was utilized to measure chemotherapy accumulation in cancer cells. In vivo subcutaneous models were performed with the USC cell line ARK1 and patient-derived HGSOC xenografts (PDX). Statistical significance (p&lt;0.05) and IC50 determination was assessed using Prism7.

Upon AXL inhibition by BGB324, the HGSOC cell lines OVCAR5, OVCAR3TP, and OVCAR3TPMes demonstrated a dose-dependent sensitization to paclitaxel and carboplatin chemotherapy. BGB324 treatment of OVCAR3TPMes cells improved response to carboplatin from untreated (IC50 of 73uM) to IC50 of 66uM, 51uM and 31uM at 0.25uM, 0.5uM, and 1uM, respectively (p&lt;0.01). Similarly, paclitaxel response improved from untreated (IC50 of 15.4nM) to IC50 of 13.0nM, 11.3nM and 9.8nM at 0.25uM, 0.5uM, and 1uM, respectively (p&lt;0.05).

To assess the dynamics of this chemoresponse, ARK1 USC cells were pre-treated with 0.5uM BGB324 and 1.0uM BGB324 and demonstrated a 31% and 43% increase in intracellular 3H-paclitaxel accumulation, respectively, when compared to cells without AXL inhibition (p&lt;0.05). RT-PCR was utilized to detect changes in multidrug resistance protein transcripts; mRNA levels of P-Glycoprotein (PGP) had a 6.3-fold reduction in OVCAR3TPMES cells treated with 1uM BGB324 (p&lt;0.05). This suggests that inhibition of AXL contributes to chemoresistance by increasing exposure of paclitaxel in tumor cells. The combination of paclitaxel and BGB324 therapy decreased USC tumor volume by 51-67% when compared to treatment with paclitaxel, BGB324, or vehicle control alone (p&lt;0.05). In PDX models, BGB324 therapy improved tumor response with combined carboplatin and paclitaxel therapy when compared to chemotherapy alone, inhibitor alone, or vehicle control (77%, 87%, and 88% decrease in tumor volume at day 11, respectively, p&lt;0.0001).

AXL expression contributes to platinum and taxane chemoresistance, and therapeutic inhibition of AXL with BGB324 restores chemosensitivity in ovarian and uterine cancer cell lines and patient derived xenograft models. Based on this data, chemoresistant tumors with AXL expression could be considered for treatment with BGB324 to restore chemosensitivity to carboplatin and paclitaxel.

Citation Format: Jeanne Quinn, Marguerite Palisoul, Lei Guo, Andrea Hagemann, Matthew Powell, David Mutch, Carolyn McCourt, Premal Thaker, Katherine Fuh. Inhibition of AXL improves response to platinum and taxane in chemotherapy-resistant uterine and ovarian cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4034.

Moving forward with actionable therapeutic targets and opportunities in endometrial cancer: A NCI clinical trials planning meeting report

The incidence of endometrial cancer (EC) in the U.S. has been rising, from an estimated annual incidence of 49,560 in 2013 to 61,380 in 2017. Meanwhile, the SEER-based relative survival of women with EC in the U.S. has remained flat [82.3% from 1987 to 1989, 82.8% from 2007 to 2013] and our recent increased understanding of EC biology and subtypes has not been translated into therapeutic advances. The U.S. National Cancer Institute (NCI) therefore convened a Uterine Clinical Trials Planning Meeting in January 2016 to initiate and accelerate design of molecularly-targeted EC trials. Prior to the meeting a group of experts in this field summarized available data, emphasizing data on human samples, to identify potentially actionable alterations in EC, and the results of their work has been separately published. The Clinical Trials Meeting planners focused on discussion of (1) novel trial designs, including window-of opportunity trials and appropriate control groups for randomized trials, (2) targets specific to serous carcinoma and promises and pitfalls of separate trials for women with tumors of this histology (3) specific recommendations for future randomized trials.

Abstract AP18: FUNCTIONAL GENOMIC SCREEN FOR ATTACHMENT AND INVASION IN METASTATIC OVARIAN CANCER

PURPOSE: To perform a biologically relevant functional genomic screen for genes involved in attachment and early invasion incorporating tumor microenvironment cells cultured from human omentum.

METHODS: Primary fibroblasts cultured from the human omentum were plated as one component to recapitulate the tumor microenvironment. An arrayed small interfering RNA (siRNA) panel targeting 719 genes encoding kinases was used. Each well contained 2 oligos per gene. Three ovarian cancer cells with known metastatic capabilities (OVCAR8, ES2, and A2780) were selected and stably labeled with GFP. Following exposure to siRNA, ovarian cancer cells are overlaid upon a mixed submesothelial matrix (NOFs, collagen I, and fibronectin). After 72 hours of attachment/early invasion, a wash step was performed, and the functional readout of the intensity of fluorescence was performed. Cell death due to the siRNA was evaluated by staining with resazurin. Data was analyzed by expressing the effect of increased or decreased attachment using the median average deviation (MAD).

RESULTS: MAD values were generated for each gene. A baseline MAD value of 0 was used and positive MAD values denoted genes that influenced an increase in adhesion when knocked down whereas negative values represented genes that had decreased adhesion when knocked down. Negative controls for adhesion/early invasion were used and found to have a MAD value of 0.52 for mock transfection reagent control and 2.45 for siNEG control. Positive controls for adhesion/early invasion had a MAD value of -6.13 for siB1- integrin and -8.91 for a known inhibitor of attachment – canthardin. The transfection efficiency control, siDEATH, had a MAD value of -8.8. Of the 719 genes encoding kinases, we found 17 genes with MAD values above +3 and 19 genes with MAD values below -3. Of these hits, JAK1 and Wee1 were identified. JAK1 has been found to contribute to ovarian cancer invasion, migration, and metastasis in preclinical models. Wee1 is involved in cell cycle progression, and a Wee1 inhibitor is currently in a Phase II trial in relapsed ovarian cancer. Both targets confirm that biologically-relevant genes can be identified through this screen by incorporating stromal cells cultured from human omentum. Additionally, across 3 cell lines, we identified kinases that overlapped in at least 2 cell lines with a MAD lower range of -1.85. There were 94 kinases identified: 9 with a role in adhesion, 7 in immune response, 17 in proliferation, 6 in apoptosis, 16 in metabolism, 33 in cell cycle, 2 in migration, 3 in ribosomal, 1 in autophagy, and 23 genes with overlapping functions.

CONCLUSIONS: By incorporating the tumor microenvironment into a functional genomic screen, biologically relevant genes for ovarian cancer cell attachment and early invasion can be identified and will be validated as potential novel therapeutic targets.

Citation Format: Katherine Fuh, Anne Gibson, Daniel Wilke, Maxene Ilagan, Andrea Hagemann, Carolyn McCourt, Premal Thaker, David Mutch, Matthew Powell, and Gregory Longmore. FUNCTIONAL GENOMIC SCREEN FOR ATTACHMENT AND INVASION IN METASTATIC OVARIAN CANCER [abstract]. In: Proceedings of the 11th Biennial Ovarian Cancer Research Symposium; Sep 12-13, 2016; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2017;23(11 Suppl):Abstract nr AP18.

AKT in cancer: new molecular insights and advances in drug development

The phosphatidylinositol-3 kinase (PI3K)-AKT pathway is one of the most commonly dysregulated pathways in all of cancer, with somatic mutations, copy number alterations, aberrant epigenetic regulation and increased expression in a number of cancers. The carefully maintained homeostatic balance of cell division and growth on one hand, and programmed cell death on the other, is universally disturbed in tumorigenesis, and downstream effectors of the PI3K-AKT pathway play an important role in this disturbance. With a wide array of downstream effectors involved in cell survival and proliferation, the well-characterized direct interactions of AKT make it a highly attractive yet elusive target for cancer therapy. Here, we review the salient features of this pathway, evidence of its role in promoting tumorigenesis and recent progress in the development of therapeutic agents that target AKT.

Beta-blocker usage after malignant melanoma diagnosis and survival: a population-based nested case-control study

BACKGROUND

Beta-blockers have potential antiangiogenic and antimigratory activity. Studies have demonstrated a survival benefit in patients with malignant melanoma treated with beta-blockers.

OBJECTIVES

To investigate the association between postdiagnostic beta-blocker usage and risk of melanoma-specific mortality in a population-based cohort of patients with malignant melanoma.

METHODS

Patients with incident malignant melanoma diagnosed between 1998 and 2010 were identified within the U.K. Clinical Practice Research Datalink and confirmed using cancer registry data. Patients with malignant melanoma with a melanoma-specific death (cases) recorded by the Office of National Statistics were matched on year of diagnosis, age and sex to four malignant melanoma controls (who lived at least as long after diagnosis as their matched case). A nested case-control approach was used to investigate the association between postdiagnostic beta-blocker usage and melanoma-specific death and all-cause mortality. Conditional logistic regression was applied to generate odds ratios (ORs) and 95% confidence intervals (CIs) for beta-blocker use determined from general practitioner prescribing.

RESULTS

Beta-blocker medications were prescribed after malignant melanoma diagnosis to 20·2% of 242 patients who died from malignant melanoma (cases) and 20·3% of 886 matched controls. Consequently, there was no association between beta-blocker use postdiagnosis and cancer-specific death (OR 0·99, 95% CI 0·68-1·42), which did not markedly alter after adjustment for confounders including stage (OR 0·87, 95% CI 0·56-1·34). No significant associations were detected for individual beta-blocker types, by defined daily doses of use or for all-cause mortality.

CONCLUSIONS

Contrary to some previous studies, beta-blocker use after malignant melanoma diagnosis was not associated with reduced risk of death from melanoma in this U.K. population-based study.