Functional homologous recombination repair.

OBJECTIVE:Cytotoxic chemotherapy for ovarian cancer can be augmented by co-administration of vascular endothelial growth factor inhibitors but these are contraindicated in patients with bowel obstruction due to the risk of gastrointestinal perforation. We evaluated the safety and feasibility of paclitaxel plus cediranib to treat patients with platinum-resistant ovarian cancer at risk of malignant bowel obstruction. METHODS:A phase II trial included eligible patients between March 2018 and February 2021, identified by clinical symptoms and radiographic risk factors for malignant bowel obstruction. Cediranib (20 mg/day) was added to paclitaxel (70 mg/m2/week) within 9 weeks of starting paclitaxel if pretreatment bowel symptoms had improved. The primary endpoint was the number of patients treated for ≥5 days with cediranib that were free of grade 3-5 gastrointestinal perforation or fistula. Secondary endpoints were hospitalization for bowel obstruction, grade ≥3 adverse events, treatment compliance assessed by relative dose intensity, objective response, progression-free survival, and overall survival. RESULTS:Thirty patients were recruited. Of these, 12 received paclitaxel alone and 17 received paclitaxel and cediranib in combination. One patient died before starting treatment. No patient developed a grade 3-5 gastrointestinal perforation or fistula (one sided 95% confidence interval (CI) upper limit 0.16). One patient required hospitalization for bowel obstruction but recovered with conservative management. The most common cediranib-related grade ≥3 adverse events were fatigue (3/17), diarrhorea (2/17), and hypomagnesemia (2/17). Relative dose intensity for paclitaxel was 90% (interquartile range (IQR) 85-100%; n=29) and for cediranib 88% (IQR 76-93%; n=17). The objective response in patients who received paclitaxel and cediranib was 65.0% (one complete and 10 partial responses). Median progression-free survival was 6.9 months (95% CI 4.4-11.5 months; n=17) and overall survival was 19.4 months (95% CI 10.1-20.4 months; n=17). Median follow-up was 12.4 months (8.9-not reached; n=17). CONCLUSIONS:The unexpectedly high withdrawal rate during paclitaxel alone, before introducing cediranib, meant we were unable to definitely conclude that paclitaxel plus cediranib did not cause gastrointestinal perforation or fistula. The regimen was however tolerated. TRIAL REGISTRATION NUMBER:EudraCT 2016-004618-93.

Abstract Purpose: A single maintenance course of a PARP inhibitor (PARPi) improves progression-free survival (PFS) in germline BRCA1/2-mutant high-grade serous ovarian cancer (gBRCAm-HGSOC). The feasibility of a second maintenance course of PARPi was unknown. Patients and Methods: Phase II trial with two entry points (EP1, EP2). Patients were recruited prior to rechallenge platinum. Patients with relapsed, gBRCAm-HGSOC were enrolled at EP1 if they were PARPi-naïve. Patients enrolled at EP2 had received their first course of olaparib prior to trial entry. EP1 patients were retreated with olaparib after RECIST complete/partial response (CR/PR) to platinum. EP2 patients were retreated with olaparib ± cediranib after RECIST CR/PR/stable disease to platinum and according to the platinum-free interval. Co-primary outcomes were the proportion of patients who received a second course of olaparib and the proportion who received olaparib retreatment for ≥6 months. Functional homologous recombination deficiency (HRD), somatic copy-number alteration (SCNA), and BRCAm reversions were investigated in tumor and liquid biopsies. Results: Twenty-seven patients were treated (EP1 = 17, EP2 = 10), and 19 were evaluable. Twelve patients (63%) received a second course of olaparib and 4 received olaparib retreatment for ≥6 months. Common grade ≥2 adverse events during olaparib retreatment were anemia, nausea, and fatigue. No cases of MDS/AML occurred. Mean duration of olaparib treatment and retreatment differed (12.1 months vs. 4.4 months; P < 0.001). Functional HRD and SCNA did not predict PFS. A BRCA2 reversion mutation was detected in a post-olaparib liquid biopsy. Conclusions: A second course of olaparib can be safely administered to women with gBRCAm-HGSOC but is only modestly efficacious. See related commentary by Gonzalez-Ochoa and Oza, p. 2563

Rationale: Referrals for home parenteral nutrition (HPN) in advanced cancer are increasing. Advanced ovarian cancer (AOC) accounts for 30% cases of malignant bowel obstruction (MBO). Current ESPEN and BIFA (British Intestinal Failure Association) guidance suggests patients with ECOG performance status (PS) > 2, albumin >32 and CRP < 10 are useful markers for predicting survival benefit and candidacy for HPN. Aim was to assess whether current guidance accurately predicts survival benefit in AOC with inoperable MBO.

Background: Despite advances in immunotherapy and targeted therapy, platinum-based chemotherapy remains crucial for many patients with advanced non-small cell lung cancer (NSCLC). Resistance to platinum chemotherapy is common, and predictive biomarkers are needed to tailor treatment to patients likely to respond. In vitro evidence implicates the transforming growth factor-β (TGF-β) superfamily ligands activin-A and growth differentiation factor 11 (GDF-11) in innate platinum resistance. We performed a validation study to assess their utility as predictive biomarkers of platinum chemotherapy response in advanced NSCLC. Patients and Methods: Our study included 123 adult patients with advanced NSCLC without a driver mutation treated with platinum chemotherapy. 98 patients were from a retrospective cohort and 25 from a prospective cohort. We performed immunohistochemistry staining for Activin-A, GDF-11 and TGF-β on tumour samples for each patient and analysed IHC expression with objective radiological response and overall survival. Results: The overall median survival was 14.8 months. We performed statistical analysis around a cytoplasmic score of 8/18 for Activin-A and GDF-11 based on previously published work, and 110/30 for TGF-β based on a calculated cutpoint for significance. No survival difference was detected between these groups for Activin-A (p=0.35), GDF-11 (p=0.57) or TGF-β (p=0.34). There was no association between rates of progressive disease and high Activin-A expression (p=0.43), high GDF-11 expression (p=1.0) or high TGF-β expression p=0.89). Conclusion: Within the confines of our study, Activin-A, GDF-11 and TGF-β expression was not a predictor of objective radiological response to chemotherapy or overall survival.

INTRODUCTION:Bevacizumab improves survival outcomes in women diagnosed with epithelial ovarian cancer (EOC). Pre-clinical data showed that the c-MET/VEGFR-2 heterocomplex negates VEGF inhibition through activation of c-MET signalling, leading to a more invasive and metastatic phenotype. We evaluated the clinical significance of c-MET and VEGFR-2 co-localisation and its association with VEGF pathway-related single nucleotide polymorphisms (SNPs) in women participating in the phase 3 trial, ICON7 (ClinicalTrials.gov identifier: NCT00262847). MATERIALS AND METHODS:Patients had FIGO stage I-IIA grade 3/poorly differentiated or clear cell carcinoma or stage IIB-IV epithelial ovarian, primary peritoneal or fallopian tube cancer. Immunofluorescence staining for co-localised c-MET and VEGFR-2 on tissue microarrays and genotyping of germline DNA from peripheral blood leukocytes for VEGFA and VEGFR-2 SNPs was performed. The significance of these biomarkers was assessed against survival. RESULTS:Tissue microarrays from 178 women underwent immunofluorescence staining. Multivariable analysis showed that greater c-MET/VEGFR-2 co-localisation predicted worse OS in patients treated with bevacizumab after adjusting for FIGO stage and debulking surgery outcome (hazard ratio [HR] 1.034, 95% confidence interval [95%CI] 1.010-1.059). Women in the c-MET/VEGFR-2HIGH group treated with bevacizumab demonstrated significantly reduced OS (39.3 versus > 60 months; HR 2.00, 95%CI 1.08-3.72). Germline DNA from 449 women underwent genotyping. In the bevacizumab group, those women with the VEGFR-2 rs2305945 G/G variant had a trend towards shorter PFS compared with G/T or T/T variants (18.3 versus 23.0 months; HR 0.74, 95%CI 0.53-1.03). CONCLUSIONS:In bevacizumab-treated women diagnosed with EOC, high c-MET/VEGFR-2 co-localisation on tumour tissue and the VEGFR-2 rs2305945 G/G variant, which may be biologically related, were associated with worse survival outcomes.

Introduction/Background Systemic treatment of platinum-resistant advanced ovarian cancers (PROC) utilises cytotoxic chemotherapy and vascular endothelial growth factor receptor (VEGFR) inhibitors. However, patients at risk for malignant bowel obstruction (MBO) are excluded from this efficacious combination due to risk of bowel perforation. Methodology We conducted a Simon’s two-stage trial combining oral VEGFR inhibitor cediranib (20 mg/day) with weekly paclitaxel (70 mg/m2), in participants with recurrent PROC and clinical and/or radiological features indicating an increased risk of developing MBO. Primary endpoint was number of patients free of grade 3–5 gastrointestinal perforation (GIP) or fistula, from those who received ≥5 days and ≤18 weeks cediranib, causally related to cediranib. With 90% power and 5% significance, 24 evaluable patients were required, with 22 free of GIP or fistula to demonstrate safety. Cediranib could start with chemotherapy, or at cycle 2 or 3, once bowel symptoms were CTCAE grade ≤2. Previous bevacizumab exposure and prior MBO were permitted. Patients were continued on cediranib maintenance after paclitaxel completion, and optionally proceeded to cediranib plus olaparib (300 mg bd) at disease progression. Results 30 participants were enrolled from March 2018 to February 2021. 90% ECOG 0–1, 97% had symptoms showing risk of bowel obstruction. 1 patient died before any treatment. 12 received paclitaxel only (bowel symptoms didn’t improve or deterioration) and subsequently progressed. 17 patients were evaluable for primary endpoint; none developed GIP or fistula. Three cediranib+paclitaxel participants developed bowel obstruction (any grade; including one receiving cediranib+olaparib). Three participants had grade 3+ SAEs causally related to cediranib+/-olaparib (one diarrhoea; one diarrhoea and TIA; one vomiting). Median progression-free survival was 5.4 months (95%CI: 4.18–8.25), and overall survival 15.2 months (95%CI: 8.52–20.5). Conclusion There is no evidence that combining cediranib and taxane chemotherapy is associated with serious toxicity or of developing GIP/fistula, although this is underpowered due to participant withdrawal.

IntroductionTreatment with immunotherapy (IO) has lead to improvements in survival for patients with advanced lung cancer (ALC) but robust predictive biomarkers remain elusive. Single cell genomics provides an opportunity to study cellular profiles in exceptional detail. Novel transcriptomic (scRNA-seq) including VDJ sequencing, allow evaluation of cellular responses to IO in real-time, providing an opportunity for a predictive test.MethodsFine needle aspirates taken from patients with ALC are exposed to IO or control invitro. Cells are collected, captured and sequenced using the 5’ VDJ kit (10X Genomics). Cellular subtypes are delineated and phenotyped using Seurat software. Comparisons between the control and treated conditions are conducted. Immunoactivation is easure and correlated with patient response.ResultsConclusionUsing scRNA-seq with VDJ sequencing, the functional capacity of effector cells can be ascertained within the tumour microenvironment and immune cell responses to immunotherapy can be measured. Single cell sequencing has the potential to be used as a functional, predictive assay for treatment with IO.Keywordssingle cell sequencing, Immunotherapy, biomarker IntroductionTreatment with immunotherapy (IO) has lead to improvements in survival for patients with advanced lung cancer (ALC) but robust predictive biomarkers remain elusive. Single cell genomics provides an opportunity to study cellular profiles in exceptional detail. Novel transcriptomic (scRNA-seq) including VDJ sequencing, allow evaluation of cellular responses to IO in real-time, providing an opportunity for a predictive test.

Lung cancer is the leading cause of cancer death in Australia with 13,000 new cases per year. Although targeted therapy and immunotherapy have drastically changed the treatment landscape, the majority of patients will receive platinum-based chemotherapy for which the response rate is approximately 30% (Reck et al, 2016). An immunohistochemistry-based, predictive biomarker would be beneficial for patients and help avoid toxicity for patients unlikely to respond. 3 potential biomarkers identified in a paper by Marini et al (2018) – activin A, growth differentiation factor-11 (GDF-11) and transforming growth factor-b (TGF-B) –were investigated in a real-world retrospective cohort to determine their relation to objective radiological response and overall survival (Marini et al, 2018).

Advanced epithelial ovarian, fallopian tube and primary peritoneal cancers (EOC) are a leading cause of gynaecological cancer-associated mortality and angiogenesis plays a key role in their growth. Vascular endothelial growth factor inhibitors (VEGFi) disrupt angiogenesis and improve the response rate, progression-free survival and in some cases, overall survival, when administered with and following cytotoxic chemotherapy, irrespective of the platinum sensitivity of EOC. Recent data have identified new indications for VEGFi in EOC: repeated exposure to VEGFi in the first- and then second-line treatment has sustained clinical efficacy; combinations of VEGFi with poly (ADP-ribose) polymerase inhibitors (PARPi) have proven effective as first-line or second-line maintenance regimens. However, recent trial data have not shown improved outcomes with combinations of VEGFi and immune checkpoint inhibitors. There remains a critical need to optimise patient selection for these effective yet somewhat toxic and expensive treatments. The search continues for validated biomarkers to optimise the use of VEGFi, of which the most promising at present is plasma Tie2. Based upon these studies, we propose a model of care incorporating VEGFi into the treatment of EOC, highlighting the need to change from the prescription of single courses of VEGFi, to allow use and re-use as clinically indicated.

Relapsed, platinum-sensitive high-grade serous ovarian carcinoma (RPS-HGSOC) is treated with platinum re-challenge. One course of olaparib maintenance monotherapy (OLAP1) improves PFS in RPS-HGSOC. It is unclear whether a second olaparib maintenance monotherapy course (OLAP2) in RPS-HGSOC following platinum re-challenge (PLAT2) is feasible.

e21737 Background: Lung cancer is the leading cause of cancer death in Australia with 13,000 new cases per year. Although targeted therapy and immunotherapy have drastically changed the treatment landscape, the majority of patients will receive platinum-based chemotherapy for which the response rate is approximately 30% (Reck et al, 2016). An immunohistochemistry-based, predictive biomarker would be beneficial for patients and help avoid toxicity for patients unlikely to respond. Marini et al (2018) identified 3 biomarkers associated with in-vitro platinum resistance – activin A, growth differentiation factor-11 and transforming growth factor-b – which were investigated in a real-world retrospective cohort to determine their relation to objective radiological response and overall survival. Methods: We identified 101 patients with advanced non-small cell lung cancer who received platinum chemotherapy at 2 cancer centres between 2014-2015. Archival formalin-fixed paraffin embedded tissue samples were stained with activin A. Slides were manually scored by 2 independent clinicians using the multiplicative quickscore method (Detre et al, 1995). Kaplan Meier analysis for overall survival, a Cox-proportional hazards model for confounding variables and a chi-square analysis was performed to analyse the relationship between high immunohistochemistry scores (greater or less than 6) and radiological response. Results: We performed statistical analysis around the median cytoplasmic score (6). The overall median survival was 15.3 months. No significant difference in survival was detected between the two populations (p value = 0.97). The immunohistochemistry score was also not associated with rates of partial response (p value = 0.98) or progressive disease (p value 0.22). Conclusions: Despite an association with lower progression-free survival in a retrospective cohort in a previous study, high expression of activin does not appear to be a useful biomarker for platinum response in the setting of non-small cell lung cancer. Further research into associated antibodies including GDF-11 and TGF-b is in progress.

The identification of clinically viable strategies for overcoming resistance to platinum chemotherapy in lung adenocarcinoma has previously been hampered by inappropriately tailored in vitro assays of drug response. Therefore, using a pulse model that closely mimics the in vivo pharmacokinetics of platinum therapy, we profiled cisplatin-induced signalling, DNA-damage and apoptotic responses across a panel of human lung adenocarcinoma cell lines. By coupling this data to real-time, single-cell imaging of cell cycle and apoptosis we provide a fine-grained stratification of response, where a P70S6K-mediated signalling axis promotes resistance on a TP53 wildtype or null background, but not a mutant TP53 background. This finding highlights the value of in vitro models that match the physiological pharmacokinetics of drug exposure. Furthermore, it also demonstrates the importance of a mechanistic understanding of the interplay between somatic mutations and the signalling networks that govern drug response for the implementation of any consistently effective, patient-specific therapy.