Treatment patterns after poly-ADP ribose polymerase (PARP) inhibitors in epithelial ovarian cancer patients.

OBJECTIVES: The primary objective of this study was to describe treatment patterns after poly-ADP ribose polymerase (PARP) inhibitor in patients with epithelial ovarian cancer. Secondary objectives were to evaluate duration of response, time to first subsequent therapy, progression-free survival and overall survival. METHODS: This was a retrospective analysis of patients with epithelial ovarian cancer treated with PARP inhibitor therapy at six Australian gynecological oncology centers. Eligible patients were identified via clinics, trial databases and pharmacy dispensing logs between January 2005 and September 2019. Information regarding clinico-pathological characteristics and treatment outcomes were collated from medical records. RESULTS: A total of 85 patients with epithelial ovarian cancer were identified. Of these, 61% had germline BRCA1/2 mutations, 9% had somatic BRCA1/2 mutations, 5% had confirmed homologous recombination deficiency and 25% were BRCA1/2 wildtype mutations. A total of seventy-seven (91%) patients received chemotherapy after PARP inhibitor, with fifty-six (72.7%) of these patients receiving platinum-based chemotherapy. Four patients (5%) had a complete response, 15 (20%) a partial response, 15 (20%) stable disease and 41 (55%) progressive disease. Median duration of response to chemotherapy was 7.0 months (range 0.2-20.4). Median time to first subsequent therapy was 17.6 and 15.1 months in patients who received a PARP inhibitor as maintenance therapy and treatment, respectively. Median progression-free survival of first line treatment after PARP inhibitor was 9.6, 3.5 and 4.6 months for platinum doublet, single agent platinum and non-platinum chemotherapy, respectively. Adjusting for age and FIGO (Federation of Gynecological Oncologists classification) stage progression-free survival did not differ between treatment groups (p=0.14). Median overall survival for the cohort was 69 months, and patients with platinum sensitive ovarian cancer had improved survival compared with those with platinum refractory or resistant disease. CONCLUSION: Platinum doublet chemotherapy resulted in non-significant improved progression-free survival compared with other regimens, suggesting potential independent mechanisms of resistance between PARP inhibitor and platinum compounds.

Pamiparib in combination with tislelizumab in patients with advanced solid tumours: results from the dose-escalation stage of a multicentre, open-label, phase 1a/b trial.

BACKGROUND: Rationale exists for combined treatment with immune checkpoint inhibitors and poly (ADP-ribose) polymerase (PARP) inhibitors in a variety of solid tumours. This study aimed to investigate the safety and antitumour effects of pamiparib, an oral PARP 1/2 inhibitor, combined with tislelizumab, a humanised anti-PD-1 monoclonal antibody, in patients with advanced solid tumours and to determine the optimum doses for further evaluation. METHODS: We did a multicentre, open-label, phase 1a/b study at five academic sites or community oncology centres in Australia. We recruited adults (aged ≥18 years) with advanced solid tumours who had received one or more previous lines of therapy, with an Eastern Cooperative Oncology Group performance score of 1 or less, and a life expectancy of 12 weeks or more. Patients were enrolled into one of five dose-escalation cohorts, with dose-escalation done in a 3 + 3 design. Cohorts 1-3 received intravenous tislelizumab 2 mg/kg every 3 weeks plus 20, 40, or 60 mg oral pamiparib twice daily, respectively; cohorts 4 and 5 received 200 mg intravenous tislelizumab every 3 weeks plus 40 or 60 mg oral pamiparib twice daily, respectively. The primary endpoints of the phase 1a dose-escalation part of the study were safety and tolerability, including the occurrence of dose-limiting toxicities and determination of the maximum tolerated dose and recommended phase 2 dose. All primary endpoints were analysed in the safety analysis set, which included all patients who received at least one dose of tislelizumab or pamiparib, with the exception of the occurrence of dose-limiting toxicities, which was analysed in the dose-limiting toxicity analysis set, which included all patients who received at least 90% of the first scheduled tislelizumab dose and at least 75% of scheduled pamiparib doses, or who had a dose-limiting toxicity event during cycle 1. Reported here are results of the phase 1a dose-escalation stage of the trial. This trial is registered with ClinicalTrials.gov, number NCT02660034, and is ongoing. FINDINGS: Between Jan 22, 2016, and May 16, 2017, we enrolled 49 patients (median age 63 years [IQR 55-67]), all of whom received at least one dose of pamiparib or tiselzumab. Four patients had dose-limiting toxicities (intractable grade 2 nausea [n=1] and grade 3 rash [n=1] in cohort 4, and grade 2 nausea and vomiting [n=1] and grade 4 immune-mediated hepatitis [n=1] in cohort 5). The recommended phase 2 dose was tislelizumab 200 mg every 3 weeks plus pamiparib 40 mg twice daily (the dose given in cohort 4). The most common treatment-emergent adverse events were nausea (in 31 [63%] of 49 patients), fatigue (26 [53%]), diarrhoea (17 [35%]), and vomiting (15 [31%]). 23 (47%) of 49 patients had immune-related adverse events, of whom nine (39%) had asymptomatic grade 3-4 hepatic immune-related adverse events, which were reversible with corticosteroid treatment. The most common adverse event of grade 3 or worse severity was anaemia (in six [12%] patients) and no grade 5 adverse events were reported. Hepatitis or autoimmune hepatitis was the only serious adverse event to occur in two or more patients (in four [8%] patients). At a median follow-up of 8·3 months (IQR 4·8-12·8), ten (20%) of 49 patients achieved an objective response according to Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1, including two complete responses and eight partial responses. INTERPRETATION: Pamiparib with tislelizumab was generally well tolerated and associated with antitumour responses and clinical benefit in patients with advanced solid tumours supporting further investigation of the combination of pamiparib with tislelizumab. FUNDING: BeiGene.

ENhAncing Lifestyle Behaviors in EndometriaL CancEr (ENABLE): A Pilot Randomized Controlled Trial.

PURPOSE: Endometrial cancer is associated with the highest comorbid disease burden of any cancer. The aim of this trial was to assess the feasibility and safety of an allied health intervention during adjuvant treatment. METHODS: A mixed-methods pilot randomized (2:1) controlled trial with concealed allocation and assessor-blinding. Eligibility criteria: adjuvant endometrial cancer treatment scheduled, disease stage I-IIIC1, ECOG 0-2 and able to perform unsupervised physical activity (PA). Participants received usual care and 8 sessions of weekly, individualized, lifestyle education (diet and PA) with behavior change and social support (intervention group), delivered predominantly by telehealth, or usual care alone. Feasibility outcomes: recruitment and consent rates, decline reasons, program acceptability, intervention adherence and retention. RESULTS: 22/44 eligible patients (50%, 95%CI: 36%, 64%) were recruited over 10 months (14 intervention, 8 usual care). The recruitment rate was 2.2 patients/month (95%CI: 1.4, 3.3). Patients who declined had too much going on (7/22, 32%) or were not interested (6/22, 27%). Mean (SD) age and BMI were 63.2 years (6.8) and 31.9 kg/m2 (6.7). A majority were FIGO stage I (15/22, 68%) and received vaginal brachytherapy (14/22, 64%). Adherence was high, 11/14 (79%, 95%CI: 52%, 92%) participants attended >70% of scheduled sessions. Retention was 100% (95%CI: 85%, 100%) at 9 weeks, however completion of objective measures was impacted by COVID-19 restrictions. Telehealth and online questionnaires enabled participation. No serious adverse events occurred. CONCLUSION: The intervention was acceptable to participants with high levels of adherence and retention. Trial findings will be used to design a future RCT. TRIAL REGISTRATION: The trial was registered on www.anzctr.org.au (ACTRN12619000631101) 29/04/2019.

Cancer Diagnoses Following Abnormal Noninvasive Prenatal Testing: A Case Series, Literature Review, and Proposed Management Model.

Noninvasive prenatal testing (NIPT) is a screening test for fetal chromosomal aneuploidy using cell-free DNA derived from maternal blood. It has been rapidly accepted into obstetric practice because of its application from 10-weeks' gestation, and its high sensitivity and specificity. NIPT results can be influenced by several factors including placental or maternal mosaicism and co-twin demise; cell-free DNA from a maternal origin can also complicate interpretation, with evidence that NIPT can detect previously unsuspected malignancies. This study aimed to develop management guidelines for women with NIPT results suspicious of maternal malignancy. The Peter MacCallum Cancer Center's experience of seven cases where abnormal NIPT results led to investigation for maternal malignancy between 2016 and 2019 were reviewed, along with the published literature. Six of the seven women (86%) referred for investigation were diagnosed with advanced malignancies, including colorectal cancer, breast cancer, melanoma, and Hodgkin lymphoma. Based on our single-center experience, as well as the available literature, guidelines for the investigation of women with NIPT results suspicious of malignancy are proposed, including utilization of fluorodeoxyglucose positron emission tomography-computed tomography, which had a high concordance with other investigations and diagnoses. These guidelines include maternal and fetal investigations, as well as consideration of the complex medical, psychologic, social, and ethical needs of these patients and their families.

Clinical Utility of Real-Time Targeted Molecular Profiling in the Clinical Management of Ovarian Cancer: The ALLOCATE Study.

PURPOSE: The ALLOCATE study was designed as a pilot to demonstrate the feasibility and clinical utility of real-time targeted molecular profiling of patients with recurrent or advanced ovarian cancer for identification of potential targeted therapies. PATIENTS AND METHODS: A total of 113 patients with ovarian cancer of varying histologies were recruited from two tertiary hospitals, with 99 patient cases suitable for prospective analysis. Targeted molecular and methylation profiling of fresh biopsy and archived tumor samples were performed by screening for mutations or copy-number variations in 44 genes and for promoter methylation of BRCA1 and RAD51C. RESULTS: Somatic genomic or methylation events were identified in 85% of all patient cases, with potentially actionable events with defined targeted therapies (including four resistance events) detected in 60% of all patient cases. On the basis of these findings, six patients received molecularly guided therapy, three patients had unsuspected germline cancer-associated BRCA1/2 mutations and were referred for genetic counseling, and two intermediate differentiated (grade 2) serous ovarian carcinomas were reclassified as low grade, leading to changes in clinical management. Additionally, secondary reversion mutations in BRCA1/2 were identified in fresh biopsy samples of two patients, consistent with clinical platinum/poly (ADP-ribose) polymerase inhibitor resistance. Timely reporting of results if molecular testing is done at disease recurrence, as well as early referral for patients with platinum-resistant cancers, were identified as factors that could improve the clinical utility of molecular profiling. CONCLUSION: ALLOCATE molecular profiling identified known genomic and methylation alterations of the different ovarian cancer subtypes and was deemed feasible and useful in routine clinical practice. Better patient selection and access to a wider range of targeted therapies or clinical trials will further enhance the clinical utility of molecular profiling.

Mechanisms of Drug Resistance in High-Grade Serous Ovarian Cancer.

Resistance in ovarian cancer is driven by a range of mechanisms, some of which are therapy specific whereas others confer multidrug resistance. This review outlines our current understanding of the heterogeneous mechanisms of both primary and acquired drug resistance in high-grade serous ovarian cancer with a focus on the most common therapeutics, including platinum and taxanes. Current therapeutic strategies for overcoming resistance, including the use of non-P- glycoprotein substrate therapies, are outlined, with an emphasis on the importance of developing resistance biomarkers to guide future therapy approaches and improve patient outcomes.