PARP inhibitors for BRCA1/2-mutated and sporadic ovarian cancer: current practice and future directions

Poly(ADP-ribose) polymerase (PARP) inhibitors cause targeted tumour cell death in homologous recombination (HR)-deficient cancers, including BRCA-mutated tumours, by exploiting synthetic lethality. PARP inhibitors are being evaluated in late-stage clinical trials of ovarian cancer (OC). Recently, olaparib was the first PARP inhibitor approved in the European Union and United States for the treatment of advanced BRCA-mutated OC. This paper reviews the role of BRCA mutations for tumorigenesis and PARP inhibitor sensitivity, and summarises the clinical development of PARP inhibitors for the treatment of patients diagnosed with OC. Among the five key PARP inhibitors currently in clinical development, olaparib has undergone the most extensive clinical investigation. PARP inhibitors have demonstrated durable antitumour activity in BRCA-mutated advanced OC as a single agent in the treatment and maintenance setting, particularly in platinum-sensitive disease. PARP inhibitors are well tolerated; however, further careful assessment of moderate and late-onset toxicity is mandatory in the maintenance and adjuvant setting, respectively. PARP inhibitors are also being evaluated in combination with chemotherapeutic and novel targeted agents to potentiate antitumour activities. Current research is extending the use of PARP inhibitors beyond BRCA mutations to other sensitising molecular defects that result in HR-deficient cancer, and is defining an HR-deficiency signature. Trials are underway to determine whether such a signature will predict sensitivity to PARP inhibitors in women with sporadic OC

Homologous recombination deficiency and ovarian cancer

The discovery that PARP inhibitors block an essential pathway of DNA repair in cells harbouring a BRCA mutation has opened up a new therapeutic avenue for high-grade ovarian cancers. BRCA1 and BRCA2 proteins are essential for high-fidelity repair of double-strand breaks of DNA through the homologous recombination repair (HRR) pathway. Deficiency in HRR (HRD) is a target for PARP inhibitors. The first PARP inhibitor, olaparib, has now been licensed for BRCA-mutated ovarian cancers. While mutated BRCA genes are individually most commonly associated with HRD other essential HRR proteins may be mutated or functionally deficient potentially widening the therapeutic opportunities for PARP inhibitors. HRD is the first phenotypically defined predictive marker for therapy with PARP inhibitors in ovarian cancer. Several different PARP inhibitors are being trialled in ovarian cancer and this class of drugs has been shown to be a new selective therapy for high-grade ovarian cancer. Around 20% of high-grade serous ovarian cancers harbour germline or somatic BRCA mutations and testing for BRCA mutations should be incorporated into routine clinical practice. The expanded use of PARP inhibitors in HRD deficient (non-BRCA mutant) tumours using a signature of HRD in clinical practice requires validation

Real-World Delivery of Rucaparib to Patients with Ovarian Cancer: Recommendations Based on an Integrated Safety Analysis of ARIEL2 and Study 10

Treatment options for women with recurrent ovarian cancer who have received two or more prior lines of chemotherapy have recently expanded with the U.S. Food and Drug Administration (FDA) and European Commission (EC) approvals of the poly(ADP‐ribose) polymerase (PARP) inhibitor rucaparib. As more oncologists begin to use rucaparib and other PARP inhibitors as part of routine clinical practice, awareness of possible side effects and how to adequately manage toxicities is crucial. In this review, we summarize the safety and tolerability of rucaparib reported in an integrated safety analysis that supported the FDA's initial approval of rucaparib in the treatment setting. Additionally, drawing on clinical data and our personal experience with rucaparib, we provide our recommendations on the management of common side effects observed with rucaparib, including anemia, blood creatinine elevations, alanine aminotransferase and aspartate aminotransferase elevations, thrombocytopenia, gastrointestinal‐related events (e.g., nausea, vomiting), and asthenia and fatigue. These side effects, many of which appear to be class effects of PARP inhibitors, are often self‐limiting and can be managed with adequate interventions such as treatment interruption and/or dose reduction and the use of supportive therapies. Supportive therapies may include blood transfusions for patients with anemia, prophylactic medications to prevent nausea and vomiting, or behavioral interventions to mitigate fatigue. Understanding and appropriate management of potential side effects associated with rucaparib may allow patients with ovarian cancer to continue to benefit from rucaparib treatment. Implications for Practice. Rucaparib was recently approved in the U.S. and European Union for use as treatment or maintenance for recurrent ovarian cancer. This review focuses on the safety and tolerability of rucaparib in the treatment setting. Similar side effects are observed in the maintenance setting. Drawing on the authors’ clinical experience with rucaparib, rucaparib prescribing information, and published supportive cancer care guidelines, this review discusses how to optimally manage common rucaparib‐associated side effects in patients with advanced ovarian cancer in the real‐world oncology setting. Adequate management of such side effects is crucial for allowing patients with ovarian cancer to remain on treatment to receive optimal efficacy benefit

Lurbinectedin in patients with pretreated endometrial cancer: results from a phase 2 basket clinical trial and exploratory translational study

Endometrial cancer; Lurbinectedin; Phase 2Càncer d'endometri; Lurbinectedina; Fase 2Cáncer de endometrio; Lurbinectedina; Fase 2Second-line treatment of endometrial cancer is an unmet medical need. Lurbinectedin showed promising antitumor activity in a phase I study in combination with doxorubicin in advanced endometrial cancer. This phase 2 Basket trial evaluated lurbinectedin 3.2 mg/m2 1-h intravenous infusion every 3 weeks in a cohort of 73 patients with pretreated endometrial cancer. The primary endpoint was overall response rate (ORR) according to RECIST v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), safety and an exploratory translational study. Confirmed complete (CR) and partial response (PR) was reported in two and six patients, respectively (ORR = 11.3%; 95%CI, 5.0-21.0%). Median DoR was 9.2 months (95%CI, 3.4-18.0 months), median PFS was 2.6 months (95%CI, 1.4-4.0 months) and median OS was 9.3 months (95%CI, 6.1-12.8 months). Molecular subtypes showed differences in PFS rate at 6 months (p53abn 23.7% vs. "No Specific Molecular Profile" [NSMP] 42.9%) and median OS (p53abn 6.6 months vs. NSMP 16.1 months). The most common treatment-related adverse events (mostly grade 1/2) were fatigue (54.8% of patients), nausea (50.7%), vomiting (26.0%) decreased appetite (17.8%). and constipation, (19.2%). The most common grade 3/4 toxicity was neutropenia (43.8%; grade 4, 19.2%; febrile neutropenia, 4.1%). In conclusion, considering the exploratory aim of this trial and the hints of antitumor activity observed together with a predictable and manageable safety profile, further biomarker-based development of lurbinectedin is recommended in this indication in combination with other agents. Clinicaltrials.gov identifier: NCT02454972.The study was funded by Pharma Mar S.A, including partial funding by grants from the Centro para el Desarrollo Tecnológico Industrial (CDTI) during the conduct of the study (grant number IDI-20150006). VS is supported by a US National Institutes of Health (NIH) grant (no. R01CA242845 and R01CA273168); MD Anderson Cancer Center Department of Investigational Cancer Therapeutics is supported by the Cancer Prevention and Research Institute of Texas (no. RP1100584), the Sheikh Khalifa Bin Zayed Al Nahyan Institute for Personalized Cancer Therapy (no. 1U01 CA180964), NCATS (Center for Clinical and Translational Sciences) Grant (no. UL1 TR000371), and the MD Anderson Cancer Center Support Grant (no. P30 CA016672)

Phase I/II sequencing study of azacitidine, epacadostat, and pembrolizumab in advanced solid tumors

Cancer epigenetics; Cancer immunotherapyEpigenética del cáncer; Inmunoterapia contra el cáncerEpigenètica del càncer; Immunoteràpia del càncerBackground Indoleamine 2,3-dioxygenase 1 (IDO1), an interferon-inducible enzyme, contributes to tumor immune intolerance. Immune checkpoint inhibition may increase interferon levels; combining IDO1 inhibition with immune checkpoint blockade represents an attractive strategy. Epigenetic agents trigger interferon responses and may serve as an immunotherapy priming method. We evaluated whether epigenetic therapy plus IDO1 inhibition and immune checkpoint blockade confers clinical benefit to patients with advanced solid tumors. Methods ECHO-206 was a Phase I/II study where treatment-experienced patients with advanced solid tumors (N = 70) received azacitidine plus an immunotherapy doublet (epacadostat [IDO1 inhibitor] and pembrolizumab). Sequencing of treatment was also assessed. Primary endpoints were safety/tolerability (Phase I), maximum tolerated dose (MTD) or pharmacologically active dose (PAD; Phase I), and investigator-assessed objective response rate (ORR; Phase II). Results In Phase I, no dose-limiting toxicities were reported, the MTD was not reached; a PAD was not determined. ORR was 5.7%, with four partial responses. The most common treatment-related adverse events (AEs) were fatigue (42.9%) and nausea (42.9%). Twelve (17.1%) patients experienced ≥1 fatal AE, one of which (asthenia) was treatment-related. Conclusions Although the azacitidine-epacadostat-pembrolizumab regimen was well tolerated, it was not associated with substantial clinical response in patients with advanced solid tumors previously exposed to immunotherapy.This study was sponsored by Incyte Corporation

Outcome of patients with advanced ovarian cancer who do not undergo debulking surgery: A single institution retrospective review

OBJECTIVE: To assess the outcome of patients with advanced ovarian cancer (OC) who were treated without surgery, having received upfront chemotherapy and no interval debulking surgery (IDS). METHODS: Retrospective analysis of medical and chemotherapy records of consecutive patients with OC between 2005 and 2013 at UCL Hospitals London, UK who received neoadjuvant chemotherapy (NACT) was then found to be unsuitable for IDS following review by the multidisciplinary team. RESULTS: Eighty-three patients (18%) out of 467 receiving NACT did not undergo IDS. Median age was 70years (range 33-88); out of these 83 patients, 43 (51.8%) presented with stage IV disease. Forty-three of these 83 patients received carboplatin and paclitaxel (CP) (51.8%) and 37 received carboplatin alone (C) (44.6%); 3 patients (3.6%) received other platinum-based combinations. Reasons for not proceeding to surgery were: poor response to chemotherapy after 3-4 cycles of NACT (61/83, 73.5%); comorbidities (12/83, 14.5%); patient decision (4/83, 4.8%). Six patients (7.2%) received 2 lines of chemotherapy. In a univariate analysis CP, age <70years, and absence of comorbidities were factors influencing OS. In a multivariate analysis only having received CP remained independently associated with OS (HR 0.49, 95% CI 0.29-0.84). CONCLUSIONS: Chemotherapy alone can provide reasonable disease control in patients unsuitable for IDS and CP should be used if possible

Mainstreamed Genetic Testing in Ovarian Cancer: Patient Experience of the Testing Process

Objective: Pathogenic BRCA variants account for between 5.8-24.8% of ovarian cancers. The identification of such a variant can have a significant impact on the affected individual and their relatives – determining eligibility for targeted therapies, predicting treatment response and granting access to disease prevention strategies. Cancer services are responding to the increased demand for genetic testing with the introduction of mainstreamed genetic testing via oncology clinics. The study aimed to evaluate patient experience of the mainstreamed genetic testing pathway at a tertiary referral centre in London. / Methods: Study participants were patients diagnosed with high-grade non-mucinous ovarian cancer, tested via a mainstreamed genetic testing pathway at the tertiary referral centre between February 2015 and June 2017. Eligible participants were invited to complete the retrospective study questionnaire. Five quantitative measures with additional free-text items evaluated the patient experience of mainstreamed genetic testing. / Results: The tertiary referral centre tested 170 ovarian cancer patients. Twenty-three pathogenic BRCA mutations were identified (23/170, 13.5%). One-hundred and six patients (106/170, 62.4%) met the study inclusion criteria. Twenty-nine of those invited (29/106, 27.4%) to participate returned the retrospective study questionnaire. Pathogenic BRCA1/2 variants were identified within four respondents (4/29, 13.8%). Motivations for genetic testing related to improved medical management, and the ability to provide relatives with genetic information. Participants did not appear to be adversely affected by result disclosure post mainstreamed genetic testing. Two individuals with a pathogenic variant reported that the support provided by the tertiary referral centre post-result disclosure could have been improved. / Conclusion: Results of the current study support further psychosocial research into the expansion of the mainstreamed genetic testing pathway. The results although promising have also highlighted the importance of genetic awareness within the multidisciplinary team and the provision of timely psychological support from genetic specialists

First-in-human phase I/II, open-label study of the anti-OX40 agonist INCAGN01949 in patients with advanced solid tumors

Inmunomodulación; Linfocitos T; Microambiente tumoralImmunomodulació; Limfòcits T; Microambient tumoralImmunomodulation; T-Lymphocytes; Tumor microenvironmentBackground OX40 is a costimulatory receptor upregulated on antigen-activated T cells and constitutively expressed on regulatory T cells (Tregs). INCAGN01949, a fully human immunoglobulin G1κ anti-OX40 agonist monoclonal antibody, was designed to promote tumor-specific immunity by effector T-cell activation and Fcγ receptor-mediated Treg depletion. This first-in-human study was conducted to determine the safety, tolerability, and preliminary efficacy of INCAGN01949. Methods Phase I/II, open-label, non-randomized, dose-escalation and dose-expansion study conducted in patients with advanced or metastatic solid tumors. Patients received INCAGN01949 monotherapy (7–1400 mg) in 14-day cycles while deriving benefit. Safety measures, clinical activity, pharmacokinetics, and pharmacodynamic effects were assessed and summarized with descriptive statistics. Results Eighty-seven patients were enrolled; most common tumor types were colorectal (17.2%), ovarian (8.0%), and non-small cell lung (6.9%) cancers. Patients received a median three (range 1–9) prior therapies, including immunotherapy in 24 patients (27.6%). Maximum tolerated dose was not reached; one patient (1.1%) receiving 350 mg dose reported dose-limiting toxicity of grade 3 colitis. Treatment-related adverse events were reported in 45 patients (51.7%), with fatigue (16 (18.4%)), rash (6 (6.9%)), and diarrhea (6 (6.9%)) being most frequent. One patient (1.1%) with metastatic gallbladder cancer achieved a partial response (duration of 6.3 months), and 23 patients (26.4%) achieved stable disease (lasting >6 months in one patient). OX40 receptor occupancy was maintained over 90% among all patients receiving doses of ≥200 mg, while no treatment-emergent antidrug antibodies were detected across all dose levels. Pharmacodynamic results demonstrated that treatment with INCAGN01949 did not enhance proliferation or activation of T cells in peripheral blood or reduce circulating Tregs, and analyses of tumor biopsies did not demonstrate any consistent increase in effector T-cell infiltration or function, or decrease in infiltrating Tregs. Conclusion No safety concerns were observed with INCAGN01949 monotherapy in patients with metastatic or advanced solid tumors. However, tumor responses and pharmacodynamic effects on T cells in peripheral blood and post-therapy tumor biopsies were limited. Studies evaluating INCAGN01949 in combination with other therapies are needed to further evaluate the potential of OX40 agonism as a therapeutic approach in patients with advanced solid tumors.This study was funded by Incyte Corporation (Wilmington, USA)