Pavlina Spiliopoulou

Metronomic oral cyclophosphamide in relapsed ovarian cancer

To describe the clinical activity of metronomic cyclophosphamide in a population of patients with recurrent ovarian cancer, and to identify predictors of clinical response. We retrospectively reviewed all patients treated at our institution with oral metronomic cyclophosphamide for relapsed ovarian cancer between January 2012 and December 2016. These were identified from electronic chemotherapy prescription records. The primary endpoint was response rate by combined Gynecologic Cancer InterGroup (GCIG) criteria. Data on patient demographics, previous therapies, platinum resistance, germline 50 out of 68 patients treated with oral metronomic cyclophosphamide were evaluable for disease response. By combination criteria (radiological plus CA125), complete response was 0%, partial response 32%, stable disease 16%, and progressive disease 52%. In the intention-to-treat population (n=68), progression-free survival and overall survival were 2.6 months and 6 months, respectively. Having a Oral metronomic cyclophosphamide showed a clinical benefit in 48% of patients with recurrent ovarian cancer.

Dual G9A/EZH2 Inhibition Stimulates Antitumor Immune Response in Ovarian High-Grade Serous Carcinoma

Abstract Ovarian high-grade serous carcinoma (HGSC) prognosis correlates directly with presence of intratumoral lymphocytes. However, cancer immunotherapy has yet to achieve meaningful survival benefit in patients with HGSC. Epigenetic silencing of immunostimulatory genes is implicated in immune evasion in HGSC and re-expression of these genes could promote tumor immune clearance. We discovered that simultaneous inhibition of the histone methyltransferases G9A and EZH2 activates the CXCL10–CXCR3 axis and increases homing of intratumoral effector lymphocytes and natural killer cells while suppressing tumor-promoting FoxP3+ CD4 T cells. The dual G9A/EZH2 inhibitor HKMTI-1–005 induced chromatin changes that resulted in the transcriptional activation of immunostimulatory gene networks, including the re-expression of elements of the ERV-K endogenous retroviral family. Importantly, treatment with HKMTI-1–005 improved the survival of mice bearing Trp53−/− null ID8 ovarian tumors and resulted in tumor burden reduction. These results indicate that inhibiting G9A and EZH2 in ovarian cancer alters the immune microenvironment and reduces tumor growth and therefore positions dual inhibition of G9A/EZH2 as a strategy for clinical development.