Metabolic Alterations and WNT Signaling Impact Immune Response in HGSOC.

PURPOSE: Our study used transcriptomic and metabolomic strategies to determine the molecular profiles of HGSOC patient samples derived from primary tumor and ascites cells. These data identified clinically relevant heterogeneity among and within patients and highlighted global and patient-specific cellular responses to neoadjuvant chemotherapy (NACT). EXPERIMENTAL DESIGN: Tissue from 61 treatment-naïve patients with HGSOC were collected. In addition, 11 benign, 32 ascites, and 18 post-NACT samples (matched to the individual patient's pre-NACT sample) were collected. RNA sequencing (RNA-seq) was performed on all samples collected. Two-dimensional spatial proteomic data was collected for two pairs of pre- and post-NACT. Untargeted metabolomics data using GCxGC-MS was generated for 30 treatment-naive tissues. Consensus clustering, analysis of differential expression, pathway enrichment, and survival analyses were performed. RESULTS: Treatment-naïve HGSOC tissues had distinct transcriptomic and metabolomic profiles. The mesenchymal subtype harbored a metabolomic profile distinct from the other subtypes. Compared with primary tumor tissue, ascites showed significant changes in immune response and signaling pathways. NACT caused significant alterations in gene expression and WNT activity, and this corresponded to altered immune response. Overall, WNT signaling levels were inversely correlated with immune cell infiltration in HGSOC tissues and WNT signaling post-NACT was inversely correlated with progression-free survival. CONCLUSIONS: Our study concluded that HGSOC is a heterogenous disease at baseline and growing molecular differences can be observed between primary tumor and ascites cells or within tumors in response to treatment. Our data reveal potential exploratory biomarkers relevant for treatment selection and predicting patient outcomes that warrant further research.

EMR 20006-012: A phase II randomized double-blind placebo controlled trial comparing the combination of pimasertib (MEK inhibitor) with SAR245409 (PI3K inhibitor) to pimasertib alone in patients with previously treated unresectable borderline or low grade ovarian cancer.

OBJECTIVE: To compare the combination of a MEK inhibitor (pimasertib) and a PI3K inhibitor (SAR245409) to pimasertib alone in recurrent unresectable borderline/low malignant potential (LMP) or low-grade serous ovarian carcinoma (LGSOC), determining whether combination is superior. METHODS: Patients with previously treated, recurrent LMP or LGSOC with measurable disease received either combination of pimasertib (60 mg daily) + SAR245409 (SAR) (70 mg daily) or pimasertib alone (60 mg BID) until progression or unacceptable toxicity. Primary endpoint was objective response rate (ORR) by RECIST 1.1, determining whether combination was superior to pimasertib alone. Secondary endpoints included progression free survival (PFS), disease control, and adverse events. RESULTS: Sixty-five patients were randomized between September 2012 and December 2014. ORR was 9.4% (80% CI, 3.5 to 19.7) in the combination arm and 12.1% (80% CI, 5.4 to 22.8) in the pimasertib alone arm. Median PFS was 7.23 months (80% CI, 5.06 to -) and 9.99 (80% CI, 7.39 to 10.35) for pimasertib alone and pimasertib + SAR, respectively. Six-month PFS was 63.5% (80% CI, 47.2% to 75.9%) and 70.8% (80% CI, 56.9% to 80.9%). Eighteen (56.3%) patients in the combination arm and 19 (57.6%) patients in the pimasertib alone arm discontinued the trial. The study was terminated early because of low ORR and high rate of discontinuation. CONCLUSIONS: Response to pimasertib alone (ORR 12%) suggests that MEK inhibition could be used as an alternative treatment method to cytotoxic chemotherapy in this population. The MEK inhibitor alone was as effective as the combination, although the trial was limited by small numbers. Additional studies investigating the role of single agent or combination MEK and PI3K inhibition are warranted to further evaluate the utility of these treatments and describe a standard of care for LGSOC.

Extending the platinum-free interval: The impact of omitting 2nd line platinum chemotherapy in intermediate platinum-sensitive ovarian cancer.

OBJECTIVES: Patients with epithelial ovarian cancer (EOC) recurring between 6 and 12 months after primary platinum chemotherapy have worse prognosis than those recurring in >12 months. Artificially prolonging the platinum-free interval (PFI) with cytotoxic chemotherapy was tested in MITO-8 with poor outcomes. This study aimed to determine the impact of using non-platinum or targeted therapy in 2nd line treatment of EOC patients recurring 6-12 months after completion of primary platinum-based chemotherapy. METHODS: A multi-institutional retrospective review of 177 patients with recurrent EOC and PFI of 6-12 months following primary chemotherapy was performed comparing platinum versus non-platinum chemotherapy or targeted therapy for 2nd line treatment. PFI1 was defined as the date of last chemotherapy to date of recurrence. PFS2/3 were defined as start of 2nd or 3rd line chemotherapy to start of subsequent line. RESULTS: Of 177 patients, the majority of patients were Caucasian, had serous histology, and underwent primary cytoreductive surgery. Median PFI1 was 8.2 months (95% CI 8-9 months). Second line platinum was omitted in 28% of patients. Bevacizumab was used in 2nd line in 16% of patients; 19% received other targeted therapies. Median PFS2 for platinum chemotherapy was longer than non-platinum (7.1 vs 3 months, p = 0.0114). Median PFS2 was significantly longer for platinum vs. targeted therapy (7.1 vs. 3 months p = 0.0431). Median OS for platinum in 2nd line vs. no platinum was 43.6 vs. 37.6 months (p = 0.0174). CONCLUSIONS: Use of non-platinum chemotherapy and even targeted therapy to prolong PFI in patients with EOC recurring between 6 and 12 months leads to worse survival.