RESUMO
Immunosuppressive myeloid-derived suppressor cells (MDSCs) and regulatory T cells (Tregs) are associated with immunologic tolerance and poor prognosis in ovarian cancer (OvCa). We hypothesized that women with germline BRCA1 and BRCA2 mutation-associated (gBRCAm) OvCa would have fewer circulating immunosuppressive immune cells compared to those with BRCA wild-type (BRCAwt) disease during their early disease course (<5 years post-diagnosis) where gBRCAm is a favorable prognostic factor. We collected and viably froze peripheral blood mononuclear cells (PBMCs) from patients with recurrent OvCa olaparib clinical trials (NCT01445418/NCT01237067). Immune subset analyses were performed using flow cytometry for Tregs, exhausted CD8+ T cells, monocytes and MDSCs. Functional marker expression, including cytotoxic T lymphocyte-associated protein 4 (CTLA-4), T cell immunoglobulin and mucin domain 3 (TIM-3) and programmed cell death protein 1 (PD-1) was evaluated. Data were analyzed using FlowJo. Pretreatment PBMCs were collected from 41 patients (16 gBRCAm/25 BRCAwt). The percentage of MDSCs among viable CD45+ PBMC was lower in gBRCAm OvCa compared with BRCAwt OvCa (median 0.565 vs. 0.93%, P=0.0086) but this difference was not seen in those women >5 years post-diagnosis. CD8+ T cells among viable CD45+ PBMCs and CTLA-4+/CD8+ T cells were higher in gBRCAm carriers than patients with BRCAwt, in particular for those <5 years post-diagnosis (median 20.4 vs. 9.78%, P=0.031 and median MFI 0.19 vs. 0.22, P=0.0074, respectively). TIM-3 expression on Tregs was associated with poor progression-free survival, independent of gBRCAm status (P<0.001). Our pilot data suggested that patients with gBRCAm OvCa may have fewer circulating MDSCs but higher CD8+ T cells in PBMCs during their early disease course. This may contribute to the observed survival benefit for these women in their first post-diagnosis decade.
RESUMO
BACKGROUND: Improved treatment for advanced cervical cancer is needed; currently, treatment options include combined chemotherapy and bevacizumab or pembrolizumab monotherapy for PD-L1 positive disease. PIK3CA and KRAS mutations have been reported in cervical cancers; this study therefore tested dual inhibition of PI3K and RAS signaling by combining the MEK inhibitor trametinib and the AKT inhibitor GSK2141795 in recurrent cervical cancer. METHODS: This was an investigator-initiated phase II study combining trametinib and GSK2141795 in patients with recurrent cervical cancer. Primary endpoint was best tumor response; secondary endpoints included progression free survival, overall survival, and safety assessment. Translational objectives included characterization of molecular alterations in PI3K and RAS signaling pathway genes. RESULTS: Planned accrual was 35 patients; 14 patients were enrolled and received at least one dose of study drug before the study was terminated due to discontinuation of GSK2141795 development. There were no confirmed responses; 1 patient had an unconfirmed PR, 8 had stable disease, 3 had progression as best response, and 2 were unevaluable. Toxicities were mostly grade 1 and 2, although 57% of patients experienced grade 3/4 adverse events and 50% patients required a dose reduction. CONCLUSIONS: The combination of trametinib and GSK2141795 was feasible but required dose holds and modifications for adverse events; however, anti-cancer activity was minimal, even in patients with PI3K or RAS pathway alterations. Although the study was terminated early after GSK2141795 development was halted, the findings in these 14 patients do not support further development of this combination in cervical cancer.
