No abstract

SRC tyrosine kinase is frequently overexpressed and activated in late-stage, poor prognosis ovarian tumours, and preclinical studies have supported the use of targeted SRC inhibitors in the treatment of this disease. The SAPPROC trial investigated the addition of the SRC inhibitor saracatinib (AZD0530) to weekly paclitaxel for the treatment of platinum resistant ovarian cancer; however, this drug combination did not provide any benefit to progression free survival (PFS) of women with platinum resistant disease. In this study we aimed to identify mechanisms of resistance to SRC inhibitors in ovarian cancer cells. Using two complementary strategies; a targeted tumour suppressor gene siRNA screen, and a phospho-receptor tyrosine kinase array, we demonstrate that activation of MAPK signalling, via a reduction in NF1 (neurofibromin) expression or overexpression of HER2 and the insulin receptor, can drive resistance to AZD0530. Knockdown of NF1 in two ovarian cancer cell lines resulted in resistance to AZD0530, and was accompanied with activated MEK and ERK signalling. We also show that silencing of HER2 and the insulin receptor can partially resensitize AZD0530 resistant cells, which was associated with decreased phosphorylation of MEK and ERK. Furthermore, we demonstrate a synergistic effect of combining SRC and MEK inhibitors in both AZD0530 sensitive and resistant cells, and that MEK inhibition is sufficient to completely resensitize AZD0530 resistant cells. This work provides a preclinical rationale for the combination of SRC and MEK inhibitors in the treatment of ovarian cancer, and also highlights the need for biomarker driven patient selection for clinical trials.

The efficacy of anti-angiogenic agents (AAAs) in epithelial ovarian cancer (EOC) remains unclear. Therefore, we conducted a systematic review and network meta-analysis (NMA) to synthesize evidence of their comparative effectiveness for improving overall survival (OS) among EOC patients. We searched six databases for randomized controlled trials (RCTs) from their inception to February 2021. We performed an NMA with hazard ratios (HRs) and 95%-confidence intervals (CIs) to evaluate comparative effectiveness among different AAAs in chemotherapy-naïve and recurrent EOC. P-score was used to provide an effectiveness hierarchy ranking. Sensitivity NMA was carried out by focusing on studies that reported high-risk chemotherapy-naïve, platinum-resistant, and platinum-sensitive EOC. The primary outcome was OS. We identified 23 RCTs that assessed the effectiveness of AAAs. In recurrent EOC, concurrent use of trebananib (10 mg/kg) with chemotherapy was likely to be the best option (P-score: 0.88, HR 1.67, 95% CI 0.94; 2.94). The NMA indicated that bevacizumab plus chemotherapy followed by maintenance bevacizumab (P-score: 0.99) and pazopanib combined with chemotherapy (P-score: 0.79) both had the highest probability of being the best intervention for improving OS in high-risk chemotherapy-naïve and platinum-resistant EOC, respectively. AAAs may not play a significant clinical role in non-high-risk chemotherapy-naïve and platinum-sensitive EOC.