Background Therapeutic Information In ovarian cancer, several single agent phase II trials of vinorelbine in recurrent OC have shown variable response rates of 3 - 30%. However, previous studies have involved "all-comers" and no reported trials have selected patients based on confirmed pure HGSOC or a biomarker of relevance. Preclinical studies suggest that genes involved in microtubule dynamics, are significantly over-expressed in C5 tumours. Importantly, increased sensitivity was demonstrated of C5-like cell lines to tubulin depolymerising agents like vincristine and vinorelbine compared with microtubule stabilizing agents like paclitaxel. Subsequent studies on patient derived xenograft (PDX) models of C5 HGSOC (including platinum resistant models) showed responses for more than 50 days when treated with vinorelbine, providing preclinical proof that vinorelbine may be an effective therapeutic option in targeting the C5 subclass of HGSOC, including in platinum resistant or refractory disease.