Background Tumour Microvessel density (MVD) is often used as a surrogate marker for tumoral angiogenic activity. In the randomized phase II neo-adjuvant CHIVA trial, ovarian cancer patients (pts) treated with standard chemotherapy plus Nintedanib (Ni) compared to chemotherapy alone had a reduced rate of complete surgical resection at interval debulking surgery (IDS), worse PFS and OS. To explain these results we assessed the predictive/prognostic value of MVD at baseline and the MVD decrease from baseline to IDS. Methods Paired tumours from baseline and IDS were available from 79/188 randomized pts. A total of 158 virtual slides of immunostained tumor section with anti-CD31 were analysed. MVD was quantified by an image processing on whole tumor section. MVD high level was defined as MVD > 33.5 vessel/mm² which is the highest Youden index on the ROC curve for PFS. The relationship between MVD at baseline and PFS and OS was evaluated using Kaplan-Meier survival estimates. Results Main characteristics of the 79 pts were similar to the overall CHIVA population: mean age (62 years), ECOG performance status = 0 (34%), high-grade serous histology (75%). At baseline, MVD was similar in both arms and was low for 35% and 30% of the pts in the Ni and control arm respectively. The rate of complete resection (CC0) was 56% in the Ni arm versus 70% in the control arm. In the low MVD group median PFS was 13.3 months (95%CI 11 – 22.2) versus 17 months (95%CI 13.7 – 20.5) in the high MVD group (p = 0.85). In the low MVD group, PFS in the Ni and control arm were 12.8 (95%CI 10.7-22.2) and 21.3 months (95%CI 12.5-NA) respectively (p = 0.08). The corresponding PFS in the high MVD group were 18.0 (95%CI 14.4-21.6) vs 14.5 months (95%CI 12.4-22.5) (p = 0.22). No difference was observed for OS. Baseline MVD was not associated with the rate of CC0. There was no significant difference in the decrease of MVD at IDS between the Ni arm (38% of the pts) and the control arm (48%, p = 0.4). Conclusions The negative impact of Nintedanib in patients with low baseline MVD tumours may be one explanation of the poor PFS rate observed in the Nintedanib arm of the CHIVA trial. Clinical trial identification 2011-006288-23. Legal entity responsible for the study ARCAGY-GINECO. Funding Health ministry grants( PHRC). Disclosure C. Blanc-Fournier: Honoraria (self): Roche. N. Raban: Travel / Accommodation / Expenses: Roche. G. Ferron: Honoraria (self): Olympus Europe; Advisory / Consultancy: AstraZeneca; Travel / Accommodation / Expenses: Roche. A. Floquet: Advisory / Consultancy, Travel / Accommodation / Expenses: Tesaro; Advisory / Consultancy: Clovis; Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Travel / Accommodation / Expenses: Roche. J. Alexandre: Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy: AstraZeneca; Honoraria (self): Ipsen; Honoraria (self), Advisory / Consultancy, Travel / Accommodation / Expenses: Novartis; Honoraria (self): PharmaMar; Research grant / Funding (institution), Travel / Accommodation / Expenses: Janssen. C. Louvet: Advisory / Consultancy, Travel / Accommodation / Expenses: MSD; Advisory / Consultancy, Travel / Accommodation / Expenses: Roche; Advisory / Consultancy: Halozyme; Advisory / Consultancy: Servier; Advisory / Consultancy: AstraZeneca. J. Florence: Advisory / Consultancy: Roche; Advisory / Consultancy: Novartis; Advisory / Consultancy: Pfizer; Advisory / Consultancy, Travel / Accommodation / Expenses: AstraZeneca; Advisory / Consultancy: Tesaro; Advisory / Consultancy, Travel / Accommodation / Expenses: Ipsen; Advisory / Consultancy: Astellas; Advisory / Consultancy: Bayer; Advisory / Consultancy, Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Advisory / Consultancy: Sanofi; Travel / Accommodation / Expenses: Janssen. All other authors have declared no conflicts of interest.
