695P - Phase I/II study of LDE225 in combination with gemcitabine and nab-paclitaxel in patients with metastatic pancreatic cancer

Abstract

BackgroundIn pancreatic cancer desmoplasia is a central feature of the tumour microenvironment. Growing evidence suggests that by targeting both tumour cells and tumour stoma, treatment efficacy is increased. LDE225 is a pharmacological Hedgehog signaling pathway inhibitor and is thought to specifically target tumour stroma. We investigated the combined use of LDE225 and chemotherapy in pancreatic cancer. MethodsThis was a multi-center, dose finding, phase I/II study for patients with metastatic pancreatic cancer. In part I of the study, we established the maximum tolerated dose of LDE225 to be 200mg once daily co-administered with gemcitabine 1000mg/m2 and nab-paclitaxel 125mg/m2 on days 1, 8 and 15 of a 4 week cycle (ESMO 2017). The objective of the phase II part was to evaluate efficacy and safety of the treatment combination and assess tumour cellularity and vascularity with diffusion weighted magnetic resonance imaging and dynamic contrast enhanced magnetic resonance imaging. Tumour response evaluation was performed using CT scan. Here we report on the phase II part of the study. ResultsIn the phase II part we included 25 patients. Most patients had WHO performance status of 0-1 (92%) and 60% were male. All patients received prior chemotherapy. Patients were treated with a median number of two cycles (IQR 1.5-5.0). Four therapy related grade 4 adverse events (AE) were observed: sepsis (2), neutropenia (2), and one grade 5 (sepsis). Most common grade 3 therapy related AEs were neutropenia (37%) and diarrhea (14.8%). Patients discontinued treatment because of progressive disease (20), bacterial infection (1), sepsis (1) and diminished quality of life (1). 2 patients are still alive. In 19 patients target lesion response was evaluable, 2 patients had partial response (10%), stable disease was seen in 10 patients (53%) and 7 patients had progressive disease (37%). The median overall survival was 6 months (IQR 3.0-8.5). Tumour vascularity and cellularity is currently being analyzed in 25 patients. ConclusionsThis study shows that LDE225 in combination with gemcitabine and nab-paclitaxel is well-tolerated in patients with metastatic pancreatic cancer and has promising efficacy. Clinical trial identificationNCT02358161. Legal entity responsible for the studyJ.W. Wilmink. FundingNovartis, Celgene and Sunpharma. DisclosureH.W.M. van Laarhoven: Research grant / Funding (institution): Roche; Research grant / Funding (institution): Bayer; Research grant / Funding (institution): BMS; Research grant / Funding (institution): Celgene; Research grant / Funding (institution): Lily; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Serono; Research grant / Funding (institution): MSD; Research grant / Funding (institution): Nordic; Research grant / Funding (institution): Philips. H.W. Wilmink: Research grant / Funding (institution): Servier; Research grant / Funding (institution): Halozyme; Research grant / Funding (institution): Novartis; Research grant / Funding (institution): Celgene; Research grant / Funding (institution): AstraZeneca; Research grant / Funding (institution): Pfizer; Research grant / Funding (institution): Roche; Advisory / Consultancy: Shire. All other authors have declared no conflicts of interest.