Abstract 5782: Selumetinib-based therapy in uveal melanoma patient-derived xenografts

• Published in: Cancer research (Chicago, Ill.) Vol. 78; no. 13_Supplement; p. 5782
• Main Authors: Decaudin, Didier, Botty, Rania EL, Diallo, Béré, Massonnet, Gerald, Fleury, Justine, Naguez, Adnan, Dubois, Marine, Davies, Emma J., Smith, Aaron, Wilson, Joanne, Howes, Colin, Smith, Paul, Cassoux, Nathalie, Mariani, Pascale, Piperno-Neumann, Sophie, Roman, Sergio Roman, Nemati, Fariba
• Format: Journal Article
• Language: English
• Published: 01-07-2018
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2018-5782

Abstract
Purpose: The prognosis of metastatic uveal melanoma (UM) patients remains one of the worst observed in human cancers. The identification of frequently mutated GNAQ/GNA11 and the activation of MAPK signaling in UM raise the possibility of using efficient targeted therapies such as MEK inhibition. The aim of our study was to evaluate drug combinations that might enhance the efficacy of the MEK inhibitor, selumetinib (AZD6244, ARRY-142886), using patient-derived xenografts.
Materials: Five UM PDXs were used in this study, i.e., MP34, MP46, MP55, MP77, and MM26, all mutated for GNAQ or GNA11. Selumetinib was administered alone or combined with chemotherapies (dacarbazine and docetaxel) or targeted therapies: the ERK inhibitor, AZ6197 and the mTORC1/2 inhibitor, vistusertib (AZD2014). All targeted therapies were administered orally five days/week at the following doses: selumetinib at 25 mg/kg/day BID, AZ6197 at 50 mg/kg QD, AZD2014 at 15mg/kg QD. Dacarbazine was administered at 40 mg/kg for 5 consecutive days every 28 days and docetaxel at 15 mg/kg weekly. Both were administered intraperitoneally.
Results: The combination of selumetinib and dacarbazine did not show improvement of antitumor efficacy in MP34, MM26 and MP55.The results showed a slight increase of overall response rate when selumetinib was combined with docetaxel, in comparison to the treatment with selumetinib or docetaxel alone. Importantly, we observed a significant antitumor effect when selumetinib was used in combination with AZ6197 or AZD2014 with respect to the monotherapies. Preliminary pharmacodynamics studies showed variation of the expression of p-ERK and also p-AKT and/or p-S6 when UM PDX were treated with AZ6197 or AZD2014 alone or in combination with selumetinib.
Conclusion: Our data suggest that ERK and mTORC1/2 targeting could represent promising therapeutic approaches for the treatment of metastatic UM patients.
Citation Format: Didier Decaudin, Rania EL Botty, Béré Diallo, Gerald Massonnet, Justine Fleury, Adnan Naguez, Marine Dubois, Emma J. Davies, Aaron Smith, Joanne Wilson, Colin Howes, Paul Smith, Nathalie Cassoux, Pascale Mariani, Sophie Piperno-Neumann, Sergio Roman Roman, Fariba Nemati. Selumetinib-based therapy in uveal melanoma patient-derived xenografts [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5782.