Abstract OT1-1-06: A phase I study of LDE225 in combination with docetaxel in patients with triple negative (TN) advanced breast cancer (ABC): GEICAM/2012-12 (EDALINE study)

Abstract

Abstract Background: LDE225 is a potent and selective oral inhibitor of Smo, a key component of the hedgehog (Hh) signaling pathway. Up-regulation of the Hh pathway is implicated in the genesis of a wide range of tumors including triple negative breast cancer. Here we report an ongoing phase I study exploring the combination of LDE225 with docetaxel in TN ABC patients to identify the Maximum Tolerated Dose (MTD) and the Recommended Phase II Dose (RP2D) (ClinicalTrials.gov Identifier: NCT02027376). Trial Design: Eligibility criteria include patients with TN ABC candidates to receive treatment with docetaxel that have received a maximum of 3 prior chemotherapy regimens. Those patients with CNS involvement are also candidates if treated and clinically stable. Treatment consists of 21-day cycles with docetaxel 75mg/m2 on day 1, every 21 day and LDE225 once daily. We use a standard 3+3 design in sequential cohorts (3 dose levels (DL) of LDE225: 400mg once daily (DL1), 600mg once daily (DL2), 800mg once daily (DL3); and a DL-1: LDE225 400mg once daily and docetaxel 60mg/m2 every three weeks). The primary endpoint is the MTD and RP2D of the combination; secondary endpoints include evaluation of safety and tolerability, in addition to pharmacodynamic (PD) and pharmacokinetic (PK) studies. Patients are treated until radiologic or symptomatic progression or unacceptable toxicity occurs. PK will be performed to evaluate whether LDE225 influences the pharmacology of docetaxel. PD assessments include Hg gene expression signature associated to pathway activation in tumor samples and changes in Smo related biomarkers in skin and blood correlative samples. Efficacy will be measured in terms of time to progression and objective response rate. A minimum of 9 and a maximum of 18 patients will be included in this phase I. The study is approved by ERBs and Competent Authority and already recruiting patients (two patients included in DL1). Citation Format: Miguel Martin, Manuel Ruiz-Borrego, José M Trigo, Silvia Antolin, Jose A Garcia-Saenz, Andres Hernando, Alberto Ocaña, Federico Rojo, Sara Lopez-Tarruella, Jesus Corral, Nuria Ribelles, Lourdes Calvo, Fernando Moreno, Rosalia Caballero, Eva Carrasco. A phase I study of LDE225 in combination with docetaxel in patients with triple negative (TN) advanced breast cancer (ABC): GEICAM/2012-12 (EDALINE study) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr OT1-1-06.