Abstract OT1-1-15: A phase II study of dovitinib as salvage therapy in patients with stage IV inflammatory breast cancer HER2-negative with local or distant relapse

Background: Inflammatory breast cancer (IBC) is an aggressive form of breast cancer that accounts for 3 to 5% of all invasive breast tumors in the United States. IBC possesses an increase of proangiogenic factors including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and platelet derived growth factor (PDGF) as compared with non-IBC. In particular, FGF family receptors play a critical role in tumorigenesis, morphogenesis, and inducers of angiogenesis. Dovitinib (TKI258) is an oral tyrosine kinase inhibitor with in vitro IC50 values of approximately 10 nmol/L against FGFR1-3, VEGFR1-3, and PDGFR. These structurally related receptors are important for the growth and survival of endothelial cells during tumor angiogenesis. Trial Design: This is a single institution, single arm phase II study. Patients receive a single daily oral dose of dovitinib 500 mg for 5 consecutive days, followed by a 2-day rest period (5 days on/2 days off schedule). Eligibility: Patients have histological confirmation of breast carcinoma with a clinical diagnosis of IBC based on presence of inflammatory changes in the involved breast, including diffuse erythema and edema (peau d’orange). Pathological evidence of dermal lymphatic invasion should be noted but is not required for diagnosis. HER2-negative. ECOG PS 0-2. Baseline MUGA or echocardiogram scans with LVEF of > 50%. Normal hematology, liver and kidney function laboratory studies. Patients must have received at least 2 chemotherapy lines for metastatic disease and have relapsed. Research Hypothesis: Dovitinib has antitumor activity in patients with HER2-negative advanced IBC. Specific Aims: Primary objective: to determine the disease control rate (CR, PR, and SD). Secondary objective: to evaluate safety profile. Exploratory biomarkers: circulating tumor cells (CTC), CTC undergoing EMT, and cancer stem cells Statistical Methods: The primary endpoint is the six-month disease control rate (ORR) as defined by RECIST 1.1. A response is anyone who experiences SD, CR or PR in the first 6 months. We will conduct this study with Simon’s two-stage design using the mini-max criterion and the response rate will be estimated accordingly. It is assumed that dovitinib will have a target ORR of 30%. An ORR of 10% or lower is considered a failure based on the typical ORR with a second line regimen for IBC and the new regimen will be rejected under this circumstance. When the probability of accepting a bad regimen (i.e. response rate 30%) is also 0.10, Simon’s design to minimize the maximum sample size requires 22 patients in the first stage. If two or less patients respond to the treatment, the trial will be stopped and the regimen will be declared as ineffective. If at least three of the first 22 patients respond to the treatment, 11 additional patients will be entered in the study to reach a total of 33 patients. By the end of the study, the new regimen will be rejected if response rate is less than or equal to 6 out of 33 patients and will be accepted otherwise. Present Accrual and Target Accrual: A total of 22 patients were accrued. Target accrual is 33 patients. Citation Format: Ricardo H Alvarez, Mariana Chavez-MacGregor, Joe Ensor, James L Murray, Kimberly Koenig, Savitri Krishnamurty, Antony Lucci, Gildy V Babiera, Wendy Woodward, Gary J Whitman, Summer A Jackson, Michael Shi, Kenneth Culver, James L Reuben, Naoto T Ueno, Vicente Valero. A phase II study of dovitinib as salvage therapy in patients with stage IV inflammatory breast cancer HER2-negative with local or distant relapse [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 OT1-1-15.