TPS3111 Background: The HER2/HER3 oncogenic heterodimer is a potent HER receptor pairing with respect to strength of interaction, receptor tyrosine phosphorylation, and downstream signaling through mitogen activated protein kinase and phosphoinositide-3 kinase pathways. MM-111 is a novel bispecific antibody fusion protein that inhibits ligand activated HER3 signaling through abrogation of ligand binding specifically in HER2 overexpressing tumors. In preclinical models of HER2+ solid tumors, MM-111 inhibits ligand-induced HER3 phosphorylation, cell cycle progression, and tumor growth. HER2 is a well-established target of anticancer agents such as trastuzumab and lapatinib, specifically in breast and gastric tumors. Preclinical data demonstrate that MM-111 potentiates the antitumor activity of both trastuzumab and lapatinib and this phase I study seeks to determine if MM-111 can be safely used in combination with various standard of care HER2 targeting regimens, namely; (1) trastuzumab, cisplatin and, capecitabine, (2) trastuzumab and lapatinib, and (3) trastuzumab and paclitaxel. Methods: This is a multi-arm phase I, open label, multicenter, dose-escalation study of MM-111 in an add-on design that evaluates the safety, pharmacokinetics (PK), and anti-tumor activity of MM-111 in combination. Each arm is designed to run as a separate phase I study to address safety and tolerability of each combination. For eligibility, patients are required to have documented advanced HER2-positive cancer, with adequate bone marrow, hepato-renal and cardiac function. The dose escalation for each arm utilizes a standard “3 + 3” design with MM-111 dosed initially at a moderate dose of 10 mg/kg and escalated up to 20 mg/kg to identify a phase II dose in combination with each regimen. Once the maximum tolerated dose or phase II dose is identified, expansion cohorts will accrue to further evaluate these combinations. The flexibility of the design allows additional combinations arms to be added. Key exploratory analyses will include an evaluation of safety, PK, and efficacy as evidenced by best overall response and duration of response.
Phase I Study to Evaluate the Pharmacokinetics of Two Dosing Regimens of Oral Fosfomycin Tromethamine in Healthy Adult Participants