Phase I study of the anti-heparin-binding epidermal growth factor-like growth factor antibody U3-1565 with cetuximab in patients with cetuximab- or panitumumab-resistant metastatic colorectal cancer

SummaryKRAS wild-type colorectal cancers initially responsive to anti-endothelial growth factor receptor (EGFR) antibodies [cetuximab (Cetu)/panitumumab (Pani)] develop acquired resistance. Overexpression of EGFR ligands such as heparin-binding EGF-like growth factor (HB-EGF) may be one resistance mechanism. This phase I study of U3-1565, anti-HB-EGF antibody, and Cetu combination therapy enrolled patients withKRAS wild-type metastatic colorectal cancer who had received two ≤ regimens with fluoropyrimidine, oxaliplatin, irinotecan, and Cetu/Pani and had disease progression on Cetu/Pani. Recommended dose (RD) was determined in the 1st stage, followed by evaluation of efficacy at the RD level in the 2nd-stage. Cetu was given at a loading dose of 400 mg/m2 followed by weekly infusions of 250  mg/m2 in levels 1 and 0. U3-1565 was administered at a loading dose of 24  mg/m2 followed by biweekly infusions of 16  mg/m2 in level 1 and 16 –12 mg/m2 in level 0. Twenty-two patients were enrolled. No dose-limiting toxicities were observed among three patients in level 1 in the first stage, which was determined as RD. Grade 3 or higher adverse events occurred in 59.1%; those in ≥5% of patients were anemia, γ-GTP elevation, and acneiform rash. Overall response rate was 0.0% [95% confidence interval (CI): 0.0%–15.4%] and disease control was achieved in 17 patients (77.3%, 95% CI: 54.6%–92.2%). Median progression-free survival time was 85.0 days (95% CI: 54.0–91.0) and med...
Source: Investigational New Drugs - Category: Drugs & Pharmacology Source Type: research