A phase 1 study evaluating safety and pharmacokinetics of losatuxizumab vedotin (ABBV-221), an anti-EGFR antibody-drug conjugate carrying monomethyl auristatin E, in patients with solid tumors likely to overexpress EGFR

SummaryLosatuxizumab vedotin (formerly ABBV-221) is a second-generation antibody-drug conjugate targeting epidermal growth factor receptor (EGFR). In this multicenter phase 1 study, eligible patients with EGFR-dependent solid tumors received losatuxizumab vedotin (3  + 3 design) intravenously at starting dose of 0.3 mg/kg over 3 h per 21-day cycle, with alternate dosing schedules utilized (2 weeks on/1 week off or weekly) to mitigate infusion reactions. Forty-five patients received ≥1 doses of losatuxizumab vedotin (13 colon, 6 non-small cell lung can cer, 5 head and neck [HNC], 5 glioblastoma multiforme, 2 breast, 14 other). Tumor samples were evaluated for EGFR protein expression by immunohistochemistry, EGFR and EGFR ligand mRNA expression by RNAseq, and results compared with outcome. Most common adverse events were infusion-related reaction ( 22/45; 49%) and fatigue (20/45; 44%). While most infusion reactions were grade ≤ 2, four patients experienced grade ≥3 infusion reactions. Several infusion reaction mitigation strategies were explored. Because of the high incidence of infusion reactions, the trial was stopped and the maxim um tolerated dose was not reached. The last cleared dose: 6 mg/kg/cycle. Nineteen patients (42%) had stable disease; 4 remained on study>6  months. One HNC patient with increased levels of EGFR and EGFR ligands (amphiregulin, epiregulin) achieved a confirmed partial response. Pharmacokinetic analysis of losatuxizumab vedoti...
Source: Investigational New Drugs - Category: Drugs & Pharmacology Source Type: research