Phase I study of YS110, a recombinant humanized monoclonal antibody to CD26, in Japanese patients with advanced malignant pleural mesothelioma.

OBJECTIVES: CD26 is a transmembrane glycoprotein with dipeptidyl peptidase IV activity that is overexpressed in malignant pleural mesothelioma (MPM). We performed a phase I study to determine the maximum tolerated dose, pharmacokinetics, and antitumor activity of YS110, a monoclonal antibody to CD26, in Japanese patients with MPM intolerant of or refractory to prior standard therapies. MATERIAL AND METHODS: The study was designed as an open-label, 3 + 3 dose-escalation, phase I trial. Patients were sequentially assigned to three dosing cohorts (2, 4, or 6 mg/kg). Each 6-week treatment cycle consisted of YS110 administration weekly for 5 weeks followed by a 1-week rest period. Treatment was continued until disease progression, death, or intolerable toxicity. Corticosteroid, antihistamine, and acetaminophen administration before each infusion was adopted to limit infusion-related reactions (IRRs). RESULTS: Nine Japanese patients (seven men and two women, mean age of 62.2 years), three in each dosing cohort, were enrolled in the study. No patient developed a dose-limiting toxicity. Adverse events of grade 3 or 4 developed in seven patients, with the most common such event being a decreased lymphocyte count. Two patients had mild or moderate IRRs. The serum concentration of YS110 increased in a dose-dependent manner. Among seven patients evaluable for tumor response, four showed stable disease and one achieved a partial response. CONCLUSIONS: YS110 showed promising antitumor efficacy and was generally well tolerated in Japanese patients with advanced MPM at doses of up to 6 mg/kg. YS110 will be tested at 6 mg/kg in a subsequent phase II study.

First-in-human phase 1 of YS110, a monoclonal antibody directed against CD26 in advanced CD26-expressing cancers.

BACKGROUND: YS110 is a humanised IgG1 monoclonal antibody with high affinity to the CD26 antigen. YS110 demonstrated preclinical anti-tumour effects without significant side effects. METHODS: This FIH study was designed to determine the maximal tolerated dose (MTD) and recommended phase 2 dose (RP2D) to assess the tolerance, pharmacokinetics (PK) and pharmacodynamics profiles of YS110 and preliminary efficacy. YS110 were initially administered intravenously once every 2 weeks (Q2W) for three doses and then, based on PK data, once every week (Q1W) for five doses in patients with CD26-expressing solid tumours. RESULTS: Thirty-three patients (22 mesothelioma) received a median of 3 (range 1-30) YS110 infusions across six dose levels (0.1-6 mg kg-1). MTD was not reached and two dose-limiting toxicities (infusion hypersensitivity reactions) led to the institution of a systemic premedication. Low-grade asthenia (30.3%), hypersensitivity (27.3%), nausea (15.2%), flushing (15.2%), chills (12.1%) and pyrexia (12.1%) were reported as ADRs. Pharmacokinetic parameters (AUC and Cmax) increased in proportion with the dose. sCD26/DPPIV assays indicated CD26 modulation. Prolonged stable diseases were observed in 13 out of 26 evaluable patients. CONCLUSIONS: YS110 is well tolerated up to 6 mg kg-1 Q1W, which has been defined as the RP2D, with encouraging prolonged disease stabilisations observed in a number of patients with advanced/refractory mesothelioma.