Phase 1 Study of CEP-37250/KHK2804, a Tumor-specific Anti-glycoconjugate Monoclonal Antibody, in Patients with Advanced Solid Tumors.

BACKGROUND

CEP-37250/KHK2804 is a recombinant, humanized, non-fucosylated, monoclonal antibody directed to sialic acid-containing glycoconjugates frequently found on certain tumor cell types.

OBJECTIVE

The objective was to determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetics, potential immunogenicity, and preliminary clinical efficacy of CEP-37250/KHK2804 monotherapy in patients with advanced cancer in a first-in-human, phase 1 study.

MATERIALS AND

METHODS

In phase 1a, patients (n = 31) with solid tumors received increasing doses of CEP-37250/KHK2804 (0.03-1.0 mg/kg) intravenously once weekly using a standard 3 + 3 dose-escalation design. In phase 1b, two dose-expansion cohorts of patients with colorectal (n = 15) and pancreatic (n = 16) cancer, respectively, received the maximum tolerated dose (MTD).

RESULTS

The MTD of CEP-37250/KHK2804 was 0.3 mg/kg weekly. Dose-limiting toxicities were infusion-related reactions and increased serum transaminases. In the overall population (N = 62), the most frequent treatment-related adverse event (AE) was an infusion-related reaction (45.2 %). Positive post-baseline CEP-37250/KHK2804 neutralizing antibodies were reported in 14 patients (22.6 %), almost exclusively in patients who developed infusion-related reactions. The most frequent treatment-related AE grade ≥3 was increased AST or ALT in six patients (9.7 %). Three patients experienced treatment-related serious cardiac events (grade 4 ECG abnormality, grade 4 atrial fibrillation, and grade 3 acute myocardial infarction, respectively). Pharmacokinetic exposure to CEP-37250/KHK2804 increased proportionally to dose, with accumulation up to two fold with repeated administration. Mean elimination half-life was 34.1 to 70.3 hours over the dose range from 0.03 to 1.0 mg/kg. No patient had a complete or partial best response. Thirteen of 40 (32.5 %) evaluable patients had unconfirmed stable disease, four of which were confirmed (10.0 %).

CONCLUSIONS

The study was stopped early due to the lack of efficacy. Additionally, safety concerns (i.e., cardiac issues, hepatic toxicity, and infusion-related reactions) made the benefit-risk assessment unfavorable for continued development of CEP-37250/KHK2804, which was halted indefinitely. [Study registered at ClinicalTrials.gov #NCT01447732].