Safety and efficacy of depatuxizumab mafodotin in Japanese patients with malignant glioma: A nonrandomized, phase 1/2 trial

INTELLANCE-J was a phase 1/2 study of a potent antibody-drug conjugate targeting epidermal growth factor receptor (EGFR), depatuxizumab mafodotin (Depatux-M), as a second- or first-line therapy, alone or combined with chemotherapy or chemoradiotherapy in 53 Japanese patients with World Health Organization (WHO) grade III/IV glioma. In second-line arms, patients with EGFR-amplified recurrent WHO grade III/IV glioma received Depatux-M plus chemotherapy (temozolomide) or Depatux-M alone regardless of EGFR status. In first-line arms, patients with newly diagnosed WHO grade III/IV glioma received Depatux-M plus chemoradiotherapy. The study was halted following lack of survival benefit with first-line Depatux-M in the global trial INTELLANCE-1. The primary endpoint was 6-month progression-free survival (PFS) in patients with EGFR-amplified tumors receiving second-line Depatux-M plus chemotherapy. Common nonocular treatment-emergent adverse events (TEAEs) with both second-line and first-line Depatux-M included lymphopenia (42%, 33%, respectively), thrombocytopenia (39%, 47%), alanine aminotransferase increase (29%, 47%), and aspartate aminotransferase increase (24%, 60%); incidence of grade >= 3 TEAEs was 66% and 53%, respectively. Ocular side effects (OSEs) occurred in 93% of patients receiving second-line Depatux-M plus chemotherapy and all patients receiving second-line Depatux-M alone or first-line Depatux-M plus chemoradiotherapy. Most OSEs were manageable with dose modifications and concomitant medications. The 6-month PFS estimate was 25.6% (95% confidence interval [CI] 11.4-42.6), and median PFS was 2.1 months (95% CI 1.9-3.9) with second-line Depatux-M plus chemotherapy in the EGFR-amplified subgroup. This study showed acceptable safety profile of Depatux-M alone or plus chemotherapy/chemoradiotherapy in Japanese patients with WHO grade III/IV glioma. The study was registered at ClinicalTrials.gov (NCT02590263).