Zalutumumab

EGFR plays an essential role in cellular signaling pathways that regulate cell growth, proliferation, and survival and is often dysregulated in cancer. Several monoclonal IgG antibodies have been clinically tested over the years, which exert their function via blocking the ligand binding domain (thereby inhibiting downstream signaling) and inducing Fc-related effector functions, such as antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP). However, these IgG antibodies do not optimally recruit neutrophils, which are the most abundant white blood cell population in humans. Therefore, we reformatted six therapeutic EGFR antibodies (cetuximab, panitumumab, nimotuzumab, necitumumab, zalutumumab, and matuzumab) into the IgA3.0 format, which is an IgA2 isotype adapted for clinical application. Reformatting these antibodies preserved Fab-mediated functions such as EGFR binding, growth inhibition, and ligand blockade. In addition, whole leukocyte ADCC was significantly increased when using this panel of IgA3.0 antibodies compared with their respective IgG counterparts, with no major differences between IgA3.0 antibodies. In vivo, IgA3.0 matuzumab outperformed the other antibodies, resulting in the strongest suppression of tumor outgrowth in a long intraperitoneal model. We showed that neutrophils are important for the suppression of tumor outgrowth. IgA3.0 matuzumab exhibited reduced receptor internalization compared with the other antibodies, possibly accounting for its superior in vivo Fc-mediated tumor cell killing efficacy. In conclusion, reformatting EGFR antibodies into an IgA3.0 format increased Fc-mediated killing while retaining Fab-mediated functions and could therefore be a good alternative for the currently available antibody therapies.

Aim: We assessed the efficiency of immune checkpoint inhibitors relative to other systemic therapies in previously treated recurrent/metastatic head and neck cancer. Materials & methods: Relative treatment effects were assessed from eligible randomized controlled trials using Bayesian network meta-analyses. Results: Among 15 trials evaluating 14 treatments, nivolumab achieved the best overall survival (OS) benefit; zalutumumab and buparlisib + paclitaxel provided the best progression-free survival benefit and objective response rate. Buparlisib + paclitaxel and zalutumumab were associated with the best OS rate at 6 and 12 months, respectively; nivolumab yielded the best OS rate at 18-24 months. Conclusion: Nivolumab was the most favorable treatment. Zalutumumab and buparlisib + paclitaxel had better efficiency, and might be a better selection for patients with programmed death-ligand 1-low/negative tumors than other treatments.