United States-based Inovio Pharmaceuticals has completed animal testing of DNA-encoded monoclonal antibodies targeting the immune checkpoint molecule CTLA-4, it was reported yesterday.

The preclinical study indicated that highly optimised dMAbs targeting mouse CTLA-4 protein can be robustly expressed in vivo, and shrank tumours in mice. The company's dMAb constructs for anti-human CTLA-4 antibodies ipilimumab (YERVOY) and tremelimumab, achieved high expression levels in mice (approximately 85µg/ml and 58µg/ml, respectively). These dMAbs exhibited long-term expression with maintenance of serum levels >15µg/ml for over a year.

Inovio research & development senior vice president, Laurent Humeau, said, 'Even though conventional monoclonal antibodies represent one of the most successful segments of the biotechnology market, accounting for over USD50 billion in sales today, manufacturing complexity and repeated dosing may limit a broader use of this technology. Inovio's dMAb products may improve upon this class using our synthetic design and in vivo production. This newly published study further support that Inovio's potent dMAb platform can be expanded to target cancer. We plan on advancing the first clinical dMAb candidate into the first-in-human study in 2019. Moreover, we expect to form partnerships to advance several dMAb products targeting cancers and infectious diseases.'

This research publication is significant because it is the first to report on the use of Inovio dMAb technology to develop novel monoclonal antibody-based therapies targeting checkpoint inhibitors. Inovio is developing additional dMAbs targeting other checkpoint molecules including PD-1.