Engineered DNA-encoded PCSK9 inhibitors may provide an effective alternative for treating high cholesterol

Elevated, low-density lipoprotein cholesterol (LDL-C) is a major risk factor for cardiovascular disease, the leading cause of death in the U.S. and worldwide. Statins are effective and widely used cholesterol-lowering medications, but have been associated with a number of side effects that have prompted development of alternative treatment strategies, including monoclonal antibodies targeting the PSCK9 protein that result in reduced degradation of LDL-C receptors on liver cells and increased cholesterol clearance from blood circulation.

"Any therapy based on recombinant monoclonal antibodies faces challenges of production among other issues as molecules may be difficult to manufacture and require multiple administrations," said lead researcher David B. Weiner, Ph.D., executive vice president, director of Wistar's Vaccine & Immunotherapy Center, and the W.W. Smith Charitable Trust Professor in Cancer Research at The Wistar Institute. "Anti-PCSK9 therapy presents an important opportunity for development of alternative approaches, possibly expanding options for such therapies."

Weiner and collaborators engineered synthetic DNA constructs that are delivered by intramuscular injection and encode the genetic instructions for the body to make its own functional monoclonal antibodies, entirely bypassing bioprocess and manufacturing factory approaches. This study provides the first proof of principle that such engineered DMAbs may be developed as a new option for coronary artery disease.

The researchers tested expression and activity of the DMAbs targeting PCSK9 in mice. A single intramuscular administration drove robust antibody expression within days and for up to two months, resulting in a substantial increase in the presence of LDL-C receptors on liver cells. This in turn resulted in a significant decrease in total cholesterol and non-high-density lipoprotein cholesterol (non-HDL-C), an important parameter for evaluating cardiovascular risk.

"We are excited about these findings that support the flexibility and versatility of the DMAb platform as a next generation approach that can be optimized for a wide host of applications," said Makan Khoshnejad, Ph.D., first author on the study and a postdoctoral fellow in the Weiner Lab.

Co-authors of this study from The Wistar Institute include Ami Patel, Krzysztof Wojtak, Sagar B. Kudchodkar, and Kar Muthumani; other co-authors include Laurent Humeau from Inovio Pharmaceuticals, Inc.; and Nicholas N. Lyssenko and Daniel J. Rader from the University of Pennsylvania.

This work was supported by funding from Inovio Pharmaceuticals, Inc.