Plexium bumps up series A by $35M as it battles rivals in the new protein-degradation space

More than a year after its initial $28 million series A raise in October 2019, protein-degradation biotech Plexium is adding another $35 million on top of that total.

It now has $63 million in the bank to work in a new and exciting R&D space, increasingly populated by early biotechs looking to exploit the body’s protein-degradation machinery—the ubiquitin proteasome system—to knock down disease-causing proteins.

These companies are aiming at “undruggable” proteins, those parts of the human proteome that are not accessible with current approaches. Plexium’s platform technology advances a pipeline of drugs that target E3 ligases, the enzymes that drive recognition of protein targets.

The San Diego-based startup’s first areas of focus will be cancer and neurodegenerative diseases, and now it has that extra cash, led by Lux Capital and Pivotal BioVentures with participation from The Column Group, DCVC Bio and other current investors, to help.

The funds will also see the biotech “accelerate the advancement of targeted, monovalent degraders” through preclinical development, while “also supporting research efforts aimed at understanding mechanisms and design principles for monovalent protein degraders,” it said in a statement.

“We are incredibly delighted to have the support of such outstanding investors and to welcome Mike to our Board as Chairman,” said Plexium CEO Swamy Vijayan.

“Mike’s deep experience with company building and translating technology and insights into drugs will be invaluable to us as we continue to grow. With his guidance and the continued backing of our investors, we are looking forward to building an exciting pharmaceutical company on the back of our groundbreaking technical abilities.”