PepGen Raises $112.5M to Move EDO Therapies to Human Trials
PepGen has raised funding totaling $112.5 million to advance toward the clinic its enhanced delivery oligonucleotide (EDO) lead programs in Duchenne muscular dystrophy (DMD) and myotonic dystrophy type 1 (DM1).
The funding round keeps PepGen on track to start Phase 1 clinical trials in 2022 for DMD, and in early 2023 for DM1. These trials will test the company’s lead EDO therapy candidates, which PepGen hopes will be able to correct the genetic cause of these types of muscular dystrophy.
“We are thrilled to … be joined by this strong syndicate as we rapidly move towards the clinic with our lead programs in DMD and DM1,” James McArthur, PhD, president and CEO of PepGen, said in a press release.
Oligonucleotides are short DNA or RNA molecules that may be used to treat many genetic diseases. Getting such therapeutic oligonucleotides into cells, however, remains a challenge.
To overcome it, scientists at PepGen designed special peptides — short chains of amino acids, the building blocks of proteins — that act as delivery agents for therapeutic cargo. This approach leads to EDOs, which according to the company may be efficiently delivered to muscle.
“PepGen has demonstrated that their EDOs achieve therapeutically differentiated levels of oligonucleotide delivery to muscle, including cardiac tissue, which is an area of unmet need for DMD patients,” said Joshua Resnick, MD, managing director of RA Capital Management.
Genes are split into exons and introns, with exons being the gene sections containing information to generate proteins. In most people with DMD, one or more exons of the DMD gene, which carries the instructions to make dystrophin, are missing due to mutations. This results in the body not being able to make dystrophin, a protein that is needed for the muscles to work well.
In some cases, skipping over exon 51 helps the body make a shorter version of the protein that is still functional. This strategy is called exon skipping.
EDO51, the company’s lead candidate to treat a subset of DMD patients amenable to exon-skipping therapy, combines a delivery peptide with a therapeutic oligonucleotide to target exon 51.
According to PepGen, preclinical studies suggest that EDO51 — at lower doses than existing therapies — may lead to high levels of exon skipping, which are expected to result in more dystrophin being made.
One already approved therapy that uses the exon-skipping strategy, and also targets exon 51, is Exondys 51 (eteplirsen). Developed by Sarepta Therapeutics, Exondys 51 was approved by the U.S. Food and Drug Administration in 2016.
PepGen believes its therapies have the potential to become best-in-class.
“We have shown in large animal studies that we can safely achieve industry-leading efficacy in exon 51 skipping, and we hope this will be transformative for DMD patients,” McArthur said. “We will build on this work to expand our DMD program and into other neuromuscular diseases, leveraging the enormous potential of our EDO platform technology to create a better future for people living with genetic diseases.”
The company hopes to broaden the strategy to include DMD patients amenable to exon-skipping therapy beyond exon 51.
“It’s extremely gratifying to witness the rapid translation of our scientific work on the optimization of cell-penetrating peptides to the development of new medicines that have the potential to radically impact the course of rare and devastating neuromuscular diseases,” said Matthew Wood, scientific co-founder of PepGen.
The company’s lead candidate in DM1, EDODM1, works by blocking toxic, extra-long RNA resulting from disease-causing mutations in the DMPK gene. The approach is thought to restore cellular function to muscles.
“We look forward to continuing our support of the company as it works toward its ultimate goal to change the treatment paradigm for people with DMD, DM1 and other rare genetic disorders,” said Alexis Dormandy, CEO of OSI.
The oversubscribed crossover financing for PepGen comes from new investors, including Viking Global Investors, Deerfield Management, Adage Capital Management, Samsara Biocapital, Laurion Capital Management, Tudor Investment, and Gray’s Creek Capital Partners.
They join PepGen’s current investors, which include CureDuchenne Ventures, the investment arm of the U.S. nonprofit CureDuchenne. Ventures provides both equity financing to biotech and pharmaceutical companies and grant funding to academic groups.
The new funding also will allow the expansion of PepGen’s team in its headquarters in Boston, the company said.