Transfer RNA are key to the protein-making process in cells, and some biotech companies are turning to these molecules as a potentially new way of treating diseases. The latest such company is hc Bioscience, which is now out of stealth backed by $24 million.
The Series A round of funding announced Wednesday was led by a syndicate that includes ARCH Venture Partners, Takeda Ventures, and 8VC.
The cause of many diseases are dysfunctional proteins. In some cases, that dysfunction is because the protein is incomplete. An error in the DNA blueprint for the protein leads to a genetic instruction to stop the protein making process prematurely, resulting in a truncated protein. This type of error is called a “nonsense mutation.” According to Cambridge, Massachusetts-based hC Bio, such mutations are responsible for 10% to 15% of all human disease.
Transfer RNA, or tRNA, are key to the protein-making process, ensuring that key amino acids are properly added to the protein as it is made. The technology of hC Bio, called PTCX, uses tRNA to suppress nonsense mutations in the genetic code, which in turn should enable the cell’s protein-making machinery to produce the proper full-length protein.
The startup also has a second technology, PTCX, that addresses diseases caused by missense mutations, in which a change in the DNA sequence leads to the wrong amino acid being incorporated into the protein. The PTCX technology marks that disease-causing protein for destruction by the cell.
Leslie Williams, president and CEO of hC Bio, and Christopher Ahern, a University of Iowa professor of molecular physiology and biophysics, co-founded the startup. Ahern’s lab identified engineered tRNAs that can be used to address the instructions that prematurely halt the protein-making process. The lab’s tRNA research was published in 2019 in Nature Communications.
“We are creating medicines to restore protein function to its intended state without editing genes,” Williams said in a prepared statement. “A single tRNA therapy has the potential to treat many diseases regardless of the gene or location of the mutation.”
Williams’s experience includes founding and serving as president and CEO of therapeutic vaccines developer ImmusanT. Her new company has not specified which diseases it aims to treat with tRNA, but it joins several biotechs developing therapies in this emerging class of genetic medicines. Last November, Cambridge-based startup Alltrna launched with tRNA technology and a $50 million from venture capital firm Flagship Pioneering. Similar to hC Bio’s PTCX technology, Alltrna is engineering tRNAs to treat diseases caused by nonsense mutations.
Another Cambridge biotech, Tevard Biosciences, is developing tRNA therapies that modulate RNA in order to address nonsense mutations and haploinsufficiencies, disorders in which one gene of a gene pair is not functioning properly, leading to insufficient levels of a protein. Tevard’s science is based in part on Ahern’s research.
