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The biotech incubator Flagship Pioneering launched Moderna to make medicines by engineering messenger-RNA. A mRNA Covid-19 vaccine made Moderna one of the highest valued biotechs. Now, Flagship has unveiled a new firm to make medicines from another class of RNA molecules.
Flagship’s venture, called Alltrna, hopes to develop medicines from transfer RNA. The promise of tRNA-based treatments is that a single medicine might treat thousands of genetic diseases, Alltrna chief executive Lovisa Afzelius told Barron’s.
The privately held Alltrna, backed with $50 million from Cambridge, Massachusetts-based Flagship, is one of several startups focusing on t-RNA treatments. The notion of many diseases treated with one tRNA medicine arises from the role that tRNA plays in a cell’s function.
The recipes for the body’s proteins are carried in the DNA genome in each cell’s nucleus. Molecules of messenger RNA carry instructions from the nucleus to the cellular protein factories called ribosomes. At the ribosome, the mRNA code is read by molecules of transfer RNA, which then piece together a protein.
Genetic diseases arise when faulty genetic code produces bad proteins— like the flawed muscle scaffolding of muscular dystrophy or the choked lung lining of cystic fibrosis. A variety of genetic mutations can sometimes lead to the same misshapen protein, so a genomic treatment that corrects one patient’s disease might not work for another’s.
But if different mutations lead to the same flaw in a protein, then preventing that protein flaw might work in each case.
Transfer RNA “is the last step in the protein synthesis process,” Afzelius told Barron’s. “If we can change that last step, then we can correct it for all the genetic aberrations.”
A large number of genetic diseases result from instructions that prematurely stop the building of a protein, said Alltrna’s innovation chief, Theonie Anastassiadis. A tRNA molecule engineered to ignore these “stop” codes might remedy a variety of disorders.
Other well-funded startups exploring tRNA treatments include ReCode Therapeutics, looking into treatments for cystic fibrosis; Shape Therapeutics, looking at neurological disorders; and Tevard Biosciences, looking at epilepsies.
The transfer-RNA molecule is one of the most ancient forms of genetic code. Some scientists think it may have predated other parts of the cell’s RNA and DNA system, in the rise of life on earth.
It took 10 years for Moderna, and its rival BioNTech (BNTX), to deliver vaccines based on messenger-RNA technology. The tRNA developers are far from starting human clinical trials.
“We are exploring an entirely new space in biology,” said Anastassiadis.
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