RNA Drugs Target Genes That Were Once Off-Limits
A unique class of RNA drugs could bring new treatments to cancer and other diseases.
Many diseases are caused by inactive or underactive genes, and there are currently no methods to turn them on.
A new class of medicines could give doctors the ability to awaken underperforming genes in patients who currently have no treatment options.
Boston-area startup RaNA Therapeutics is developing a novel kind of medicine that can boost the activity of genes that may be silenced or underactive and thus cause disease. The medicine would use a small RNA-like molecule that blocks the function of a long RNA molecule that is hampering the expression of such a gene.
By activating genes, RaNA’s medicines could do something completely new, says Jeannie Lee, a molecular biologist at Harvard Medical School and scientific founder of the company. Most drugs work by changing the function or stability of a gene product—for example, by blocking an enzyme that is overly active. “Current therapeutics go after something that is already expressed,” says Lee. “There are currently no methodologies to turn on a gene that is silent.”
RaNA’s technology, which is still at the stage of testing in lab animals, could be used to treat cancers as well as rare genetic diseases. Often, part of the changes that take place in a cancer cell includes silencing of so-called tumor-suppressor genes. And in some genetic diseases, a normal gene may be aberrantly silenced or just weakly expressed.
RaNA’s approach could also target complex metabolic diseases, says Art Krieg, the company’s CEO and cofounder. “In diabetes and other metabolic diseases, there are a lot of different targets that have been identified, and so the ability to reach in and selectively turn on just one gene, we think, is going to have very broad therapeutic applications,” Krieg says.
In lab tests, RaNA has seen a range of effects on gene expression, from a fourfold increase to a 100-fold increase. “It varies from gene to gene,” says Krieg. “It certainly is not rare to see 10-fold increases,” he says.
The company formed less than two years ago and soon thereafter announced $20.7 million in investments from GlaxoSmithKline’s venture fund SR One, Monsanto, and others. The company hopes to start testing its products in patients in 2015, says Krieg. RaNA is keeping mum about which diseases it will target for now. Broadly, Krieg says, the company will go after diseases for which there are currently no drugs available. It’s pursuing leads in diseases involved in the nervous system, inflammation, and a muscle disease. The treatment paradigm would likely involve an infusion once every month or so, says Krieg. Depending on the disease, it could be delivered through a vein, a muscle, or a spinal tap.