After years chasing a hard-to-drug group of targets called solute carriers, Jnana Therapeutics is revealing its lead program and a new $50 million financing to get it into the clinic.
That program targets phenylketonuria (PKU), a rare, inherited disorder in which patients lack, or don’t make enough of, an enzyme to break down an amino acid called phenylalanine. Also called Phe, the substance builds up in the blood and brain and can lead to intellectual disability, psychiatric disorders and seizures. Diagnosed at birth, PKU affects children and adults of all ages.
There are two approved treatments for PKU, both from BioMarin, as well as gene therapies in development. However, some of them don’t work for patients of all ages, while others only work for patients with specific mutations, said Jnana CEO Joanne Kotz, Ph.D.
RELATED: Roche, Jnana take aim at metabolite transporters in $40M discovery deal
With its treatment, Jnana aims to treat all patients with PKU regardless of their age or the mutation underpinning their disease. It works by blocking SLC6A19, a membrane protein that’s responsible for the reabsorption of Phe in the kidney. This increases the amount of Phe that is excreted via urine and lowers the level of disease-causing Phe in the blood.
Kotz declined to share when the treatment might enter the clinic but said the series B proceeds are sufficient to get it into human trials.
SLC6A19 is a member of the solute carrier family of proteins, which sit on the cell surface, or inside the cell, and control the movement of metabolites such as glucose, cholesterol, amino acids and metals in and out of cells or to the right location within cells.
The new funding, from RA Capital Management and all of Jnana’s existing backers including Polaris Partners, Versant Ventures, Avalon Ventures and the venture arms of AbbVie and Pfizer, will also bankroll the development of Jnana’s earlier-stage pipeline and the expansion of its drug discovery platform beyond solute carriers, or SLCs.
RELATED: FierceBiotech's 2018 Fierce 15 | Jnana Therapeutics
Jnana launched in 2017 with $50 million to build a platform that would enable the systematic discovery of drugs targeting SLCs. Although there are more than 400 proteins in this family, only 20 of them are the targets of approved drugs, Kotz said in a previous interview. The main hurdle was the lack of technology to go after these targets in a systematic way.
But as it built that drug discovery technology, the company found it could find small molecules that bind to other types of proteins, not just solute carriers. The company isn’t giving anything away, but is looking at “highly validated but challenging-to-drug targets that fit into well-known disease pathways,” Kotz said. One area of focus is immune-mediated disease, which the company is already pursuing in its earlier-stage pipeline.
Besides conditions involving the immune system, Jnana continues to focus on metabolite-dependent diseases, such as PKU, which are caused by too little or too much of a metabolite, Kotz said. As it develops its pipeline, the company is also pushing ahead with two partners.
RELATED: Nirogy Therapeutics emerges with $16.5M to target metabolite transporters
Jnana teamed up with Neurocrine Biosciences in 2018 to develop SLC-targeting drugs for central nervous system disorders. And, in July last year, it inked a discovery deal that saw Roche hand over $40 million upfront and promise $1 billion more in milestones to work on “a broad set of targets” in immunology and neurological diseases.
As it nears the clinic, Jnana will build its team from 50 to about 80 staffers over the next year or two, Kotz said. And as for future partnerships, the company is always open to suitors.
“At the right point, we will be looking to create additional partnerships that either allow us to more efficiently advance into the clinic with our current programs or to broaden our pipeline in a way that lets us speed up our ability to get new medicines to patients,” Kotz said.