Stuart Schreiber’s bid to tackle huge class of crucial proteins nabs another $50M
Four years after launching with prestigious co-founders and ambitions to go after a family of ancient and crucial proteins, it’s still not clear how far Jnana Therapeutics has advanced. But it’s pushed far enough that investors are willing to infuse more cash.
Jnana announced a $50 million Series B on Wednesday led by RA Capital. Although light compared to the megarounds that have become increasingly routine for biotechs, it contains the same melange of A-list investors that backed the company’s scientists from the beginning, including Polaris, Versant, AbbVie and Pfizer.
Stuart SchreiberFounded by Vertex co-founder Stuart Schreiber, a couple of his colleagues at the Broad Institute, and Bristol Myers vet Joel Barrish, Jnana’s big idea was to go after SLCs, a family of about 450 proteins that traffic metabolites into and out of cells. Although drug developers had targeted these receptors individually — SGLT2 inhibitors, a highly effective class of diabetes drugs, for example —no one had ever tried to go after them comprehensively.
“What’s made them really hard to go after from a drugging perspective is they’re incredibly diverse, one from the other,” CEO and co-founder Joanne Kotz told Endpoints News. “They’re diverse in terms of their structure, a wide variety of structures within the family. They’re diverse in terms of their substrate; huge variety of metabolites, all the way from cholesterol to iron.”
There was also the problem that the proteins are bound to a membrane, so they couldn’t be easily isolated to study in a dish. Jnana came up with a couple technological solutions: It tried to study directly in live cells, instead of isolating them. And, rather than immediately look for small molecules that inhibit a given protein, its scientists first come up with “binders” that latch on anywhere.
“The advantage this gives us is that we can develop a common approach to looking at binding that you can move from one to the next,” Kotz said.
So far the fruits of those efforts remain unclear. The team has won high-profile partners, snaring a collaboration with Neurocrine to go after SLCs in the central nervous system, and a $40 million upfront, $1 billion milestone deal with Roche to go after receptors relevant for neurology and immunology.
All of the company’s programs, though, remain preclinical and executives have yet to say precisely how preclinical they are. With the financing on Thursday, Jnana disclosed that its lead program would be in PKU, a rare genetic disease caused by an overabundance of a molecule called phenylalanine (Phe) in the blood; Jnana will look to block a receptor in kidney cells that reabsorbs Phe, thereby allowing more of the metabolite to filter out into the kidney.
Kotz, though, declined to say how far along the program was or if they yet had a lead molecule.
“What I can say is that our Series B funding is sufficient to get the PKU program into the clinic,” she said.
Meanwhile, the company is now looking to go beyond SLCs and into other classes. Kotz claimed they had developed a platform sufficiently that they can quickly build small molecule binders to virtually any proteins, and then either try to inhibit or degrade those proteins. She sees it as part of a wave of renewed interest from pharma in new small molecule technologies, pointing to Bayer’s recent $2 billion buyout of Vividion.
“We joke internally that SLCs as a target class are so diverse, so challenging, that in order to build a platform to drug any SLC, we had to build what we laughingly refer to as a Ferrari engine,” she said. “A platform that really has the capability to drug any protein.”
