Neurology drug developer Karuna Therapeutics is building its pipeline with a pair of molecules originally developed for kidney disease. It’s a small bet that could pay off big by diversifying production with drugs that could compete with Boehringer Ingelheim’s drug candidate targeting the same target.
Karuna’s new assets come from startup Goldfinch Bio, which is shutting down. According to financial conditions announced On Thursday, Boston-based Caruna paid $15 million upfront for the two small molecules.
Goldfinch discovered drugs with technology that analyzes anonymized human kidney data to identify potential drug targets. This technology identifies ways to target transient receptor potential canonical (TRPC) channels 4 and 5, pathways associated with certain kidney diseases. The research led to a lead program, GFB-887, which reached the mid-stage of testing. Although activity was shown in the kidney, Caruna President of Research and Development and Chief Scientific Officer Steve Paul notes that preclinical and clinical studies also show antidepressant and anxiety-reducing properties.
“We are fortunate to have discovered an advanced clinical-stage drug candidate targeting these important [central nervous system] targets and will now investigate GFB-887 in a variety of mood and anxiety disorders, where there remains a significant unmet medical need for mechanistically novel drugs,” Paul said in a prepared statement.
Going after TRPC 4/5 brings a different dimension to Karuna, who has focused her research on targeting muscarinic receptors found in the central nervous system. Lead drug candidate KarXT, an agonist of two muscarinic receptors, M1 and M4, has reached Phase 3 testing in schizophrenia. After publication positive data in the study last August, the biotechs said they plan to seek FDA approval in mid-2023. The remaining programs are preclinical and being developed for undisclosed purposes.
Karuna said he expects to report more details on plans for GFB-887 in the second half of this year. By then, Boehringer Ingelheim may have Phase 2 data for its drug candidate targeting TRPC4/5 in depression. A positive result from this study could lead to Karuna’s new assets, William Blair analyst Miles Minter wrote in a research note. He added that to his knowledge, Karuna now has the only other TRPC4/5 inhibitors being developed for neuropsychiatric disorders and may have a once-daily dosing advantage compared to the twice-daily dosing of Boehringer’s drug candidate Ingelheim.
The $15 million upfront payment is insignificant for what has the potential to become a high-value asset, Minter said. Depending on research progress, Karuna could pay up to $520 million in milestone payments for each TRPC4/5 drug candidate. The biotech will also pay royalties to the Goldfinch properties from sales if the molecules reach the market.
Goldfinch, which spun off from venture capital firm Third Rock Ventures, initially tested GFB-887 in focal segmental glomerulosclerosis (FSGS), a rare disease that causes scarring of the kidney’s glomeruli, the parts of the kidney that filter waste from the blood. Almost a year ago, the company announced mixed preliminary data from phase 2 for the medicine. Although the results showed a reduction in urinary protein levels indicative of FSGS, no treatment effect was observed in the original group of patients with diabetic nephropathy. Fierce Biotech was the first to report last week Goldfinch was closing. Executives told Fierce that the move follows the company’s failure to secure additional financing.
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