Renasant Bio launches to develop kidney disease treatment

Renasant Bio has launched with $54.5 million in seed financing to develop treatments for autosomal dominant polycystic kidney disease (ADPKD), which causes severe kidney damage. The financing was led by venture capital firm 5AM VentureManagement, with additional funding from Atlas Venture, OrbiMed, and Qiming Venture Partners USA.

ADPKD is the most common inherited cause of end-stage kidney disease and is characterized by cysts that form on the kidneys. Most people with ADPKD have mutations in either the PKD1 or PKD2 gene, causing faulty PC1 or PC2 proteins, which are important for ion flux in cells. But defects can occur anywhere in these genes, making universal treatments difficult.

Tolvaptan is the only drug on the market to treat ADPKD and only manages the progression of the disease. Seeing market potential, 5AM Ventures set out to find a way to treat the underlying cause of the illness, not just slow the illness down.

In 2022 they approached University of California, San Francisco, faculty members Jeremy Reiter and Markus Delling, who had an idea to follow the example of cystic fibrosis, another genetic disease that causes malfunctioning ion channels, which is treated with drugs called correctors and potentiators that help protein function.

A year later, Emily Conley, former CEO of Federation Bio, joined as CEO, and they’ve been fundraising and building a team ever since, she says.

“Given the capital that we’ve raised and the progress we’ve been making on the science . . . we figured now was the time to debut out of stealth,” Conley says.

The company’s lead program is an oral small-molecule corrector that helps PC1 and PC2 make the correct shapes to traffic in the cell and perform their function. They are also working on a potentiator that helps the proteins maintain ion flux in the cell.

“We believe the holy grail is to find a corrector that can work across a very broad set of mutations, and this is what has gotten our investors so excited that we have data supporting this approach,” Conley says.

Renasant Bio joins a growing field of companies developing treatments for ADPKD. Novartis has an anti-microRNA in Phase 1 clinical trials that upregulates PKD1 and PKD2 gene expression. Vertex Pharmaceuticals has a molecule in Phase 3 clinical trials that blocks a protein implicated in the disease, and it also has a small-molecule corrector in Phase 1.

Vertex’s small-molecule corrector will target only 10% of patients, according to a March 2024 press release from the company. Conley declined to say the percentage of patients that Renasant Bio’s corrector will target, but she says it’s much broader.

The firm’s seed financing will take them through candidate drug nomination for the corrector program and help advance the potentiator into preclinical development. The molecules will be developed as standalone therapies and may enter clinical trials within a couple of years, Conley says.