About half of all patients with the most severe form of Alport syndrome, a rare, genetic type of chronic kidney disease, will need dialysis or a transplant by age 25.
On Monday, Reata Pharmaceuticals (NASDAQ: RETA) announced that its investigational drug for those with Alport syndrome, bardoxolone methyl (bard), met the main goal of a Phase 3 clinical trial. After 48 weeks of treatment, patients in the study who received bard saw their kidney function—as measured by a blood test that estimates how much blood passes through filters in the kidneys each minute—improve compared to a placebo.
Data from the study show patients who received the Reata drug saw their levels of eGFR, the measure of kidney function, improve from baseline by an average of 4.72 milliliters per minute (mL/min) compared to those who received a placebo. Those in the study who got a placebo experienced an average decline in their levels of eGFR of -4.78 mL/min. When this measure falls too low, patients require kidney dialysis or a transplant.
The experimental treatment also met a secondary goal established for the trial: a significant change in kidney function compared to placebo persisting after four weeks subsequent to the 48-week treatment, when patients were no longer receiving the drug or a placebo. In that time patients who had been receiving bard saw an average change of -0.96 mL/min to their levels of eGFR. Patients who received the placebo experienced an average decline of -6.11 mL/min.
Reata CEO Warren Huff (pictured), in a conference call Tuesday, said that the data indicate the drug “has the potential to modify the course of the disease and may delay or prevent the need for dialysis or a kidney transplant.”
The Plano, TX-based company now plans to ask the FDA to review the drug. No FDA-approved treatment for Alport syndrome currently exists. According to an estimate by the Alport Syndrome Foundation, 30,000 to 60,000 people in the US have the condition.
A total of 157 people, about 15 percent of whom were children, were enrolled in the Reata study and randomly assigned to receive bard or placebo on a 1:1 basis. Those who completed the trial will receive the drug for another year, the results of which will be measured after 100 weeks of treatment.
The company’s stock price closed Monday at $213.67, about 207 percent higher than the start of October, when its shares traded at $75.49 each. Reata has seen significant growth in its market value since going public in 2016 at $11 per share—about 5 percent of the value at which it is currently trading.
Other biotechs are also eying the rare kidney diseases space. Earlier this year Chinook Therapeutics launched with $65 million and a plan to target kidney diseases starting with rare conditions, although it wouldn’t identify which it aimed to tackle.
At the time Jerel Davis, a managing director with Chinook backer Versant Ventures, told Xconomy that he believed interest in new drugs for kidney disease was intensifying in a manner similar to the heightened investor enthusiasm in recent years for potential treatments for nonalcoholic steatohepatitis (NASH), a liver condition whose incidence is rising.
Goldfinch Bio is also working on treatments for kidney diseases, and this year partnered with Gilead Sciences (NASDAQ: GILD) to advance those efforts.
Reata also plans to ask the FDA to review its other lead drug candidate, omaveloxolone, after that treatment met the goal of a late-stage study testing it as a potential treatment for another rare disease—a mitochondrial disorder known as Friedreich’s ataxia.
Both drugs are supposed to target a transcription factor called Nrf2 that helps regulate important biological processes, including mitochondrial function.
The Texas biotech is also studying bard in Phase 3 trials as a treatment for other conditions in which mitochondrial dysfunction is believed to play a role, including connective tissue disease-associated pulmonary arterial hypertension and autosomal dominant polycystic kidney disease.