IRVING, Texas—Reata Pharmaceuticals Inc., a clinical-stage biopharmaceutical company, recently announced results from two Phase 2 studies of bardoxolone methyl (bardoxolone) in patients with chronic kidney disease (CKD). Reata reported positive one-year results for the Phase 2 portion of CARDINAL, a study of bardoxolone in patients with CKD due to Alport syndrome, and positive final results for the Phase 2 autosomal dominant polycystic kidney disease (ADPKD) cohort of PHOENIX.
In the Phase 2 portion of CARDINAL, significantly increased estimated glomerular filtration rate (eGFR) at week 48 was observed in patients treated with bardoxolone. Reata collected historical eGFR data for 22 out of the 25 Phase 2 study subjects. The historical eGFR data demonstrate that the Phase 2 study subjects’ kidney function was declining at an average annual rate of 4.2 mL/min/1.73 m2 prior to study entry. The observed 10.4 mL/min/1.73 m2 improvement after one year of treatment with bardoxolone represents a recovery of approximately two years of average eGFR loss.
Significantly increased eGFR from baseline at week 52 after withdrawal of active drug for four weeks (the retained eGFR benefit) by a mean of 4.1 mL/min/1.73 m2 was also observed with bardoxolone-treated patients. These results provide evidence that bardoxolone may delay or prevent kidney failure. The U.S. Food and Drug Administration has provided Reata with guidance that, in Alport syndrome patients, a significant improvement in placebo-corrected retained eGFR after one year of bardoxolone treatment may support accelerated approval and, after two years of bardoxolone treatment, may support full approval.
In the Phase 2 ADPKD cohort of PHOENIX, significantly increased eGFR at week 12 from baseline—which was the primary endpoint of the study—was observed in bardoxolone-treated patients. Reata collected historical eGFR data for 29 of the 31 Phase 2 study subjects. The historical eGFR data demonstrate that these subjects’ kidney function was declining at an average annual rate of 4.8 mL/min/1.73 m2 prior to study entry. The observed 9.3 mL/min/1.73 m2 improvement after 12 weeks of treatment with bardoxolone represents a recovery of approximately two years of average eGFR loss.
“The results announced today add to the large body of clinical evidence that bardoxolone treatment has the potential to prevent or delay kidney failure in rare forms of chronic kidney disease,” said Warren Huff, Reata’s president and CEO. “Importantly, today’s CARDINAL data demonstrate that one year of bardoxolone treatment can improve kidney function in Alport syndrome patients that have had progressive loss of kidney function while on standard of care. Further, the magnitude of the observed retained eGFR benefit after withdrawal of drug vs. the historical rate of eGFR loss suggests that the Phase 3 portion of CARDINAL is conservatively powered with respect to the key secondary endpoint of retained eGFR benefit. Additionally, the eGFR increase at week 12 observed in patients with ADPKD suggests that long-term improvements from treatment with bardoxolone in other forms of CKD may translate to patients with ADPKD.”