Otsuka Pharmaceutical has shared more detailed data behind its kidney disease drug’s phase 3 win, showing the monoclonal antibody halved patients’ urine protein-to-creatinine ratio (UPCR) levels.
Elevated UPCR levels can be indicative of kidney dysfunction, and the Japanese company evaluated sibeprenlimab in a trial of about 510 patients with a chronic kidney disease called immunoglobulin A (IgA) nephropathy. The biopharma already revealed last year that the study had hit its primary endpoint of demonstrating a statistically significant and clinically meaningful reduction in 24-hour UPCR levels compared to placebo after nine months of treatment.
Now, the company has fleshed out the win with some extra data points, including that patients who received sibeprenlimab reported a 51.2% reduction in proteinuria from baseline when compared to placebo.
The proportion of patients who experienced a treatment-emergent adverse event (TEAE), 76.3%, was less than the 84.5% of patients affected in the placebo cohort, Otsuka observed. This trend continued among serious TEAEs, which affected 3.9% and 5.4%, respectively, of the sibeprenlimab and placebo cohorts.
Sibeprenlimab targets a protein called A proliferation-inducing ligand (APRIL), and the drug is designed to limit the production of Gd-IgA1, which is a key driver of IgA nephropathy. The phase 3 study is the largest IgAN trial to date, and Otsuka unveiled the data at the European Renal Association Congress in Vienna.
The FDA is due to make a call on whether to approve sibeprenlimab for IgAN by Nov. 28. If sibeprenlimab does make it to market, it will enter a space that’s become increasingly crowded in recent months thanks to Calliditas Therapeutics’ Tarpeyo and Novartis’ dual offering of Fabhalta and Vanrafia as well as Travere Therapeutics’ Filspari.
In comparison to sibeprenlimab's 51.2% reduction in UPCR levels, Tarpeyo was shown to reduce UPCR levels by 34% at nine months, while Vanrafia achieved a 38% decrease.
“IgAN is a progressive, autoimmune, chronic kidney disease that can lead to end-stage kidney disease over the lifetime of many patients,” Otsuka CEO Andy Hodge said in the release. “While current supportive care helps manage symptoms, there remains a significant unmet need for treatments that target the underlying cause of the disease.”
“We are excited by these interim results and remain committed to developing therapies for patients living with this serious and complex condition,” Hodge added.