Otsuka Pharmaceutical’s kidney disease drug has hit the primary endpoint of a phase 3 trial by demonstrating in an interim analysis the reduction of patients’ urine protein-to-creatine ratio (UPCR) levels.
Elevated UPCR levels can be indicative of kidney dysfunction, and the Japanese company has been evaluating its monoclonal antibody sibeprenlimab in a trial of about 530 patients with a chronic kidney disease called immunoglobulin A (IgA) nephropathy.
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. While Otsuka didn’t share any data, it said the interim analysis had shown that the trial hit its primary endpoint of a statistically significant and clinically meaningful reduction in 24-hour UPCR levels compared to placebo after nine months of treatment.
“The positive interim data from this trial suggest that by targeting APRIL, we could provide a new therapeutic strategy for people living with this progressive kidney disease,” Otsuka Chief Medical Officer John Kraus, M.D., Ph.D., said in the release. “We look forward to the completion of this study and reviewing the full results at a future timepoint.”
The trial will continue to evaluate kidney function by assessing estimated glomerular filtration rate over 24 months, with completion expected in early 2026. In the meantime, Otsuka is planning to review the interim data with the FDA with a view to securing an accelerated approval pathway.
If sibeprenlimab does make it to market, it will enter a space that’s become increasingly crowded in recent months. Calliditas Therapeutics’ Tarpeyo received the first full FDA approval for an IgAN drug in December 2023, with the agency handing Novartis’ complement inhibitor Fabhalta an accelerated approval a couple of months ago. Last month, the FDA converted Filspari’s conditional IgAN nod into a full approval.
Otsuka expanded its metabolic disorder pipeline in August via the $800 million acquisition of Boston-based Jnana Therapeutics and its clinical-stage oral phenylketonuria drug.