“Remarkable” Phase 2 Oxylanthanum Carbonate Data, With Pablo Pergola, MD, PhD

Hyperphosphatemia remains a common and clinically important challenge for individuals with chronic kidney disease (CKD) undergoing dialysis. Although phosphate binders play a critical role in helping regulate phosphate levels, their utility is often hampered by large pill sizes, high daily pill counts, strict dosing requirements, and gastrointestinal intolerance. These barriers frequently lead to poor adherence, limiting their effectiveness in long-term disease management.

“When you talk about efficacy… there are several things that affect how you can get that done. One is the potency, so how well the medication works in binding the phosphate from the intestine. But a very potent drug that you cannot take doesn't work. If it sits on the counter or on your table, then the efficacy is zero,” Pablo Pergola, MD, PhD, research director of the Clinical Advancement Center at Renal Associates PA, explained to HCPLive. “You need to have something that's potent that the patients can take, so it relates to that pill burden, availability, and accessibility, so the patient can take it, they tolerate it, and it works. Then you get the efficacy that you need.”

Oxylanthanum carbonate (OLC), an investigational lanthanum-based phosphate binder, has been developed using nanoparticle technology designed to minimize pill size and reduce overall pill burden. Findings from a phase 2, open-label, single-arm, multicenter trial published in the Clinical Journal of the American Society of Nephrology point to OLC’s potential as a promising new therapy for managing hyperphosphatemia in patients with CKD receiving dialysis.1

For more on the shortcomings of current phosphate binders, check out part 1 of the interview with Pergola here.

The trial enrolled patients with serum phosphate (sP) ≥4.0 and ≤7.0 mg/dl for ≥ 8 weeks before screening while receiving thrice weekly hemodialysis and a stable phosphate binder regimen. The primary objective was to evaluate the tolerability of OLC at clinically effective doses with a goal sP concentration ≤5.5 mg/dl.

The trial included washout, titration, and maintenance periods. Patients started titration when sP was >5.5 mg/dl and entered maintenance once sP was ≤5.5 mg/dl. The starting dose of OLC during titration was 1500 mg/d (500 mg thrice daily).

A total of 86 patients were treated with OLC during the study. At screening, sP was ≤5.5 mg/dl in 59% of patients. Among the cohort, 91% of patients entered maintenance and 71 achieved sP ≤5.5 mg/dl on a median OLC dose of 500 mg 3 times a day. Of note, two-thirds of patients required ≤ 3 OLC tablets per day to achieve target sP levels, with most requiring no more than one tablet with each meal.

“This is not trivial. I've done multiple studies with phosphate bindings in the past, and I had never seen a drug performed this way. It's really remarkable,” Pergola said. “It's a small study, I understand, but finding this kind of efficacy is unheard of.”

Editors’ note: Pergola has relevant disclosures with Alexion, Ardelyx, AstraZeneca, Bayer, CSL, DISC, Novo Nordisk, Renibus, Unicycive, and Vera.

References

1. Unicycive Therapeutics. Unicycive Therapeutics Announces the Publication of Oxylanthanum Carbonate Pivotal Trial Data in Clinical Journal of the American Society of Nephrology. July 24, 2025. Accessed August 28, 2025. https://ir.unicycive.com/news/detail/107/unicycive-therapeutics-announces-the-publication-of

2. Brooks A. Oxylanthanum Carbonate May Offer Desirable Alternative to Current Phosphate Binders. HCPLive. April 10, 2025. Accessed August 28, 2025. https://www.hcplive.com/view/oxylanthanum-carbonate-may-offer-desirable-alternative-current-phosphate-binders