Chinese biopharmaceutical company Alebund Pharmaceuticals Limited announced on Wednesday the completion of patient enrolment in the global Phase III pivotal multi-regional clinical trial (RESPOND-2, Study AP301-HP-03) of AP301, a novel fibre-iron-based phosphate binder, for the treatment of hyperphosphataemia.

Conducted in the United States and China, the trial has enrolled a total of 282 chronic kidney disease (CKD) patients on maintenance dialysis with hyperphosphataemia -- 138 in the US and 144 in China.

Alebund says that as a next-generation fibre-iron-based phosphate binder, AP301 is designed to have a higher phosphate-binding capability, favourable gastrointestinal tolerability, minimal risk of iron overload, and no requirement for chewing before swallowing, with the potential to improve treatment adherence and effectively control hyperphosphataemia.

RESPOND-2 is a double-blind, randomised, multi-regional Phase III clinical trial comprised of three treatment phases: an 8-week double-blind dose titration phase (AP301 versus AP301 ineffective low dose, 2:1 randomisation), a 24-week open-label treatment phase, and a 3-week double-blind randomised withdrawal phase (AP301 maintenance dose versus AP301 ineffective low dose, 1:1 re-randomisation). The primary endpoint is the change in serum phosphate levels from baseline to the end of the dose titration phase (AP301 versus AP301 ineffective low dose). The key secondary endpoint is the change in serum phosphate level from the end of the open-label treatment phase to the end of the randomised withdrawal phase (AP301 maintenance dose versus AP301 ineffective low dose).

Based on existing clinical data for AP301, Alebund reached an agreement with the FDA that this global Phase III multi-regional clinical trial will serve as the single pivotal study to support US registration of AP301.