Allena Pharmaceuticals agrees with FDA on Phase III program and approval pathway of reloxaliase for enteric hyperoxaluria.

Allena Pharmaceuticals, Inc. announced that it has reached alignment with the FDA on both the design of URIROX-2, its second pivotal Phase III trial of reloxaliase in patients with enteric hyperoxaluria, and its strategy to pursue a Biologics License Application (BLA) submission for reloxaliase using the accelerated approval regulatory pathway.

Allena�s URIROX program consists of two pivotal Phase III clinical trials, URIROX-1 and URIROX-2 , which are designed to evaluate the safety and efficacy of reloxaliase in patients with enteric hyperoxaluria. URIROX-1 is currently enrolling patients, and Allena initiated URIROX-2 in the fourth quarter of 2018.

The primary efficacy endpoint for URIROX-2 is the percent change from baseline in 24-hour urinary oxalate (UOx) excretion measured during Weeks 1-4, the same primary efficacy endpoint as URIROX-1. Key secondary efficacy endpoints for URIROX-2 include the proportion of subjects with a greater 20% reduction from baseline in 24-hour UOx excretion measured during Weeks 1-4, which is also a secondary endpoint for URIROX-1, and data on UOx change from baseline measured during Weeks 16 to 24. Twenty-four-hour UOx excretion is an established biomarker that is routinely measured in clinical practice to assess and manage patients at risk for enteric hyperoxaluria and calcium oxalate kidney stones. Data from multiple independent studies suggest that a therapeutic strategy that reduces 24-hour UOx excretion by approximately 20% could result in a 25-50% reduction in the incidence of kidney stone recurrence and may increase renal survival.

The FDA agreed that, if positive, biomarker data on 24-hour UOx excretion in URIROX-1 and URIROX-2 would be used for a BLA filing for accelerated approval of reloxaliase in enteric hyperoxaluria and that patients would continue in URIROX-2 to confirm clinical benefit during the long-term follow-up phase of the trial.

Comment: Allena expects to submit a BLA filing to the FDA after 400 patients have been randomized and followed for six months. For the long-term follow-up phase of the trial, subjects would continue in the study for a minimum treatment period of two years to confirm clinical benefit post-approval.