FDA Greenlights Substantive Review Phase for Advicenne's Sibnayal in Rare Kidney Disorder

French pharmaceutical firm Advicenne SA (ALDVI.PA) has reached a significant regulatory milestone: the FDA has officially greenlit the review process for its New Drug Application targeting distal Renal Tubular Acidosis treatment. The candidate therapy, Sibnayal—a fixed-dose formulation combining potassium citrate and potassium bicarbonate—now enters the intensive scrutiny phase that regulatory experts anticipate will extend through September 2026.

The regulatory pathway accelerated following the agency’s completion of its standard 60-day preliminary evaluation, with the formal NDA submission recorded on November 2, 2025. The FDA has designated September 3, 2026, as the PDUFA target action date, marking the anticipated conclusion of the substantive review process for this rare renal condition therapy.

Strategic Advantage Through Global Data Integration

What distinguishes Advicenne’s submission is its 505(b)(2) regulatory strategy, which leverages clinical evidence generated across European trials. This approach enabled the company to reference existing European clinical data while simultaneously pursuing a renewed Marketing Authorization in Europe—a dual-track approach that strengthens the overall evidence package for addressing distal Renal Tubular Acidosis globally.

Commitment Through Review Phase

Didier Laurens, steering the organization as Chief Executive Officer, emphasized the company’s resolve during the critical evaluation window: “The substantive review phase represents our opportunity to demonstrate why Sibnayal represents a meaningful advancement for patients experiencing dRTA. We remain prepared to address every FDA inquiry comprehensively and rapidly. Our aspiration remains constant—delivering a purpose-designed therapeutic option for dRTA patients, their families, and the broader care ecosystem in the United States.”

The approval timeline positions 2026 as a pivotal year for determining whether this specialized formulation will become the first U.S. therapy purpose-built for managing distal Renal Tubular Acidosis, a significant development for a patient population with limited targeted treatment options.