FDA Issues CRL to Sydnexis for SYD-101 in Pediatric Myopia
The FDA has issued a complete response letter (CRL) for Sydnexis' new drug application (NDA) for SYD-101, a proprietary 0.01% atropine formulation designed to slow the progression of myopia in children.
The NDA for SYD-101 was supported by data from the phase 3 STAR (Study of Atropine for the Reduction of Myopia Progression) trial, which the company's calls the largest global clinical study ever conducted in pediatric myopia. The trial enrolled over 800 children aged 3 to 14 years at treatment initiation.
The STAR study met its primary efficacy endpoint, showing a statistically significant reduction in the proportion of patients with confirmed progression of -0.75 diopters (D). A key secondary endpoint—annual myopia progression rate—also achieved statistical significance at 12, 24, and 36 months. In a subgroup of fast progressors (children experiencing more than -0.5D per year), SYD-101 demonstrated a greater than 50% reduction in myopia progression over 3 years.
While the FDA acknowledged that the primary endpoint was met, the agency stated in its CRL that it does not consider the data sufficient to support the effectiveness of low-dose atropine in children with myopia. The letter cited no deficiencies related to safety or product quality.
“While we are surprised and disappointed with this decision, Sydnexis is committed to working with the FDA to address the items outlined in the CRL and determining the best path forward toward approval for SYD-101,” said Perry Sternberg, Chief Executive Officer of Sydnexis. “Our goal is to provide eye care professionals in the U.S. with the first FDA-approved option to help slow the progression of pediatric myopia, rather than continued reliance on compounded formulations of atropine. We remain confident in our data and the potential of SYD-101 to fill a critical innovation gap and treat the most common eye disease in children.”
In June 2025, the European Commission (EC) granted marketing authorization for SYD-101, marketed under the brand name Ryjunea, making it the the first and only approved pharmaceutical treatment option to treat myopia progression in EU countries. In the EU, the treatment is licensed to Santen S.A.
Watch the EyewireTV coverage of the EU approval here.
Sydnexis said it remains focused on advancing discussions with the FDA and exploring potential next steps to make SYD-101 available to U.S. patients.
About SYD-101
SYD-101 is a proprietary low-dose atropine formulation developed to slow the progression of pediatric progressive myopia. According to Sydnexis, its formulation is engineered for optimized tolerability, stability, and clinical performance, featuring:
Enhanced ocular tissue permeability demonstrated in preclinical models
Room-temperature stability for up to 3 years
Near-neutral pH for improved ocular comfort and safety