Sydnexis Inc. announced the US Food and Drug Administration (FDA) issued a complete response letter (CRL) for the new drug application (NDA) for SYD-101, the company's proprietary 0.01% atropine formulation developed to slow the progression of pediatric myopia in children. Specifically, the FDA says that the data do not support the effectiveness of low-dose atropine in children with myopia. 

Sydnexis’ NDA for SYD-101 was supported by the results of the phase 3 STAR (Study of Atropine for the Reduction of Myopia Progression) trial, comprised of more than 800 children ages 3-14 at treatment initiation. Specifically, the study met its primary efficacy endpoint of proportion of patients with confirmed myopia progression of -0.75 D, which the FDA had encouraged the company to use, according to a company-issued press release. A key secondary endpoint, annual myopia progression rate, also met statistical significance at 12, 24, and 36 months, according to Sydnexis. In a subgroup of fast progressors [more than -0.5 D/yr] at 36 months, the company says SYD-101 demonstrated a reduction in progression of more than 50%.

According to the company, it plans to continue working with the FDA to address the items outlined in the CRL and determining the best path forward toward approval for SYD-101.

SYD-101 is currently approved in the European Union, where it is licensed to Santen S.A. and marketed as Ryjunea.