Shares of the New York company at last check were nearly 20% higher at $26.34. They'd more than quadrupled in 2021 through Friday's close.
The disorder is found almost exclusively in girls, “affecting nearly every aspect" of children's lives: "their ability to speak, walk, eat, and even breathe easily,” the International Rett Syndrome Foundation, Cincinnati, says.
“The hallmark of Rett syndrome is near constant repetitive hand movements. Rett syndrome is usually recognized in children between 6 to 18 months as they begin to miss developmental milestones or lose abilities they had gained.”
Anavex said in a statement that predictive biomarker of response established with Sigmar1 mRNA expression "correlates significantly with responses in primary clinical efficacy endpoints from the U.S. Phase 2 randomized, double-blind, placebo-controlled trial of Anavex 2-73 in in adult female patients with Rett syndrome."
Anavex 2-73 activates the sigma-1 receptor, Sigmar1. The company said data suggested that activation of Sigmar1 results in the restoration of complete housekeeping function within the body and is pivotal to restoring neural cell homeostasis and promoting neuroplasticity.
Rett syndrome is caused by a spontaneous mutation of one gene, MECP2, the company said. The study demonstrates for the first-time that a biomarker correlates with clinical efficacy in Rett syndrome.
The biomarker-driven clinical evidence "opens the possibility of successful treatment for both adults and children with Rett syndrome and early interventions for modifying the course of the disease,” Walter Kaufmann, principal investigator and chief medical officer of Anavex, said in a statement.
Anavex 2-73 is currently being evaluated for Rett syndrome in two other late-stage placebo-controlled clinical studies, the company said.
In 2016, Anavex shares soared after the company said that data indicated Anavex 2-73 may successfully treat Parkinson's disease.
In January, the company said it had received a grant from the Michael J. Fox Foundation for Parkinson's Research to develop the drug to treat Parkinson's.