CytRx Corp. began a Phase III trial of Flocor, its solution for treatment of vascular occlusive crisis in sickle cell disease.

To enroll 350 patients at 30 sites, the study is fueled partly by a grant from the FDA, said Joe Medlin, director of investor relations for Norcross, Ga.-based CytRx.

"[The FDA grant] is a rare event," Medlin said.

In the double-blind, randomized trial, the primary endpoint will be duration of vascular occlusive crisis, a painful condition that occurs an average of two times per year in sickle cell patients.

Flocor (purified poloxamer 188) is a surfactant molecule that works by altering the way cells and molecules interact with water, rather than by binding to receptors. The drug is made by polymerizing propylene oxide with propylene glycol.

"It surrounds red blood cells and prevents them from sticking to each other or adhering to blood vessel lining," Medlin told BioWorld Today.

"In your fingers, it feels slippery," he said. "When you shake it up, it gets foamy."

About 60,000 people of African American, Caribbean, Middle Eastern and South American ancestry in the U.S. are afflicted with sickle cell disease, a genetic condition that shortens life span by 15 to 20 years.

In addition to sickle cell disease, CytRx will examine other indications in which blood blockage is a factor, such as heart attack and stroke, Medlin said.

A subsidiary, Vaxcel Inc., of Atlanta, is developing Optivax, a vaccine adjuvant.

CytRx's stock (NASDAQ:CYTR) closed Wednesday at $3.125, up $0.25. — Randall Osborne