Global Blood Therapeutics said Friday its approved sickle cell treatment, Oxbryta, helped lower markers of the disorder in a real-world study. But GBT stock yo-yoed.
Researchers examined the medical records of 216 patients who received Oxbryta for at least a year. During that time, patients experienced a boost in hemoglobin, a protein in red blood cells that carries oxygen. The increase was sustained for the yearlong treatment period.
Further, evidence of hemolysis — red blood cell breakdown — declined, as did the number of immature red blood cells and level of bilirubin. Bilirubin, a yellowish pigment created when red blood cells break down, is usually higher in sickle cell patients.
On today's stock market, GBT stock fell 1.7% to 22.63. Shares opened with a 4.3% gain, but quickly tapered off.
The news sent shares of Crispr Therapeutics — which is working on a CRISPR gene-editing approach to the same disease — down 11.1% to 63.76. Shares of Crispr partner Vertex Pharmaceuticals fell 1.9% to 254.88..
GBT Stock: Next-Generation Oxbryta
GBT also unveiled first-phase test results for a next-generation version of Oxbryta. Like its predecessor, the new drug called GBT601 attempts to block the process by which red blood cells become deformed, or sickled. Researchers studied GBT601 in six patients.
In the study, patients experienced increases in hemoglobin and improvement in markers of hemolysis.
At the end of the treatment, there was an average 76.1% decrease in the number of deformed red blood cells compared to pre-treatment levels. Patients then stopped treatment and, after 15 weeks, sickled red blood cell levels returned to pre-treatment levels.
Bullishly for GBT stock, the drug was well tolerated in sickle cell patients and healthy volunteers.
Still, GBT shares remain well below their key moving averages, according to MarketSmith.com.
Follow Allison Gatlin on Twitter at @IBD_AGatlin.
