The Food and Drug Administration will review an approval application for a drug designed to target the root cause of damage from sickle cell disease.
South San Francisco, California-based Global Blood Therapeutics said Thursday that the FDA had accepted its application seeking accelerated approval for voxelotor, an oral drug that it developed to treat SCD. The drug would be the first to target hemoglobin polymerization. The agency is expected to make its decision by Feb. 26, 2020 due to a priority review, which cuts the review time from the standard 10 months to six months.
In addition, the company said the FDA would not require an advisory committee meeting for the drug, despite investors’ expectations that it would. The basis of the filing is a Phase III study, results of which were published last month in the New England Journal of Medicine.
Shares of GBT rose 14 percent on the Nasdaq following the news.
A spokesperson for the company wrote in an email it is working with the FDA on the details of the confirmatory trial, noting that it would use transcranial doppler, or TCD flow velocity as its primary endpoint in order to demonstrate the drug’s ability to reduce the risk of stroke. The plan is to start the confirmatory trial in the fourth quarter of this year.
“The FDA acceptance of our [New Drug Application] for voxelotor under priority review is a major milestone in the development of this investigational therapy and further illustrates the significance the agency places on getting important and innovative treatments to individuals living with SCD as quickly as possible,” GBT CEO Ted Love said in a statement.
In a note to investors Monday, analysts with the investment bank Cowen had written that 89 percent of investors they surveyed thought that the FDA would require an advisory committee review of voxelotor. They noted that while the “totality of data” had been encouraging, with trends seen on clinical endpoints like veno-occlusive crisis and safety, the primary endpoint of increase in hemoglobin represented a novel biomarker endpoint for SCD.
The published data from HOPE showed that among 274 patients enrolled and randomized to receive the drug at 1,500mg, 900mg or placebo, 51 percent of those receiving the 1,500mg had a hemoglobin response at week 24, compared with 7 percent of those in the placebo group, according to the intent-to-treat analysis. In the 900mg group, 33 percent of patients had a hemoglobin response. In the per-protocol analysis, hemoglobin response rates were 59 percent in the 1,500mg group, 38 percent in the 900mg group and 9 percent in the placebo group. In addition, fewer patients in the high-dose group saw worsening of anemia, while seeing greater reductions in bilirubin, than those receiving placebo.
Annualized incidence rates of vaso-occlusive crisis, a secondary endpoint, were 2.77 for the 1,500mg group, 2.76 for the 900mg group and 3.19 for the placebo group. Among patients with at least two crises in the past year, the respective rates were 2,88, 3.39 and 3.5, respectively. The total number of VOCs in the respective groups were 179, 183 and 219, while the percentages of patients experiencing at least one crisis were 67 percent, 66 percent and 69 percent.
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