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Spark Surges After Gene Therapy Helps 3 Hemophilia Patients

  • Clotting protein levels rise as high as 30 percent of normal
  • Drug is partnered with Pfizer, now in early-stage trial
Updated on

Spark Therapeutics Inc. surged the most since October after the biotechnology company said its gene therapy helped three hemophilia B patients increase clotting ability enough to stop their regular infusion treatments.

The therapy, called SPK-9001, is co-owned by Pfizer Inc., which will take over development after Spark completes early-stage trials. The treatment gives patients a functioning copy of the gene that produces factor IX, a protein that clots blood. Spark rose 22 percent to $50.33 at 9:51 a.m. in New York, after earlier reaching $51.83.