Spark sheds $1B in value on hemophilia gene therapy data
Spark Therapeutics’ experimental gene therapy, SPK-8011, sharply lowered the number of bleeds in a dozen patients with hemophilia A, prompting the company to push forward into Phase 3 clinical trials.
Rather than encouraging investors, the update caused shares to drop by more than 30% in value, erasing nearly $1B off Spark’s market capitalization. While the therapy boosted levels of a clotting factor in five of seven patients given the highest dose, the other two individuals experienced a drop in factor activity. Spark may also be suffering from comparisons to BioMarin Pharmaceutical, which is further along in developing a rival hemophilia A gene therapy.
