BioMarin Pharmaceutical, a California-based biotechnology company, said a patient in a clinical trial of its hemophilia gene therapy Roctavian has developed leukemia, although testing suggests that the case may be naturally occurring.
Genetic testing of diseased blood cells showed that a majority of them had a mutation known to be associated with the specific type of leukemia, B-cell acute lymphoblastic leukemia, BioMarin said in a regulatory filing on Monday. Meanwhile, additional testing indicated that diseased blood cells had low levels of Roctavian vector DNA, indicating that the genetic material isn’t being copied when new cells grow, the company added.
