Additional Relevant Details BioMarin Pharmaceutical announced today preliminary data from an ongoing Phase 1/2 clinical trial with BMN 270, an investigational gene therapy treatment for hemophilia A. A total of eight patients with severe hemophilia A received a single dose of BMN 270, six of whom have been treated at the highest dose of 6 x 1013 vg/kg, and to date, post-treatment follow-up ranges from five to 16 weeks. At last observation, patients at the highest dose experienced increasing Factor VIII activity levels ranging between 4% and 60% (as a percentage calculated based on the numbers of International Units (IU) per milliliter of whole blood), with five of six patients treated at the high dose now over 5% and two of six at over 50%. (See Table 1) All high dose patients improved from severe to either moderate, mild or normal range in terms of factor levels based on World Federation of Hemophilia criteria.Liver function tests have been monitored closely during the course of the trial.  The first three patients were not administered prophylactic corticosteroids.  Two of these patients experienced elevated alanine aminotransferase (ALT) levels. Patient 3, the first patient treated at the highest dose level, experienced a mild ALT elevation at week 4, which prompted administration of a course of corticosteroids. ALT levels in this patient continued to rise modestly during the corticosteroid therapy, which was completed at week 14. Two weeks later a new corticosteroid regimen was initiated when ALT levels became minimally abnormal for the first time.  The expression of Factor VIII continued to increase during this elevation of ALT and is currently at 57%. In addition, 28 weeks after dosing, Patient 1 treated at the lowest dose experienced a rise in ALT level to 128 IU/L, although this patient had never documented Factor VIII expression above 1%.  After the third patient, all patients were to be started on prophylactic corticosteroid therapy and to date no further patients have experienced abnormal ALT levels.  BioMarin plans to discuss these findings with UK regulatory authorities prior to dosing the remaining patients.