Phase 1 trial reveals high efficacy for hemophilia A gene therapy
- The hemophilia A community received good news on Wednesday when BioMarin announced the results of a phase 1 trial, which showed that its gene therapy may have cured six of the nine participants of their hemophilia A symptoms by increasing plasma factor VIII (FVIII) levels to the normal level of 50%. Patients with severe symptoms register FVIII levels under 1%.
- Hemophilia A patients suffer from deficiency of the FVIII clotting protein, which leads to increased bleeding periods that can have a destructive impact on joints and diminish quality of life, according to the National Hemophilia Foundation.
- This therapy has the potential to be life-changing for all of the hemophilia A patients who receive up to three prophylactic treatments each week, while also enduring numerous internal bleeding episodes that must be managed on an emergency basis. Each year, about 800 newborns are diagnosed with the condition.
Standard of care in hemophilia has evolved from large-volume IV infusions of fresh plasma to cryo-plasma and lyophilized plasma, which allow for lower-volume treatment. However, the real game changer came in the 1990s when FVIII cloning facilitated the development of recombinant FVIII.
Although BioMarin's is still in the first phase, its findings could be just as monumental as the introduction of biologic FVIII.
BioMarin's gene therapy (BMN 270) decreased the number of bleeding events from 17 in the first eight weeks post-injection, to just two in the following 20 weeks. Likewise, patients required significantly fewer infusions while on treatment: during the first eight weeks patients needed 22 infusions; however, the number of infusions dropped to 4 during the next 20 weeks.
BMN 270 is an adeno-associated virus, which was reengineered to express FVIII by a team of doctors at University College London, Forbes reports. When BioMarin presented earlier data, there was evidence of worrisome increases in ALT liver enzymes; but the problem was reportedly not present during the most recent study.
"For the first time, patients have reason to hope to avoid bleeding and the opportunity to live a normal life," said John Pasi, a primary investigator for the BMN 270 trial.
BioMarin is a rare disease biopharmaceutical company that recorded $890 million in total revenues last year.