Genzyme and Third Rock Ventures bet $35 million six months ago on a Cambridge, MA-based gene therapy company. Despite all the ups and downs with gene therapy over the years, now we can see why they placed the bet.
The newly renamed Bluebird Bio, formerly known as Genetix Pharmaceuticals, is coming out today with an eye-opening paper in Nature. The study says Bluebird’s experimental gene therapy offered a startling benefit for the first patient enrolled in a clinical trial, designed to treat a genetic blood disorder called beta-thalassemia. The patient, in his early 20s, had been forced to live with monthly blood transfusions since the age of four, because the thalassemia made it impossible for him to produce enough hemoglobin to carry adequate oxygen through the blood.
Since getting a single shot of the gene therapy 27 months ago, the young man has been able to produce enough hemoglobin on his own to quit getting blood transfusions. That has made it possible for him to feel vigorous enough to hold down a full-time job as a cook in Paris, said Bluebird CEO Nick Leschly. An estimated 60,000 people around the world suffer from thalassemia.
“For the first time, a patient with severe beta-thalassemia is living without the need for transfusions over a sustained period of time,” said one of the study’s co-authors, Marina Cavazzana-Calvo, a professor of hematology at the University of Paris, in a statement. Leschly hasn’t spoken to the patient, but added: “The treating physician who has talked to him has said his life has been transformed.”
Gene therapy has been one of the most glamorous, and some would say overhyped fields of biotech of the past two decades. The idea is to alter viruses that carry copies of genes into cells, where they can replace missing or faulty genes at the root of certain types of disease. This technique rode a wave of scientific enthusiasm in the early 1990s, leading to the formation of more than 100 biotech companies, and to a nearly two-decade long research effort at Genzyme. Some promising anecdotal stories have emerged over the years, but there have also been some high-profile safety concerns and clinical failures. There are still no FDA-approved gene therapies on the U.S. market.
But Genzyme and Third Rock made their $35 million investment back in March based on renewed optimism. Bluebird, which has been around since the early ’90s, is planning its next moves around the treatment of beta-thalassemia and a debilitating brain disorder called adrenoleukodystrophy.
Of course, one patient in a clinical trial is only one patient, and it’s nowhere near the kind of convincing evidence that Bluebird will need to win market clearance from regulators and broad market acceptance from doctors and patients. But it’s the sort of data that will prompt Bluebird to recruit about another 10 patients to see if the experience can be replicated, setting the stage for more rigorous testing, Leschly says.
For now, scientists will dig into the details and wonder about why this might be working. The Bluebird treatment uses a genetically engineered lentivirus to deliver a copy of a gene that enables the body to produce hemoglobin, the protein that carries oxygen in red blood cells throughout the body. While many gene therapies of the past have struggled
