Manny Johnson of Boston, 21, previously required monthly blood transfusions to keep his severe sickle cell disease under control. After receiving a new gene therapy treatment, he’s been symptom-free for six months.
The hope to improve people’s lives is what drives many members of industry and academia to bring new products and therapies to market. At the BIO International Convention last week in Boston, there was lots of discussion about how translational science intersects with patients’ needs and why the best therapeutic developmental pipelines are consistently putting patients first.
“Our mission is to de-risk entry of new therapies in the ASD drug discovery and development space,” said Sahin, who is also a professor of neurology at Harvard Medical School.
One big challenge, says Sahin, is knowing how well — or how poorly — autism therapies are actually affecting people with ASD. Externally, ASD is recognized by its core symptoms of repetitive behaviors and social deficits. …
Sickled cells occluding a blood vessel. (Image: Elena Hartley)
Boston Children’s Hospital is now enrolling patients age 3 to 35 in a clinical trial of gene therapy for sickle cell disease. Based on technology developed in its own labs, it differs from other gene therapy approaches by having a two-pronged action. It represses production of the mutated beta hemoglobin that causes red blood cells to form the stiff “sickle” shapes that block up blood vessels. It also increases production of the fetal form of hemoglobin, which people normally stop making after birth.
Fetal hemoglobin doesn’t sickle and works fine for oxygen transport. The gene therapy being tested now restores fetal hemoglobin production by turning “off” a silencing gene called BCH11A.
“BCL11A represses fetal hemoglobin and also activates beta hemoglobin, which is affected by the sickle-cell mutation,” David Williams, MD, the trial’s principal investigator, told Vector last year. Williams is also president of the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. “So when you knock BCL11A down, you simultaneously increase fetal hemoglobin and repress sickling hemoglobin, which is why we think this is the best approach to gene therapy in this disease.”
The therapy is the product of multiple discoveries, the first dating back 70 years. Click selected images below to enlarge. …
David Williams, MD, the principal investigator of the clinical trial, discusses gene therapy and its impact on children with adrenoleukodystrophy
Adrenoleukodystrophy — depicted in the 1992 movie “Lorenzo’s Oil” — is a genetic disease that most severely affects boys. Caused by a defective gene on the X chromosome, it triggers a build-up of fatty acids that damage the protective myelin sheaths of the brain’s neurons, leading to cognitive and motor impairment. The most devastating form of the disease is cerebral adrenoleukodystrophy (CALD), marked by loss of myelin and brain inflammation. Without treatment, CALD ultimately leads to a vegetative state, typically claiming boys’ lives within 10 years of diagnosis.
Today, the Food and Drug Administration approved a gene therapy known as CAR T-cell therapy that genetically modifies a patient’s own cells to help them combat pediatric acute lymphoblastic leukemia (ALL), the most common childhood cancer. It is the first gene therapy to be approved by the FDA.
“This represents the progression of the field of gene therapy, which has been developing over the last 30 years,” says gene therapy pioneer David A. Williams, MD, who is chief scientific officer of Boston Children’s Hospital and president of the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center. “It’s a realization of what we envisioned to be molecular medicine when this research started. The vision — that we could alter cells in a way to cure disease — is now coming true.” …
Right now, there are about 7,000 rare diseases affecting 10 percent of Americans. Only five percent of these diseases have any FDA-approved treatment options.
Panelists:
David Williams, MD: President, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center; Senior VP, Chief Scientific Officer and Chief of Hematology/Oncology, Boston Children’s
Wayne Lencer, MD: Chief of Gastroenterology, Hematology and Nutrition, Boston Children’s
Even at a place like Boston Children’s Hospital, where doctors regularly see children with rare diseases from all over the world, there are big challenges when it comes to drug discovery and treatment.
“Roughly 70 percent of drugs to treat children are used off-label,” says David Williams, Boston Children’s chief scientific officer. “That’s because these drugs were initially developed for adults and have not been tested formally in children.”
In order to cure rare diseases in children and adults, scientists must bridge the gap between research and industry. On May 25, Boston Children’s Technology and Innovation Development Office (TIDO) and MassBio held a candid panel discussion about what it will take to advance the development of rare disease therapies. Here are three of the biggest takeaways …
(Graphs courtesy Alexandra Biffi, Dana-Farber/Boston Children’s Cancer and Blood Disorders Center)
Gene therapy stalled in the early 2000s as adverse effects came to light in European trials (leukemias triggered by the gene delivery vector) and following the 1999 death of U.S. patient Jesse Gelsinger. But after 30 years of development, and with the advent of safer vectors, gene therapy is becoming a clinical reality. It falls into two main categories:
In vivo: Direct injection of the gene therapy vector, carrying the desired gene, into the bloodstream or target organ.
Ex vivo: Removal of a patient’s cells, treating the cells with gene therapy, and reinfusing them back into the patient, as in hematopoietic stem cell transplant and CAR T-cell therapy.
When Boston Children’s Hospital decided to hire its first chief scientific officer (CSO) in eight years, the institution sought an individual who could spotlight the hospital’s robust scientific enterprise and effectively connect it to clinical medicine and industry. David Williams, MD, president of the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center and director of clinical and translational research at Boston Children’s, was the ideal choice.
An award-winning researcher, Williams trained in the clinic but also pursued basic science, developing techniques for introducing genes into mouse and human blood cells. He focused on blood stem cell biology, leukemia and gene therapy to correct genetic blood disorders, becoming a 16-year Howard Hughes Medical Institute Investigator, a Member of the National Academy of Medicine and a Fellow of the American Association for the Advancement of Science. He has secured multiple patents for techniques still in use today.
Williams spoke about his vision as CSO to align basic research and clinical care at Boston Children’s and the challenges ahead. …
David Williams, MD, is Boston Children’s Hospital’s newly appointed Chief Scientific Officer. He is also president of the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center and director of Clinical and Translational Research at Boston Children’s. Vector connected with him to get his forecast on where biomedical research and therapeutic development will go in the year ahead.…
Research going back to the 1980s has shown that sickle cell disease is milder in people whose red blood cells carry a fetal form of hemoglobin. The healthy fetal hemoglobin compensates for the mutated “adult” hemoglobin that makes red blood cells stiffen and assume the classic “sickle” shape.
Normally, fetal hemoglobin production tails off after birth, shut down by a gene called BCL11A. In 2008, researchers Stuart Orkin, MD, and Vijay Sankaran, MD, PhD, at the Dana-Farber/Boston Children’s Cancer and Blood Disorders Center showed that suppressing BCL11A could restart fetal hemoglobin production; in 2011, using this approach, they corrected sickle cell disease in mice.
Now, the decades-old discovery is finally nearly ready for human testing — in the form of gene therapy. Today in the Journal of Clinical Investigation, Dana-Farber/Boston Children’s researchers report that a precision-engineered gene therapy vector suppressing BCL11A production overcame a key technical hurdle. …
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