bluebird bio (BLUE) Confirms FDA Approval of ZYNTEGLO Gene Therapy
bluebird bio, Inc. (Nasdaq: BLUE) today announced the U.S. Food and Drug Administration (FDA) has approved ZYNTEGLO® (betibeglogene autotemcel), also known as beti-cel, a one-time gene therapy custom-designed to treat the underlying genetic cause of beta‑thalassemia in adult and pediatric patients who require regular red blood cell (RBC) transfusions.
“The FDA approval of ZYNTEGLO offers people with beta-thalassemia the possibility of freedom from burdensome regular red blood cell transfusions and iron chelation, and unlocks new possibilities in their daily lives,” said Andrew Obenshain, chief executive officer, bluebird bio. “After more than a decade of research and clinical development, and through the perseverance of clinicians, patients, and their families, the approval of ZYNTEGLO marks a watershed moment for the field of gene therapy. As the first ex-vivo lentiviral vector gene therapy approved in the U.S. for the treatment of people with beta-thalassemia, we are ushering in a new era in which gene therapy has the potential to transform existing treatment paradigms for diseases that currently carry a lifelong burden of care.”
Beta-thalassemia is a rare, genetic blood disease caused by mutations in the beta-globin gene and characterized by significantly reduced or absent adult hemoglobin production. Patients with the most severe form, sometimes called transfusion-dependent beta-thalassemia or beta-thalassemia major, experience severe anemia and lifelong dependence on regular red blood cell transfusions, a lengthy process that patients typically undergo every 2-5 weeks. Despite advances in treatment and improved transfusion techniques, transfusions only temporarily address symptoms of anemia and people with beta‑thalassemia who require regular transfusions have an increased risk for morbidity and mortality due to complications from treatment-related iron overload. Data from the Cooley’s Anemia Foundation indicate that the median age of death of patients with transfusion-dependent beta‑thalassemia in the U.S. who died during the last decade was just 37 years. bluebird estimates that there are approximately 1,300-1,500 individuals with transfusion-dependent beta-thalassemia in the U.S.
“Transfusion-dependent beta-thalassemia is associated with an intense treatment burden and significant health risks related to regular red blood transfusions and iron management,” said Alexis A. Thompson, MD, MPH, Chief of the Division of Hematology, Children's Hospital of Philadelphia. “As a clinician and an investigator in the ZYNTEGLO clinical development program, I celebrate the therapeutic potential of this treatment for patients and its implications for the field of gene therapy, all made possible through the incredible courage of patients and families who participated in the clinical trials.”
“The Cooley’s Anemia Foundation applauds the FDA’s approval of ZYNTEGLO for people with beta‑thalassemia who require regular red blood cell transfusions. The availability of a one-time gene therapy which offers the possibility of transfusion independence opens up new and exciting opportunities for those who are medically eligible to receive this treatment option,” said Craig Butler, National Executive Director, Cooley’s Anemia Foundation. “While advances in treatment have been of enormous benefit to those with beta-thalassemia, a potentially curative therapy may offer a true life-changing experience.”
The approval of ZYNTEGLO is the culmination of nearly 10 years of clinical research of gene therapy in patients with transfusion-dependent beta-thalassemia. ZYNTEGLO works by adding functional copies of a modified form of the beta-globin gene (βA-T87Q-globin gene) into a patient’s own hematopoietic (blood) stem cells (HSCs) to allow them to make normal to near normal levels of total hemoglobin without regular RBC transfusions. The functional beta-globin gene is added into a patient’s cells outside of the body (ex-vivo), and then infused into the patient. Though ZYNTEGLO is designed to be administered to the patient once, the treatment process is comprised of several steps that may take place over the course of several months.
Due to the complex nature of gene therapy, ZYNTEGLO will be available exclusively at Qualified Treatment Centers (QTCs) which are carefully selected based on their expertise in relevant areas such as stem cell transplantation, cell and gene therapy, and beta-thalassemia; and receive specialized training to administer ZYNTEGLO. Information on bluebird’s QTC network, as well as personalized support focused on the needs of each patient throughout their treatment journey and information on insurance coverage and access will be available through bluebird’s patient support program, my bluebird support. Patients can call 833-888-NEST (833-888-6378) for more information, and additional details will be available at mybluebirdsupport.com in the coming days.
ZYNTEGLO was reviewed under Priority Review, and the Company received a Priority Review voucher upon approval. ZYNTEGLO was previously granted Orphan Drug designation and Breakthrough Therapy designation.
Clinical Data Supporting Approval of ZYNTEGLO
bluebird bio has the longest and most robust clinical program in transfusion-dependent beta‑thalassemia (TDT) in the field of gene therapy. The approval of ZYNTEGLO is based on data from bluebird bio’s Phase 3 studies HGB-207 (Northstar-2) and HGB-212 (Northstar-3), and the long-term follow-up study LTF-303.
The single-arm, open-label, 24-month Phase 3 studies of ZYNTEGLO included 41 patients aged 4 to 34 years with both non-β0/β0 and β0/β0 genotypes, with longest follow up out to 4 years. Eighty-nine percent (32/36) of evaluable patients across ages and genotypes achieved transfusion independence (TI), which is defined as no longer needing red blood cell transfusions for at least 12 months while maintaining a weighted average total hemoglobin of at least 9 g/dL. Results in these patients were durable as of last follow-up.
The most common non-laboratory adverse reactions (≥20%) were mucositis, febrile neutropenia, vomiting, pyrexia, alopecia, epistaxis, abdominal pain, musculoskeletal pain, cough, headache, diarrhea, rash, constipation, nausea, decreased appetite, pigmentation disorder, and pruritus. The most common Grade 3 or 4 laboratory abnormalities (>50%) include neutropenia, thrombocytopenia, leukopenia, anemia, and lymphopenia.
Enrollment is complete and all patients have been treated in the Phase 3 Northstar-2 (HGB-207) and Northstar-3 (HGB-212) studies evaluating ZYNTEGLO. Follow-up in HGB-212 is ongoing. bluebird bio is also conducting a long-term follow-up study, LTF-303, to monitor safety and efficacy for patients with TDT who have participated in bluebird bio-sponsored clinical studies of lentiviral vector (LVV) gene therapy through 15 years post-treatment.
Across all studies, all patients who achieved transfusion independence have remained transfusion-free.
Investor Conference Call Information
bluebird bio will host a call for analysts and investors on Thursday, August 18, 2022, at 8:00 am ET. Please note that there is a new process to access the call via telephone. To register and receive a dial in number and unique PIN to access the live conference call, please follow this link https://register.vevent.com/register/BIf8d187c3d45b4919a79fdc98742f39da to register online.
The live webcast of the call and slide deck may be accessed by visiting the “Events & Presentations” page within the Investors & Media section of the bluebird website at http://investor.bluebirdbio.com. A replay of the webcast will be available on the bluebird website for 90 days following the event.