Medication Pearl of the Day: Betibeglogene Autotemcel (Zynteglo)
Indication: Zynteglo is an autologous hematopoietic stem cell-based gene therapy indicated for the treatment of adult and pediatric patients with β-thalassemia who require regular red blood cell (RBC) transfusions.
Insight:
- Dosing: Dosing of Zynteglo is based on the number of CD34+ cells in the infusion bag(s) per kg of body weight.
- Dosage forms: Zynteglo is a cell suspension for intravenous infusion. A single dose of Zynteglo contains a minimum of 5.0 × 106 CD34+ cells/kg of body weight, in 1 or more infusion bags.
- Adverse events: The most common non-laboratory adverse reactions (incidence ≥ 20%) were mucositis, febrile neutropenia, vomiting, pyrexia (fever), alopecia (hair loss), epistaxis (nosebleed), abdominal pain, musculoskeletal pain, cough, headache, diarrhea, rash, constipation, nausea, decreased appetite, pigmentation disorder, and pruritus (itch).
- Mechanism of action: Zynteglo adds functional copies of a modified β-globin gene into patients’ hematopoietic stem cells (HSCs) through transduction of autologous CD34+ cells with BB305 LVV. After Zynteglo infusion, transduced CD34+ HSCs engraft in the bone marrow and differentiate to produce RBCs containing biologically active βA-T87Q-globin (a modified β-globin protein) that will combine with α-globin to produce functional adult Hb containing βA-T87Q-globin. βA-T87Q-globin can be quantified relative to other globin species in peripheral blood using high-performance liquid chromatography.
Source: Package Insert - ZYNTEGLO (fda.gov)