Developing gene therapies for rare diseases: an interview with Geoff MacKay

Geoff MacKay is a pioneer in cell and gene therapy with a track record of successful leadership at innovative biotechs. He is currently the president and CEO of AVROBIO, a clinical-stage lentiviral gene therapy company that treats lysosomal disorders, and a board member of Talaris Therapeutics and Satellos Bioscience. He is also the founding CEO of eGenesis, a biotech that applies CRISPR-Cas9 gene editing to xenotransplantation and the former president and CEO of Organogenesis, a world-leading cell therapy company. Earlier in his career, MacKay spent 11 years at Novartis in senior leadership positions within the global transplantation and immunology franchise.

Wild-type HIV infection after treatment with lentiviral gene therapy for β-thalassemia

Betibeglogene autotemcel (beti-cel) gene therapy (GT) for patients with transfusion-dependent β-thalassemia uses autologous CD34+ cells transduced with BB305 lentiviral vector (LVV), which encodes a modified β-globin gene. BB305 LVV also contains select HIV sequences for viral packaging, reverse transcription, and integration. This case report describes a patient successfully treated with beti-cel in a phase 1/2 study (HGB-204; #NCT01745120) and subsequently diagnosed with wild-type (WT) HIV infection. From 3.5 to 21 months postinfusion, the patient stopped chronic red blood cell transfusions; total hemoglobin (Hb) and GT-derived HbAT87Q levels were 6.6 to 9.5 and 2.8 to 3.8 g/dL, respectively. At 21 months postinfusion, the patient resumed transfusions for anemia that coincided with an HIV-1 infection diagnosis. Quantitative polymerase chain reaction assays detected no replication-competent lentivirus. Next-generation sequencing confirmed WT HIV sequences. Six months after starting antiretroviral therapy, total Hb and HbAT87Q levels recovered to 8.6 and 3.6 g/dL, respectively, and 3.5 years postinfusion, 13.4 months had elapsed since the patient’s last transfusion. To our knowledge, this is the first report of WT HIV infection in an LVV-based GT recipient and demonstrates persistent long-term hematopoiesis after treatment with beti-cel and the ability to differentiate between WT HIV and BB305-derived sequences.