Mustang Bio Announces Updated Clinical Data on MB-107 Lentiviral Gene Therapy for Patients with X-Linked Severe Combined Immunodeficiency - Seite 2

Lentiviral Gene Therapy with Low Dose Busulfan for Infants with X-SCID Results in the Development of a Functional Normal Immune System: Interim Results of an Ongoing Phase I/II Clinical Study (Abstract Number: 2058)
Poster presentation: Ewelina Mamcarz, M.D., Department of Bone Marrow Transplantation and Cellular Therapy, St. Jude Children’s Research Hospital, Memphis, TN, USA

Interim data from the multicenter Phase 1/2 clinical trial for infants under the age of two treated with the lentiviral gene therapy preceded by low exposure-targeted busulfan conditioning were published in the New England Journal of Medicine. Updated data presented at the 2019 ASH Annual Meeting include three more patients (n=11), 8 months additional median follow up (23.6 months; range: 1.5 to 33.9 months), more extensive analysis of T and B cell functional recovery, and detailed vector integration site studies.

Data Highlights:

• Lentiviral gene therapy using low dose busulfan conditioning has been well tolerated, with no serious adverse events other than hematologic related to busulfan
• All 11 patients had robust hematopoietic recovery within 3-4 weeks post cell infusion without blood product support
• Nine patients, with a follow up of greater than 3 months, achieved normal-for-age T-cell and natural killer (NK)-cell numbers within 3-4 months post gene therapy
• Five patients are off intravenous immunoglobulin (IVIG) therapy thus far, of whom 3 responded to vaccines
• Median vector copy number (VCN) at 12 months post-gene therapy in seven patients, who have been followed for more than 12 months, was 2.25 VCN/cell (range: 1.24-3.03) in T cells, 0.34 VCN/cell (range: 0.23-1.25) in B cells, 1.55 VCN/cell (range 1.27-3.39) in NK cells, and 0.08 VCN/cell (range: 0.03-0.76) in myeloid cells in peripheral blood, and 0.10 (range: 0.05-0.66) in CD34+ bone marrow cells, respectively

“The results from treatment with low-dose busulfan conditioning and the novel lentiviral gene therapy in newly diagnosed infants with XSCID continue to be very promising,” said Dr. Mamcarz. “We are pleased that the therapy has been well tolerated and all patients with a follow up of more than 3 months recovered from pre-existing infections, are off protective isolation and prophylactic antimicrobials, and have normal growth in respect to height and weight. This reinforces our belief that the lentiviral gene therapy has the potential to be an attractive alternative to current XSCID therapies.”