US-based biopharmaceutical firm Mustang Bio has entered an exclusive worldwide licence agreement with St. Jude Children’s Research Hospital for a new gene therapy to treat X-linked severe combined immunodeficiency (X-SCID or bubble boy disease).
Bubble boy disease is said to be the most common form of severe combined immunodeficiency. It is known to affect around one in 50,000 to 100,000 newborns globally.
Under the agreement, the partners will develop the ex-vivo lentiviral gene therapy, which involves a low busulfan dose before the reinfusion of the patient’s own gene-modified blood stem cells.
The drug candidate is being assessed in a Phase I/II multi-centre clinical trial in infants under the age of two. A separate Phase I/II trial is also being conducted at the National Institutes of Health (NIH).
Mustang Bio president and CEO Manuel Litchman said: “We look forward to working with St. Jude to advance this programme through ongoing Phase I/II trials, with the goal of providing a novel, long-term treatment to the more than 80% of infants who lack fully matched bone marrow transplant donors and those patients who continue to have significant impairment of immunity.”
The gene therapy was found to be well tolerated in early studies on a total of eight patients aged under two.
Amongst these patients, six experienced reconstituted immune systems three to four months post therapy. It is reported that the remaining two achieved positive progression in early recovery stages.
St. Jude assistant member Ewelina Mamcarz said: “Our therapy has been well tolerated thus far, and none of the infants required any blood product support after low dose of busulfan.
“Most importantly, we observe recovery of all cells of the immune system, which is truly an achievement over prior gene therapy trials, where B cell reconstitution did not occur, and patients required intravenous immunoglobulin for life.”