St. Jude, Mustang gene therapy produces functional immunity in SCID-X1 patients

St. Jude and Mustang reported late Wednesday that their gene therapy led to fully functioning immune systems in newly diagnosed infants with X-linked severe combined immunodeficiency (SCID-X1) who were treated in the Phase I/II LVXSCID-ND trial. The news sent shares of Mustang Bio Inc. (NASDAQ:MBIO) up $5.99 (225%) to $8.65 in early after-hours trading Wednesday.

The gene therapy comprises a lentiviral vector delivering IL-2 receptor γ chain (IL2Rγ; CD132) given with a conditioning regimen of busulfan...