Sung-Yun Pai, MD, on High T-Cell Reconstitution in X-SCID With Lentiviral Gene Therapy

“The current trial is taking the successful elements from the second-generation trial, moving the control of the transgene, the elongation factor 1L, to a lentiviral format, and trying to improve the immune reconstitution by 2 means. One is that we took the transgene, and we changed it into a codon optimization format, meaning that each copy of the transgene should generate more protein, and the second improvement that we did was to introduce low dose conditioning.”

Lentiviral gene therapy delivering codon optimized IL2RG resulted in 100% survival and robust T-cell recovery more rapid than after standard hematopoietic stem cell transplantation (HCT) in patients with X-linked severe combined immunodeficiency (SCID-X1).

These data, from a phase 1/2 clinical trial (NCT03311503), were presented at the the American Society of Gene and Cell Therapy (ASGCT) 2023 Annual Meeting, held May 16-20, in Los Angeles, California, by investigator Sung-Yun Pai, MD, chief, immune deficiency cellular therapy program, and tenured senior investigator, National Cancer Institute Center for Cancer Research.

CGTLive spoke with Pai to learn more about the gene therapy, the 2 previous trials assessing it and lessons learned from them, and the now third generation trial and the updated findings she presented from it. She discussed the data, including a 100% high T-cell reconstitution rate in the 13 treated patients. She compared the rate with gene therapy to that of the rate with standard of care HCT, with which 50% have high T-cell reconstitution by 6 months of transplant.

Click here to read more coverage of ASGCT 2023.

REFERENCE

Pai SY, Booth C, Kohn DB, et al. Universal survival and superior immune reconstitution after lentiviral gene therapy with low dose conditioning for X-linked SCID (SCID-X1). Presented at: ASGCT 2023 Annual Meeting; May 16-20; Los Angeles, California.