Persistence and expression of the adenosine deaminase gene for 12 years and immune reaction to gene transfer components: long-term results of the first clinical gene therapy trial

Abstract Successful gene therapy trials of ADA-SCID and SCID-X1 demonstrated the curative potential of oncoretroviral gene transfer. Integration of the retroviral vectors used in these studies has been thought to be a random process but severe side effects in gene therapy and in vitro studies revealed preferred insertion of these vectors mainly around transcription start sites. In SCID patients proliferation advantage of gene corrected cells was one reason for the success of the trials, whereas in the most recent chronic granulomatous disease (CGD) gene therapy trial corrected cells do not have any selective advantage therefore the two patients received mild busulfan treatment before transplantation. High efficiency transduction and conditioning have helped in the successful correction of the patients. Peripheral blood granulocytes show a stable expression (>10%) of the transgene (gp91phox) in patient 1 (15 months post treatment) as well as in patient 2 (11 months post treatment). We reasoned that, unlike T cells, which have the capability to proliferate independent of their bone marrow progenitors, granulocytes more directly reflect the influence of retrovirus insertion, and should therefore allow to closely monitor clonal fate in vivo and its potential relation to vector insertion. To study the clonality of the corrected myelopoiesis, the long term activity of individual cell clones, and the distribution of integration sites in active cells we carried out high sensitive LAM-PCR. The highly polyclonal composition of transduced cells forming myelopoiesis caused the sustained expression of gp91phox. Individual clones carrying the transgene could be detected at multiple time points. To define whether corrected cells have a proliferation advantage due to their vector integration we started large-scale sequencing and mapping of involved insertion sites. We here present >700 unique mappable integration sites of the two treated patients. The distribution of the SFFV based retroviral vector integration sites in this trial turned non random 5 months after transplantation. Corrected long-term myelopoiesis expanded 3- to 5- fold in the two patients due to activating common integration sites (CIS) in the zinc finger transcription factor homologs MDS1/EVI1, PRDM16, or in SETBP1, suggesting that these genes influence regulation of normal long-term hematopoiesis in humans. Our data indicate that the therapeutic benefit in this trial was activated through insertional side effects, therefore our findings have important implications in novel gene therapy approaches.

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Long-term follow-up of a randomized AAV2-GAD gene therapy trial for Parkinson’s disease

JCI Insight ◽

10.1172/jci.insight.90133 ◽

2017 ◽

Vol 2 (7) ◽

Cited By ~ 35

Author(s):

Martin Niethammer ◽

Chris C. Tang ◽

Peter A. LeWitt ◽

Ali R. Rezai ◽

Maureen A. Leehey ◽

...

Keyword(s):

Parkinson’S Disease ◽

Gene Therapy ◽

Parkinson's Disease ◽

Gene Therapy Trial ◽

Long Term Follow Up ◽

Therapy Trial

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Faculty Opinions recommendation of Long-term follow-up of a randomized AAV2-GAD gene therapy trial for Parkinson's disease.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.727492597.793532001 ◽

2017 ◽

Author(s):

Joseph Jankovic ◽

Arjun Tarakad

Keyword(s):

Parkinson’S Disease ◽

Gene Therapy ◽

Parkinson's Disease ◽

Gene Therapy Trial ◽

Long Term Follow Up ◽

Therapy Trial

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Retrovirus gene therapy for X-linked chronic granulomatous disease can achieve stable long-term correction of oxidase activity in peripheral blood neutrophils

Blood ◽

10.1182/blood-2009-05-222760 ◽

2010 ◽

Vol 115 (4) ◽

pp. 783-791 ◽

Cited By ~ 135

Author(s):

Elizabeth M. Kang ◽

Uimook Choi ◽

Narda Theobald ◽

Gilda Linton ◽

Debra A. Long Priel ◽

...

Keyword(s):

Gene Therapy ◽

Chronic Granulomatous Disease ◽

Oxidase Activity ◽

Severe Infection ◽

Granulomatous Disease ◽

Gene Therapy Trial ◽

Blood Neutrophils ◽

Severe Infections ◽

Therapy Trial

Abstract Chronic granulomatous disease (CGD) is associated with significant morbidity and mortality from infection. The first CGD gene therapy trial resulted in only short-term marking of 0.01% to 0.1% of neutrophils. A recent study, using busulfan conditioning and an SFFV retrovirus vector, achieved more than 20% marking in 2 patients with X-linked CGD. However, oxidase correction per marked neutrophil was less than normal and not sustained. Despite this, patients clearly benefited in that severe infections resolved. As such, we initiated a gene therapy trial for X-CGD to treat severe infections unresponsive to conventional therapy. We treated 3 adult patients using busulfan conditioning and an MFGS retroviral vector encoding gp91phox, achieving early marking of 26%, 5%, and 4% of neutrophils, respectively, with sustained long-term marking of 1.1% and 0.03% of neutrophils in 2 of the patients. Gene-marked neutrophils have sustained full correction of oxidase activity for 34 and 11 months, respectively, with full or partial resolution of infection in those 2 patients. Gene marking is polyclonal with no clonal dominance. We conclude that busulfan conditioning together with an MFGS vector is capable of achieving long-term correction of neutrophil oxidase function sufficient to provide benefit in management of severe infection. This study was registered at www.clinicaltrials.gov as #NCT00394316.

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