Gene therapy for immunodeficiency due to adenosine deaminase deficiency.

BACKGROUND: We investigated the long-term outcome of gene therapy for severe combined immunodeficiency (SCID) due to the lack of adenosine deaminase (ADA), a fatal disorder of purine metabolism and immunodeficiency. METHODS: We infused autologous CD34+ bone marrow cells transduced with a retroviral vector containing the ADA gene into 10 children with SCID due to ADA deficiency who lacked an HLA-identical sibling donor, after nonmyeloablative conditioning with busulfan. Enzyme-replacement therapy was not given after infusion of the cells. RESULTS: All patients are alive after a median follow-up of 4.0 years (range, 1.8 to 8.0). Transduced hematopoietic stem cells have stably engrafted and differentiated into myeloid cells containing ADA (mean range at 1 year in bone marrow lineages, 3.5 to 8.9%) and lymphoid cells (mean range in peripheral blood, 52.4 to 88.0%). Eight patients do not require enzyme-replacement therapy, their blood cells continue to express ADA, and they have no signs of defective detoxification of purine metabolites. Nine patients had immune reconstitution with increases in T-cell counts (median count at 3 years, 1.07x10(9) per liter) and normalization of T-cell function. In the five patients in whom intravenous immune globulin replacement was discontinued, antigen-specific antibody responses were elicited after exposure to vaccines or viral antigens. Effective protection against infections and improvement in physical development made a normal lifestyle possible. Serious adverse events included prolonged neutropenia (in two patients), hypertension (in one), central-venous-catheter-related infections (in two), Epstein-Barr virus reactivation (in one), and autoimmune hepatitis (in one). CONCLUSIONS: Gene therapy, combined with reduced-intensity conditioning, is a safe and effective treatment for SCID in patients with ADA deficiency. (ClinicalTrials.gov numbers, NCT00598481 and NCT00599781.)

Infusion of suicide-gene-engineered donor lymphocytes after family haploidentical haemopoietic stem-cell transplantation for leukaemia (the TK007 trial): a non-randomised phase I-II study.

BACKGROUND: Procedures to prevent severe graft-versus-host disease (GVHD) delay immune reconstitution secondary to transplants of haploidentical haemopoietic stem cells for the treatment of leukaemia, leading to high rates of late infectious mortality. We aimed to systematically add back genetically engineered donor lymphocytes to facilitate immune reconstitution and prevent late mortality. METHODS: In a phase I-II, multicentre, non-randomised trial of haploidentical stem-cell transplantation, we infused donor lymphocytes expressing herpes-simplex thymidine kinase suicide gene (TK-cells) after transplantation. The primary study endpoint was immune reconstitution defined as circulating CD3+ count of 100 cells per muL or more for two consecutive observations. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00423124. FINDINGS: From Aug 13, 2002, to March 26, 2008, 50 patients (median age 51 years, range 17-66) received haploidentical stem-cell transplants for high-risk leukaemia. Immune reconstitution was not recorded before infusion of TK-cells. 28 patients received TK-cells starting 28 days after transplantation; 22 patients obtained immune reconstitution at median 75 days (range 34-127) from transplantation and 23 days (13-42) from infusion. Ten patients developed acute GVHD (grade I-IV) and one developed chronic GVHD, which were controlled by induction of the suicide gene. Overall survival at 3 years was 49% (95% CI 25-73) for 19 patients who were in remission from primary leukaemia at the time of stem-cell transplantation. After TK-cell infusion, the last death due to infection was at 166 days, this was the only infectious death at more than 100 days. No acute or chronic adverse events were related to the gene-transfer procedure. INTERPRETATION: Infusion of TK-cells might be effective in accelerating immune reconstitution, while controlling GVHD and protecting patients from late mortality in those who are candidates for haploidentical stem-cell transplantation. FUNDING: MolMed SpA, Italian Association for Cancer Research.

Interferon ß-1a (IFNß-1a) in COVID-19 patients (INTERCOP): study protocol for a randomized controlled trial.

BACKGROUND: Pharmacological therapies of proven efficacy in coronavirus disease 2019 (COVID-19) are still lacking. We have identified IFNß-1a as the most promising drug to be repurposed for COVID-19. The rationale relies on the evidence of IFNß anti-viral activity in vitro against SARS-CoV-2 and animal models resembling SARS-CoV-2 infection and on a recent clinical trial where IFNß was indicated as the key component of a successful therapeutic combination. METHODS: This is a randomized, controlled, open-label, monocentric, phase II trial (INTERCOP trial). One hundred twenty-six patients with positive swab detection of SARS-CoV-2, radiological signs of pneumonia, and mild-to-moderate disease will be randomized 2:1 to IFNß-1a in addition to standard of care vs standard of care alone. No other anti-viral drugs will be used as part of the regimens, both in the control and the intervention arms. IFNß-1a will be administered subcutaneously at the dose of 44 mcg (equivalent to 12 million international units) three times per week, at least 48 h apart, for a total of 2 weeks. The primary outcome is the time to negative conversion of SARS-CoV-2 nasopharyngeal swabs. Secondary outcomes include improvement or worsening in a clinical severity score measured on a 7-point ordinal scale (including transfer to intensive care unit and death), oxygen- and ventilator-free days, mortality, changes in pulmonary computed tomography severity score, hospital stay duration, reduction of viral load measured on nasopharyngeal swabs, number of serious adverse events, and changes in biochemical markers of organ dysfunction. Exploratory outcomes include blood cell counts, cytokine and inflammatory profile, peripheral mRNA expression profiles of interferon-stimulated genes, and antibodies to SARS-CoV-2 and to IFNß-1a. INTERCOP is the first study to specifically investigate the clinical benefits of IFNß-1a in COVID-19 patients. DISCUSSION: Potential implications of this trial are multifaceted: should the primary outcome be fulfilled and the treatment be safe, one may envisage that IFNß-1a be used to reduce the infectivity of patients with mild-to moderate disease. In case IFNß-1a reduced the duration of hospital stay and/or ameliorated the clinical status, it may become a cornerstone of COVID-19 treatment. TRIAL REGISTRATION: EudraCT 2020-002458-25. Registered on May 11, 2020 ClinicalTrials.gov Identifier: NCT04449380.

Clinical improvement and normalized Th1 cytokine profile in early and long-term interferon-alpha treatment in a suspected case of hyper-IgE syndrome.

We are reporting on a 7-months-old boy with suspected hyper-IgE syndrome, presenting with a therapy resistant severe eczema and an overall reduction of in vitro cytokine production. Interferon-alpha (IFN-alpha) treatment resulted in a marked and stable clinical improvement and normalization of in vitro T-cell cytokine production, indicating a valid therapeutic potential of IFN-alpha as immunomodulating drug.

Lentiviral hematopoietic stem cell gene therapy in patients with Wiskott-Aldrich syndrome.

Wiskott-Aldrich syndrome (WAS) is an inherited immunodeficiency caused by mutations in the gene encoding WASP, a protein regulating the cytoskeleton. Hematopoietic stem/progenitor cell (HSPC) transplants can be curative, but, when matched donors are unavailable, infusion of autologous HSPCs modified ex vivo by gene therapy is an alternative approach. We used a lentiviral vector encoding functional WASP to genetically correct HSPCs from three WAS patients and reinfused the cells after a reduced-intensity conditioning regimen. All three patients showed stable engraftment of WASP-expressing cells and improvements in platelet counts, immune functions, and clinical scores. Vector integration analyses revealed highly polyclonal and multilineage haematopoiesis resulting from the gene-corrected HSPCs. Lentiviral gene therapy did not induce selection of integrations near oncogenes, and no aberrant clonal expansion was observed after 20 to 32 months. Although extended clinical observation is required to establish long-term safety, lentiviral gene therapy represents a promising treatment for WAS.

Antitumor effects of HSV-TK-engineered donor lymphocytes after allogeneic stem-cell transplantation.

The extensive exploitation of the antitumor effect of donor lymphocytes infused after allogeneic hematopoietic stem-cell transplantation (allo-HSCT) is limited by the risk of graft-versus-host disease (GvHD). To overcome this limitation, we investigated the therapeutic potential of donor lymphocytes engineered with the suicide gene thymidine kinase of herpes simplex virus (TK) in 23 patients experiencing recurrence of hematologic malignancies after allo-HSCT. Long-term follow-up of infused patients included analysis of engraftment of genetically engineered lymphocytes, in vivo assessment of antitumor effect, and control of GvHD by ganciclovir. All 17 patients evaluable for engraftment and graft-versus-leukemia (GvL) had circulating TK(+) cells detectable beginning at a median time of 18 days. Eleven patients (65%) experienced a substantial clinical benefit resulting in 6 (35%) complete remissions and 5 (29%) partial responses. The antitumor effect tightly correlated with the in vivo expansion of TK(+) cells. Seven patients received ganciclovir, resulting in elimination of TK(+) cells and effective and selective treatment of GvHD. Immunization against HSV-TK was observed in 7 patients but did not preclude an effective GvL. These data validate the feasibility, safety, and efficacy of TK(+) cells in the context of allografting and represent the basis for a broader application of this technology.