gammadelta T lymphocytes count is normal and expandable in peripheral blood of patients with follicular lymphoma, whereas it is decreased in tumor lymph nodes compared with inflammatory lymph nodes.

gammadelta T lymphocytes are attractive effector cells for immunotherapy. In vitro, they can be expanded and kill efficiently a variety of tumor cells. The frequency and distribution of gammadelta T lymphocytes were compared in tumor lymph nodes of 51 patients with follicular lymphoma lymph nodes (FL-LNs) and 28 patients with inflammatory lymph nodes (I-LNs). gammadelta and CD8 T lymphocytes were less abundant in FL-LNs than in I-LNs (p

Phase I study of dystrophin plasmid-based gene therapy in Duchenne/Becker muscular dystrophy.

Nine patients with Duchenne or Becker muscular dystrophy were injected via the radialis muscle with a full-length human dystrophin plasmid, either once with 200 or 600 microg of DNA or twice, 2 weeks apart, with 600 microg of DNA. In the biopsies taken 3 weeks after the initial injection, the vector was detected at the injection site in all patients. Immunohistochemistry and nested reverse transcription-polymerase chain reaction indicated dystrophin expression in six of nine patients. The level of expression was low (up to 6% weak, but complete sarcolemmal dystrophin staining, and up to 26% partial sarcolemmal labeling). No side effects were observed, nor any cellular or humoral anti-dystrophin responses. These results suggest that exogenous dystrophin expression can be obtained in Duchenne/Becker patients after intramuscular transfer of plasmid, without adverse effects, hence paving the way for future developments in gene therapy of hereditary muscular diseases.

Immunotherapy of metastatic melanoma by intratumoral injections of Vero cells producing human IL-2: phase II randomized study comparing two dose levels.

BACKGROUND: Systemic IL-2 has shown some activity in metastatic melanoma, but its use is severely limited by toxicity. TG2001 is a product in which the human IL-2 cDNA was incorporated into the genome of Vero cells, a monkey fibroblast cell line. The goal of this intratumorally applied therapy was to create an antitumor immune response stimulated by xeno-antigens and local production of IL-2 in the close vicinity of tumor-specific antigens. TG2001 was reported to have a good safety profile in two previous dose-escalating phase I studies performed in 18 patients with various solid tumors, with encouraging clinical responses in three patients. The objectives of this study were to evaluate the tolerance and incidence of tumor regression in patients with metastatic melanoma, following repeated administration of Vero-IL-2 cells. PATIENTS AND METHODS: This was on open-label, randomized phase II study comparing two doses of Vero-IL-2, 5x10(5) and 5x10(6) cells. Twenty-eight patients with metastatic melanoma were enrolled in the study, 14 in each treatment group. Patients received TG2001 by intratumoral injection on days 1, 3, and 5 every 4 weeks for four cycles, and every 8 weeks thereafter, until evidence of progressive disease (PD). Criteria for patient selection included histologically proven metastatic melanoma, with one tumor accessible for product administration, and at least another tumor site for response assessment. Evaluation included tumor measurements, humoral and T cell-mediated local and systemic immune response, humoral response to Vero cells, adverse events and standard laboratory parameters. RESULTS: None of the patients achieved a confirmed objective response. Stable disease (SD) was seen in six (43%) and eight patients (57%) at the 5x10(5) and the 5x10(6) dose level, respectively. Two patients, one in each group, died during the study (i.e., within 1 month after the last injection) due to PD. Three patients exhibited antibody responses to Vero cells. T-cell immunity, serum cytokine levels and cytokine mRNA expression in tumor biopsies did not show meaningful alterations after therapy, except for a trend toward an increase in intratumoral TH2 cytokine (IL-4 and/or IL-10) levels. The study drug was well tolerated at both dose levels and side effects mainly consisted of injection site pain and erythema, and pyrexia. CONCLUSION: The intratumoral administration of TG2001 was generally well tolerated in patients with metastatic melanoma, and transient disease stabilization was observed in 50% of patients.

Current protocol of a research phase I clinical trial of full-length dystrophin plasmid DNA in Duchenne/Becker muscular dystrophies. Part I: rationale.

Since the identification of abnormalities in the dystrophin gene as primary cause of Duchenne muscular dystrophy, gene therapy has been seen as an obvious option among various approaches to treat the disease. It is also considered to be especially challenging, as in this context, one must achieve massive transfer of the gene with a sustained lifelong correction of the muscle phenotype. Our goal is to allow large scale transfection of skeletal muscle fibers of Duchenne muscular dystrophy patients with the full-length 11-kb human dystrophin cDNA. Extensive in vitro and in vivo studies, together with safety considerations and the prospects of a very efficient intra-arterial delivery procedure, led us progressively to focus our efforts on plasmid DNA administration. We are now conducting a phase I safety clinical trial which will pave the way for future therapeutic gene therapy trials for Duchenne muscular dystrophy.

Current protocol of a research phase I clinical trial of full-length dystrophin plasmid DNA in Duchenne/Becker muscular dystrophies. Part II: clinical protocol.

A phase I open clinical study on gene therapy in Duchenne and Becker muscular dystrophy, without direct individual benefit for the patient, is being performed at the Pitié-Salpêtrière Hospital, Paris. The aims of this project are: (a) to determine the tolerance and the safety of the intramuscular administration of dystrophin cDNA and (b) to study the quality of the gene transfer in vivo in human patients affected by Duchenne and Becker muscular dystrophy. This clinical trial is conducted sequentially and includes three cohorts of three patients each. Patients must be at least 15 years of age. Diagnosis of Duchenne and Becker muscular dystrophy was confirmed by molecular analysis of the dystrophin gene and for each patient the abnormal expression of dystrophin was confirmed, in skeletal muscle, with antibodies directed against the deleted part of the dystrophin. This phase I study is scheduled to be completed by the end of 2002.

Therapeutic cancer vaccines.

Therapeutic vaccination against cancer-associated antigens represents an attractive option for cancer therapy in view of the comparatively low toxicity and, so far, excellent safety profile of this treatment. Nevertheless, it is now recognized that the vaccination strategies used for prophylactic vaccinations against infectious diseases cannot necessarily be used for therapeutic cancer vaccination. Cancer patients are usually immunosuppressed, and most cancer-associated antigens are self antigens. Therefore, various immunostimulation techniques are under investigation in an effort to bolster immune systems and to overcome immune tolerance to self antigens. Various strategies to stimulate antigen presentation, T-cell reactivity and innate immune activity are under investigation. Similarly, strategies to produce an immunological 'danger signal' at the site of the tumor itself are under evaluation, as it is recognized that while tumor-specific T-cells can be activated at the site of vaccination, they require appropriate signals to be attracted to a tumor. The detection, evaluation and quantification of specific immune responses generated by vaccination with cancer-associated antigens is another important area of therapeutic cancer vaccine evaluation receiving much attention and novel strategies. Multiple clinical trials have been undertaken to evaluate therapeutic vaccines in patients. Aggressive protocols such as those combining specific stimulation of T-cells and chemotherapy or strategies to block immune regulation are having some success.

Metastatic Breast Tumour Regression Following Treatment by a Gene-Modified Vaccinia Virus Expressing MUC1 and IL-2.

MUC1 is expressed by glandular epithelial cells. It is overexpressed in the majority of breast tumours, making it a potential target for immune therapy. The objectives of the present study were to evaluate the anti-tumour activity and tolerance of repeated administration of TG1031 (an attenuated recombinant vaccinia virus containing sequences coding for human MUC1 and the immune stimulatory cytokine IL-2) in patients with MUC1-positive metastatic breast cancer. This was an open-label, randomised study comparing two dose levels, 5 x 10E6 and 5 x 10E7, with 14 patients in each arm. The treatment was administered intramuscularly every 3 weeks for the first 4 doses and every 6 weeks thereafter, until progression. Two patients had a partial tumour regression ( > 50%), and 15 patients had stable disease as their best overall response until at least the 5th injection. Partial regression lasted for 11 months in one patient and for 12 months in the second patient who then underwent surgical resection of her hepatic metastases. The most frequent adverse events included inflammation at injection site: 7 patients, itching or pain at injection site: 5 patients, and moderate fever: 6 patients. One responding patient developed antinuclear, anti-DNA, and increased anti-TPO antibodies after the fifth injection, and which resolved at the end of treatment. The treatment regimes were well tolerated with a low toxicity profile. Although clinical efficacy remains limited, this study demonstrates the potential use of MUC1-based immune therapy in breast cancer.

Gene-based cancer immunotherapy and vaccines.

Extract: Cancer cells are able to escape immune detection and/or rejection by a variety of measures. Cell surface molecules, which are required for the effective policing of tissues by the immune system, are often modified, reduced or eliminated. In addition cancer cells secrete soluble molecules that inhibit the patients' ability to develop an immune response. The ability of the immune system to recognize and reject cancerous growths has been demonstrated in a series of experimental model systems. Efforts are now being made to use this knowledge for the treatment of cancer. Described below are two different gene-based approaches to stimulate the rejection of an established cancer in patients. The first involves procedures which modify the tumor itself, render it a more attractive target to the immune system, and allow immune cells to penetrate the tumor and kill the cancerous cells. The second approach requires a very powerful vaccine to stimulate a strong immune response against the tumor associated antigens in patients with an established cancer. Early efforts to harness the power of the immune system to eliminate cancer were made by Dr. William Coley very early in the 20th century. Dr. Coley injected cancerous tissue, usually sarcomas (tumors of the supportive tissues such as bone, cartilage fat or muscle), with a mix of bacteria and/or their toxins. This would result in an inflammatory response in the tumor and the influx of many immune cells.

[About a phase I gene therapy clinical trial with a full-length dystrophin gene-plasmid in Duchenne/Becker muscular dystrophy]. / A propos d'un essai de phase I de thérapie génique effectué avec un plasmide contenant l'intégralité du gène dystrophine dans la myopathie de Duchenne/Becker.

This is the first gene transfer trial in Duchenne/Becker patients. The aim of the study was to provide evidence on transgene expression and safety of the intramuscular administration of a plasmid containing a full-length dystrophin CDNA. Nine Duchenne/Becker patients, distributed in three cohorts of three patients, were injected into their radialis muscles either once with 200 microg (first cohort) or 600 microg (second cohort) or twice, two weeks apart, with 600 microg plasmidic DNA (third cohort). The patients were enrolled sequentially upon evaluation of the data by an independant pilot committee. In the biopsies taken three weeks after the initial injection from the injected site, the plasmid was detected in all patients. An exogenous dystrophin expression was found in 6/9 patients. The level of expression was low, up to 6 % of weak complete sarcolemmal labelling, and up to 26% of partial sarcolemmal staining. Dystrophin in RNAs were detected by nested RT-PCR in five out of the six biopsies with exogenous dystrophin-positive fibers. Interestingly, neither humoral or cellular antidystrophin responses were observed. No local or general adverse effects were seen. This paves the way for future developments in gene therapy in hereditary muscle diseases, and specifically in Duchenne/Becker myopathies.

Gene-based vaccines and immunotherapeutics.

DNA vaccines, comprised of plasmid DNA encoding proteins from pathogens, allergens, and tumors, are being evaluated as prophylactic vaccines and therapeutic treatments for infectious diseases, allergies, and cancer; plasmids encoding normal human proteins are likewise being tested as vaccines and treatments for autoimmune diseases. Examples of in vivo prophylaxis and immunotherapy, based on different types of immune responses (humoral and cellular), in a variety of disease models and under evaluation in early phase human clinical trials are presented. Viral vectors continue to show better levels of expression than those achieved by DNA plasmid vectors. We have focused our clinical efforts, at this time, on the use of recombinant viral vectors for both vaccine as well as cytokine gene transfer studies. We currently have four clinical programs in cancer immunotherapy. Two nonspecific immunotherapy programs are underway that apply adenoviral vectors for the transfer of cytokine genes into tumors in situ. An adenovirus-IFN gamma construct (TG1042) is currently being tested in phase II clinical trials in cutaneous lymphoma. A similar construct, adenovirus-IL2 (TG1024), also injected directly into solid tumors, is currently being tested in patients with solid tumors (about one-half of which are melanoma). Encouraging results are seen in both programs. Two cancer vaccine immunotherapy programs focus on two cancer-associated antigens: human papilloma virus E6 and E7 proteins and the epithelial cancer-associated antigen MUC1. Both are encoded by a highly attenuated vaccinia virus vector [modified vaccinia Ankara (MVA)] and both are coexpressed with IL-2. Encouraging results seen in both of these programs are described.

Phase I trial of antigen-specific gene therapy using a recombinant vaccinia virus encoding MUC-1 and IL-2 in MUC-1-positive patients with advanced prostate cancer.

MUC-1 is overexpressed on many tumor cells. In addition, aberrant glycosylation of MUC-1 on human tumors leads to exposure of cryptic peptide epitopes that play a role in tumor immunity. As such, it has been identified as a potential target for immunotherapy. The purpose of this phase 1 clinical trial was to determine the maximum tolerated dose, safety of a multiple-dose regimen, and the immunologic effect of vaccinia virus expressing MUC-1 and IL-2 genes (VV/MUC-1/IL-2) in patients with advanced prostate cancer. Five x 10(5), 5 x 10(6), and 5 x 10(7) plaque-forming units (pfu) of vaccinia viruses were used in the dose-escalating study. Viruses were given via intramuscular injection, and clinical response and immune function modulation were analyzed. No grade 3 or 4 toxicity was observed. Objective clinical response was observed after the fourth injection (0.3 ng/mL) in only one patient who received an intermediate dose of virus. Systemic immune modulation in this patient included (1) up-regulation of IL-2 (CD25) and T cell (TcR alphabeta) receptors, (2) increase in the CD4/CD8 ratio (2.5-fold) (3) augmentation of T-helper type 1 cell (TH1) (interferon-gamma and tumor necrosis factor-alpha) but not TH2 (IL-4) cytokine mRNA expression, (4) induction of natural killer cell activity and MHC independent MUC-1 specific cytotoxic T-cell activity, and (5) normalization of mRNA expression of T-cell-associated signal transduction molecules TcR-zeta and p56lck. These results suggest that VV/MUC-1/IL-2 gene therapy with a maximum tolerated dose of 5 x 10(7) pfu is safe and well tolerated.

Adenovirus-mediated intralesional interferon-gamma gene transfer induces tumor regressions in cutaneous lymphomas.

Primary cutaneous lymphomas have been successfully treated with interferons (IFNs), counterbalancing the T-helper 2 (Th2)-skewing state. We undertook a phase 1, open-label, dose-escalating trial of repeated intratumoral administration of TG1042 in patients with advanced primary cutaneous T-cell lymphomas (CTCLs) and multilesional cutaneous B-cell lymphomas (CBCLs). TG1042 is a third-generation, nonreplicating human adenovirus vector containing a human IFN-gamma cDNA insert. Nine patients (7 CTCL, 2 CBCL) were enrolled at the following TG1042 doses: 3 x 10(9), 3 x 10(10), and 3 x 10(11) total particles. Local clinical response was observed in 5 of 9 treated patients (3 patients with complete response [CR] and 2 patients with partial response [PR]). Out of these, 3 patients showed systemic CR with the clearance of other noninjected skin lesions. Clinical response lasted for a median of 3 months (range, 1-6 months). Adverse events were mostly of grades 1 and 2. Seven of 9 treated patients had a detectable TG1042-derived IFN-gamma message in injected lesions after the first treatment cycle. A TG1042-IFN-gamma message was also detectable after several treatment cycles. We demonstrate the induction of humoral immune response to lymphoma tumor-antigen se70-2 after treatment. Our study shows that intralesional injections of TG1042 are both safe and well tolerated.

Phase I immunotherapy with a modified vaccinia virus (MVA) expressing human MUC1 as antigen-specific immunotherapy in patients with MUC1-positive advanced cancer.

BACKGROUND: The MUC1 protein is a highly glycosylated mucin normally found at the apical surface of mucin-secreting epithelial cells in many types of tissues. MUC1 is expressed, but heavily underglycosylated, in different human tumors. TG4010 is a viral suspension of a recombinant vaccinia vector (MVA) containing DNA sequences coding for the human MUC1 antigen and interleukin-2 (IL-2). This product was developed for use as a vaccine in cancer patients whose tumors express the MUC1 antigen. The objective of the present study was to determine the safety of the product and to define the dose of TG4010 to be used in further clinical trials. MATERIALS AND METHODS: Thirteen patients with different solid tumors were treated by repeated intramuscular injection with increasing doses of TG4010 in two separate phase I studies, one in Europe (Basel-CR) and one in the United States (UCLA-RF): a total of 6 patients were treated at a dose of 5 x 10(6) pfu, 3 patients at 5 x 10(7) pfu, and 4 patients at 10(8) pfu. Safety, efficacy, and different immunological tests were the endpoints of the study. RESULTS: Tolerance of TG4010 was excellent, and side effects mainly consisted of injection site pain and influenza-like symptoms. There was no apparent detrimental effect of repeated injections of the vaccinia virus. Four of thirteen evaluable patients showed stabilization of their disease for 6 to 9 months. One lung cancer patient who was initially progressing after the first injections later showed a marked decrease in the size of his metastases that lasted for 14 months. Some T cell proliferative immune responses were seen in five patients. CONCLUSIONS: The administration of TG4010 was generally well tolerated in patients with metastatic tumors, and transient disease stabilization was observed in several patients, warranting further clinical studies with the product.