Bruce Acres

Therapeutic vaccination with TG4010 and first-line chemotherapy in advanced non-small-cell lung cancer: a controlled phase 2B trial

BACKGROUND Chemotherapy is the standard of care for advanced stages of non-small-cell lung cancer (NSCLC). TG4010 is a targeted immunotherapy based on a poxvirus (modified vaccinia virus Ankara) that codes for MUC1 tumour-associated antigen and interleukin 2. This study assessed TG4010 in combination with first-line chemotherapy in advanced NSCLC. METHODS 148 patients with advanced (stage IIIB [wet] or IV) NSCLC expressing MUC1 by immunohistochemistry, and with performance status 0 or 1, were enrolled in parallel groups in this open-label, phase 2B study. 74 patients were allocated to the combination therapy group, and received TG4010 (10(8) plaque forming units) plus cisplatin (75 mg/m(2) on day 1) and gemcitabine (1250 mg/m(2) on days 1 and 8) repeated every 3 weeks for up to six cycles. 74 patients allocated to the control group received the same chemotherapy alone. Patients were allocated using a dynamic minimisation procedure stratified by centre, performance status, and disease stage. The primary endpoint was 6-month progression-free survival (PFS), with a target rate of 40% or higher in the experimental group. Analyses were done on an intention-to-treat basis. This study is completed and is registered with ClinicalTrials.gov, number NCT00415818. FINDINGS 6-month PFS was 43·2% (32 of 74; 95% CI 33·4-53·5) in the TG4010 plus chemotherapy group, and 35·1% (26 of 74; 25·9-45·3) in the chemotherapy alone group. Fever, abdominal pain, and injection-site pain of any grade according to National Cancer Institute Common Toxicity Criteria were more common in the TG4010 group than in the chemotherapy alone group: 17 of 73 patients (23·3%) versus six of 72 (8·3%), 12 (16·4%) versus two (2·8%), and four (5·5%) versus zero (0%), respectively. The most common grade 3-4 adverse events were neutropenia (33 [45·2%] of patients in the TG4010 plus chemotherapy group vs 31 [43·1%] in the chemotherapy alone group) and fatigue (18 [24·7%] vs 13 [18·1%]); the only grade 3-4 events that differed significantly between groups were anorexia (three [4·1%] vs 10 [13·9%]) and pleural effusion (none vs four [5·6%]). 38 of 73 patients (52·1%) in the TG4010 plus chemotherapy group and 34 of 72 (47·2%) in the chemotherapy alone group had at least one serious adverse event. INTERPRETATION This phase 2B study suggests that TG4010 enhances the effect of chemotherapy in advanced NSCLC. A confirmatory phase 2B-3 trial has been initiated. FUNDING Transgene SA, Advanced Diagnostics for New Therapeutic Approaches (ADNA)/OSEO.

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

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.

A phase II study of Tg4010 (Mva-Muc1-Il2) in association with chemotherapy in patients with stage III/IV non-small cell lung cancer

Background: TG4010 is a recombinant viral vector expressing both the tumor-associated antigen MUC1 and Interleukine-2. This vector is based on the modified virus of Ankara, a significantly attenuated strain of vaccinia virus. TG4010 has been designed to induce or amplify a cellular immune response directed against tumor cells expressing MUC1. Methods: A multicenter, randomized phase II study has explored two schedules of the combination of TG4010 with first line chemotherapy in patients with stage IIIB/IV non-small cell lung cancer. In Arm 1, TG4010 was combined upfront with cisplatin (100 mg/m2 day 1) and vinorelbine (25 mg/m2 day 1 and day 8). In Arm 2, patients were treated with TG4010 monotherapy until disease progression, followed by TG4010 plus the same chemotherapy as in Arm1. Response rate was evaluated according to RECIST. Median time to progression and median overall survival were calculated according to the Kaplan–Meier method. Results: Sixty-five patients were enrolled, 44 in Arm 1 and 21 in Arm 2, in accordance with the two stage Simon design of the statistical plan. In Arm 1, partial response was observed in 13 patients out of 37 evaluable patients (29.5% of the intent to treat population, 35.1% of the evaluable patients). In Arm 2, two patients experienced stable disease for more than 6 months with TG4010 alone (up to 211 days), in the subsequent combination with chemotherapy, one complete and one partial response were observed out of 14 evaluable patients. Arm 2 did not meet the criteria for moving forward to second stage. The median time to progression was 4.8 months for Arm 1. The median overall survival was 12.7 months for Arm 1 and 14.9 for Arm 2. One year survival rate was 53% for Arm 1 and 60% for Arm 2. TG4010 was well tolerated, mild to moderate injection site reactions, flu-like symptoms, and fatigue being the most frequent adverse reactions. A MUC1-specific cellular immune response was observed in lymphocyte samples from all responding patients evaluable for immunology. Conclusions: The combination of TG4010 with standard chemotherapy in advanced non-small cell lung cancer is feasible and shows encouraging results. A randomized study evaluating the addition of TG4010 to first line chemotherapy in this population is in progress.

Recombinant vaccinia virus encoding human MUC1 and IL2 as immunotherapy in patients with breast cancer

Polymorphic epithelial mucin, encoded by the MUC1 gene, is present at the apical surface of glandular epithelial cells. It is over-expressed and aberrantly glycosylated in most breast tumors, resulting in an antigenically distinct molecule and a potential target for immunotherapy. This transmembrane protein, when produced by tumor cells, is often cleaved into the circulation, where it is detectable as a tumor marker (CA 15.3) by various antibodies, allowing for early detection of recurrences and evaluation of treatment efficacy. The objective of the current study was to examine the clinical and environmental safety and immunogenicity of a live recombinant vaccinia virus expressing the human MUC1 and IL2 genes (VV TG5058), referred to here as TG1031. The study was an open-label phase 1 and 2 trial in nine patients with advanced inoperable breast cancer recurrences to the chest wall. The patients were vaccinated intramuscularly with a single dose of TG1031; three patients were treated at each of three progressive dose levels ranging from 5×105 to 5×107 plaque-forming units. A boost injection at their original dose level was administered in patients responding immunologically, clinically, or both. Vaccination resulted in no significant clinical adverse effects, and there was no environmental contamination by live TG1031. All patients had been vaccinated as children, and patients treated at the highest dose level mounted a significant anti-vaccinia antibody response. None of the nine patients had a significant increase in MUC1-specific antibody titers after one single injection, whereas five patients had a detectable increase in vaccinia virus antibody titers. Peripheral blood mononuclear cells of one patient at the intermediate dose level showed a proliferative response to in vitro culture with vaccinia virus, with a stimulation index of 6. A second patient treated at the intermediate dose level had a stimulation index of 7 to MUC1 peptide and of 14 after a boost injection. This patient had a concomitant decrease in carcinoembryonic antigen serum levels and remained clinically stable for 10 weeks. Evidence of MUC1-specific cytotoxic T lymphocytes was detected in two patients. Immunohistochemical analysis revealed an increase in T memory cells (CD45RO) in tumor biopsies after vaccination. The absence of serious adverse events, together with the documentation of immune stimulations in vivo, warrant the further use of TG1031 in immunotherapy trials of breast cancer.

MUC1-specific immune responses in human MUC1 transgenic mice immunized with various human MUC1 vaccines

Abstract Analyses of MUC1-specific cytotoxic T cell precursor (CTLp) frequencies were performed in mice immunized with three different MUC1 vaccine immunotherapeutic agents. Mice were immunized with either a fusion protein comprising MUC1 and glutathione S-transferase (MUC1-GST), MUC1-GST fusion protein coupled to mannan (MFP) or with a recombinant vaccinia virus expressing both MUC1 and interleukin-2. Mouse strain variations in immune responsiveness have been observed with these vaccines. We have constructed mice transgenic for the human MUC1 gene to study MUC1-specific immune responses and the risk of auto-immunity following MUC1 immunization. Transgenic mice immunized with MUC1 were observed to be partially tolerant in that the MUC1-specific antibody response is lower than that observed in syngeneic but non-transgenic mice. However, a significant MUC1-specific CTLp response to all three vaccines was observed, indicating the ability to overcome T cell, but to a lesser extent B cell, tolerance to MUC1 in these mice. Histological analysis indicates no evidence of auto-immunity to the cells expressing the human MUC1 molecule. These results suggest that it is possible to generate an immune response to a cancer-related antigen without damage to normal tissues expressing the antigen.

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.

Abstract: 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 × 105, 5 × 106, and 5 × 107 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 &agr;β) receptors, (2) increase in the CD4/CD8 ratio (2.5-fold) (3) augmentation of T-helper type 1 cell (TH1) (interferon-γ and tumor necrosis factor-&agr; ) 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-ζ and p56lck. These results suggest that VV/MUC-1/IL-2 gene therapy with a maximum tolerated dose of 5 × 107 pfu is safe and well tolerated.

MUC1 as a target antigen for cancer immunotherapy.

The cancer-associated antigen MUC1 is overexpressed and modified by tumor cells in over half of all cancer cases. Despite various complexities associated with this antigen, it is well worth pursuing as a vaccine for the immunotherapy of cancer. In this review, the authors describe the discovery of MUC1 and its association with cancer, recent observations showing that the immunology of MUC1 is complicated, animal data showing that it can be a target for immune-mediated tumor rejection, and finally, preliminary clinical results to show that vaccine-based immunotherapy with MUC1 does have an impact on the therapy of cancer.

Bypassing tumor-associated immune suppression with recombinant adenovirus constructs expressing membrane bound or secreted GITR-L

Recent evidence has resurrected the concept of specialized populations of T lymphocytes that are able to suppress an antigen-specific immune response. T-regulatory cells (T-reg) have been characterized as CD4+ CD25+ T cells. Previous reports describing differential gene expression analysis have shown that the glucocorticoid-induced tumor necrosis family receptor family-related gene (GITR) is upregulated in these cells. Furthermore, antibodies specific for GITR have been shown to inhibit the T-suppressor function of CD4+ CD25+ T-reg. The ligands for both mouse and human GITR have been cloned recently. We have inserted the sequences for natural, membrane-bound GITR-ligand (GITR-L) and a truncated secreted form of GITR-L (GITR-Lsol) into the adenovirus-5 genome. Coculture experiments show that cells infected with Ad-GITR-L and supernatants from cells infected with Ad-GITR-Lsol can increase the proliferation of both CD4+ CD25- and CD8+ T cells in response to anti-CD3 stimulation, in the presence, as well as in the absence, of CD4+ CD25+ T cells. The virus constructs were injected into growing B16 melanoma tumors. Ad-GITR-L was shown to attract infiltration with both CD4+ and CD8+ T cells. Both constructs were shown to inhibit tumor growth.

Immunotherapy of established tumors in mice by intratumoral injection of an adenovirus vector harboring the human IL-2 cDNA: induction of CD8(+) T-cell immunity and NK activity.

Intratumoral (i.t.) injections of an adenovirus encoding the human interleukin-2 (IL-2) under the control of the RSV (Ad-pRSV-IL-2) or CMV (Ad-pCMV-IL-2) promoter were performed in established mastocytoma P815 tumors in B6D2 mice. Both early and long-term survival were found increased in mice treated with Ad-pCMV-IL-2 as compared with those obtained with Ad-pRSV-IL-2: tumor regression was observed in 30–50% of mice for the former and 5–15% for the latter. Difference in efficacy between the two vectors was directly correlated to the amount of IL-2 produced i.t. between 24 and 48 hours postinjection, which reached 10–20 ng/tumor for Ad-pCMV-IL-2 and 0.3–0.5 ng/tumor for Ad-pRSV-IL-2. In both cases, expression in the tumor was clearly detectable for a period of 7–10 days postinjection. Serum IL-2 was not detectable in mice treated with Ad-pRSV-IL-2, whereas expression peaked at a total of 1–2 ng at 24 hours but declined very rapidly in the Ad-pCMV-IL-2–treated group. Constant production of IL-2 inside the tumor was necessary for successful therapy because i.t. injections of recombinant IL-2 at levels up to 1 μg for five consecutive days did not lead to antitumoral activity. Evidence of induced systemic immunity following Ad-pCMV-IL-2 injections was obtained from rechallenge experiments in which tumor-free mice after treatment rejected a subsequent contralateral injection of a lethal dose of P815 tumor cells and from the observation that regression of nontreated tumors occurred in animals bearing bilateral tumors that were treated i.t. in a single tumor with Ad-pCMV-IL-2. P815-specific cytotoxic T lymphocytes (CTL) were found specifically in spleen cells from cured mice or rechallenged mice but not in control mice. Interestingly, limiting dilution analysis of anti-P815 CTL precursor (CTLp) frequency revealed a significant increase in mice cured of their tumor as compared to that obtained in naive mice or control mice treated or not with Ad-IL-2 but whose tumor was growing. In vivo depletion of T-cell subsets, as well as natural killer cells at the time of i.t. injections with Ad-pCMV-IL-2, demonstrated that both CD8+ T cells and natural killer cells, but not CD4+ T cells, were required for successful therapy. Finally, mice preimmunized with Ad-null viruses were severely compromised in their capacity to eradicate established P815 tumors after Ad-pCMV-IL-2 therapy, at least when neutralizing antibody titers reached a critical level. Cancer Gene Therapy (2001) 8, 321–332

Transduction of human dendritic cells with a recombinant modified vaccinia Ankara virus encoding MUC1 and IL-2

Abstract. The epithelial mucin MUC1 is considered an opportune target antigen for cancer immunotherapy, as it is over-expressed and exhibits aberrant glycosylation in malignant cells. Because dendritic cells (DC) are powerful initiators of immune responses, efforts have focused on tumor antigen-bearing DC as potent cancer vaccines. In this study we have characterized the transduction of monocyte-derived DC with a highly attenuated vaccinia virus vector [modified vaccinia Ankara (MVA)] encoding human MUC1 and the immunostimulatory cytokine IL-2. Analysis of transduced DC cultures generated from a number of donors revealed MUC1 expression in the range of 27–54% of the cells and a co-regulated secretion of bioactive IL-2. As shown by FACS analysis with MUC1-specific antibodies, the MVA-MUC1/IL-2-transduced DC predominantly expressed the fully processed glycoform of MUC1, typical of that displayed by normal epithelia. Over a 3-day period after transduction, transgene expression declined concurrent with an increase in MVA-induced cytopathic effects. The transduced DC stimulated allogeneic lymphocyte proliferation, indicating that DC immunostimulatory function is not impaired by vector transduction. In the presence of IL-2, MVA-transduced DC were able to enhance autologous lymphocyte proliferation. Also, vector expression was analyzed in DC cultures treated with TNF-α, a known DC maturation factor. As indicated by the up-regulation of several DC maturation markers, neither virus infection nor transgene expression influenced the maturation capacity of the cells. The MVA-MUC1/IL-2 vector effectively transduced both immature and TNF-α-matured DC. Overall, our results are encouraging for the clinical application of MVA-MUC1/IL-2-transduced DC.