Clinical activity of a htert (vx-001) cancer vaccine as post-chemotherapy maintenance immunotherapy in patients with stage IV non-small cell lung cancer: final results of a randomised phase 2 clinical trial.

BACKGROUND: The cancer vaccine Vx-001, which targets the universal tumour antigen TElomerase Reverse Transcriptase (TERT), can mount specific Vx-001/TERT572 CD8 + cytotoxic T cells; this immune response is associated with improved overall survival (OS) in patients with advanced/metastatic non-small cell lung cancer (NSCLC). METHODS: A randomised, double blind, phase 2b trial, in HLA-A*201-positive patients with metastatic, TERT-expressing NSCLC, who did not progress after first-line platinum-based chemotherapy were randomised to receive either Vx-001 or placebo. The primary endpoint of the trial was OS. RESULTS: Two hundred and twenty-one patients were randomised and 190 (101 and 89 patients in the placebo and the Vx-001 arm, respectively) were analysed for efficacy. There was not treatment-related toxicity >grade 2. The study did not meet its primary endpoint (median OS 11.3 and 14.3 months for the placebo and the Vx-001, respectively; p = 0.86) whereas the median Time to Treatment Failure (TTF) was 3.5 and 3.6 months, respectively. Disease control for >6months was observed in 30 (33.7%) and 26 (25.7%) patients treated with Vx-001 and placebo, respectively. There was no documented objective CR or PR. Long lasting TERT-specific immune response was observed in 29.2% of vaccinated patients who experienced a significantly longer OS compared to non-responders (21.3 and 13.4 months, respectively; p = 0.004). CONCLUSION: Vx-001 could induce specific CD8+ immune response but failed to meet its primary endpoint. Subsequent studies have to be focused on the identification and treatment of subgroups of patients able to mount an effective immunological response to Vx-001. CLINICAL TRIAL REGISTRATION: NCT01935154.

A randomised, placebo-controlled, multicentre, Phase 2 clinical trial to evaluate the efficacy and safety of GV1001 in patients with benign prostatic hyperplasia.

OBJECTIVES: To evaluate the efficacy and safety of three dosing schemes of GV1001 in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Eligible patients were men aged ≥50 years, with an International Prostate Symptom Score (IPSS) of ≥13, maximum urinary flow rate (Qmax ) of 5-15 mL/s, post-void residual urine volume (PVR) of ≤200 mL, and prostate volume of ≥30 mL. After a 4 week run-in period, patients were randomly assigned to one of three treatment schedules: Group 1, GV1001 0.4 mg, 2-week interval; Group 2, GV1001 0.56 mg, 2-week interval; Group 3, GV1001 0.56 mg, 4-week interval) or placebo (Group 4). The eligible patients were administered GV1001 or placebo, for a total of seven intradermal injections that were administered at 2-week intervals at weeks 0, 2, 4, 6, 8, 10, and 12. Treatment continued for 12 weeks, and efficacy was evaluated at weeks 4, 8, 12, 13, and 16. Safety was evaluated throughout the 16-week period. The primary efficacy variable was change from baseline (CFB) in total IPSS. Secondary endpoints were CFB in Qmax , PVR, prostate volume, International Index of Erectile Function score, plasma testosterone level, dihydrotestosterone level, and prostate-specific antigen level. RESULTS: A total of 161 patients were included (Group 1, n = 41; Groups 2-4, n = 40). Most patients (88.8%) received all planned doses of the study treatment. At week 13, a statistically significant difference in the mean CFB in IPSS was seen in GV1001 treatment Groups 1 and 2 vs the control group for the full analysis population (-3.5 [control] vs -7.2 and -6.8 in Groups 1 and 2, respectively; both P < 0.05). There were also statistically significant differences in CFB at weeks 8, 12, 13, and 16 in treatment Groups 1 and 2 vs control in the per-protocol population. There was a statistically significant reduction in prostate gland volume at week 16 vs control in all treatment groups (0.8 [control] vs -4.6, -2.5, and -4.2 mL in Groups 1-3, respectively; all P < 0.05). There were no statistically significant differences found in other secondary outcome measures. Adverse event (AE) reporting was similar across all four groups. No treatment-emergent AEs were considered to be related to the study drug. CONCLUSIONS: The results indicate that GV1001 was effective and well tolerated, and may provide potential beneficial effects in patients with BPH. Compared with medical therapies that require daily dosing, the convenient dosing regimen of GV1001 may provide greater patient adherence. Further investigation of these observations will require large-scale clinical evaluation.

A telomerase-derived peptide regulates reactive oxygen species and hepatitis C virus RNA replication in HCV-infected cells via heat shock protein 90.

GV1001, a synthetic peptide derived from human telomerase, has a range of diverse biological activities, including an antioxidant function. Here, we investigated the role of GV1001 in hepatitis C virus (HCV)-infected Huh7.5 (JFH-1) cells. We showed that GV1001 inhibited the production of ROS with decreased MAP kinase signaling. Interestingly, GV1001 lost its antioxidant activity as ROS levels decreased, resulting in a reduction in extracellular heat shock protein 90 (eHSP90) as low-density lipoprotein receptor-related protein 1 (LRP1) was blocked or knocked-down. GV1001 binds to eHSP90 and is delivered into the cell by endocytosis via LRP1. Endocytosed GV1001 finally suppressed ROS generation, presumably by hindering the interaction between eHSP90 and NADPH oxidase (NOX). Importantly, GV1001 suppressed HCV RNA replication in JFH-1 cells by inhibiting the binding of HSP90 to FKBP8, a member of the FK506-binding protein family. We also found that HSP90 expression was high in HCV-infected hepatocytes. Therefore, our data suggest that GV1001 may be a good therapeutic agent by controlling HCV RNA replication, as well as by preferentially targeting cells under conditions of oxidative stress.

Long-term toxicity study of rAd5-hTERTC27 in SD rats and Cynomolgus monkeys by intravenous injection.

rAd5-hTERTC27, a replication-defective adenovirus vector carrying hTERTC27, has been proposed for possible use against hepatocellular carcinoma (HCC). In this study, we investigated the long-term toxicity of rAd5-hTERTC27 in SD rats and Cynomolgus monkeys. rAd5-hTERTC27 was administered intravenously once a week for 13 weeks followed by a one-month recovery period. As of 4 months, all animals displayed overall good health. Anti-adenoviral antibodies emerged in a dose-independent manner. The levels of complement components, C3 and C4, in the rAd5-hTERTC27 middle-dose and high-dose groups and C4 in the rAd5-EGFP group increased significantly after the 2nd treatment in monkeys. Slight-mild pathological changes of the liver occurred only in the rAd5-hTERTC27 high-dose group (2/16) in rats and not in any other group in either rats or monkeys. With the increase of the dose, the incidence of lymphocyte depletion in the spleen of rats and reactive hyperplasia of the splenic corpuscle in monkeys increased. However, the changes in the liver and spleen were reversible. Given the above data, intravenous administration of rAd5-hTERTC27 (up to 4×10(10)VP/kg in rats and 0.9×10(10)VP/kg in monkeys) appears to be well-tolerated, providing support for its potentially safe use in clinical trials for the treatment of HCC.

Gemcitabine and capecitabine with or without telomerase peptide vaccine GV1001 in patients with locally advanced or metastatic pancreatic cancer (TeloVac): an open-label, randomised, phase 3 trial.

BACKGROUND: We aimed to assess the efficacy and safety of sequential or simultaneous telomerase vaccination (GV1001) in combination with chemotherapy in patients with locally advanced or metastatic pancreatic cancer. METHODS: TeloVac was a three-group, open-label, randomised phase 3 trial. We recruited patients from 51 UK hospitals. Eligible patients were treatment naive, aged older than 18 years, with locally advanced or metastatic pancreatic ductal adenocarcinoma, and Eastern Cooperative Oncology Group performance status of 0-2. Patients were randomly assigned (1:1:1) to receive either chemotherapy alone, chemotherapy with sequential GV1001 (sequential chemoimmunotherapy), or chemotherapy with concurrent GV1001 (concurrent chemoimmunotherapy). Treatments were allocated with equal probability by means of computer-generated random permuted blocks of sizes 3 and 6 in equal proportion. Chemotherapy included six cycles of gemcitabine (1000 mg/m(2), 30 min intravenous infusion, at days 1, 8, and 15) and capecitabine (830 mg/m(2) orally twice daily for 21 days, repeated every 28 days). Sequential chemoimmunotherapy included two cycles of combination chemotherapy, then an intradermal lower abdominal injection of granulocyte-macrophage colony-stimulating factor (GM-CSF; 75 µg) and GV1001 (0·56 mg; days 1, 3, and 5, once on weeks 2-4, and six monthly thereafter). Concurrent chemoimmunotherapy included giving GV1001 from the start of chemotherapy with GM-CSF as an adjuvant. The primary endpoint was overall survival; analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN4382138. FINDINGS: The first patient was randomly assigned to treatment on March 29, 2007, and the trial was terminated on March 27, 2011. Of 1572 patients screened, 1062 were randomly assigned to treatment (358 patients were allocated to the chemotherapy group, 350 to the sequential chemoimmunotherapy group, and 354 to the concurrent chemoimmunotherapy group). We recorded 772 deaths; the 290 patients still alive were followed up for a median of 6·0 months (IQR 2·4-12·2). Median overall survival was not significantly different in the chemotherapy group than in the sequential chemoimmunotherapy group (7·9 months [95% CI 7·1-8·8] vs 6·9 months [6·4-7·6]; hazard ratio [HR] 1·19, 98·25% CI 0·97-1·48, p=0·05), or in the concurrent chemoimmunotherapy group (8·4 months [95% CI 7·3-9·7], HR 1·05, 98·25% CI 0·85-1·29, p=0·64; overall log-rank of χ(2)2df=4·3; p=0·11). The commonest grade 3-4 toxic effects were neutropenia (68 [19%] patients in the chemotherapy group, 58 [17%] patients in the sequential chemoimmunotherapy group, and 79 [22%] patients in the concurrent chemoimmunotherapy group; fatigue (27 [8%] in the chemotherapy group, 35 [10%] in the sequential chemoimmunotherapy group, and 44 [12%] in the concurrent chemoimmunotherapy group); and pain (34 [9%] patients in the chemotherapy group, 39 [11%] in the sequential chemoimmunotherapy group, and 41 [12%] in the concurrent chemoimmunotherapy group). INTERPRETATION: Adding GV1001 vaccination to chemotherapy did not improve overall survival. New strategies to enhance the immune response effect of telomerase vaccination during chemotherapy are required for clinical efficacy. FUNDING: Cancer Research UK and KAEL-GemVax.

Preclinical safety evaluation of rAd5-hTERTC27 by intravenous injection.

The safety of rAd5-hTERTC27, a replication defective adenovirus vector carrying hTERTC27 for possible use against hepatocellular carcinoma (HCC) was assessed. In single-dose evaluations, intravenous dose levels of up to 2×10(11)VP/kg in rats and 9×10(10)VP/kg in monkeys were well tolerated with no abnormal changes in general signs, body weight and food consumption, and no significant differences in biochemical parameters, urinalysis, ECG, and systemic necropsy observations between the rAd5 groups and solvent control group except that slight hematological change was observed. No hemolytic effect using rabbit blood, local perivasculitis following intravenous injection in rabbits or systemic anaphylaxis in guinea pigs following intravenous dosing was seen. No effects on the central nervous system of mice occurred following intravenous dosing with the exception of an increase in sleep duration at the dose of 1.2×10(11)VP/kg (p<0.05) but not at lower doses of 2×10(10) and 6×10(10)VP/kg in the hypnotic synergism test. These results demonstrate that administration of rAd5-hTERTC27 was well tolerated in an initial set of safety studies as part of an evaluation to allow human trials for the treatment of HCC.

The use of polyethylenimine-DNA to topically deliver hTERT to promote hair growth.

The present study investigates the efficacy of polyethylenimine (PEI)-DNA complex that expressed human telomerase reverse transcriptase (hTERT) to transfect hair follicle stem cells and produce sufficient hTERT to stimulate hair growth. Transfection with pLC-hTERT-DNA-PEI complex (D+P group) in vitro induced expression of proliferating cell nuclear antigen in 35.8% of the purified stem cell population, suggesting enhanced cell proliferation. In vivo transfection efficiency of rat dorsal skin was determined by staining for ß-gal activity. Cells positive for ß-gal were located in the bulge region and dermal sheath of hair follicles. The follicles in the hTERT-transfected region entered anagenon day 15 after transfection, whereas non-transfected (Neg) controls remained in telogen. The similar effect was observed in 50-day-old rat dorsal skin. D+P group displayed a specific expression of hTERT and sufficient to initiate a transition to the anagen phase and promote new hair synthesis 18 days after the transfection. hTERT promoted follicle neogenesis following wounding. In all, 60 days after wounding, tissues of the D+P group showed more newly regenerating hair follicles (83±52 regenerated follicles per rat) in contrast to control group tissues (15±15 regenerated follicles per rat). These studies provide a potential approach for gene therapy of skin disease.

Clinical outcome of patients with various advanced cancer types vaccinated with an optimized cryptic human telomerase reverse transcriptase (TERT) peptide: results of an expanded phase II study.

BACKGROUND: TERT (telomerase reverse transcriptase) plays a critical role in tumor cell growth and survival. In an expanded phase II study, we evaluated the immunological and clinical responses to the TERT-targeting Vx-001 vaccine in patients with advanced solid tumors. METHODS: HLA-A*0201-positive patients received two subcutaneous injections of the optimized TERT(572Y) peptide followed by four injections of the native TERT(572) peptide, every 3 weeks. Peptide-specific immune responses were evaluated by enzyme-linked immunosorbent spot at baseline, and after the second and the sixth vaccinations. RESULTS: Fifty-five patients were enrolled and 34 (62%) completed the six vaccinations. A TERT-specific T-cell immune response was observed in 55% and 70% of patients after the second and the sixth vaccinations, respectively. The disease control rate (DCR) was 36% [95% confidence interval (CI) 24% to 49%], including one complete and one partial response. Immunologically responding patients had a better clinical outcome than nonresponders [DCR: 44% versus 14% (P = 0.047); progression-free survival (PFS): 5.2 versus 2.2 months (P = 0.0001) and overall survival: 20 versus 10 months (P = 0.041)]. Multivariate analysis revealed that the immunological response was an independent variable associated with increased PFS (hazard ratio = 3.35; 95% CI 1.7-6.7). CONCLUSION: Vx-001 vaccine was well tolerated and induced a TERT-specific immunological response, which was significantly correlated with improved clinical outcome.

A phase II open label trial evaluating safety and efficacy of a telomerase peptide vaccination in patients with advanced hepatocellular carcinoma.

BACKGROUND: The sole effective option for patients with advanced HCC is sorafenib and there is an urgent need to develop new therapeutic approaches. Immunotherapy is a promising option that deserves major investigation. In this open label, single arm clinical trial, we analyzed the effect of a low dose cyclophosphamide treatment in combination with a telomerase peptide (GV1001) vaccination in patients with advanced HCC. METHODS: 40 patients with advanced HCC were treated with 300 mg/m2 cyclophosphamide on day -3 followed by GM-CSF + GV1001 vaccinations on days 1, 3, 5, 8, 15, 22, 36 followed by 4-weekly injections. Primary endpoint of this phase II trial was tumor response; secondary endpoints evaluated were TTP, TTSP, PFS, OS, safety and immune responses. RESULTS: None of the patients had a complete or partial response to treatment, 17 patients (45.9%) demonstrated a stable disease six months after initiation of treatment. The median TTP was 57.0 days; the median TTSP was estimated to be 358.0 days. Cyclophosphamide, GV1001 and GM-CSF treatment were well tolerated and most adverse events, which were of grade 1 or 2, were generally related to the injection procedure and injection site reactions. GV1001 treatment resulted in a decrease in CD4+CD25+Foxp3+ regulatory T cells; however, no GV1001 specific immune responses were detected after vaccination. CONCLUSIONS: Low dose cyclophosphamide treatment followed by GV1001 vaccinations did not show antitumor efficacy as per tumor response and time to progression. Further studies are needed to analyze the effect of a combined chemo-immunotherapy to treat patients with HCC. TRIAL REGISTRATION: NCT00444782.

Role of Senescence and Neuroprotective Effects of Telomerase in Neurodegenerative Diseases.

Cell senescence is characterized by the irreversible arrest of cell proliferation and has been implicated as one of the critical causes of Alzheimer's disease, Parkinson's disease, and other neurodegenerative diseases. Telomere dysfunction, oxidative stress, DNA damage, senescence-associated secretory phenotype, and mitochondrial dysfunction contribute to the development of cellular senescence. Telomerase reverse transcriptase (TERT), which is the catalytic subunit of telomerase, can counteract cellular senescence with telomerase RNA template in a telomere-dependent manner. In addition, TERT has also been confirmed to exert extra-telomeric and neuroprotective roles in neurodegenerative diseases. In this review, we focus on the close relationship between cellular senescence and neurodegenerative diseases, and in particular, we elucidate the neuroprotective role of TERT in neurodegenerative diseases.

Exogenous TERC alone can enhance proliferative potential, telomerase activity and telomere length in lymphocytes from dyskeratosis congenita patients.

Dyskeratosis congenita (DC) is an inherited multi-system disorder characterised by muco-cutaneous abnormalities, bone marrow failure and a predisposition to malignancy. Bone marrow failure is the principal cause of mortality and is thought to be the result of premature cell death in the haematopoietic compartment because DC cells age prematurely and tend to have short telomeres. DC is genetically heterogeneous and patients have mutations in genes that encode components of the telomerase complex (DKC1, TERC, TERT, NOP10 and NHP2), and telomere shelterin complex (TINF2), both important in telomere maintenance. Here, we transduced primary T lymphocytes and B lymphocyte lines established from patients with TERC and DKC1 mutations with wild type TERC-bearing lentiviral vectors. We found that transduction with exogenous TERC alone was capable of increasing telomerase activity in mutant T lymphocytes and B lymphocyte lines and improved the survival and thus overall growth of B-lymphocyte lines over a prolonged period, regardless of their disease mutation. Telomeres in TERC-treated lines were longer than in the untreated cultures. This is the first study of its kind in DC lymphocytes and the first to demonstrate that transduction with TERC alone can improve cell survival and telomere length without the need for exogenous TERT.

Direct vaccination with pseudotype baculovirus expressing murine telomerase induces anti-tumor immunity comparable with RNA-electroporated dendritic cells in a murine glioma model.

Baculovirus pseudotyped with vesicular stomatitis virus G protein (Bac-VSV-G) was found to efficiently transduce and express transgenes on mammalian cells. In this study, this recombinant virus was used for induction of anti-tumor immunity against murine telomerase reverse transcriptase (mTERT) and was compared with RNA-electroporated dendritic cells (DCs) in a murine glioma model. Splenocytes from the mice vaccinated with Bac-VSV-G expressing mTERT (Bac-VSVG-mTERT) showed significantly increased numbers of mTERT-specific IFN-gamma-secreting T cells using an ELISPOT technique, and also showed increased NK cell activity. In addition, the TERT-specific T cells activated by Bac-VSVG-mTERT and mTERT RNA-electroporated DCs were predominantly CD4+ T cells and CD8+ T cells, respectively. The protective anti-tumor effect of Bac-VSVG-mTERT was similar to that of mTERT RNA-electroporated DCs. These results suggest that the pseudotype baculovirus expressing TERT may be a good candidate for a genetic vaccine for use in the treatment of malignant gliomas.

GV-1001, an injectable telomerase peptide vaccine for the treatment of solid cancers.

GemVax AS, a subsidiary of Pharmexa A/S, is developing GV-1001, an injectable formulation of a promiscuous MHC class II peptide derived from the telomerase reverse transcriptase catalytic subunit (hTERT), for the potential treatment of solid tumors, including pancreatic, liver and NSCLC. GV-1001 is currently undergoing phase II clinical trials for pancreatic, liver and NSCLC as well as a phase III trial for pancreatic cancer.

Reduction of ischaemia-reperfusion injury in a rat lung transplantation model by low-concentration GV1001.

OBJECTIVES: Lung ischaemia-reperfusion (IR) injury is one of the major complications following lung transplantation. The novel peptide GV1001, which is derived from human telomerase reverse transcriptase, has been reported to possess both antitumour and anti-inflammatory effects. In this study, we focused on the anti-inflammatory effects of GV1001 to investigate the IR injury prevention effect of GV1001 in a rat lung transplantation model. METHODS: An orthotopic left lung transplantation rat model was established using the modified cuff technique. We applied 50 ml of normal saline (control), Perfadex (low-potassium standard dextran containing perfusion solution), Perfadex with 5 mg GV1001 (5-mg GV, low concentration) and Perfadex with 50 mg GV1001 (50-mg GV, high concentration) as both flushing and preservation solutions. The left lung was stored in the same solution as the flushing solution at 4°C for 3 h. After transplantation, the recipient rats were monitored for 3 h. Arterial blood gas analysis (ABGA), bronchoalveolar lavage (BAL) analysis, wet/dry ratio, histological analysis, apoptotic cell analysis and cytokine [tumour necrosis factor alpha (TNF-α) and interleukin 6 (IL-6)] analysis were performed to determine the reduction or prevention effect of GV1001 regarding lung IR injury. RESULTS: Compared with the control group, the neutrophil count in BAL, reperfusion oedema and cytokine (TNF-α, IL-6) levels of the transplanted lung were significantly decreased in the 5-mg GV group. Compared with the Perfadex group (16.85 ± 2.43), the neutrophil count in BAL was also significantly decreased in the 5-mg GV group (5.39 ± 0.81) (P< 0.001). In addition, the cytokine (TNF-α, IL-6) levels of the transplanted lung were also significantly decreased in the 5-mg GV group (41.99 ± 12.79, 1069.74 ± 98.48 pg/ml) compared with the Perfadex group (90.73 ± 23.87, 2051.92 ± 243.57 pg/ml) (P < 0.05 and P < 0.001, respectively). However, the 50-mg GV group showed less effect than the 5-mg GV group. CONCLUSIONS: Adding a low concentration of GV1001 to the lung preservation solution (Perfadex) provided potential protective effects against IR injury after lung transplantation in rats. Therefore, GV1001 should be considered as a promising anti-inflammatory agent for IR injury.

Telomerase inhibition enhances apoptosis in human acute leukemia cells: possibility of antitelomerase therapy.

Telomerase is a ribonucleoprotein enzyme that maintains protective structures at the ends of eukaryotic chromosomes. We examined the impact of telomerase inhibition by the dominant-negative human catalytic subunit of telomerase (DN-hTERT) on the biological features of acute leukemia. We introduced vectors encoding dominant- negative (DN)-hTERT, wild-type (WT)-hTERT, or a control vector expressing only a drug-resistant marker into a telomerase-positive human acute lymphoblastic leukemia cell line, HAL-01. Expression of DN-hTERT dramatically inhibited telomerase activity, leading to apoptotic cell death. Mutant telomerase expression also enhanced daunorubicin-induced apoptosis. Nude mice (n=5 per group) received subcutanous implants of HAL-01 cells expressing the control vector or DN-hTERT or WT-hTERT. Implantation of HAL-01 cells expressing control vector (n=5) rapidly produced tumors, whereas implantation of those expressing DN-hTERT (n=5) did not. Thus, telomerase inhibition both growth of HAL-01 cells in vitro and tumorigenic capacity in vivo. Furthermore, the G-quadruplex-interactive telomerase-specific inhibitor, telomestatin, shortened the telomere length and induced apoptosis in freshly isolated primary acute leukemia cells. These results suggest that antitelomerase therapy may be useful in some acute leukemias in combination with antileukemic agents such as daunorubicin.

Immunological features of T cells induced by human telomerase reverse transcriptase-derived peptides in patients with hepatocellular carcinoma.

Human telomerase reverse transcriptase (hTERT) is a catalytic enzyme required for telomere elongation. In this study, we investigated the safety and immunogenicity of an hTERT-derived peptide (hTERT461) as a vaccine and characterized the hTERT-specific T cell responses induced. Fourteen hepatocellular carcinoma (HCC) patients were enrolled in the study. The hTERT-derived peptide was emulsified in incomplete Freund's adjuvant and administered via subcutaneous immunization three times biweekly. The maximum toxicity observed was grade 2 according to the common terminology criteria and mainly consisted of skin reactions at the site of vaccination. The vaccination induced hTERT-specific immunity in 71.4% of patients and 57.1% of patients administered with hTERT461 peptide-specific T cells could prevent HCC recurrence after vaccination. In phenotypic analysis, the post-vaccinated increase in hTERT-specific T cells was due to an increase in cells with the effector memory phenotype, with the potential to produce multiple cytokines. Seven hTERT-specific T cell receptors were obtained from the vaccinated patients, showing their cytotoxic activities to hTERT-derived peptide-bearing cells. In conclusion, the safety and effects of immune boosting by hTERT461 peptide have shown the potential of the peptide to provide clinical benefits in HCC patients.

Telomerase as drug and drug target for the treatment of thyroid cancer.

Telomerase is known to be activated in almost all cancer cells and is quiescent in almost all normal cells. Therefore, it follows that therapeutic strategies directed against cancer would include the targeting of telomerase, as well as the use of telomerase. Several approaches have been used both in vitro and in vivo and include the following: 1) antisense; 2) immunotherapy directed against hTERT; and 3) the use of telomerase promoter to direct cytotoxic therapy. Herein we review these approaches and discuss their potential applicability against thyroid cancer.

Telomerase (GV1001) vaccination together with gemcitabine in advanced pancreatic cancer patients.

Telomerase is expressed in 85-90 % of pancreatic adenocarcinomas and might be a target for active cancer immunotherapy. A study was conducted to investigate safety and immunogenicity in non-resectable pancreatic carcinoma patients using a 16-amino acid telomerase peptide (GV1001) for vaccination in combination with GM-CSF and gemcitabine as first line treatment. Three different vaccine treatment schedules were used; [A (n=6), B (n=6) and C (n=5)]. Groups A/B received GV1001, GM-CSF and gemcitabine concurrently. Group C received initially GV1001 and GM-CSF while gemcitabine was added at disease progression. Group D (n=4) was treated with gemcitabine alone. Adverse events (AE) related to vaccination were mild (grades I-II). Grade III AEs were few and transient. An induced GV 1001­specific immune response was defined as an increase ≥2 above the baseline value in one of the assays (DTH, proliferation, ELISPOT and cytokine secretion assays, respectively). A telomerase­specific immune response was noted in 4/6 patients in group A, 4/6 patients in group B and 2/5 patients in group C. An induced ras­specific immune response (antigenic spreading) was seen in 5 of the 17 patients. The cytokine pattern was that of a Th1-like profile. A treatment induced telomerase or ras response was also noted in group D. All responses were weak and transient. A significant decrease in regulatory T-cells over time was noted in patients in groups A and B (p<0.05). Telomerase vaccination (GV1001) in combination with chemotherapy appeared to be safe but the immune responses were weak and transient. Measures have to be taken to optimize immune responses of GV1001 for it to be considered of clinical interest.

Protective effect of peptide GV1001 against renal ischemia-reperfusion injury in mice.

BACKGROUND: Ischemia reperfusion injury (IRI) is a common complication after kidney transplantation. Peptide GV1001 is a peptide vaccine representing a 16-amino acid human telomerase reverse transcriptase sequence, which has been reported to possess potential antineoplastic and anti-inflammatory activity. This study aimed to investigate the potential effects of peptide GV1001 on renal IRI. METHODS: Peptide GV1001 was subcutaneously administered to C57BL6/J mice 30 minutes before and 12 hours after bilateral IRI. Sham operation and phosphate-buffered saline (PBS) injection were used as controls. Blood and renal tissues were harvested at 1 day after IRI. RESULTS: Peptide GV1001 treatment significantly attenuated renal functional deterioration after IRI (peptide GV1001 group vs PBS group; blood urea nitrogen, P < .05; creatinine, P < .05). Peptide GV1001 treatment also attenuated renal tissue injury (tubular injury score; the peptide GV1001 group vs PBS group; P < .001). Renal apoptosis was also lower in the peptide GV1001 group. Immunohistochemical studies showed that IRI increased perirenal infiltration of both neutrophils and macrophages, and that peptide GV1001 significantly attenuated this process. Expression of interleukin-6 and monocyte chemotactic protein-1 was significantly reduced by peptide GV1001 treatment. CONCLUSIONS: Peptide GV1001 ameliorates acute renal IRI by reducing inflammation and apoptosis; therefore, it is promising as a potential therapeutic agent for renal IRI. The mechanisms of protection should be explored in further studies.