A phase 1 trial extension to assess immunologic efficacy and safety of prime-boost vaccination with VXM01, an oral T cell vaccine against VEGFR2, in patients with advanced pancreatic cancer.

VXM01 is a first-in-kind orally applied tumor vaccine based on live attenuated Salmonella typhi carrying an expression plasmid encoding VEGFR2, an antigen expressed on tumor vasculature and a stable and accessible target for anti-angiogenic intervention. A recent randomized, placebo-controlled, phase I dose-escalation trial in advanced pancreatic cancer patients demonstrated safety, immunogenicity and transient, T-cell response-related anti-angiogenic activity of four priming vaccinations applied within one week. We here evaluated whether monthly boost vaccinations are safe and can sustain increased frequencies of vaccine-specific T cells. Patients with advanced pancreatic cancer were randomly assigned at a ratio of 2:1 to priming with VXM01 followed by up to six monthly boost vaccinations, or placebo treatment. Vaccinations were applied orally at two alternative doses of either 106 colony-forming units (CFU) or 107 CFU, and concomitant treatment with standard-of-care gemcitabine during the priming phase, and any treatment thereafter, was allowed in the study. Immunomonitoring involved interferon-gamma (IFNγ) ELIspot analysis with long overlapping peptides spanning the entire VEGFR2 sequence. A total of 26 patients were treated. Treatment-related adverse events preferentially associated with VXM01 were decreases in lymphocyte numbers in the blood, increased frequencies of neutrophils and diarrhea. Eight out of 16 patients who received at least one boosting vaccination responded with pronounced, i.e. at least 3-fold, increase in VEGFR2-specific T cell response over baseline levels. In the VXM01 vaccination group, VEGFR2-specific T cells peaked preferentially during the boosting phase with an average 4-fold increase over baseline levels. In conclusion, prime/boost vaccination with VXM01 was safe and immunogenic and increased vaccine specific T cell responses compared with placebo treatment.

Anti-angiogenic activity of VXM01, an oral T-cell vaccine against VEGF receptor 2, in patients with advanced pancreatic cancer: A randomized, placebo-controlled, phase 1 trial.

VEGFR-2 is expressed on tumor vasculature and a target for anti-angiogenic intervention. VXM01 is a first in kind orally applied tumor vaccine based on live, attenuated Salmonella bacteria carrying an expression plasmid, encoding VEGFR-2. We here studied the safety, tolerability, T effector (Teff), T regulatory (Treg) and humoral responses to VEGFR2 and anti-angiogenic effects in advanced pancreatic cancer patients in a randomized, dose escalation phase I clinical trial. Results of the first 3 mo observation period are reported. Locally advanced or metastatic, pancreatic cancer patients were enrolled. In five escalating dose groups, 30 patients received VXM01 and 15 placebo on days 1, 3, 5, and 7. Treatment was well tolerated at all dose levels. No dose-limiting toxicities were observed. Salmonella excretion and salmonella-specific humoral immune responses occurred in the two highest dose groups. VEGFR2 specific Teff, but not Treg responses were overall increased in vaccinated patients. We furthermore observed a significant reduction of tumor perfusion after 38 d in vaccinated patients together with increased levels of serum biomarkers indicative of anti-angiogenic activity, VEGF-A, and collagen IV. Vaccine specific Teff responses significantly correlated with reductions of tumor perfusion and high levels of preexisting VEGFR2-specific Teff while those showing no antiangiogenic activity had low levels of preexisting VEGFR2 specific Teff, showed a transient early increase of VEGFR2-specific Treg and reduced levels of VEGFR2-specific Teff at later time points - pointing to the possibility that early anti-angiogenic activity might be based at least in part on specific reactivation of preexisting memory T cells.

Double-blind, placebo-controlled first in human study to investigate an oral vaccine aimed to elicit an immune reaction against the VEGF-Receptor 2 in patients with stage IV and locally advanced pancreatic cancer.

BACKGROUND: The investigational oral DNA vaccine VXM01 targets the vascular endothelial growth factor receptor 2 (VEGFR-2) and uses Salmonella typhi Ty21a as a vector. The immune reaction elicited by VXM01 is expected to disrupt the tumor neovasculature and, consequently, inhibit tumor growth. VXM01 potentially combines the advantages of anti-angiogenic therapy and active immunotherapy. METHODS/DESIGN: This phase I trial examines the safety, tolerability, and immunological and clinical responses to VXM01. The randomized, placebo-controlled, double blind dose-escalation study includes up to 45 patients with locally advanced and stage IV pancreatic cancer. The patients will receive four doses of VXM01 or placebo in addition to gemcitabine as standard of care. Doses from 106 cfu up to 1010 cfu of VXM01 will be evaluated in the study. An independent data safety monitoring board (DSMB) will be involved in the dose-escalation decisions. In addition to safety as primary endpoint, the VXM01-specific immune reaction, as well as clinical response parameters will be evaluated. DISCUSSION: The results of this study shall provide the first data regarding the safety and immunogenicity of the oral anti-VEGFR-2 vaccine VXM01 in cancer patients. They will also define the recommended dose for phase II and provide the basis for further clinical evaluation, which may also include additional cancer indications. TRIAL REGISTRATION: EudraCT No.: 2011-000222-29, NCT01486329, ISRCTN68809279.

Incidence of febrile neutropenia and myelotoxicity of chemotherapy: a meta-analysis of biosimilar G-CSF studies in breast cancer, lung cancer, and non-Hodgkin's lymphoma.

BACKGROUND: The aim of this meta-analysis of 3 clinical studies, conducted with breast cancer, lung cancer, and non-Hodgkin's lymphoma patients, was to compare a new granulocyte colony-stimulating factor (G-CSF) biosimilar, XM02, with filgrastim in terms of its prophylactic effect on the development of febrile neutropenia (FN) during the first chemotherapy cycle in relation to the myelotoxic potency of the applied chemotherapy regimen. PATIENTS AND METHODS: Overall, 608 patients (363 under XM02 and 245 under filgrastim) were included in the meta-analysis. The majority of patients were allocated to the chemotherapy categories docetaxel-doxorubicin (45.4%) and cyclophosphamide-hydroxy daunomycin (adriamycin)-oncovin (vincristine)-prednisolone (CHOP)/platinum(Pt)-vinorelbine or Pt-vinblastine/ Pt-etoposide (43.1%); another 11.5% were allocated to the category Pt-gemcitabine/Pt-docetaxel or Pt-paclitaxel. RESULTS: FN in the XM02 and filgrastim groups was reported for 12.1 and 12.5% of patients, respectively, under docetaxeldoxorubicin, for 13.5 and 11.9% under CHOP/Pt-vinorelbine or Pt-vinblastine/Pt-etoposide, and for 15.6 and 12.0% under Pt-gemcitabine/Pt-docetaxel or Pt-paclitaxel. CONCLUSIONS: The incidence of FN in the first cycle of chemotherapy under primary G-CSF prophylaxis is low (in the range of 12-16%) and not directly correlated with the myelotoxic potency of the applied chemotherapy regimen. XM02 demonstrated to be non-inferior to filgrastim regarding the incidence of FN, irrespective of the myelotoxicity of the chemotherapy regimen.

XM02, the first biosimilar G-CSF, is safe and effective in reducing the duration of severe neutropenia and incidence of febrile neutropenia in patients with small cell or non-small cell lung cancer receiving platinum-based chemotherapy.

BACKGROUND: Recombinant granulocyte colony-stimulating factors such as Neupogen are used to treat chemotherapy-induced neutropenia. The aim of the study was to show that a new granulocyte colony-stimulating factor, XM02, is as safe and effective as Neupogen in the treatment of chemotherapy-induced neutropenia in patients with small cell or non-small cell lung cancer. PATIENTS AND METHODS: A total of 240 patients receiving platinum-based chemotherapy were randomized in cycle 1 to treatment with daily injections (subcutaneous 5 microg/kg/d) of XM02 (n = 160) or Filgrastim Neupogen (n = 80) for at least 5 days and a maximum of 14 days. In subsequent cycles, all patients received XM02. RESULTS: The mean duration of severe neutropenia was 0.5 and 0.3 days in cycle 1 for XM02 and Filgrastim, respectively. In the analysis of covariance for duration of severe neutropenia in cycle 1, the estimated treatment difference "XM02 minus Filgrastim" was 0.157 days, with 95% confidence level (-0.114 days, 0.428 days), which was included in the prespecified equivalence range (-1, 1). There was no statistically significant difference of the end point incidence of febrile neutropenia in cycle 1 between XM02 and Filgrastim (p = 0.2347). The adverse event profile was similar between XM02 and Filgrastim. CONCLUSION: XM02 demonstrated similar efficacy and safety profile as the reference medication Filgrastim in cycle 1. In conclusion, treatment with XM02 is beneficial in ameliorating severe neutropenia and febrile neutropenia in lung cancer patients receiving myelosuppressive chemotherapy. XM02 is safe and well tolerated in the doses applied in this study.

Pharmacokinetic and pharmacodynamic profile of new biosimilar filgrastim XM02 equivalent to marketed filgrastim Neupogen: single-blind, randomized, crossover trial.

OBJECTIVE: Filgrastim XM02 is a biosimilar non-glycosylated recombinant methionyl form of human granulocyte colony-stimulating factor (r-MetHuG-CSF) expressed in Escherichia coli for subcutaneous and intravenous administration in the treatment of different forms of neutropenia and stem cell mobilization. This study was conducted to compare the pharmacokinetic and pharmacodynamic characteristics of the new biosimilar filgrastim XM02 with the marketed filgrastim (Neupogen). METHODS: Two filgrastim doses (5 and 10 microg/kg) of the new biosimilar filgrastim XM02 and the marketed filgrastim were administered either as intravenous infusion or subcutaneous injection in four single-dose, crossover, randomized substudies, conducted in 36 subjects each. Serum concentrations of filgrastim were determined using an enzyme-linked immunosorbent assay test kit on samples taken at intervals up to 48 hours after administration. The CD34+ stem cell count up to 15 days after administration was determined by flow cytometry using a validated CD34+ cell enumeration kit, and the absolute neutrophil count (ANC) up to 96 hours after dosing was determined by the Beckman Coulter AcT differential automated hematology analyzer. The primary pharmacokinetic endpoint was the AUC (48 h) (area under the serum concentration-time curve) of filgrastim serum concentration determined by the linear trapezoidal rule. Equivalence (biosimilarity) between the two filgrastim products was assessed by 90% confidence limits obtained from analyses of variance of log-transformed pharmacokinetic and pharmacodynamic endpoints, applying 80-125% equivalence intervals. RESULTS: The mean serum concentration profiles of filgrastim, ANC and CD34+ cells over time were similar for the two filgrastims. The 90% confidence intervals for all test/reference ratios for pharmacokinetic and pharmacodynamic endpoints lay within the accepted bioequivalence range of 80-125%. Both filgrastims showed similar safety profiles and were well tolerated. CONCLUSIONS: Equivalence of the two filgrastims was clearly demonstrated for all four dose/route of administration groups. Equivalence could be demonstrated for the serum concentration profile, for the ANC profile and, even more importantly, for the CD34+ cell count, which is a marker for the ability of the granulocyte colony-stimulating factor to mobilize stem cells.