HER1 therapeutic cancer vaccine: An active immunotherapy treatment for patients with tumors expressing the receptor of epidermal growth factor (EGF-R)

Her1 vaccine: It consists of immunizing patients with positive tumors for the epidermal growth factor receptor (EGF-R) with a preparation of EGF-R extracellular domain(HER1-ECD) adjuvanted in VSSP (very small size proteoliposomes) and Montanide ISA51. VSSP adyuvant confers to vaccine the capacity to activate dendritic cells and polarize the immune response towards a TH1 immune pattern, developing TCD8+ cells and antibodies with anti-metastatic effect. The extracellular domain of the epidermal growth factor receptor was obtained from HEK293 transfectome by using a productive process in a bioreactor in perfusion as mode of fermentation. The protein was purified by immune-affinity chromatography by using specific anti-EGF-R antibody. Phase I trial, uncontrolled, open and sequential, was conducted in 25 with hormone refractory prostate cancer patients. Five dose levels of HER1-ECD were scaled: 100, 200, 400, 600 and 800 µg in each immunization. The trial showed that the vaccine was safe, not causing severe or very severe related events. The vaccine preparation was shown to be immunogenic. There was a trend towards the survival benefit in some patients. At the present time another clinical trial is underway in three locations of advanced solid tumors that overexpress the EGF receptor: prostate, colon and head and neck cancer

Safety and Immunogenicity of a Human Epidermal Growth Factor Receptor 1 (HER1)-Based Vaccine in Prostate Castration-Resistant Carcinoma Patients: A Dose-Escalation Phase I Study Trial

Metastatic castration-resistant prostate cancer (CRPC) remains incurable due to the lack of effective therapies. Activation of the human epidermal growth factor receptor 1 (HER1) in prostate cancer contributes to metastatic progression as well as to disease relapse. Here, we determined the toxicity and immunogenicity of a HER1-based cancer vaccine in CRPC patients included in a phase I clinical trial. CRPC patients (n = 24) were intramuscularly vaccinated with HER1 vaccine consisting of the extracellular domain of HER1 molecule (ECD) and very small size proteoliposome from Neisseria meningitidis (VSSP) and Montanide ISA-51 VG as adjuvants. Patients were included in five groups according to the vaccine dose (100, 200, 400, 600, and 800 μg). The primary endpoints were safety and immunogenicity. The anti-HER1 antibodies were measured by an ELISA, the recognition of an HER1 positive tumor cell line and the inhibition of HER1 phosphorylation by sera were determined by flow cytometry and western blot analysis, respectively. The HER1-specific T cell response was assessed by determination of IFN-γ-producing T cells using ELISpot assay. The vaccine was well tolerated. No grade III or IV adverse events were reported. High titers of anti-HER1 antibodies were observed in most of the evaluated patients. There were no significant differences regarding the geometric means of the anti-HER1 titers among the dose groups except the group of 100 μg in which antibody titers were significantly lower. A Th1-type IgG subclasses pattern was predominant in most patients. Only patients receiving the higher doses of vaccine showed significant tumor cell recognition and HER1 phosphorylation inhibition by hyperimmune sera. Forty two percent of the patients showed a specific T cell response against HER1 peptides pool in post-treatment samples. There was a trend toward survival benefit in those patients showing high anti-HER1 specific antibody titers and a significant association between cellular immune response and clinical outcome

Fenotipska heterogenost u staničnoj liniji NCI-H125 utječe na biološku aktivnost na receptore za epidermalni faktor rasta

We evaluated the influence of some morphological changes of the NCI-H125 cell line in surface expression of the epidermal growth factor receptor (EGFR) and their impact on some biological activity assays using this molecule as target. Hematoxylin and eosin (H/E) staining, light microscopy immunocytochemistry, flow cytometric antibody-receptor binding test, cell viability determination and cell cycle analysis were performed. Phenotypic changes and inconsistency in EGFR expression were detected in NCI-H125 cell cultures. A significant reduction in the growth rate, mainly characterized by cell cycle arrest in the G0-G1 phase, was also evidenced. Differential distribution of cell viability in NCI-H125 subpopulations and its relationship with the EGFR surface expression were determined. Nuclear alterations observed in NCI-H125 were not apoptosis related. A lack of control of cell cultures affects the reliability and reproducibility of biomedical and biotechnological research using EGFR as target. Therefore, rigorous control of the above mentioned parameters in these experiments is recommended.U članku je opisan utjecaj morfoloških promjena na staničnoj liniji NCI-H125 koje su povezane s površinskom ekspresijom receptora za epidermalni faktor rasta (EGFR) i njihov utjecaj na biološko djelovanje. U radu je korišteno bojanje s hematoksilinom i eozinom (H/E), imunocitokemijska mikroskopija, test vezanja protutijela na receptor pomoću protočne citometrije, testovi vijabilnosti stanica i analiza staničnog ciklusa. U staničnoj kulturi NCI-H125 detektirane su promjene fenotipa i nedosljednost u ekspresiji EGFRa. Primijećena je značajna redukcija rasta, uglavnom zbog zadržavanja staničnog ciklusa u G0-G1 fazi, te različitost u vijabilnosti NCI-H125 subpopulacije i povezanost s ekspresijom EGFRa na površini. Primijećena različitost u jezgri NCI-H125 stanica nije povezana s apoptozom. Nemogućnost kontroliranja stanične kulture utječe na pouzdanost i ponovljivost biomedicinskih i biotehnoloških istraživanja koja su usmjerena na EGFR. Stoga se preporuča stroga kontrola svih opisanih parametara

The combination of very-small size proteoliposomes and alum is a safe adjuvant alternative for inducing anti-EGF antibodies: a preclinical study

Immunization with human recombinant EGF chemically bound to the P64k protein of Neisseria meningitides (hrEGF-P64k) and adjuvanted in Montanide ISA 51 VG (Montanide) is an efficient strategy to induce polyclonal antibodies (PAbs) response targeting this self -antigen in cancer patients, which is the basis of the CIMAvax-EGF vaccine. The neutralizing potential of EGF-specific induced PAbs supports promising clinical data obtained to date with this vaccine. Herein, we evaluated a combination of very small-size proteoliposomes (VSSP) and aluminum hydroxide (Alum) as a novel adjuvant to induce specific PAbs with neutralizing and anti-proliferative properties on tumor cells, considering EGF as a model antigen. Toxicity at the injection site was not detected for the vaccine formulation containing VSSP/Alum, and it was immunogenic in BALB/c mice, as evidenced by the induction of high titers of EGF-specific polyclonal antibodies (PAbs). While schedule optimization increased the magnitude of the PAbs response induced by VSSP/Alum, induced PAbs’s avidity and intrinsic neutralizing potential were comparable to the humoral response induced by Montanide. Also, VSSP addition switched IgG subclasses distribution into a Th1-like pattern, as obtained with Montanide and desirable for a cancer vaccine. Finally, equivalent PAbs titers were induced by the vaccine formulations adjuvanted in VSSP/Alum or Montanide in tumor-bearing-mice, and immunosuppressed mice, suggesting the feasibility of the VSSP/Alum combined adjuvant for inducing anti-EGF antibodies in cancer patients at advanced stages of the disease