Showing papers by "Steffen Goletz published in 2017"

Cetuximab Resistance in Head and Neck Cancer Is Mediated by EGFR-K521 Polymorphism.

Abstract: Head and neck squamous cell carcinomas (HNSCC) exhibiting resistance to the EGFR targeting drug cetuximab poses a challenge to their effective clinical management. Here we report a specific mechanism of resistance in this setting based upon the presence of a single nucleotide polymorphism encoding EGFR-K521 (K-allele), which is expressed in >40% of HNSCC cases. Patients expressing the K-allele showed significantly shorter progression-free survival upon palliative treatment with cetuximab plus chemotherapy or radiation. In several EGFR-mediated cancer models, cetuximab failed to inhibit downstream signaling or to kill cells harboring a high K-allele frequency. Cetuximab affinity for EGFR-K521 was reduced slightly but ligand-mediated EGFR activation was intact. We found a lack of glycan sialyation on EGFR-K521 that associated with reduced protein stability, suggesting a structural basis for reduced cetuximab efficacy. CetuGEX™, an antibody with optimized Fc glycosylation targeting the same epitope as cetuximab, restored HNSCC sensitivity in a manner associated with antibody-dependent cellular cytotoxicity (ADCC) rather than EGFR pathway inhibition. Overall, our results highlight EGFR-K521 expression as a key mechanism of cetuximab resistance to evaluate prospectively as a predictive biomarker in HNSCC patients. Further, they offer a preclinical rationale for the use of ADCC-optimized antibodies to treat tumors harboring this EGFR isoform.

A new fully human recombinant FSH (follitropin epsilon): two phase I randomized placebo and comparator-controlled pharmacokinetic and pharmacodynamic trials.

Abstract: Study question What are the differences and similarities of pharmacokinetic (PK) and pharmacodynamic (PD) characteristics of the novel recombinant human FSH follitropin epsilon expressed in the human cell line GlycoExpress compared with a Chinese hamster ovary (CHO) derived compound and a urinary derived product? Summary answer Overall follitropin epsilon, with a fully human glycosylation, shows a comparable PK profile at single-dose as well as multiple-dose administration compared to recombinant CHO-derived FSH as well as urinary derived FSH, whereas the PD properties differ from product to product with follitropin epsilon being most active in PD parameters. What is known already Recombinant FSH produced in CHO and FSH obtained from the urine of postmenopausal women show comparable PK and PD properties. However, more recently a comparative study of a recombinant FSH produced in the human cell line PerC6 and a CHO-derived FSH preparation revealed differences in PK and PD properties of the molecule. Study design, size, duration Both studies were randomized, placebo- and comparator-controlled, single-blind phase I studies in healthy pituitary-suppressed female volunteers aged 18 and 40 years. The single-dose, dose escalation study included 19 women (April 2011 to September 2011) with three ascending dose levels per subject or placebo/comparators with a 14-day washout phase between dosings. The multiple-dose study included 57 women (October 2011 to April 2012) in five cohorts with three dose levels versus placebo and two comparators. Randomization to the respective treatment was performed after successful downregulation of the pituitary gland prior to Investigational Medicinal Product dosing. Participants/materials, setting, methods In the single-dose study, 12 subjects received follitropin epsilon (25, 75, 150 and 300 IU) in three of four possible ascending doses and seven subjects received one dose of two comparators (150 IU Bravelle and 150 IU Gonal-f) and placebo in random order in each treatment period. In the multiple-dose study, 30 subjects received follitropin epsilon (75 IU or 150 IU once daily [QD], or 150 IU every other day [QAD], 10 subjects each) and 27 subjects received 150 IU Gonal-f, 150 IU Bravelle, or placebo for 7 days (11/10/6 subjects). Blood samples for measuring PK as well as PD parameters were collected systematically before, during and after dosing. Adverse events (AEs) and other relevant safety parameters were recorded. Data were summarized using descriptive statistics. Main results and the role of chance The single- and multiple-dose PK parameters maximum concentration (Cmax) and area under the concentration-time curve (AUC0-last) increased in a linear fashion with increasing dose levels of follitropin epsilon. Follitropin epsilon showed PK characteristics comparable to the comparators indicating that well established treatment schemes could be applied. There was a dose-response effect of single and multiple doses of follitropin epsilon on follicular growth, which was shown for the biomarker inhibin B as well as for the mean number and size of follicles. Multiple doses of 75 IU follitropin epsilon given daily, as well as 150 IU follitropin epsilon every second day, showed a follicle growth comparable with 150 IU Gonal-f given daily, while in case of daily administration of 150 IU Bravelle only weak follicle stimulation was observed. Multiple doses of 150 IU follitropin epsilon induced a much higher follicle growth compared to the same dose of Gonal-f. All single and multiple follitropin epsilon doses tested were safe and well tolerated, and overall there were no relevant differences between follitropin epsilon and the comparators in terms of safety. The average number of AEs increased with increasing dose levels. No clinically relevant abnormalities were reported for any of the other safety parameters assessed. No follitropin epsilon anti-drug antibodies were observed. Limitations, reasons for caution The studies were conducted as a single-blind design. Hormone levels or other parameters assessed in serum are generally not considered as being subject to bias. Other assessments directly performed by the investigators, such as transvaginal ultrasound assessments, may have been subject to personal bias. No prospective calculations of statistical power had been made, as is common practice for first in human and early phase I studies in healthy volunteers. Wider implications of the findings These early development studies showed that follitropin epsilon exhibits comparable PK characteristics, as well as inducing stronger PD effects in terms of follicle growth and serum inhibin B, than the comparators. Follitropin epsilon induced a dose-dependent increase in follicular growth. The results warrant further studies with this new fully human recombinant FSH. Study funding/competing interest(s) The studies were sponsored by GLYCOTOPE GmbH, Berlin, Germany. K.A-E. is an employee of QPS-Netherlands, B.V., which received funding for the studies from Glycotope GmbH; I.D. and C.K. are employees of Dinox B.V., which received funding for the studies from Glycotope GmbH; L.S. and S.G. are employees and shareholders of Glycotope GmbH; B.D. and K.E. are employees of Glycotope GmbH. Trial registration number www.clinicaltrials.gov: NCT01354886 (single-dose); NCT01477073 (multiple-dose). Trial registration date The single-dose trial was registered on 11 May 2011 while the multiple-dose trial was registered on 09 November 2011. Date of first subject's enrolment First subject was enroled in the single-dose trial in 27 April 2011 and in the multiple-dose trial in 02 October 2011.

Human Cell Line-Derived Monoclonal IgA Antibodies for Cancer Immunotherapy

Abstract: IgA antibodies have great potential to improve the functional diversity of current IgG antibody-based cancer immunotherapy options. However, IgA production and purification is not well established, which can at least in part be attributed to the more complex glycosylation as compared to IgG antibodies. IgA antibodies possess up to five N-glycosylation sites within their constant region of the heavy chain as compared to one site for IgG antibodies. The human GlycoExpress expression system was developed to produce biotherapeutics with optimized glycosylation and used here to generate a panel of IgA isotype antibodies directed against targets for solid (TA-mucin 1, Her2, EGFR, Thomsen–Friedenreich) and hematological (CD20) cancer indications. The feasibility of good manufacturing practice was shown by the production of 11 g IgA within 35 days in a one liter perfusion bioreactor, and IgA antibodies in high purity were obtained after purification. The monoclonal IgA antibodies possessed a high sialylation degree, and no non-human glycan structures were detected. Kinetic analysis revealed increased avidity antigen binding for IgA dimers as compared to monomeric antibodies. The IgA antibodies exhibited potent Fab- and Fc-mediated functionalities against cancer cell lines, whereby especially granulocytes are recruited. Therefore, for patients who do not sufficiently benefit from therapeutic IgG antibodies, IgA antibodies may complement current regiment options and represent a promising strategy for cancer immunotherapy. In conclusion, a panel of novel biofunctional IgA antibodies with human glycosylation was successfully generated.

Iga antibodies with enhanced stability

Abstract: The present invention pertains to IgA antibodies having an optimized glycosylation pattern. These IgA antibodies exhibit an increased stability and an extended shelf life. Compositions comprising IgA antibodies having an improved glycosylation pattern and methods for improving the shelf life of IgA antibodies are provided.

Means and methods for modifying multiple alleles

Abstract: The present invention relates to a method of modifying at least one gene in a cell via CRISPR/Cas, wherein the at least one gene has at least three alleles. The present invention further relates to cells obtainable by the method of the invention. Additionally, the present invention provides a method of producing a protein in a cell obtainable by the method of modifying at least one gene of the invention. Moreover, the invention relates to proteins obtainable by the method of producing a protein and use thereof, for example in therapy.

Serum-free cultivation of progenitor dendritic cells

Abstract: The invention relates to a method for the serum-free cultivation of progenitor cell lines for dendritic cells comprising culturing said cell lines in serum-free cell culture and to progenitor cell lines for dendritic cells obtainable by said method The invention also provides methods for differentiating said progenitor cells into dendritic cells and to dendritic cells obtainable from said progenitor cell lines through differentiation as well as to a vaccine composition comprising said dendritic cells

Natural microorganisms which are naturally capable of binding toxins and/or toxin receptors

Abstract: The present invention relates to means and method for isolating naturally-occurring microorganisms (non-pathogenic bacteria, yeasts or fungi) capable of binding toxins from microorganisms such as bacteria, viruses, fungi, yeasts, or protozoans and/or receptors for these toxins on the surface of mammalian cells, thereby making these receptors inaccessible for said toxins. The naturally-occurring microorganisms that are obtainable by the means and methods of the present invention can be used for adsorbing toxins from pathogenic microorganisms and/or blocking receptors for such toxins on the surface of mammalian cells. These toxin-receptor interactions are known to be critical for disease pathogenesis, making both the toxins and receptors a target for the naturally-occurring microorganisms of the present invention.