Immunogenicity assay development and validation for biological therapy as exemplified by ustekinumab.

Introduction of biotherapeutics has been a major milestone in the treatment of different chronic diseases. Nevertheless, the immune system can recognize the administered biological as non-self and respond with generation of anti-drug antibodies (ADA), including neutralizing ADA (nADA). Immunogenic responses may result in altered drug dynamics and kinetics leading to changes in safety and efficacy. However, there are several challenges with standard techniques for immunogenicity testing. Ustekinumab (UST), used in different inflammatory diseases, is a therapeutic antibody directed against the shared p40 subunit of interleukin (IL)-12 and IL-23, interfering in the pathogenically crucial T helper type 1 (Th1)/Th17 pathway. We established and validated different approaches for detection and quantitation of UST, UST-specific ADA and nADA. Addressing the obstacle of complex formation of UST with nADA, we developed an acidification assay to approach the total amount of nADA. Validated methods were based on surface plasmon resonance spectroscopy (SPR), enzyme-linked immunosorbent assay (ELISA) and a cell-based approach to characterize neutralizing capacity of nADA. Parameters assessed were determination and quantitation limits, linearity, range, precision, accuracy and selectivity. Quantitation of ADA and UST was feasible at lower concentrations using ELISA, whereas SPR showed a wider linear range for determination of ADA and UST. Accuracy, precision and linearity for quantitation were comparable using ELISA, SPR and the cell-based approach. All validated parameters fulfill the requirements of regulatory agencies. A combination of the testing approaches could address the increasing demand of precision medicine as it can be suitable for capturing the whole spectrum of immunogenicity and is transferable to other biologicals.

Rapid EPA and DHA incorporation and reduced PGE2 levels after one week intervention with a medical food in cancer patients receiving radiotherapy, a randomized trial.

BACKGROUND & AIMS: In cancer patients, metabolic alterations, reduced immune competence and anti-cancer treatment can increase the risk of infections. A rapid-acting nutritional intervention might reduce this risk and support overall treatment. The present study investigated whether one week of intervention with a specific medical food led to fatty acid incorporation and functional immunological changes. METHODS: In a randomized, double-blind study, 38 cancer patients receiving radiotherapy consumed daily for one week 400 ml of specific medical food, which is high in protein and leucine, and enriched with fish oil and specific oligosaccharides (Active group), or iso-caloric/iso-nitrogenous product (Control group). Blood samples were taken at day 0 (baseline) and day 7. RESULTS: After one week of intervention, the incorporation of EPA and DHA in white blood cells was significantly higher in the Active group (2.6% and 2.6% of total fatty acids) compared to the Control group (1.0% and 2.2% of total fatty acids) (p < 0.001 and p < 0.05). Serum PGE2 levels decreased in the Active group and increased in the Control group (p < 0.01). No differences were observed on cytokine production in LPS-stimulated whole blood cultures. CONCLUSIONS: In cancer patients receiving radiotherapy, nutritional intervention with a specific medical food rapidly increased the percentage EPA and DHA in white blood cell phospholipids and reduced serum levels of the inflammatory mediator PGE2 within one week. CLINICAL REGISTRATION NUMBER: NTR2121.

Treatment of relapsed acute lymphocytic leukemia in adults.

Thirty-three patients with ALL/AUL in first relapse were treated with an induction of prednisone, vindesine, daunorubicin, Erwinia asparaginase, i.t. MTX (phase I), high-dose cytarabine, and etoposide (phase II). Twenty-one (64%) achieved a complete remission, one a partial remission. Side effects of induction-phase I were predominantly hematological with subsequent infections and gastrointestinal toxicity. In phase II some patients had additional cutaneous, ocular, and hepatic toxicity. The treatment efficiently induced remissions with tolerable toxicity in relapsed ALL. The disease-free survival, however, needs to be improved.

Maintenance of cotton-top tamarins fed an experimental pelleted diet versus a highly diverse sweetened diet.

The future study of colon disease in captive callitrichid colonies may require manipulation of diets. The limited knowledge of the nutritional requirements for these species and the varied diets and supplementations fed to these animals in various colonies suggest the importance of testing the palatability and acceptability of diets for these primates. Individually housed cotton-top tamarins (Saguinus oedipus) were given either the regular Oak Ridge Associated Universities (ORAU) diet (monkey chow slurry, canned diet and supplements), a similar slurry using an experimental natural ingredient diet plus supplements, or the experimental diet without supplements. Neither dry food consumption, body weight, fecal output, nor the histological evaluation of the colons were affected by these diets. Daily intake of protein and calories were higher than previously reported estimates for the species. These results demonstrate that a natural ingredient non-sweetened pelleted diet is palatable for cotton-top tamarins for a period of 3.5 months, however, further testing over longer time periods is necessary. The nonnutritional (e.g. psychological) advantages of providing a highly diverse diet to primates housed in a relatively monotonous environment should be considered before adopting such a diet for an entire colony.