Rapid identity testing of antibody-based hot targeted radionuclide therapies by bio-layer interferometry.

Targeted Radionuclide Therapies (TRT) involve the tailored combination of a therapeutic radionuclide and a targeting molecule, as for instance antibodies or fragments thereof. Despite their short shelf-life, these drug products must meet stringent regulatory standards before use. We introduce a novel, efficient method utilizing Bio-Layer Interferometry (BLI) for rapid identity testing of TRT drug products in less than five minutes. This approach not only reduces radioactive waste but also minimizes operator exposure to radiation. This label-free method has been successfully developed and validated for three different TRT products, ensuring compliance with Good Manufacturing Practices (GMP). Furthermore, we outline our strategic approach to the production and testing of custom biosensors for each product, firmly grounded in Quality-by-Design (QbD) principles.

Advances in influenza virus-like particles bioprocesses.

Introduction: Influenza Virus-like Particles (VLPs) are one of the most promising vaccine strategies to complement traditional egg-based processes and contribute to shortening the response time when facing future pandemics. Research programs have taken advantage of the potential of this approach to produce influenza VLPs on a variety of cellular platforms, reaching the industrial level of development and recent commercialization.Area covered: This review aims to give an overview of available strategies for influenza-VLP production and their respective stages of development, from small-scale preclinical studies to large-scale industrial processes. Recent trends and fulfillments in purification schemes of influenza VLP were also reviewed with regards to quality and potency requirements that go along with influenza vaccine manufacturing.Expert opinion: In the next five years, it is expected that there will be licensing of new influenza vaccine products based on VLP strategy. Few VLP upstream processes are mature enough and close to fully complement or seriously concurrence the ovoculture process. Nevertheless, many improvements have yet to be achieved in downstream processes. In the next few years, research efforts in this field are expected to provide purification strategies and tools to achieve higher recovery yields and improve the cost-effectiveness of VLP processes.

SPRi-based hemagglutinin quantitative assay for influenza vaccine production monitoring.

Influenza vaccine manufacturers lack tools, whatever the involved production bioprocess (egg or cell-based), to precisely and accurately evaluate vaccine antigen content from samples. Indeed, the gold standard single-radial immunodiffusion (SRID) assay, which remains the only validated assay for the evaluation of influenza vaccine potency, is criticized by the scientific community and regulatory agencies since a decade for its high variability, lack of flexibility and low sensitivity. We hereby report an imaging surface plasmon resonance (SPRi) assay for the quantification of both inactivated vaccine influenza antigens and viral particles derived from egg- and cell-based production samples, respectively. The assay, based on fetuin-hemagglutinin interactions, presents higher reproducibility (<3%) and a greater analytical range (0.03-20 µg/mL) than SRID for bulk monovalent and trivalent vaccine and its limit of detection was evaluated to be 100 times lower than the SRID's one. Finally, viral particles production through cell culture-based bioprocess was also successfully monitored using our SPRi-based assay and a clear correlation was found between the biosensor response and total virus particle content.

Influenza viruses production: Evaluation of a novel avian cell line DuckCelt®-T17.

The influenza vaccine manufacturing industry is looking for production cell lines that are easily scalable, highly permissive to multiple viruses, and more effective in term of viral productivity. One critical characteristic of such cell lines is their ability to grow in suspension, in serum free conditions and at high cell densities. Influenza virus causing severe epidemics both in human and animals is an important threat to world healthcare. The repetitive apparition of influenza pandemic outbreaks in the last 20years explains that manufacturing sector is still looking for more effective production processes to replace/supplement embryonated egg-based process. Cell-based production strategy, with a focus on avian cell lines, is one of the promising solutions. Three avian cell lines, namely duck EB66®cells (Valneva), duck AGE.CR® cells (Probiogen) and quail QOR/2E11 cells (Baxter), are now competing with traditional mammalian cell platforms (Vero and MDCK cells) used for influenza vaccine productions and are currently at advance stage of commercial development for the manufacture of influenza vaccines. The DuckCelt®-T17 cell line presented in this work is a novel avian cell line developed by Transgene. This cell line was generated from primary embryo duck cells with the constitutive expression of the duck telomerase reverse transcriptase (dTERT). The DuckCelt®-T17 cells were able to grow in batch suspension cultures and serum-free conditions up to 6.5×106cell/ml and were easily scaled from 10ml up to 3l bioreactor. In the present study, DuckCelt®-T17 cell line was tested for its abilities to produce various human, avian and porcine influenza strains. Most of the viral strains were produced at significant infectious titers (>5.8 log TCID50/ml) with optimization of the infection conditions. Human strains H1N1 and H3N2, as well as all the avian strains tested (H5N2, H7N1, H3N8, H11N9, H12N5) were the most efficiently produced with highest titre reached of 9.05 log TCID50/ml for A/Panama/2007/99 influenza H3N2. Porcine strains were also greatly rescued with titres from 4 to 7 log TCID50/ml depending of the subtypes. Interestingly, viral kinetics showed maximal titers reached at 24h post-infection for most of the strains, allowing early harvest time (Time Of Harvest: TOH). The B strains present specific production kinetics with a delay of 24h before reaching the maximal viral particle release. Process optimization on H1N1 2009 human pandemic strain allowed identifying best operating conditions for production (MOI, trypsin concentration, cell density at infection) allowing improving the production level by 2 log. Our results suggest that the DuckCelt®-T17 cell line is a very promising platform for industrial production of influenza viruses and particularly for avian viral strains.