Saturday, 22 December 2012

Research aggregates and neutralisation of beta interferon

EpubBarnard et al. Characterization and quantitation of aggregates and particles in interferon-β products: Potential links between product quality attributes and immunogenicity. J Pharm Sci. 2012. doi: 10.1002/jps.23415. 

Interferon-β (IFN-β) products have been used for many years in the treatment of multiple sclerosis and include recombinant IFN-β-1b (Betaseron®) and IFN-β-1a (Avonex® and Rebif®). All three products lead to the formation of neutralizing antibodies (NAbs) and resulting loss of efficacy in patients but to different extents. Across several clinical trials, the reported rates of neutralizing-antibody formation were 22%-47% (Betaseron®), 5%-35% (Rebif®), and 2%-13% (Avonex®). In the current study, all products were purchased from the pharmacy and aggregates were characterized and/or quantified using size-exclusion chromatography (SEC), analytical ultracentrifugation, gel electrophoresis, and dot-blotting immunoassays. Particle characterization and counting were performed using microflow imaging, particle tracking analysis, and resonant mass measurement. Betaseron® and Rebif®, which are formulated with human serum albumin, had the greatest amount of aggregated protein and particles (e.g., 9%-15% high molecular weight species by SEC and >100,000 particles/mL by flow imaging). Avonex® was found to have the least amount of aggregated protein, with >95% monomer content by both SEC and analytical ultracentrifugation, and the particles detected in Avonex® were determined to be primarily silicone oil droplets. These results strongly suggest that protein aggregate and particle contents are key product quality attributes in a given product's propensity to elicit the production of NAbs in patients.


Many years ago Prof G had the idea that aggregates were the cause of neutralizing antibodies (i.e. antibodies that bind to the active part and stop the drug working) and this is how a new formulation of Rebif was born. It seems aggregates are still a bit of a problem. If MSers get neutralizing antibodies the drug fails, so the less aggregates the better. 

CoI: None

1 comment:

  1. Research on NAB is interesting on a patient basis if IFN treatment fails. But it cannot be considered as an argument for the preferential use of one of the IFN as they have not the same efficacy. Even if you calculate a probability for the efficacy of IFN including the rate of NAB, more than once a week regimen are more efficient (confirmed by clinical trials). NAB argument for initialization of IFN treatment is only a nice marketing argument. It is interesting for treatment failures and as you state for formulation improvement.

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