Featured Customer: Edwin Moore, Ph.D.

Companies developing biosimilars face many challenges, and the first challenge is to thoroughly characterize the innovator product to compare to their company’s product. Characterization is a critical first step to establishing the attributes of the innovator product to design and then demonstrate that the biosimilar product is comparable to the innovator. The breadth of analytical characterization methods is necessary to elicit all aspects of the innovator product and demonstrate on a sufficient number of lots of innovator product and on an equal number of biosimilar product lots such that the two products are statistically comparable. Once analytical comparability is established, the biosimilar company develops CMC aspects using cGMP processes, including state-of-the-art analytical controls of critical quality attributes, quality risk management assessment, and clinical development as defined by regulatory authorities.

How are the product standards for the various biopharmaceuticals evolving? Please list a few products that are being actively targeted by regulatory bodies for inclusion in pharmacopoeial monographs

The adulteration of heparin in 2008 provided a realization that monographs need to be updated to reflect newer analytical controls. Work by FDA, industry, and academia were incorporated into the USP and EP monographs for heparin to provide more robust methodologies for detecting impurities. NMR, SEC, and more specific bioassay were added.

Pharmacopoeial organizations had already begun to expand the standards for biologics and the expansion continued to develop new chapters and monographs that provided standardized methods for the industry. New Expert Committees were convened by the USP to handled greater breadth of biologics standards. Standards have been added and updated for host cell proteins, for glycosylation and carbohydrate, and for cell and tissue base products to mention a few of the additional initiatives.

Please share with us the work done by you and your team on methods for characterization of heparins.

Baxter team members were at the forefront of testing immediately following the discovery of tainted heparin product. NMR was first method found to distinguish adulterated product and traced back to raw material supplies. Baxter scientists collaborated with FDA, other industry scientists, and academics to prove the contaminating compound was highly sulfated chondroitin sulfate. Investigators also demonstrated that the existing compendial methods, including the bioassay for sheep blood clotting, could not differentiate adulterated material. Baxter did additional analysis including capillary electrophoresis and the use of SEC-MALS to better define the acceptable molecular weight range for heparin. While the use of MALS was demonstrated to be superior to absorbance detection, the USP and EP decided not to require MALS because of the additional cost to testing labs, believing that absorbance was adequate. We also worked with Wyatt scientist to test Mobius and demonstrated that the combination of charge and molecular mass could differentiate highly sulfated chondroitin sulfate from heparin, and could be another method for characterizing heparin raw materials for contaminants.

How effective was the Size Exclusion Chromatography-Multi Angle Light Scattering (SEC-MALS) technique in the characterization of heparins? We understand that quite a significant amount of work was done using light scattering instruments for upgrading product standards with respect to heparin. Please update current status in this key area.

An international team was formed to standardize heparin molecular weight determination. Laboratories from pharmaceutical industry, government agencies, and academics characterized samples performing molecular weight determinations with their methods. The reference method for the molar mass of the heparin samples was SEC-MALS. In addition, Baxter used SEC-MALS and SEC absorbance. The international team concluded that SEC was needed as a control measure and that absorbance detection was adequate.

Please explain, the role played by the Wyatt Light Scattering Systems in your research and also in the various macromolecules where you found the systems highly useful in characterization.

I have used light scattering for protein characterization. I had used MALS for both biologic molecules (e.g. hemoglobin and heparin) as well as recombinant proteins (e.g. hemoglobin, erythropoietin).

More recently for research at UIUC, we have used MALS for studies of inhibition of amyloid β aggregation and disassembly of fibrils by a multivalent polypropyl peptide conjugate (mPPC). MALS has been used characterize the molar mass of the polymer, as well as follow the inhibition of Aβ aggregation and disassembly of fibrils.

What are the other orthogonal techniques that manufacturers of biosimilars are expected to use for generation of data to prove ‘equivalence’ to the innovator’s product?

Orthogonal techniques are dependent on the properties of the drug molecule. The expectation is that current state-of-the-art technologies should be used to investigate all properties of the molecule. NMR, mass spectroscopy, LC-LC-MS, and capillary electrophoresis are among the techniques that would be expected to explore the protein and carbohydrate structures including content and sequencing. Impurities would be characterized and quantitated as well, including protein aggregates and subvisible particulate, for stored lots and after accelerated degradation. MALS and FFF are useful for characterizing protein aggregates and subvisible protein particles. Orthogonal potency methods would be used if alternate methods are possible.

We gather that you are an active member of the American Association of Pharmaceutical Scientists (AAPS) –Pharmaceutical Impurities Focus group. Please outline the recent initiatives of this group in small molecule as well as biopharmaceuticals

AAPS is now organized in communities. The AAPS Pharmaceutical Impurities community has five strategic initiatives described in the table below. The community consists of scientists from industry, government and academic institutions. Our objective is to provide discussion to address issues in impurities characterization and quantitation that are relevant to impurity controls in pharmaceutical products. We facilitate discussion through blogs, by programming at the annual meeting (PharmSci 360), workshops, and publications.