Physicochemical and Biological Examination of Two Glatiramer Acetate Products.

Herein we compared 40 mg/mL lots of the active ingredient, glatiramer acetate, manufactured by Mylan/Natco to the active ingredient, glatiramer acetate in Copaxone (Teva Pharmaceuticals, Ltd., Netanya Israel) using physicochemical (PCC) methods and biological assays. No differences were seen between the Mylan/Natco and Teva lots with some low resolution release PCC assays (amino acid analysis, molecular weight distribution, interaction with Coomassie Brilliant Blue G-250). Changes in polydispersity between Mylan/Natco and Copaxone lots were found using size exclusion chromatography and the high resolution PCC method, known as Viscotek, and suggestive of a disparity in the homogeneity of mixture, with a shift towards high molecular weight polypeptides. Using RPLC-2D MALLS, 5 out of 8 Mylan/Natco lots fell outside the Copaxone range, containing a high molecular weight and high hydrophobicity subpopulation of polypeptides not found in Copaxone lots. Cation exchange chromatography showed differences in the surface charge distribution between the Copaxone and Mylan/Natco lots. The Mylan/Natco lots were found to be within Copaxone specifications for the EAE model, monoclonal and polyclonal binding assays and the in vitro cytotoxicity assay, however higher IL-2 secretion was shown for three Mylan/Natco lots in a potency assay. These observations provide data to inform the ongoing scientific discussion about the comparability of glatiramer acetate in Copaxone and follow-on products.

Compositional differences between Copaxone and Glatopa are reflected in altered immunomodulation ex vivo in a mouse model.

Copaxone (glatiramer acetate, GA), a structurally and compositionally complex polypeptide nonbiological drug, is an effective treatment for multiple sclerosis, with a well-established favorable safety profile. The short antigenic polypeptide sequences comprising therapeutically active epitopes in GA cannot be deciphered with state-of-the-art methods; and GA has no measurable pharmacokinetic profile and no validated pharmacodynamic markers. The study reported herein describes the use of orthogonal standard and high-resolution physicochemical and biological tests to characterize GA and a U.S. Food and Drug Administration-approved generic version of GA, Glatopa (USA-FoGA). While similarities were observed with low-resolution or destructive tests, differences between GA and USA-FoGA were measured with high-resolution methods applied to an intact mixture, including variations in surface charge and a unique, high-molecular-weight, hydrophobic polypeptide population observed only in some USA-FoGA lots. Consistent with published reports that modifications in physicochemical attributes alter immune-related processes, genome-wide expression profiles of ex vivo activated splenocytes from mice immunized with either GA or USA-FoGA showed that 7-11% of modulated genes were differentially expressed and enriched for immune-related pathways. Thus, differences between USA-FoGA and GA may include variations in antigenic epitopes that differentially activate immune responses. We propose that the assays reported herein should be considered during the regulatory assessment process for nonbiological complex drugs such as GA.

Equivalence of complex drug products: advances in and challenges for current regulatory frameworks.

Biotechnology and nanotechnology provide a growing number of innovator-driven complex drug products and their copy versions. Biologics exemplify one category of complex drugs, but there are also nonbiological complex drug products, including many nanomedicines, such as iron-carbohydrate complexes, drug-carrying liposomes or emulsions, and glatiramoids. In this white paper, which stems from a 1-day conference at the New York Academy of Sciences, we discuss regulatory frameworks in use worldwide (e.g., the U.S. Food and Drug Administration, the European Medicines Agency, the World Health Organization) to approve these complex drug products and their follow-on versions. One of the key questions remains how to assess equivalence of these complex products. We identify a number of points for which consensus was found among the stakeholders who were present: scientists from innovator and generic/follow-on companies, academia, and regulatory bodies from different parts of the world. A number of topics requiring follow-up were identified: (1) assessment of critical attributes to establish equivalence for follow-on versions, (2) the need to publish scientific findings in the public domain to further progress in the field, (3) the necessity to develop worldwide consensus regarding nomenclature and labeling of these complex products, and (4) regulatory actions when substandard complex drug products are identified.

The similarity question for biologicals and non-biological complex drugs.

For small - low molecular weight - molecule medicines a robust regulatory system has evolved over the years. This system guarantees high and constant quality of our (generic) medicines. Pharmaceutical equivalence and bioequivalence assessment are the pillars under that system. But there are complex medicines where the question of equivalence is more challenging to answer. For biologicals the paradigm of similarity rather than equality (the emergence of 'biosimilars') was developed in the past decade. This has been a program where an evolutionary, science based approach has been chosen by the frontrunner regulatory body, the EMA, with a 'learn and confirm' character. In addition, there is another group of complex drugs, the non-biological complex drugs, NBCDs, where the generic paradigm can be challenged as well. The NBCDs are defined as: 1. consisting of a complex multitude of closely related structures; 2. the entire multitude is the active pharmaceutical ingredient; 3. the properties cannot be fully characterized by physicochemical analysis and 4. the consistent, tightly controlled manufacturing process is fundamental to reproduce the product. NBCDs encompass product families such as the glatiramoids, liposomes, iron-carbohydrate colloids and many candidates of the group of the upcoming nanoparticulate systems. Following the main principles of regulatory pathways for biologicals (with appropriate product-by-product adjustments), instead of that for small molecules, would be the more logical strategy for these NBCDs. The status and outstanding regulatory issues for biosimilars and NBCD-similars/follow on versions were discussed at a conference in Budapest, Hungary (October 2014) and this commentary touches upon the issues brought up in the presentations, deliberations and conclusions.

Different pharmaceutical products need similar terminology.

In the last decade, discussions on the development of the regulatory framework of generic versions of complex drugs such as biologicals and non-biological complex drugs have attracted broad attention. The terminology used is far from harmonized and can lead to multiple interpretations of legal texts, reflection papers, and guidance documents regarding market introduction as well as reimbursement. This article describes the meaning of relevant terms in different global regions (Europe, USA, WHO) and offers a proposal for a globally accepted terminology regarding (non-) biological complex drugs.

How to regulate nonbiological complex drugs (NBCD) and their follow-on versions: points to consider.

The aim of this critical review is to reach a global consensus regarding the introduction of follow-on versions of nonbiological complex drugs (NBCD). A nonbiological complex drug is a medicinal product, not being a biological medicine, where the active substance is not a homo-molecular structure, but consists of different (closely related and often nanoparticulate) structures that cannot be isolated and fully quantitated, characterized and/or described by state of the art physicochemical analytical means and where the clinical meaning of the differences is not known. The composition, quality and in vivo performance of NBCD are highly dependent on manufacturing processes of both the active ingredient as well as in most cases the formulation. The challenges posed by the development of follow-on versions of NBCD are illustrated in this paper by discussing the 'families' of liposomes, iron-carbohydrate ('iron-sugar') drugs and glatiramoids. It is proposed that the same principles for the marketing authorization of copies of NBCD as for biosimilars be used: the need for animal and/or clinical data and the need to show similarity in quality, safety and efficacy. The regulatory approach of NBCD will have to take into consideration the specific characteristics of the drugs, their formulation and manufacturing process and the resulting critical attributes to achieve their desired quality, safety and efficacy. As with the biosimilars, for the NBCD product, family-specific methods should be evaluated and applied where scientifically proven, including sophisticated quality methods, pharmacodynamic markers and animal models. Concerning substitution and interchangeability of NBCD, it is also advisable to take biosimilars as an example, i.e. (1) substitution without the involvement of a healthcare professional should be discouraged to ensure traceability of the treatment of individual patients, (2) keep an individual patient on a specific treatment if the patient is doing well and only switch if unavoidable and (3) monitor the safety and efficacy of the new product if switching occurs.

The glatiramoid class of immunomodulator drugs.

Glatiramer acetate (GA) is a complex heterogenous mixture of polypeptides with immunomodulatory activity approved for treatment of relapsing-remitting multiple sclerosis. GA is the first, and was until recently, the only member of the glatiramoids, a family of synthetic copolymer mixtures comprising the four amino acids, L-glutamic acid, L-alanine, L-lysine and L-tyrosine, in a defined molar ratio. Another glatiramoid, protiramer, was recently evaluated in preclinical studies and in two small Phase II clinical trials with relapsing-remitting multiple sclerosis patients. Due to the complexity and heterogeneity of GA and other glatiramoids, the clinically active epitopes within the mixture cannot be identified and the consistency of polypeptide sequences within the mixture is dependent on a tightly controlled manufacturing process. Although no two glatiramoids can be proved identical, it is possible to differentiate among members of the glatiramoid class using analytical methods and immunological and biological markers. Even slight differences in the distribution of molecular masses or in the composition of antigenic polypeptide sequences among glatiramoids can significantly influence their efficacy, toxicity and immunogenicity profiles. Experience with GA may be instructive regarding important safety and efficacy considerations for new glatiramoid mixtures now in development.