Demonstration of Biological and Immunological Equivalence of a Generic Glatiramer Acetate.

BACKGROUND: In April 2015, the US Food and Drug Administration approved the first generic glatiramer acetate, Glatopa® (M356), as fully substitutable for Copaxone® 20 mg/mL for relapsing forms of multiple sclerosis (MS). This approval was accomplished through an Abbreviated New Drug Application that demonstrated equivalence to Copaxone. METHOD: This article will provide an overview of the methods used to establish the biological and immunological equivalence of the two glatiramer acetate products, including methods evaluating antigenpresenting cell (APC) biology, T-cell biology, and other immunomodulatory effects. RESULTS: In vitro and in vivo experiments from multiple redundant orthogonal assays within four biological processes (aggregate biology, APC biology, T-cell biology, and B-cell biology) modulated by glatiramer acetate in MS established the biological and immunological equivalence of Glatopa and Copaxone and are described. The following were observed when comparing Glatopa and Copaxone in these experiments: equivalent delays in symptom onset and reductions in "disease" intensity in experimental autoimmune encephalomyelitis; equivalent dose-dependent increases in Glatopa- and Copaxone- induced monokine-induced interferon-gamma release from THP-1 cells; a shift to a T helper 2 phenotype resulting in the secretion of interleukin (IL)-4 and downregulation of IL-17 release; no differences in immunogenicity and the presence of equivalent "immunofingerprints" between both versions of glatiramer acetate; and no stimulation of histamine release with either glatiramer acetate in basophilic leukemia 2H3 cell lines. CONCLUSION: In summary, this comprehensive approach across different biological and immunological pathways modulated by glatiramer acetate consistently supported the biological and immunological equivalence of Glatopa and Copaxone.

Equivalent Gene Expression Profiles between Glatopa™ and Copaxone®.

Glatopa™ is a generic glatiramer acetate recently approved for the treatment of patients with relapsing forms of multiple sclerosis. Gene expression profiling was performed as a means to evaluate equivalence of Glatopa and Copaxone®. Microarray analysis containing 39,429 unique probes across the entire genome was performed in murine glatiramer acetate--responsive Th2-polarized T cells, a test system highly relevant to the biology of glatiramer acetate. A closely related but nonequivalent glatiramoid molecule was used as a control to establish assay sensitivity. Multiple probe-level (Student's t-test) and sample-level (principal component analysis, multidimensional scaling, and hierarchical clustering) statistical analyses were utilized to look for differences in gene expression induced by the test articles. The analyses were conducted across all genes measured, as well as across a subset of genes that were shown to be modulated by Copaxone. The following observations were made across multiple statistical analyses: the expression of numerous genes was significantly changed by treatment with Copaxone when compared against media-only control; gene expression profiles induced by Copaxone and Glatopa were not significantly different; and gene expression profiles induced by Copaxone and the nonequivalent glatiramoid were significantly different, underscoring the sensitivity of the test system and the multiple analysis methods. Comparative analysis was also performed on sets of transcripts relevant to T-cell biology and antigen presentation, among others that are known to be modulated by glatiramer acetate. No statistically significant differences were observed between Copaxone and Glatopa in the expression levels (magnitude and direction) of these glatiramer acetate-regulated genes. In conclusion, multiple methods consistently supported equivalent gene expression profiles between Copaxone and Glatopa.

Rapid and efficient in vitro generation of pancreatic islet progenitor cells from nonendocrine epithelial cells in the adult human pancreas.

The absence of efficient and directed methods for the differentiation of adult pancreatic progenitor cell populations to pancreatic islet cells has raised doubts concerning the regeneration potential inherent in the adult pancreas. Relatively low levels of islet cell differentiation have been reported using adult pancreatic cells in vivo and in vitro. In the present study, we initially enriched for a nonendocrine epithelial component of the adult human pancreas and defined conditions that are permissive to islet cell differentiation in vitro. Sequential progression of cell differentiation in the permissive conditions allowed for incremental evaluation of changes occurring in the cell population. Optimization of the differentiation process, for the efficient production of islet endocrine cells, was accomplished by identifying specific factors and culture conditions that increased islet progenitor production 250-fold. Ultimately, 85% percent of the nonendocrine epithelial cells isolated from human pancreatic tissue and cultured in the optimized conditions for 8 days, readily re-expressed pancreatic duodenal homeobox-1 (Pdx1). Sixty-five percent of these Pdx1-expressing cells were capable of additional islet endocrine cell differentiation. This represents a significant advancement in the differentiation of an adult pancreatic progenitor cell population in vitro and suggests that the nonendocrine compartment of the human pancreas remains an important cell resource for the generation of transplantable islets to treat diabetes.