Development of Glatopa® (Glatiramer Acetate): The First FDA-Approved Generic Disease-Modifying Therapy for Relapsing Forms of Multiple Sclerosis

Abstract

The multiple sclerosis (MS) treatment landscape in the United States has changed dramatically over the past decade. While many disease-modifying therapies (DMTs) have been approved by the US Food and Drug Administration (FDA) for the treatment of relapsing forms of MS, DMT costs continue to rise. The availability of generics and biosimilars in the MS-treatment landscape is unlikely to have a major impact on clinical benefit. However, their availability will provide alternative treatment options and potentially lower costs through competition, thus increasing the affordability of and access to these drugs. In April 2015, the first generic version of the complex drug glatiramer acetate (Glatopa® 20 mg/mL) injection was approved in the United States as a fully substitutable generic for all approved indications of the 20 mg/mL branded glatiramer acetate (Copaxone®) dosage form. Despite glatiramer acetate's complex nature-being a chemically synthesized (ie, nonbiologic) mixture of peptides-the approval occurred without conducting any clinical trials. Rather, extensive structural and functional characterization was performed to demonstrate therapeutic equivalence to the innovator drug. The approval of Glatopa signifies an important milestone in the US MS-treatment landscape, with the hope that the introduction of generic DMTs and eventually biosimilar DMTs will lead to future improvements in the affordability and access of these much-needed treatments for MS.

Keywords: disease-modifying therapy; generic drugs; glatiramer acetate; multiple sclerosis.

Figure 1.

Examples of structural and biological analyses used to establish equivalence of Glatopa and Copaxone 20 mg/mL, which includes assessment of (A), molar mass distributions; (B), amino acid levels for the first 5 cycles of N-terminal analysis by Edman degradation; (C), total amino acid composition; (D), the proteolipid peptide version of the experimental autoimmune encephalomyelitis (EAE) prophylaxis model; and (E), the myelin oligodendrocyte glycoprotein version of the EAE prophylaxis model.