Results of GATE Trial Pave Way for More-Affordable MS Therapy

The first generic versions of a leading therapy for multiple sclerosis (MS) may soon be on the way, thanks to results of an international trial recently presented by Jeffrey Cohen, MD, Director of Cleveland Clinic’s Mellen Center for Multiple Sclerosis Treatment and Research.

Dr. Cohen served as lead investigator of the GATE trial and presented its results at MS Boston 2014, the joint meeting of the Americas and European Committees for Treatment and Research in Multiple Sclerosis (ACTRIMS/ECTRIMS).

The double-blind randomized study set out to compare the proprietary version of the MS medication glatiramer acetate (Copaxone®) with a generic version of the compound (produced by Synthon Pharmaceuticals) and with placebo in 735 ambulatory patients with relapsing-remitting MS. All treatments were given by daily subcutaneous injection for nine months.

A paucity of affordable therapies

Copaxone was approved by the FDA in 1997, but no generic versions are currently available for it or other leading MS therapies.

“Some of the first MS medications are going off patent, which creates an opportunity for generic versions to be approved, which could bring patients significant savings in medication costs,” Dr. Cohen says. Many MS medications cost patients between $40,000 and $50,000 a year.

Not a standard generic equivalence study

Yet because glatiramer acetate is a complex polypeptide mixture, the standard pharmacokinetic comparisons used in generic equivalence studies are not possible. “This complexity means that small differences in how a generic version is manufactured could produce significant changes in the safety or efficacy of the compound,” Dr. Cohen explains.

The GATE study found no such changes between Copaxone and the compound’s generic version. Among the key study findings reported by Dr. Cohen:

• The numbers of gadolinium-enhancing MRI lesions were the same over months 7 to 9 (the study’s primary endpoint) in patients treated with Copaxone and its generic version, and both groups showed superiority over placebo.
• Rates, types and severity of adverse effects were similar with Copaxone and the generic version.

Now in the FDA’s hands

The fate of Synthon’s generic version of the compound now rests in the FDA’s hands. Although the GATE results bode well for its eventual approval, Dr. Cohen suspects the compound’s complexity may result in a longer-than-typical review time.

Still, the tide may be turning on generic versions of MS therapies — and patients stand to benefit in the pocketbook.