Regulators in the USA have received another citizen petition from Teva Pharmaceutical Industries questioning the criteria for assessing generic versions of its multiple sclerosis blockbuster Copaxone.

The Israeli firm is asking the US Food and Drug Administration to refuse to approve any abbreviated New Drug Application for a “purported generic version” of Copaxone (glatiramer acetate) based primarily on “the inability to establish acceptable ‘sameness’ of the active ingredients”. Teva says its request should be upheld due to “the complexity of the mechanism of action of a glatiramoid and the inapplicability of leveraging conventional pharmacokinetic and pharmacodynamic testing methods to demonstrate bioequivalence”.

The world’s largest generics group itself, Teva is urging the FDA to insist that any copycat undergo preclinical testing as well as “full-scale clinical trials with measured clinical endpoints in MS patients to prove safety and efficacy”. The company has also requested that the agency convene a “multidisciplinary advisory committee to consider the approval of follow-on glatiramer acetate products in the interest of public health”.

For over a year, Teva has asked the FDA to not accept for review Copaxone ANDAs from Momenta Pharmaceuticals and Novartis unit Sandoz, as well as Mylan. In May, the agency turned down a second citizen petition, saying that “a finding of sameness does not, however, necessitate a finding of ‘complete chemical identity’,” though it promised to consider other criteria to determine sameness, “taking into account the complexity of the active ingredient”.

The US patents on Copaxone are valid until 2014 and the drug is a major earner for the Petah Tikva-headquartered firm. Third-quarter sales were $808 million, up 4% on the like, year-earlier period.