Sanofi-Aventis Sues FDA Over Generic Lovenox Approval

Yael Waknine

July 29, 2010

July 29, 2010 (Washington, DC) — Sanofi-Aventis, which makes enoxaparin sodium injection (Lovenox), has filed a lawsuit in federal court against the US Food and Drug Administration (FDA), seeking a reversal of the agency's recent approval for a generic formulation of the drug made by Novartis's Sandoz and codeveloped/marketed with Momenta Pharmaceuticals.

The company is charging the FDA with failure to ensure that the generic product has the same active ingredient as the reference drug.

"If not remedied, FDA's decision will cause Sanofi-Aventis irreparable harm and may result in entry into the market of a generic product that is not clinically equivalent to Lovenox with respect to safety or efficacy," the court document states.

The company also charged the agency with exceeding its authority and ignoring its own precedent regarding the approval of generic drugs that have not been fully characterized, branding the approval as "capricious and otherwise unlawful."

Statutes in the federal Food, Drug, and Cosmetic Act preclude approval of a generic formulation's abbreviated new drug application (ANDA) if additional safety and efficacy data are required, as was the case for enoxaparin injection. Such products are generally not considered fully substitutable and require submission of a full new drug application (NDA).

"By requiring Sandoz to submit immunogenicity data not contained in the Lovenox NDA and required to address FDA safety concerns, FDA exceeded its authority to approve the drug under an ANDA," explained Emmy Tsui, a spokesperson for Sanofi-Aventis. "In addition, the company believes that FDA's criteria for determining that the Sandoz drug was the same as Lovenox were arbitrary and inconsistent with prior agency precedent."

In a news release issued on the July 23, 2010 approval date, the FDA declared that its action was consistent with current scientific evidence, precedent, and the agency's legal authority.

FDA officials remarked that although the naturally sourced drug product has some degree of batch-to-batch variability and its active ingredient has not been fully characterized, "sameness" can be demonstrated by comparing five specific molecular criteria.

"Before approving generic enoxaparin sodium injection, we expected, among other things, a series of sophisticated analytical tests and a study in healthy volunteers to ensure that the drug would be as safe and effective as the brand name product," said Dr Keith Webber, deputy director of the FDA's Office of Pharmaceutical Science, in an agency news release.

According to Sanofi-Aventis, however, these data are not sufficient to garner approval for generic enoxaparin; head-to-head clinical trials with the reference drug should be required as part of an NDA.

Thus far, Sanofi-Aventis has not succeeded in halting sales of generic enoxaparin.

In a status conference held by the US District Court for the District of Columbia on July 26, 2010, the Hon Emmet G Sullivan denied the company's request for a restraining order to stop sales of the product, which began shipping immediately on approval. A hearing to consider a preliminary injunction has been scheduled for August 17, 2010, Momenta officials said in a news release.

This is only the latest chapter in Sanofi-Aventis's attempts to block a generic enoxaparin competitor. In 2007, a district court ruled that the Lovenox patents were unenforceable, a decision upheld the following year. Last year, a key Lovenox patent was voided after the US Supreme Court ruled that the company had misled the US Patent and Trademark Office.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.