Momenta Battle Over Amphastar Generic Continues

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By Dana A. Elfin

There’s no end in sight to the long-running patent dispute between Momenta Pharmaceuticals, Sandoz Inc. and Amphastar Pharmaceuticals over Amphastar’s sales of a rival generic version of the blood thinner Lovenox ( Momenta Pharms., Inc. v. Amphastar Pharms., Inc. , 2017 BL 206311, D. Mass., No. 11-11681-NMG, 6/16/17 ).

The suit will continue because Judge Nathaniel M. Gorton of the U.S. District Court for the District of Massachusetts rejected the parties’ requests to rule on invalidity, noninfringement and patent defense issues in a June 16 opinion.

The generic companies have been battling over competing generic versions of Lovenox (enoxaparin sodium) for nearly six years even as revenues from generic enoxaparin products have been declining due to a highly competitive and saturated market. But, financially, the prolonged litigation may be worth it for Momenta and Sandoz because they could be awarded significant monetary damages if they ultimately prevail in their infringement suit.

Patent Damages

Under the patent statute, damages must be “adequate to compensate for the infringement.” Lost profits and price erosion are among the considerations used in assessing damages. If Momenta and Sandoz prevail in this case, those factors could be significant ones because of how market forces have played out for generic Lovenox.

Amphastar started marketing its generic in January 2012, and it is the company’s largest product by net revenues, according to Amphastar’s 2016 annual 10-K report filed with the Securities and Exchange Commission.

Although Amphastar’s generic Lovenox product is its biggest revenue driver, those product revenues have been on the decline. In 2014, Amphastar netted $107.5 million from generic Lovenox sales, but that number fell to $84.5 million in 2015, and declined further to $59.3 million in 2016, the company said.

Momenta’s sales of its generic Lovenox product have also been declining and aren’t expected to contribute significantly to the company’s bottom line, according to Bloomberg Intelligence analyst Elizabeth Krutoholow.

Momenta First

In 2009, U.S. sales of Sanofi’s brand-name Lovenox, then the top-selling hospital medicine in the U.S., were $2.7 billion.

Momenta’s generic was the first generic version of the top-selling Sanofi anticoagulant on the market. Partnering with Sandoz, the generics arm of pharmaceutical giant Novartis SA, Momenta introduced the generic in July 2010.

Since then, many more players have entered the generic enoxaparin market. Increased competition has dragged down product prices and sales, Krutoholow told Bloomberg BNA in a June 20 email.

Saturated Market

In addition to the Momenta and Amphastar generics, Israeli company Teva Pharmaceuticals Industries Ltd. also markets a generic version of enoxaparin.

Sanofi also markets an authorized generic enoxaparin product through its subsidiary, Winthrop, and through Fresenius Kabi USA. Authorized generics are generic drug products introduced by branded companies, either directly or through partnering arrangements with other generic companies.

Momenta and Sandoz brought the current patent infringement suit against Amphastar two days after the FDA approved Amphastar’s generic in 2011.

The infringement suit claims Amphastar’s product infringes Momenta’s U.S. Patent No. 7,575,886 (the ‘886 patent), which covers manufacturing quality control processes for producing batches of generic enoxaparin.

Judge Won’t Rule Now

Amphastar asked Gorton to find Momenta’s patent invalid because the four manufacturing steps claimed in the patent didn’t qualify as patentable subject matter. But Gorton refused to issue definitive rulings on the issues at this stage of the litigation.

“Viewing the facts in the light most favorable to Momenta, it persuasively contends that the ‘886 patent '[is] directed to a new and useful method’ of ensuring the quality of enoxaparin and thus Amphastar’s motion for summary judgment on the basis of patent-ineligibility will be denied,” he wrote.

Similarly, he declined to find the ‘886 patent invalid for indefiniteness or to find Amphastar’s generic didn’t infringe the patent.

Patent Defenses to Jury

Gorton also declined to rule on Amphastar’s waiver and estoppel defenses to patent infringement because disputed fact issues remained on those defenses. The court also declined Momenta’s alternative request to hold a hearing on Amphastar’s patent defenses rather than having a jury consider them.

“This Court agrees that there is significant overlap between the evidence of infringement, validity and damages on the one hand, and the equitable defenses on the other hand,” he wrote. “Courts have availed themselves of advisory jury verdicts on equitable defenses when such evidence overlaps with jury questions.”

Accordingly, Gorton said he would submit the patent defenses to the jury for an advisory verdict.

Lovenox is used to prevent deep vein thrombosis (DVT), a potentially deadly blood clotting condition. Approved for use in 1993, Lovenox is made from heparin, a blood-thinning drug whose active ingredient is a naturally derived complex mixture of sugar molecules.

Momenta’s headquarters is in Cambridge, Mass. Sandoz is based in Princeton, N.J.

Amphastar is based in Rancho Cucamonga, Calif. International Medication Systems Ltd. (IMS), a wholly owned manufacturing subsidiary of Amphastar, also is a named defendant in the suit.

Choate, Hall & Stewart LLP, in Boston, represents Momenta.

Morrison & Foerster LLP in San Diego, Palo Alto, Calif., and Washington; Donnelly, Conroy & Gelhaar LLP in Boston and Choate, Hall & Stewart LLP, in Boston, represent Sandoz.

Wilson Sonsini Goodrich & Rosati in San Diego, Palo Alto, Calif., Austin, Texas and New York, King & Spalding LLP in Washington; Akin Gump Strauss Hauer & Feld LLP in Washington; Michelman and Robinson LLP in Irvine, Calif., and Rose, Chinitz & Rose in Boston represent Amphastar.

To contact the reporter on this story: Dana A. Elfin in Washington at

To contact the editor responsible for this story: Brian Broderick at

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