Chief Judge Leonard Stark of the U.S. District Court for the District of Delaware. Photo: Jason Doiy/ALM

U.S. District Judge Leonard Stark has turned down Amgen's bid to enjoin Cipla Ltd. from selling a generic version of Amgen's $1.3 billion a year calcium and thyroid medication, Sensipar.

Cipla's claim that Amgen Inc. and Teva Pharmaceuticals USA Inc. engaged in a “fraudulent scheme” to restrain competition is “far from proven,” Stark ruled in a 37-page opinion made public last Friday. But he did find that a settlement Amgen previously struck with Cipla now permits Cipla to launch generic cinacalcet—albeit at risk of infringing Amgen's 9,375,405 patent.

“Based on the record evidence, it seems plausible that Amgen and Teva may have colluded to divide up the market for cinacalcet, in order to share supracompetitive profits and deter true generic competition,” Stark wrote in Cipla v Amgen. “This collusion, if proven, could be an antitrust violation under a rule of reason analysis.

“However,” he added, “it also seems plausible that Amgen and Teva may have reasonably assessed the risks each faced on appeal (and otherwise) and reached a rational compromise of their patent disputes. If this is what the evidence ultimately shows, then Cipla will fail to prove patent misuse.”

Cipla and Amgen had settled previous litigation over cinacalcet, with Cipla conceding infringement in exchange for the opportunity to begin marketing its product a few months before the 2021 expiration of Amgen's patent.

Their agreement permitted Cipla to launch earlier if other generic makers entered the field—specifically, “if [i] any Third Party that has made an At Risk Launch of a Generic Cinacalcet Product … is found not to have infringed one or more valid and enforceable claims of the '405 patent or [ii] has not ceased or agreed to cease selling” such product.

Subsequently, U.S. District Judge Mitchell Goldberg found that Teva's cinacalcet product did not infringe, and Teva shipped 400,000 bottles of it to wholesalers. But Teva suddenly changed course a few days later, agreeing with Amgen to stop selling the drug, paying Amgen $40 million, and asking Goldberg if he'd be willing to vacate his ruling.

Cipla is represented by a Farnan team led by former U.S. District Judge Sue Robinson and by Hughes Hubbard & Reed attorneys led by partner James Dabney. They allege that the Teva-Amgen settlement was a hoax—that while Teva discontinued direct sales into the market, it continued to move product indirectly through wholesalers and pharmacies. Amgen and Teva “colluded with one another” while “misleading Cipla, regulators, courts, competitors, and the public,” they contend.

Stark described the allegations as “extravagant” and “far from proven.” But he turned away Amgen's motion for a preliminary injunction, finding that Amgen and Teva's conduct likely meets the conditions described in the license agreement that allow Cipla to launch, though it could still be found at trial to infringe.

Teva has been “not found to have infringed” Amgen's '405 patent. Nothing in the licensing clause required Goldberg's decision to be final on appeal, Stark wrote. And “while it may be that Teva has, in fact, ceased and/or agreed to have ceased selling its generic product, the record is not sufficiently clear, and at this stage doubts must be resolved against Amgen,” Stark concluded.

Amgen is represented by Morris, Nichols, Arsht & Tunnell and Gibson, Dunn & Crutcher. An email seeking comment from Gibson Dunn partner M. Sean Royall was not immediately returned Monday evening.