Amgen Sues FDA for Extra Six Months on Sensipar

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By Dana A. Elfin

Amgen Inc. accused the FDA of wrongfully refusing to award it an extra six months of market exclusivity for testing its kidney disease drug Sensipar in children, the company said ( Amgen, Inc. v. Price , D.D.C., No. 17-cv-01006, complaint filed 5/25/17 ).

The Food and Drug Administration‘s denial of pediatric exclusivity for Sensipar is arbitrary and conflicts with the statutory language governing pediatric exclusivity awards, according to a complaint the Thousand Oaks, Calif.-based company filed May 25 in the U.S. District Court for the District of Columbia.

Once Sensipar’s patent protection and any associated exclusivity grants run out, the FDA is free to approve generic competitors. Because Sensipar (cinacalcet hydrochloride tablets), a drug used to treat chronic kidney disease in adults undergoing dialysis, brought in nearly $1.6 billion for the company in 2016, Amgen is eager to protect the lucrative franchise from generic competition.

Pediatric exclusivity awards an extra six months of market exclusivity in return for testing drugs in children.

Time Is Running Out

The timing for the FDA to reconsider its pediatric exclusivity denial is critical for Amgen. The company will lose any rights to pediatric exclusivity if the FDA doesn’t grant exclusivity to Sensipar by June 8, Amgen said.

Under the statute, the Best Pharmaceuticals for Children Act, 21 USC 355a, pediatric exclusivity must be awarded to a drug no later than nine months before that drug is set to lose its patent protection. Sensipar is set to lose patent protection March 8, 2018.

The FDA informed Amgen of its decision to deny it pediatric exclusivity in a May 22 letter, the complaint said. The FDA wrongly based its denial on its conclusion that Amgen’s clinical studies were insufficient to support a pediatric labeling indication, it said.

"[T]he statute contemplates no such showing of safety,” Amgen said in its complaint. "[I]t only requires that the studies ‘fairly respond’ to the [FDA’s] Written Request.”

FDA Requested Studies in 2010

The FDA issued a written request for Amgen to conduct pediatric studies on Sensipar in 2010 to determine if the drug was effective and could be used safely in children.

Amgen undertook three studies. Amgen’s clinical studies were troubled by safety issues and a smaller than expected number of participants.

Because Amgen “fairly responded” to the written request, “FDA’s refusal to accept the study reports and its denial of pediatric exclusivity violate the plain language of the statute and the agency’s previous treatment of similarly-situated entities,” the complaint said.

Pediatric Subject Died

After a 14-year-old participant died during the second of Amgen’s pediatric clinical trials of Sensipar in February 2013, the FDA suspended the trials for 14 months. Despite Amgen’s subsequent recommendation that the pediatric program be halted, the FDA disagreed and recommended Amgen continue the program, culminating in the agency’s denial of pediatric exclusivity.

The court has scheduled a June 2 hearing on Amgen’s motion for a temporary restraining order and preliminary injunction. The case is before Judge Randolph D. Moss.The law firm of Hogan Lovells US LLP in Washington filed the complaint on behalf of Amgen.

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

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

For More Information

The complaint is at

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