Amgen sued FDA for a 6-month reprieve from Sensipar generics—and lost

Amgen faces a potential loss of exclusivity for blockbuster Sensipar this year. (Amgen on Flickr)

Amgen has more than a billion dollars in annual sales riding on its ability to protect calcium reducer Sensipar from generic competition, but now its defenses have suffered a legal defeat. On Tuesday, a U.S. District Judge nixed Amgen's attempt to squeeze six extra months of exclusivity out of the FDA.

U.S. District Judge Randolph Moss ruled that the FDA acted reasonably when it decided not to grant Sesnipar pediatric exclusivity, which comes with six extra months of protection from copycat competition.

Amgen had argued the agency applied different standards to its Sensipar decision than it did in granting pediatric exclusivity to Johnson & Johnson's Ortho Tri-Cyclen. But Moss didn't buy that argument.

"Amgen has not met its burden of demonstrating that the FDA applied different standards," the judge wrote in a Tuesday opinion (PDF). "The Court, accordingly, is now satisfied that the FDA has offered a reasoned—and reasonable—basis for distinguishing the Ortho Tri-Cyclen precedent." 

Amgen said it would appeal and asked for an injunction blocking Sensipar copies until the appeals court can review the case, according to Bernstein analyst Ronny Gal. Sensipar's primary patent expires on March 8.

Free Daily Newsletter

Like this story? Subscribe to FiercePharma!

Biopharma is a fast-growing world where big ideas come along daily. Our subscribers rely on FiercePharma as their must-read source for the latest news, analysis and data on drugs and the companies that make them. Sign up today to get pharma news and updates delivered to your inbox and read on the go.
Amgen additionally has a 2026 formulation patent and has sued generic drugmakers for infringement. Gal noted, however, that generic competitors may be able to work around that patent.

Sensipar generated $1.7 billion last year, with $1.37 billion coming from the U.S. The drug first won FDA approval in 2004, and the FDA has already tentatively approved four copycats. 

Moving forward, Gal highlighted several "moving parts" with the Sensipar generic risk. First, he said, there's the question of the injunction, which could block generic launches until after the lawsuits play out. He also said Amgen might choose to settle with the would-be generics makers.  

When Sensipar's patent expires—and unless told otherwise—the FDA could convert tentative generic approvals into final nods, allowing those manufacturers to launch despite the outstanding patent fight. Such an "at-risk" launch would end in big penalties for the generics makers if Amgen later won the court battle. 

RELATED: Amgen sinks after Q4 earnings miss despite tax benefits and plan for U.S. plant

Amgen executives cited uncertainty around Sensipar's loss of exclusivity as a big reason for the billion-dollar gap between the low end and high end of the company's 2018 guidance. On the company's fourth-quarter conference call, commercial chief Tony Hooper said the 2018 "outlook for Sensipar is somewhat uncertain given the ongoing litigations." 

"It is of course conceivable that competitors maybe able to bring generic products to market at some point in 2018, although we believe we have strong litigation positions," he added.

Gal noted that consensus estimates call for $1.31 billion in Sensipar sales this year, down from more than $1.7 billion, "but there could be more downside if generic entry is less orderly."