Amgen nabs Onyx for $10.4B. What's next for Kyprolis?

So, Amgen ($AMGN) has wrapped up its deal for Onyx Pharmaceuticals ($ONXX), at a $125-per-share, $10.4 billion price. Now what? Let's look at the fate of Kyprolis, the multiple myeloma drug central to the deal. As goes Kyprolis, in a way, so does the rest of Onyx's operations.

Launched last summer, Kyprolis brought in $64 million by year's end, and by the end of the second quarter this year, it racked up another $125 million. It's expected to hit $2 billion to $2.4 billion in sales by 2019, analysts figure; some think it will peak at $3 billion. That's a nice chunk of change for Amgen, whose biggest-selling drugs are threatened by new competition from biosimilars.

But that success depends on a few things: one, a successful launch in Europe, and two, expanding Kyprolis to a broader market. Right now, Kyprolis is approved as a third-line treatment, a sort of last-ditch effort for myeloma patients who've failed on two previous regimens. Data from a trial in second-line patients was reportedly a sticking point as sale negotiations neared an end; whether that data led Onyx to agree to a $125-per-share price, rather than the rumored $130, isn't clear.

The third thing? Its ability to compete with Celgene's ($CELG) new drug Pomalyst. During the second-quarter earnings call, EVP Helen Torley talked up Kyprolis demand, saying that some doctors were opting to use Kyprolis rather than retreating with older drugs, including Celgene's Revlimid, pushing its share of the third-line treatment market to 40%. One of the reasons for that is that Onyx was able to get Kyprolis into 300 more clinics and hospitals during the quarter, growing the user base to 2,400-plus facilities. But Pomalyst was just launched in February. As Celgene, a myeloma heavyweight, promotes its new baby, the battle for market share will intensify.

When Amgen takes over, does the user base mushroom--and demand along with it? Does Amgen's sales prowess give Kyprolis an edge over Pomalyst?

Amgen CEO Robert Bradway figures his company can help drive Kyprolis forward. Though the company sells only one  cancer-fighting treatment, Vectibix, it markets a variety of drugs that either combat cancer's side effects or support patients through treatment--including the anemia fighters Aranesp and Epogen and white-blood-cell stimulators Neupogen and Neulasta. So, it has a big sales and distribution network in the U.S. and, importantly, in Europe.

"Amgen has a unique opportunity to add value to Kyprolis, a product which is at an early and promising stage of its launch," Bradway said in a statement about the deal.

But Bradway wasn't just talking about marketing. Amgen has a long history of running clinical trials, and so the ongoing Kyprolis trials--in second-line and first-line patients, in combination with other drugs and as a monotherapy--could benefit from its expertise. Plus, it's adept on the regulatory side, so it could help usher Kyprolis onto the European market 

All of this begs a big question: staffing. With Amgen adding its sales-and-marketing heft, regulatory expertise and R&D assistance to the mix, where does that leave Onyx's executive team and rank-and-file? Do CEO Tony Coles and other execs bow out? Coles certainly has an incentive to do so, given the $25 million or so he'd be owed, in cash and vested options and stock awards. Does Amgen cut a bunch of Onyx jobs? No doubt there's opportunity, with duplication in admin, sales, even R&D.

- see the release from Onyx

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Editor's Note: This story was updated to add Amgen's cancer treatment Vectibix. Additional details about its other oncology drugs were also inserted.