After a big 2015, Regeneron predicts slowing 2016 sales for launch superstar Eylea

Last month, Regeneron ($REGN) announced 2015 Eylea sales that had investors excited. But that didn't soften the blow on Tuesday, when it warned that the med's growth in the U.S. would slow down.

The company forecasts 20% expansion for the blockbuster med in the U.S. this year--less than half of what it saw in 2015, when sales grew 54% to hit $2.68 billion. Regeneron markets the drug in the states and collects a share from international partner Bayer.

That 20% is "roughly in line" with consensus sales growth estimates of about 19% to 21%, according to Evercore ISI analyst Mark Schoenebaum. But shareholders--used to a breakneck pace from the eye therapy, which trounced sales estimate after sales estimate following its U.S. launch in late 2011--sent the company's stock price downward on the news.

As execs reminded investors on the company's conference call, though, the therapy is in its fifth year of launch. Taking that into account, it's a "pretty big deal" to still be expecting a yearly 20% leap, they noted. Plus, Eylea's market share is still ahead of its competitors'; in patients with diabetic macular edema, its slice of the pie is roughly double that of Roche's ($RHHBY) Lucentis and cancer med Avastin, which is frequently used off-label in the eye.

And of course, following the launch of PCSK9 therapy Praluent, a treatment it shares with Sanofi ($SNY), Regeneron is no longer a one-trick pony. But the cholesterol-fighter generated just $7 million in Q4 end-user sales for the Tarrytown, NY-based company, missing the $17.8 million mark analysts expected to see.

As Regeneron's commercial EVP, Bob Terifay, explained on a conference call, that $7 million tally "understates patient and physician demand." Formulary and reimbursement decisions are coming along, and in the meantime, the company is offering the product for free to certain patients--including many on Medicare Part D plans.

While the company is still "actively engaged" in discussions with payers, it feels good about where things stand right now. Praluent has been up against rival Repatha from Amgen ($AMGN), and it's fared particularly well among Medicare Part D patients; 80% of those patients have a single PCSK9 med in an exclusive or preferred position, and for 95% of them, that med is Praluent.

Amgen, though, has done plenty well for its part, too. After PBM leader Express Scripts ($ESRX) announced it would cover both meds, CVS Health ($CVS)--the No. 2 heavyweight--struck and exclusive deal with the California biotech.

- read Regeneron's release

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