The formularies are here! Brace yourselves for the 48 new exclusions

It started in 2011 with just a handful of drugs. CVS Caremark ($CVS) chucked 34 meds off its formulary, partly in a snit over copay coupons, partly just to see what would happen. It was a pilot program, the pharmacy benefits manager (PBM) said. It made a few headlines, but unless you were a patient who had to switch meds or a brand manager with a product kicked off the team, the headlines passed by with not much note.

Now, CVS' excluded list comprises almost 100 drugs and related products. Express Scripts ($ESRX) has added its own 66 exclusions to the mix. The changes aren't just noted. They're analyzed. They have the power to move markets. Just look at what's happened in the past few days.

Companies with drugs newly barred from the PBMs' doors see their stock prices drop--just ask Horizon Pharma ($HZNP), whose combo painkillers Duexis and Vimovo got the boot from Express Scripts last week. Luckier drugmakers with reinstated products--such as GlaxoSmithKline ($GSK) and its Advair respiratory med--feel the boost.

Welcome to the new era of U.S. formulary management, where drugmakers have to wheel and deal like never before to keep a place. Glaxo got Advair back into Express Scripts' graces by offering discounts--fairly hefty discounts, we're told. Glaxo's price breaks also persuaded CVS to nix Advair competitor Symbicort, which had spent the past 6 months using formulary status to steal market share.

Some other notable moves, this time in diabetes: CVS decided against AstraZeneca's ($AZN) new diabetes fighter Farxiga and shoved its Byetta treatment out, too. The PBM already bars Onglyza and its sister drug Kombiglyze, so the new exclusions hamstring AstraZeneca's diabetes franchise with CVS patients. Or, as Leerink Partners analyst Seamus Fernandez put it, the changes are "a headwind for broader uptake of AZN's diabetes portfolio in 2015." CVS decided to bar Sanofi's ($SNY) fast-acting insulin Apridra, too.

Meanwhile, Express Scripts kept the ropes up against Novo Nordisk's ($NVO) Victoza and NovoLog, and Sanofi's Apidra, too. On the other hand, Eli Lilly's ($LLY) Humalog and AstraZeneca's Byetta and Bydureon won the PBM's blessing again, so they're good to go with CVS customers.

Express Scripts stiff-armed Vivus' ($VVUS) new erectile dysfunction drug Stendra, marketed by Auxilium Pharmaceuticals ($AUXL), putting another obstacle in the way of a treatment that has already spent more than a year on the shelf, waiting for a marketing partner. CVS nixed the Merck KGaA multiple sclerosis treatment Rebif. Express Scripts tossed off Amgen's ($AMGN) anemia drugs Epogen and Aranesp. CVS will stop covering the sleep drug Lunesta, which recently got generic competition.

Ironically enough, among the first round of CVS no-go drugs were Lilly's Humalog and a sister diabetes drug Humalin. At the time, Lilly told The Wall Street Journal that staying on the list wasn't worth it: "In light of the aggressive pricing required to win this business--and the fact that only a small percentage of Lilly's insulin franchise would be impacted by this change--we ultimately decided it did not make good business sense for Lilly to be included." These days? Not so much.

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