ARS is working to get the product onto the ordinary "formularies," or lists of drugs covered without special prior authorization procedures, at big pharmacy benefit managers like Cigna's Express Scripts, UnitedHealth's Optum Rx and CVS Health's Caremark. The company expects to have the product on formularies for about 80% of health plan enrollees by July.

For now, while ARS is still getting Neffy onto formularies, it's using coupons to overcome patient resistance to high out-of-pocket costs, according to Eric Karas, the chief commercial officer at ARS.

"Most commercial patients only pay $25 for each prescription, which is lower than the average co-pay of $40 for a generic auto-injector," Karas said Friday during a conference call ARS held with securities analysts. "Our co-pay support is automatically applied at the point of sale, ensuring that Neffy is accessible to more patients."

"You go into the pharmacy, and they just say, your copay is $25, and you walk away happy," said Richard Lowenthal, the chief executive officer at ARS. "We're trying to make that as seamless as possible for the vast majority of the population as quickly as possible."

ARS is also posting a scorecard on its website that shows which plans are covering Neffy.

"There's two purposes of this," Lowenthal said. "One is that I want I want the patients to know they're covered. And the doctors. The scorecard is also being shared by our sales force with the doctors. But I also want them to know who's not covering Neffy. Because, if your insurer is not covering it, and you see this whole list of insurers that are, you go and call up your insurer and say, 'Hey, why are you guys not covering this, and all these other insurers are covering it?'" We think that puts a lot of pressure on insurance companies to cover it more quickly."

What it means: For employers and benefits advisors, the Neffy rollout shows how much small differences in out-of-pocket costs and prescription coverage lists affect which prescription drugs or other treatments health plan participants end up using.

The backdrop: U.S. consumers now spend about $3 billion on epinephrine per year, and 6.5 million patients have received prescriptions for epinephrine in the last three years, according to Richard Lowenthal, the chief executive officer of ARS.

Drug manufacturers could increase sales to more than $10 billion per year if they could reach the 17 million people with severe allergies who rarely or never fill EpiPen prescriptions, Lowenthal said.

For a product like Neffy, getting on plans' unrestricted formularies, without prior authorization requirements, is critical, Lowenthal said.

Many allergists are willing to take the time to go through a prior authorization process for Neffy, but pediatricians and general practitioners are not, he said.

If Neffy really increases epinephrine spending by $7 billion per year, that would average more than $20 in extra prescription spending per year insured American.

Courting GPOs and PBMs: Pharmacy benefit managers help manage employers and insurers provide prescription benefits, and group purchasing organizations help plans join to buy the drugs.

Deals with three GPOs — Ascent, MSR and Zinc — are on track to make Neffy available to 80% of health plan enrollees without restrictions by July 1, Lowenthal said.