But as they entered their teenage years in suburban Virginia, they found the advice increasingly hard to follow. The device they carried to inject the medicine, known as an EpiPen, was shaped like a large felt-tip marker and they would frequently forget it. As the twins entered college, they found themselves thinking there had to be a better way.
This week, the brothers’ invention — a slimmer device shaped like a smartphone — hit pharmacy shelves nationwide, the culmination of a single-minded quest that began 15 years ago and ended in a $230 million licensing deal with the French pharmaceutical giant Sanofi.
The product, called the Auvi-Q, boldly challenges the superiority of the EpiPen at a time when food allergies among children and teenagers are on the rise. Sanofi and the Edwards brothers clearly hope it will appeal to a gadget-hungry generation with its compact, rectangular design and automated voice instructions that guide a user through the injection process. Both the Auvi-Q and EpiPen contain the drug epinephrine, which can halt a severe allergic reaction, known as anaphylaxis.
Evan Edwards said the device was special because it was designed by people who were intimately familiar with patients’ needs. “This wasn’t just an invention,” he said. “This was something that I knew I was going to carry with me every single day.”
Mylan Inc., which sells the EpiPen, has recently stepped up its marketing of the device and this week showed no signs of backing down. In an interview this week, Mylan’s chief executive took issue with claims that up to two-thirds of EpiPen users do not carry their devices, saying the company would take “appropriate action” to challenge the claims.
Heather Bresch, the chief executive, said she welcomed efforts by Sanofi to raise awareness about the dangers of severe allergic reactions. “However, we certainly don’t condone or find it acceptable to do it in a misleading way, and that’s what we believe they’re doing,” she said.
A spokeswoman for Sanofi said the company stood by its claims.
Energized by their idea to create a new epinephrine device, the twins split up to attend college but geared their studies to their single-minded goal. Evan chose engineering, studying at the University of Virginia. Eric pursued a medical path, eventually earning a doctorate in pharmaceutical sciences from Virginia Commonwealth University.
“We would choose our courses out of the undergraduate bulletin,” Eric said. “You take this; I’ll take that.”
One of the courses Evan chose was an invention and design class taught by Larry G. Richards, an engineering professor at the University of Virginia, where students were encouraged to share their ideas with each other. “Evan came to us early in the semester and said, ‘I’ve got this really great idea,’ ” Mr. Richards recalled. “He told us the idea and I said, ‘Evan, this is too good to share with the students in the class. You want to protect your intellectual property here.’ ”
Working with Mr. Richards and another professor, Evan continued to refine the idea, earning a grant for college inventors that provided initial start-up financing for their project. After college, the brothers founded a company, Intelliject, to bring their idea to market, relying on early investments from family and friends.
The product evolved as the years passed, retaining its rectangular profile but picking up other features along the way. Eric had the idea of adding voice instructions to help others use the device in situations where they might be too panicked to read written instructions. A retractable needle was also added later, with the thought that patients would be more comfortable if they didn’t have to see it.
Intelliject licensed the product to Sanofi in 2009, a deal that included an initial payment of $25 million and up to $205 million in future milestone payments and royalties. The Food and Drug Administration approved the Auvi-Q last summer.
The Auvi-Q has created a stir among allergy sufferers, including bloggers and others who have praised its compact design and “cool” factor. Sanofi also cited internal market surveys that show up to two-thirds of patients do not regularly carry their epinephrine injectors, and about half of parents said they feared others would not be able to properly use their child’s injector in the event of an emergency.
“Anaphylaxis is scary enough,” Evan Edwards said, referring to the severe reaction that can be set off by allergens. “But the treatment shouldn’t be.”
Ms. Bresch, the Mylan chief executive, noted that Sanofi did not provide studies showing users would be any more likely to carry the Auvi-Q. She also cited a marketing study conducted in Canada on Sanofi’s behalf that found 84 percent of participants knew how to use an auto-injector.
“EpiPen has been tried and true for 25 years,” Ms. Bresch said, and argued that her product’s distinctive shape worked to its advantage. “It’s not easily confused with a BlackBerry or your phone in your purse or your backpack.”
Other online commenters wondered if younger children might lose the Auvi-Q because of its size. It is smaller than a deck of cards.
Sanofi has set a price for the Auvi-Q that is comparable to the EpiPen, charging $240 for two auto-injectors and a training device. Lori Lukus, a Sanofi spokeswoman, said the company’s market research indicated that a “large percentage” of insurers would cover the product.
Still, the Auvi-Q faces long odds: several other companies have tried and failed to challenge the dominance of the EpiPen. Last year, the manufacturer of the only competing products on the market, the Adrenaclick and Twinject, announced it would stop making them.
One allergy specialist, Dr. Scott H. Sicherer, said the Auvi-Q could provide an alternative for patients who have complained over the years about the EpiPen’s bulky size. He said some have already asked about it.
“People might find it easier to have that in a pocket compared to carrying a giant Magic Marker,” said Dr. Sicherer, a researcher at the Jaffe Food Allergy Institute at Mount Sinai Medical Center in Manhattan.
Still, he noted that he had seen several EpiPen competitors come and go. In the past, when he presented patients with alternatives, “the patients have mostly been more comfortable taking the EpiPen.”
This article has been revised to reflect the following correction:
Correction: February 1, 2013
An earlier version of this article used an outdated company name on first reference. It is Sanofi, not Sanofi-Aventis. The company changed its name in 2011.