Drug price wars 'drive value': Medical exec

Express Scripts has taken heat for its deal to exclusively provide AbbVie's hepatitis C drug on its largest formulary plan, shutting out competitors like Gilead Sciences. The December move partly forced Gilead's hand in discounting its hepatitis C offering by about 46 percent.

As the benefit manager negotiates for 85 million people, pharmaceutical companies "can no longer afford being left out" of plans controlled by Express Scripts and other companies, Dr. Steve Miller, chief medical officer at Express Scripts, said on Friday.

"It gives pharmacy benefit managers like Express Scripts the opportunity to pit these drugs against each other and try to get better value for our patients and our clients," Miller said in an interview on CNBC's "Closing Bell."

Hepatitis C sufferers and supporters hold placards during a demonstration outside of US laboratory Gilead Sciences office in Madrid on February 5, 2015.
Javier Soriano | AFP | Getty Images
Hepatitis C sufferers and supporters hold placards during a demonstration outside of US laboratory Gilead Sciences office in Madrid on February 5, 2015.

Gilead shares slid after it announced the expected price cut in its Wednesday earnings call. The stock continued to shed value, dropping about 2.5 percent in Friday trading.

Read MorePricing war heats up over hepatitis C drugs

While they may scare investors and threaten pharmaceutical margins, price cuts are fundamentally better for consumers, Miller argued.

"We like to have the most choice for patients. Clearly what we'd really like is good pricing from all the products," he said.

Read MoreMap: Where California's unvaccinated people live

He noted that Express Scripts has made exclusive deals in the past, though others never got as much attention. Pitting companies against each other "drives value," Miller added.

Gilead declined to comment on its hepatitis C pricing.