(Adds Amgen and analyst comment, in paragraphs 6-7)
Aug 1 (Reuters) - Express Scripts Holding Co, the largest U.S. pharmacy benefit manager, said on Friday it will remove an additional 25 products from its list of preferred drugs in 2015, including anemia drugs Epogen and Aranesp, sold by Amgen Inc.
But it will still cover Procrit, a similar anemia drug sold by Johnson & Johnson, on the list, known as a formulary.
"The products we have chosen to exclude from our formulary are those that cost significantly more than other available options but that fail to provide additional health benefit," the company said in an emailed statement.
Express Scripts, which like other pharmacy benefit managers administers prescription drug benefits for employers and health plans, said patients who fill a prescription for an excluded drug will pay the full retail price.
Epogen and second-generation drug Aranesp have been hugely profitable for Amgen. Their use has waned in recent years due to safety concerns, including increased risk of heart problems, but they still generated U.S. sales of $2.7 billion last year.
Amgen, in an emailed statement, said it does not contract for Epogen in the retail sector, and use of Aranesp in the retail setting is significantly less than in hospitals or clinics.
RBC Capital Markets analyst Michael Yee estimated that Amgen's anemia drug sales through Express Scripts account for less than 1 percent of U.S. sales.
Amgen contracts directly to supply Epogen to kidney dialysis providers DaVita Healthcare Partners Inc and Fresenius Medical Care AG. Aranesp, like Procrit, is used to treat anemia in cancer patients and chronic kidney disease patients who are not undergoing dialysis.
All three are bioengineered forms of a human protein that stimulates production of red blood cells.
Express Scripts has been a vocal critic of rising prescription drug prices. For 2014, it excluded coverage of certain specialty drugs from five therapeutic categories, including multiple sclerosis. It has also criticized the $84,000 cost of Sovaldi, the hepatitis C treatment introduced in December by Gilead Sciences Inc.
For 2015, Express Scripts said, it will no longer cover Incivek, an older hepatitis C drug sold by Vertex Pharmaceuticals Inc, and plans to make a determination on Sovaldi "once clinically equivalent competitors" are approved by regulators in coming months.
Other drugs excluded next year are a testosterone gel and extended release Zohydro, a long-acting opioid painkiller sold by Zogenix Inc.
"Of the more than 4,000 drugs available to patients, only 66 will be excluded from our 2015 formulary," the company said.
Express Scripts said it knows that there are rare instances when a patient may require one of the excluded drugs, and it has a process for physicians to pursue in those cases.
The company, which has nearly 25 million people on its preferred formulary, can drive enormous revenue toward drugmakers whose products it selects.
(Reporting by Deena Beasley; Editing by Jonathan Oatis and Leslie Adler)