(Reuters) — Express Scripts Holding Corp., the largest U.S. pharmacy benefit manager, said on Friday that it would exclude about 20 new medications in 2016 from insurance coverage, including two diabetes drugs and a weight loss drug.

For the past several years, Express Scripts has been excluding medicines from its coverage list, a reflection of concern about cost to its health insurers and corporate customers, it says. The 2016 list includes 80 drugs or medical items.

Express Scripts said it can negotiate lower drug prices when it excludes drugs from its coverage list, which determines whether tens of millions of people with private insurance can easily use an insurance co-pay to buy their medicine.

One of the drugs Express Scripts is excluding for 2016 is AstraZeneca P.L.C. diabetes treatment Onglyza, which had sales of $391 million in the first half of 2015. AstraZeneca was not immediately available for comment.

It also said it would exclude Qysmia, a weight loss drug made by Vivus Inc. Vivus has struggled to gain insurer reimbursement for the drug and on Thursday said it would cut about 60 jobs as part of a restructuring. Company representatives were not immediately available for comment.

The 2016 formulary continues to exclude Gilead Sciences Corp.'s pricey hepatitis C treatments Harvoni and Sovaldi in favor of its nearest competitor, AbbVie Inc.'s Viekera Pak. Sovaldi set off the debate about expensive drugs in 2014 with its $1,000-per-pill regimen.

Express Scripts said earlier this week that it would cover the industry's latest pricey and innovative new drug, Regeneron Pharmaceutical Inc.'s and Sanofi S.A.'s Praluent to treat high cholesterol. Later this year, once a competing drug from Amgen Inc. is approved, its pharmacy committee will review if it will add both drugs to its formulary.

Express Scripts added back about 10 drugs that had been cut from the list in 2015, saying it negotiated better prices with their manufacturers. It said that in 2016, the cuts will save its customers $1.3 billion, up from the $1.05 billion it estimates in savings for 2015. There are about 4,000 drugs on the market, it said.