Spending on prescription medicines in the United States will increase 4-7 percent through 2021, reaching $580 billion to $610 billion, according to a report released by QuintilesIMS Holding that lowered its prior long-term forecast.

QuintilesIMS, which compiles data for the pharmaceutical industry, had previously forecast average spending growth of 6-9 percent through 2021. It reduced its projections due to fewer new medicines approved in 2016 than prior years and as drugmakers face increasing pricing pressure and competition.

Taking likely manufacturer discounts and rebates into account, spending would grow 2-5 percent to $375 billion to $405 billion in 2021, as net price increases for patent-protected branded drugs slows, the report said.

Under pressure from politicians and insurers over the cost of many branded medicines, several drugmakers have pledged to limit annual price hikes to under 10 percent.

“We’re forecasting moderation in pricing reflecting what … we expect will be a continuing