Eli Lilly will cut prices for some older insulins later this year and immediately expand a cap on costs insured patients pay to fill prescriptions.

The moves announced Wednesday promise critical relief to some people with diabetes who can face annual costs of more than $1,000 for insulin they need in order to live. Lilly’s changes also come as lawmakers and patient advocates pressure drugmakers to do something about soaring prices.

Lilly said it will cut the list price for its most commonly prescribed insulin, Humalog, and for another insulin, Humulin, by 70% in the fourth quarter, which starts in September. The drugmaker didn’t detail what the new prices would be.

List prices are what a drugmaker initially sets for a product and what people who have no insurance or plans with high deductibles are sometimes stuck paying.

Patient advocates have long called for insulin price cuts to help uninsured people who would not be affected by price caps tied to insurance coverage.

Lilly’s planned cuts “could actually provide some substantial rice relief,” said Stacie Dusetzina, a health policy professor at Vanderbilt University who studies drug costs.

She noted that the moves likely won’t affect Lilly much financially because the insulins are older and some already face competition.

“It makes it easier for Lilly to go ahead and make these changes,” she said.

Lilly also said Wednesday that it will cut the price of its authorized generic version of Humalog to $25 a vial starting in May. The company also is launching in April a biosimilar insulin to compete with Sanofi’s Lantus.

Lilly CEO David Ricks said in a statement that it will take time for insurers and the pharmacy system to implement its price cuts, so the drugmaker will immediately cap monthly out-of-pocket costs at $35 for people who are not covered by Medicare’s prescription drug program.

That cap applies to people with commercial coverage. Lilly said people without insurance can find savings cards to receive insulin for the same amount at its InsulinAffordability.com website.

The federal government in January started applying that cap to patients with coverage through its Medicare program for people age 65 and older.

Insulin is made by the pancreas and used by the body to convert food into energy. People who have diabetes don’t produce enough insulin.

People with Type 1 diabetes must take insulin every day to survive. More than 8 million Americans use insulin, according to the American Diabetes Association. Research has shown that prices for insulin have more than tripled in the last two decades, and pressure is growing on drugmakers to slow the increases.

The state of California has said it plans to explore making its own cheaper insulin. Drugmakers also may face competition from companies like the nonprofit Civica, which plans to produce three insulins at a recommended price of no more than $30 a vial, a spokeswoman said.

Drugmakers may be seeing “the writing on the wall that high prices can’t persist forever,” said Larry Levitt, an executive vice president with the nonprofit Kaiser Family Foundation, which studies health care.

“Lilly is trying to get out ahead of the issue and look to the public like the good guy,” Levitt said.

Indianapolis-based Eli Lilly and Co. became the first company to commercialize insulin in 1923, two years after University of Toronto scientists discovered it. The drugmaker then built its reputation around producing insulin even as it branched into cancer treatments, antipsychotics and other drugs.

Humulin and Humalog and its authorized generic brought in a total of more than $3 billion in revenue for Lilly last year. They rang up more than $3.5 billion the year before that.

“These are treatments that have had a really long and successful life and should be less costly to patients,” Dusetzina said.