(Reuters) – Health insurer Cigna Corp on Wednesday launched a program aimed at ensuring some diabetes patients pay no more than $25 for a 30-day supply of insulin in the wake of heightened public scrutiny over soaring prices of the life-saving drug.

U.S. lawmakers have pulled up healthcare companies over rising costs of medicine, with powerful committees in Congress holding hearings in January on insulin affordability.

The annual cost of insulin for treating a type 1 diabetes patient in the United States nearly doubled to $5,705 in 2016 from $2,864 in 2012, according to a recent study.

The program will be for eligible people with diabetes in participating health plans, the company said.

Cigna, which bought pharmacy benefits manager Express Scripts last year, said it was partnering with insulin manufacturers to lower copayments to $25 at the point of sale.

For users of insulin plans managed by Cigna and Express Scripts, the average out-of-pocket cost for insulin was $41.50 for a 30-day supply in 2018, the company said.

Eli Lilly last month announced plans of selling a half-price version of its popular insulin injection, Humalog.