Drugmaker Eli Lilly will begin offering a cheaper version of its top-selling insulin after facing increasing pressure from lawmakers and the public about the rising costs of prescription drugs, especially diabetes treatments, the company announced Monday.

Lilly will begin selling an "authorized generic" of Humalog 100, its top-selling insulin, for $137.35 per vial – a 50 percent decrease from its current list price of about $275 per vial, the company said in a statement. The product – called Insulin Lispro – will be available in pharmacies "as quickly as possible" and sold through ImClone Systems, a Lilly subsidiary, according to the company. It will be offered in vial and pen options.

As an authorized generic, the treatment will be identical to the brand-name product and will only differ by the label. The company will continue selling Humalog at its regular price to insurers and employers while it makes the cheaper version available to patients who pay out of pocket, meaning those without health coverage will benefit most from the offering.

The announcement comes as the skyrocketing cost of insulin and other life-saving drugs has been the focus of state- and federal-level debate, with lawmakers publicly criticizing high drug prices and people sharing their personal struggles affording necessary medicines. Committees in both congressional chambers have also started investigating pricing practices of major insulin makers.

Lilly's move garnered bipartisan support on Monday.

Democratic Rep. Diana DeGette of Colorado tweeted that she was "glad to see steps are being taken by some to reduce the cost of insulin, but we still have a long way to go to make it truly affordable for all," calling the increase in insulin pricing "unfathomable." And Sen. Chuck Grassley, R-Iowa, also welcomed the news in a tweet, but said it was only one piece of a puzzle and that "more needs to be done."

David Ricks, Lilly's chairman and chief executive officer, echoed those sentiments in a statement, saying: "While this change is a step in the right direction, all of us in the health care community must do more to fix the problem of high out-of-pocket costs for Americans living with chronic conditions."

Still, congressional investigations into drug pricing – including Lilly's – will continue, Democrat Sen. Ron Wyden of Oregon vowed in a Monday tweet.

"There will be a lot of PR acrobatics about generic insulin," Wyden wrote. "I'm not going to stop investigating how [Eli Lilly] and other insulin makers keep raising prices on a decades old drug."

