(CNN) The skyrocketing prices of insulin are a nationwide issue and Colorado has become the first state to pass legislation that tackles the problem.
Colorado Gov. Jared Polis signed a bill into law Wednesday that places a $100 per month cap on insulin co-pays, regardless of how much insulin a patient uses. Insurance companies will pay anything more than the $100 co-pay, according to the new law.
The law also enlists the Colorado attorney general to investigate the rising prices of insulin in the state and to make recommendations back to the legislature.
"Today we will finally declare that the days of insulin price gouging are over in Colorado," Gov. Polis said before signing the bill on Wednesday.
The bill was sponsored by Democratic state Rep. Dylan Roberts, who lost his brother to Type 1 diabetes in August 2016.
"Colorado is leading the way with this measure, but this is just a first step," Roberts told CNN on Thursday. "We won't stop until all the pharmaceutical companies and drug middlemen start taking more accountability and stop gouging patients with their high costs."
Insurance and pharmaceutical companies were aware of the bill and took part in the discussions, Roberts said. He added that he had not heard from any of the companies in the day since the bill was signed.
Roberts, 29, started working on the issue when he first joined the legislature two years ago.
"Knowing personally what living with Type 1 diabetes is like and the cost of it, this will mean a lot for the families and individuals in Colorado," Roberts said.
The cap will go into effect on January 1, 2020. The attorney general may begin investigating insulin prices immediately.
Roberts' little brother, Murphy, inspired him to fight for the cause and go into politics.
Murphy Roberts was diagnosed with Type 1 diabetes when he was 11, according to Roberts' website. He volunteered alongside Roberts when campaigning for Barack Obama's presidential campaign in 2008.
Murphy was on a hike when he had a diabetic seizure in August 2016. He suffered a brain injury from his fall and died the next day. He was 22 years old.
"I think he would tell me good job and probably to look at it and say, 'What's next?'" Roberts said, when asked what his brother would think. "You've got to keep going and find out about the underlying cause of insulin prices and figure out what to do next."
The average cost of insulin has tripled over the course of a decade. It went from $4.34 per milliliter in 2002 to $12.92 per milliliter in 2013, according to a study published in the medical journal JAMA in 2016.
A report from the Health Care Cost Institute, an independent research group funded by four health insurance companies, found that individuals with Type 1 diabetes spent, on average, $5,705 per person on insulin in 2016, an increase of $2,841 since 2012.
The amount of insulin a patient uses varies on the person.
The American Diabetes Association supported the Colorado legislation, saying it's the first of its kind in the nation, according to a statement from Wednesday.
"With the prices of insulin nearly tripling between 2002 and 2013, people with diabetes often face financial hardships affording their insulin," said LaShawn McIver, senior vice president of government affairs & advocacy for the ADA. "Many are faced with tough decisions to either cut back or skip doses, or forgo other necessities to pay for insulin."
More than 400,000 Coloradans live with diabetes, the ADA said. There are more than 30 million Americans who have diabetes and 7.4 million of them rely on taking insulin daily to survive.
"Drug pricing in the US is totally out of control," Roberts said. "Having the attorney general's legal team and recommending legal action will be really helpful to determine what we do next."