Having just hosted the latest of a decades-long string of presidential debates, St. Louis is rightfully proud of serving as a setting for vital national conversations. On Oct. 20, the Gateway City will be the site of another gathering that could also prove historically consequential — but in a way that should concern the millions of Americans with serious medical conditions.

A Boston-based nonprofit called the Institute for Clinical and Economic Research is convening a major policy meeting in St. Louis about how to control health care costs. Specifically, it will focus on how much to limit the price of life-saving medical drugs, as well as how to limit the inevitable harm — especially to patients — these policies could cause.

This is certainly a conversation worth having, but ICER has already reached its conclusions — and patients say they aren’t the right ones.

ICER is now taking aim at the medicines for one specific disease: Non-small-cell lung cancer, which affects more than 200,000 Americans every year. Its goal is to look at the various medications that treat the condition and then set its own arbitrary limits on spending for each. ICER actually did the same thing in St. Louis this year for medications treating multiple myeloma, a form of blood cancer.

Sounds harmless, right? Wrong.

This process is funded by and in constant communication with health insurance companies that desire limits on spending to protect their own bottom line. Through ICER, a de facto front group, the industry is seeking to convince government regulators to allow caps on drug access, ostensibly for the good of the system.

But what about the good of the patient?

If drug spending is artificially limited, the end result is that patients will be denied the treatments they need to survive.

That’s certainly the case for Thomas Hardy, a St. Louis resident with multiple myeloma. Like practically every patient with this condition, he is living life to the fullest and focused on his treatments.

He’d never heard of ICER and never dreamed any entity would seek to limit access to the medicines he needs based on price alone: “I’m horrified by ICER’s cost-cutting proposals.”

He also pointed out that, according to a recent study by Dr. Robert Goldberg of the Center for Medicine in the Public Interest, 44,000 people with his condition would die over the next five years under ICER’s cost-cap proposal. He says: “I don’t intend to be in that number.”

He’s not alone. Other patients are on their way to St. Louis to make their voices heard this week.

Julie Williams of Syracuse, N.Y., has advanced non-small cell lung cancer. She’s had it for more than six years and she’s only survived thanks to medical innovation and the targeted improvements of personalized and precision medicine. She says that if ICER’s policies had been in place and prevented access to her drugs, “There’s a very real chance I wouldn’t be alive today.”

There are others, too. Jeff Julian is an All-American swimmer who represented the U.S. National team and now coaches at the University of Southern California. He also has non-small cell lung cancer. He tells me: “The last thing we should do is stand between patients and their medicines.”

By all means, let’s look honestly at health care costs. For its part, ICER can use its expertise and influence to play a role in advancing needed reforms of regulatory burdens and severe flaws of current insurance design. But let’s draw the line at proposals that would cut off patient access to the medicines they need to live.

That’s why Jeff Julian and Julie Williams — from opposite coasts of this country — are meeting in the middle in St. Louis: To lend their urgent voices of value to the growing chorus of patients who, perhaps better than all of us, know a threat to survival when they see one.