FRANKFURT, Nov 4 (Reuters) - Boehringer Ingelheim and Eli Lilly said their diabetes drug Jardiance was shown to slow the progression of chronic kidney disease (CKD), as they seek to catch up with market segment leader AstraZeneca.

In a statement on Friday, the two partners said Jardiance cut the risk of kidney disease progression and cardiovascular death by 28%, citing results from a late-stage trial which included people with and without diabetes.

In March, the trial was stopped early because an independent monitoring panel found the drug's benefit to be sufficiently clear, and that withholding it from a comparator patient group on placebo was no longer justifiable.

Unlisted Boehringer of Germany and partner Lilly said they would soon seek an extended authorization for CKD with regulators worldwide.

For AstraZeneca, the added approval of rival product Farxiga for use in CKD contributed to a 53% increase in sales of the pill to $3 billion last year.

That drug was shown in a 2020 trial, known as DAPA-CKD, to cut by 39% the risk of kidney disease progression, or death from kidney or cardiovascular causes.

Compared with AstraZeneca's trial, the study testing Lilly's Jardiance included a wider group of kidney patients, such as those who had not yet started shedding the blood protein albumin through urine.

"DAPA-CKD essentially enrolled a higher-risk population. We've enrolled a much broader population that is more representative of what you see in clinical practice," said Waheed Jamal, head of cardiovascular and metabolic medicine at Boehringer Ingelheim.

Both drugs fall in the category of SGLT2 inhibitors that block the kidney from reabsorbing blood sugar, which is then excreted through urine.

Initially targeted at diabetes, the drug class has been also proven beneficial for non-diabetics, such as those with heart failure. Some experts expect it to slow the onset of complete loss of kidney function, which requires costly and burdensome dialysis.

Boehringer recorded about 3.9 billion euros ($3.84 billion) in global Jardiance sales last year, and it made royalty payments of about $1.5 billion to Lilly.

About 37 million people in the United States are estimated to have CKD, but many are not aware because the condition is difficult to diagnose, according to the U.S. Centers for Disease Control and Prevention. ($1 = 1.0145 euros) (Reporting by Ludwig Burger; Editing by Emelia Sithole-Matarise)