UPDATE 3-AstraZeneca diabetes drug shows promise in heart failure

* Farxiga met main goal of DAPA-HF trial

* Rival treatments yet to show a benefit in heart failure

* AstraZeneca shares rise 1.7% (Adds analyst, executive comments, background, shares)

By Pushkala Aripaka and Ludwig Burger

Aug 20 (Reuters) - AstraZeneca made strides on Tuesday towards its goal of adding heart failure to the conditions that can be treated by its diabetes drug Farxiga, putting it ahead of a rival medicine from Eli Lilly.

The British drugmaker said Farxiga was successful in reducing the risk of deadly heart attacks or disease progression in patients with a common form of heart failure in a clinical trial that could help win regulatory approval for its wider use.

Farxiga, already one of AstraZeneca's top 10 drugs by sales, met the main goal of the so-called DAPA-HF trial, which tested the medicine in addition to the standard treatment in patients whose heart cannot pump enough blood.

Farxiga is part of the SGLT2-inhibitor class of antidiabetics that cause the kidneys to expel blood sugar from the body through urine.

Rival treatments in the diabetes market include Eli Lilly and Boehringer Ingelheim https://www.boehringer-ingelheim.us/press-release/us-fda-grants-fast-track-designation-empagliflozin-treatment-chronic-heart-failure 's Jardiance, but they have yet to show a benefit for heart failure patients.

Around 40% of participants in the Farxiga trial suffered from type-2 diabetes, as is common among heart failure patients, while the rest did not.

The results are welcome news for AstraZeneca after U.S. regulators declined to approved Farxiga for use as a supplement to insulin in adults with type-1 diabetes where insulin alone was not able to control blood sugar levels.

Diabetes is associated with a high risk of heart failure.

Heart failure affects about 64 million people worldwide and half of patients die within five years of diagnosis, AstraZeneca said.

The company, which did not a publish peak sales estimate for the drug, said trial participants suffered from the HFrEF subtype of heart failure, accounting for about half of heart failure cases.

"This (the study results) will give the drug broad applicability and is strong validation of its utility, particularly in diabetics," Liberum analysts said.

"The result will also reinforce Farxiga's utility in diabetes at a time when oral GLP-1 might enter the market," they added, referring to a rival group of drugs.

GLP-1 drugs imitate an intestinal hormone that stimulates the production of insulin. Danish insulin producer Novo Nordisk has already grabbed a chunk of the diabetes market with its GLP-1 drug Ozempic https://in.reuters.com/article/novo-nordisk-results/novo-nordisks-new-diabetes-obesity-drugs-lift-sales-outlook-idINKCN1UZ0SK.

"The Dapa-HF study was seen as a 'wild-card' by the market, with a low probability of success, today being the first time a Phase III study has reported a heart failure benefit for an SGLT-2, in non-diabetic patients," JP Morgan analysts said.

They added that peak sales potential for the indication could exceed $900 million.

AstraZeneca shares were up 1.7% at 7,405 pence as of 0948 GMT, the biggest boost to the UK's blue-chip FTSE 100.

AstraZeneca said it would present more details from the trial at a later stage and discuss results with drug regulators. (Reporting by Pushkala Aripaka in Bengaluru and Ludwig Burger in Frankfurt; Editing by Patrick Graham and Mark Potter)