By Mariam Sunny

July 15 (Reuters) - U.S.-based Kailera Therapeutics and

Chinese firm Jiangsu Hengrui Pharmaceuticals'

experimental weight-loss drug has helped overweight patients

lose up to 17.7% of body weight in a late-stage study in China,

the companies said on Tuesday.

Up to 88% of participants who received the drug, known as

KAI-9531 outside China, lost at least 5% of their weight after

48 weeks compared to placebo, meeting the study's main goals.

The data comes at a time when U.S. drugmakers are

increasingly looking to China to secure the rights to promising

drug candidates at a lower cost and access important early data

that could pave the way for global trials.

"As we think about commercial opportunity, this is a really

good first look as to what we think we're going to be able to

leverage in terms of (obesity treatment) marketplace going

forward," Kailera CEO Ron Renaud said.

The startup was launched last year with a rare $400 million

early-stage funding and four obesity drug candidates licensed

from Hengrui, in a move to grab a slice of the obesity treatment

market primed to be worth $150 billion by the end of the decade.

KAI-9531, administered as a weekly injection, belongs to a

the GLP-1 class of treatments that include Eli Lilly's ( LLY )

Zepbound and Novo Nordisk's Wegovy.

The drugs work by helping control blood sugar levels and

triggering a feeling of fullness.

"Where we're really focused is where weight loss matters

most, which is in people living with higher BMIs (body mass

index)," Chief Commercial Officer Jamie Coleman said.

"Today's treatments...leave a lot of clinical need on the

table for people who need to lose more than 20% (of weight)."

In the study that included 567 participants, a six-milligram

dose of the drug led to an average weight loss of 17.7% compared

to placebo.

The companies said the side effects were mild to moderate

and gastrointestinal-related, consistent with similar

treatments.

Hengrui plans to seek regulatory approval in China, while

Kailera will pursue global trials with higher doses and extended

treatment durations.

Earlier this year, an eight-milligram dose of the drug led

to an average weight loss of 22.8% in a mid-stage trial.