Sept 29 (Reuters) - Shares of Structure Therapeutics soared 70% on Friday to hit the highest levels since their debut on the Nasdaq as early data from the drug developer's oral obesity treatment exceeded analysts' expectations.

Analysts said data from the drug was "impressive" and "exceptional", and showed a "highly competitive" profile against larger rivals Eli Lilly and Pfizer who are also developing obesity pills.

Structure's once-daily drug, GSBR-1290, helped participants reduce up to 4.5 kgs of body weight on average after four weeks of treatment, the company said, citing data from a small study of 24 healthy overweight or obese participants.

The drug belongs to the same class of treatments as Novo Nordisk's blockbuster weight-loss drug Wegovy and Eli Lilly's diabetes drug Mounjaro, which is expected to be approved for weight loss later this year.

While too early to conclude superiority, Structure's 1290 compares favorably to early data from Lilly's obesity pill, orforglipron, in similar patients, BMO Capital Markets analyst Evan Seigerman said.

Orforglipron is currently in late-stage development.

Seigerman added that the data also puts Structure's drug "staunchly ahead" of Pfizer's twice-daily obesity pill danuglipron.

California-based Structure said it plans to start testing GSBR-1290 in two mid-stage studies as a treatment for type 2 diabetes and obesity next year.

The company is focused on developing oral obesity drugs that are simpler to manufacture than the current injectables, it said earlier.

Wegovy and Mounjaro are both weekly injections.

The treatments, known as GLP-1s, help regulate blood sugar, slow the rate at which the stomach empties food and decrease appetite.

GLP-1s have also kickstarted a new market for obesity drugs that is estimated to reach $100 billion within a decade.

Structure "delivered better-than-expected efficacy and tolerability" for its oral drug, said Leerink Partners Research analyst David Risinger.

Structure, which has gained 44% since its debut on the Nasdaq in February, was set to add $1.1 billion to its market value if gains hold. (Reporting by Bhanvi Satija in Bengaluru; Editing by Sriraj Kalluvila and Shweta Agarwal)