July 17 (Reuters) - Roche said on Wednesday its CT-996, a new drug being developed to treat obesity and type 2 diabetes, has had positive results for weight loss in phase one of its clinical trial.

Roche is among a growing number of would-be rivals to Novo Nordisk and Eli Lilly, whose weight-loss drugs have caused a storm in demand as experts up their sales forecasts for such treatments to as much as $150 billion by the early 2030s.

Data for Roche's oral drug, to be taken once daily, showed that treatment resulted in a placebo-adjusted mean weight loss of 6.1% within four weeks, the Swiss drugmaker said in a statement.

The drug "was well-tolerated, with mostly mild or moderate gastrointestinal-related adverse events, consistent with the safety profile of the incretin drug class," according to the statement.

"We are pleased to see the clinically meaningful weight loss in people treated with our oral GLP-1 therapy CT-996, which could eventually help patients address both chronic weight management and glycaemic control indications," Chief Medical Officer Levi Garraway said.

Based on the phase-one results, CT-996 will advance into phase-two clinical development, Roche said.

Roche shares indicated 2% higher on premarket.

(Reporting by Paolo Laudani, Editing by Rachel More and Sherry Jacob-Phillips)