India, April 10 -- The flood of cheap copies of Novo Nordisk A/S' blockbuster drug semaglutide in India is already reshaping the country's fast-growing obesity market, cutting into Eli Lilly & Co.'s early lead and offering a first real test of how Novo may fare as its patents expire worldwide. Within days of dozens of generics hitting the Indian market, semaglutide's share in the country's GLP-1 segment jumped to 33% in March from 25% a month earlier, according to researcher Pharmarack. That gain came at the expense of tirzepatide - the active ingredient in Lilly's Mounjaro - whose share fell to 64% from 71%, Pharmarack said. The data, which counts sales of non-branded versions between March 21-31, marks the first meaningful snapshot of demand after India opened the door to non-patented semaglutide. While Canada was the first country to lose semaglutide patent protection in January, regulators there haven't approved any generics so far. It also offers an early sign of the rush to generics Lilly will face globally as semaglutide approaches patent cliffs elsewhere. The price war and surge in demand are being closely watched as patents for the blockbuster treatment expire in major emerging markets this year, with India a key test case for how quickly generics can erode a branded drug's dominance. Mounjaro sales in March dropped to Rs.114 crore ($12.3 million) in March from Rs.135 crore a month earlier, Pharmarack data show. Lilly will lose exclusivity on the drug next decade. This is a "gold rush phase" as generics come on board, said Sheetal Sapale, vice president of commercial at Pharmarack. Though Mounjaro still dominates the market in India, it's taken a "major hit" following the launch of semaglutide copies, she said. Representatives for Novo Nordisk and Eli Lilly didn't immediately respond to requests from Bloomberg News for comment. Torrent Pharmaceuticals Ltd. has emerged as the biggest local player in semaglutide after Novo, trumping rivals including Sun Pharmaceutical Industries Ltd. and Dr Reddy's Laboratories Ltd. Torrent has an 8% market share, while Novo still holds 70%, according to Pharmarack. Indian drugmakers moved quickly after semaglutide's patent expired on March 20, rolling out versions that cost as little as Rs.1,290....