Novo Nordisk CEO Mike Doustdar defended the drugmaker's lawsuit against Eli Lilly over advertising for its weight-loss drugs, saying competition should be fierce but fair, CNBC reported Wednesday.

Novo sued Lilly last month, alleging its advertising misleads consumers about the efficacy of Lilly's Zepbound compared with Novo's Wegovy. Lilly has said it stands firmly behind its advertising, CNBC reported.

Doustdar said Lilly's comparisons rely on an older, lower-dose version of Wegovy and do not reflect Novo's newer 7.2-milligram dose, which was approved by the FDA in March.

Novo said a study of the higher dose showed average weight loss of about 19% over 72 weeks, compared with 20.2% for the maximum tolerated Zepbound dose in Lilly's cited trial, CNBC reported.