March 21 (Reuters) - Altimmune Inc's (ALT.O) experimental obesity drug helped reduce weight by over 10% on average in a mid-stage trial, the company said on Tuesday, but safety concerns sent its shares tumbling more than 50%. Wolleben added that the drug showed " a little bit worse" tolerability than previous data. Patients who received a 2.4 milligram dose of Altimmune's experimental drug, pemvidutide, achieved average weight loss of 10.7% at the end of week 24, the company said. The data looked competitive to mid-stage data from Novo Nordisk's (NOVOb.CO) obesity drug Wegovy and Eli Lilly's (LLY.N) candidate for the condition, most analysts said. While Novo Nordisk's drug Wegovy is already available, Lilly expects approval for its obesity drug candidate, tirzepatide, this year.

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