1. Weekly vs daily administration, liraglutide and exenatide had to be injected daily which made the drug less attractive for patients and doctors vs metformin which is well known and a cheap pill.

2. Greater magnitude of effect. Liraglutide had less impact at prescribed dosage for both lowering A1C and weight loss so in combo with (1) made it less attractive than semaglutide.

3. Magnitude of weight loss from (2) now so significant it easily beats all previously approved weight loss drugs with few side effects. So entire GLP-1 agonist class of drugs reexamined as direct weight loss treatments vs just a modest but very welcome side effect of diabetes treatment. And once weekly administration meant it would have much better patient compliance than a daily injection.