Phase 2 trials test efficacy and find the right dose, typically 100-500 patients. Phase 2 readouts often establish 'this is a real drug' but the dose may be refined in phase 3. Retatrutide's phase 2 (24.2% weight loss) was followed by phase 3 TRIUMPH; cagrilintide's phase 2 dose-finder set up the combination trials. Phase 2 results are evidence — but you should always check whether phase 3 has confirmed the signal.
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