Study wrapper · #156
Tirzepatide Efficacy and Tolerability According to Early Weight Response: A Post Hoc Analysis of the SURMOUNT-1 and SURMOUNT-2 Trials.
Editor's note
This is a post hoc analysis of two pivotal Phase 3 tirzepatide trials (SURMOUNT-1 and -2; N=2384 in the tirzepatide arm), splitting participants by whether they lost at least 5% of body weight by Week 8. Both early and non-early responders reached clinically meaningful weight reduction and cardiometabolic improvement at Week 72, though early responders did better; gastrointestinal tolerability was similar between groups. The parent trials are registration-quality and double-blind, which anchors the data — but 'post hoc' matters: these subgroups were not randomised, the analysis is exploratory, and early responders differed at baseline (more likely female, White, lower HbA1c). The practical takeaway the authors draw is measured: a slow early response did not preclude meaningful longer-term benefit. Read this as a useful refinement of how to interpret early weight trajectories, not as a new efficacy claim beyond what SURMOUNT already established.
Plain-language abstract
In two large trials of tirzepatide for weight management (SURMOUNT-1 and SURMOUNT-2), researchers went back and divided the roughly 2,400 people who received the drug into 'early responders' (those who lost at least 5% of their weight by week 8) and 'non-early responders.' They wanted to know whether an early response predicts later results. Both groups achieved meaningful weight loss and improvements in heart-and-metabolism markers such as HbA1c by week 72, but early responders improved more. Stomach-and-gut side effects — the most common issue with these drugs — followed a similar pattern and severity in both groups. Early responders were more likely to be female, White, and to have lower starting blood-sugar levels. Because this analysis was planned after the trials finished and the groups were not randomly assigned, it is exploratory. The main message: a slower start did not prevent people from still achieving clinically meaningful weight loss later on.