The REDEFINE trials
Cagrilintide's evidence base is genuinely strong for an unapproved drug: a clean monotherapy dose-finding trial, a…
From a dose-finding trial to phase 3
Cagrilintide's evidence base is genuinely strong for an unapproved drug: a clean monotherapy dose-finding trial, a phase 1b combination study, a phase 2 in diabetes, and two large phase 3 REDEFINE trials in NEJM. This unit walks that ladder and the honest debate over how impressive the phase 3 result really was.
It also teaches a durable skill: why you must cite the peer-reviewed paper, not the press-release topline, when a drug's headline number becomes a market event.
Key terms
The evidence ladder
Cagrilintide's development answered one question at a time. A phase 1b study of the combination's safety and a phase 2 dose-finding trial of cagrilintide alone ran side by side, the combination study starting first; a phase 2 in type 2 diabetes followed, then phase 3. That progression is part of why the program is taken seriously despite being a single manufacturer's effort.
Notice how each rung sets up the next: the phase 1b showed the combination could be given safely, monotherapy dose-finding mapped cagrilintide alone from 0.3 to 4.5 mg before 2.4 mg went forward, the phase 2 showed a large weight-loss advantage in diabetes while missing its primary glycemic endpoint against semaglutide, and only then did the large phase 3 trials run. This is textbook drug development, and it is why the REDEFINE results arrived on a solid mechanistic and dose foundation rather than as an isolated result.
AdvancedWhy the phase 1b interaction study mattered
Before a combination can be tested for efficacy, you must prove the two drugs are safe together and do not interfere. The Enebo 2021 phase 1b did exactly that, showing cagrilintide and semaglutide could be co-administered without a meaningful pharmacokinetic interaction: cagrilintide exposure did not affect semaglutide exposure or elimination. That unglamorous safety rung came first; the phase 3 REDEFINE 1 trial later gave the two together, each at 2.4 mg.