Amylin analogue mechanism: satiety signalling separate from GLP-1 — does this still hold?

Amylin analogue mechanism: satiety signalling separate from GLP-1 — does this still hold? — that is the question, and I have not found it answered plainly anywhere I have looked.

Session topic: SURMOUNT-4 (JAMA, 2024). Please read it before posting; the discussion is much better when everyone has.

The question I would like us to start with is what the trial set out to estimate, rather than what it found. Once that is on the table we can talk about whether the design could have answered it, and only then about the numbers.

Specific things I would like covered: the population and how far it generalises, how discontinuation was handled, whether the comparator was a fair one, and what the absolute rather than relative effect looks like.

I will summarise at the end and the summary will feed the relevant digest page.

On the opening post — agreed on the reasoning, with one qualification.

The dosing interval: cagrilintide's half-life is roughly 7 to 8 days, suitable for weekly dosing. The pharmacokinetics are the reason the dosing schedule makes sense.

Cagrilintide alone is discussed less than in combination because the published data is almost entirely from combination trials. The phase 2 combination data was consistent with more effect than either component alone, but phase 2 cannot establish whether that is synergy or simply additivity.

Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.

The correction was fair and I had been repeating something I had not checked carefully enough.

For anyone arriving from searches on "amylin agonist": this subcategory discusses published clinical evidence and what it does and does not establish. It does not endorse or recommend the compounds discussed.

Worth separating two things that post #2 runs together.

Amylin signalling is distinct from GLP-1 signalling. Amylin slows gastric emptying and promotes satiety through a different receptor and different neural pathways. The hypothesis behind combination is two complementary satiety mechanisms with one injection.

This follows post #4 rather than contradicting it.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

Reading the phase 2 paper: it establishes tolerability and efficacy in a selected population on a defined dose escalation. It does not establish the lowest effective dose or the durability over years.

The CagriSema phase 2 paper: a fixed combination of the two components in one weekly injection. The trade-off of a fixed combination is that you cannot titrate the components independently and you cannot attribute effect to one component from a combination trial.

Two things before anyone answers the substance.

First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.

What is genuinely unknown about long-term amylin agonism: real-world response rates, whether effect is durable with continued use, whether satiety adaptation occurs over months or years, safety profile in populations not enrolled in the trials.

Picking up post #9: that is the part I would want checked first.

Nausea profile of amylin analogues: the historical agent pramlintide required multiple daily doses and had a difficult tolerability profile. A weekly formulation is a substantially different proposition and data from that is more relevant than data from pramlintide.

Cagrilintide molecular characteristics: it is a synthetic amylin analogue, substituted to prevent the amyloidogenicity of human amylin. The sequence is short and analytically straightforward to confirm by LC-MS.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.