Fibrosis stages F2 to F3, without cirrhosis. That is the whole of the approved population [1]. Semaglutide 2.4 mg holds conditional US approval for metabolic dysfunction-associated steatohepatitis with significant fibrosis. Earlier stages are not included, and neither is F4. Entry requires non-invasive testing — elastography, or a blood-based fibrosis score — to establish the stage. No telehealth intake stages a liver.
These drugs have acquired a formal liver indication, which is genuinely new. It is narrower than the sentence “approved for liver disease” suggests, and the narrowness is the useful part. The trial behind it is read in the phase 3 liver evidence.
What was approved, and for whom
Two drugs now hold conditional US approval for metabolic dysfunction-associated steatohepatitis with significant fibrosis [1]. They are resmetirom, a liver-directed thyroid hormone receptor-beta agonist, and semaglutide 2.4 mg. The population is fibrosis stage F2 to F3, without cirrhosis. Earlier stages are not included. Neither is F4.
An international expert panel has consolidated the phase 3 data, the FDA labels and early clinical experience into one care pathway. It covers how to diagnose MASH with significant fibrosis using non-invasive tests. It covers how to choose and start a therapy, and how to monitor it. And it defines response, non-response, and when to switch or combine the two agents.
Why the stage is the eligibility criterion
Because fibrosis is the endpoint that predicts outcomes, and it is also the one the drugs move least reliably. A mediation analysis of a phase 2 MASH trial split the liver effects in two [2]. One part ran through weight loss, and one did not. Liver fat behaved like a weight problem. Weight reduction carried 77.4% of the effect on one steatosis measure and 58.2% on another.
Fibrosis did not. Only 36.3% of the effect on fibrosis improvement was attributed to weight. The blood markers pointed the same way, with weight mediating between 16.5% and 38.6%. That is the mechanistic reason the indication is staged rather than written around a weight threshold. The fuller reading is in the mediation analysis.
The same pattern shows up in clinical cohorts. In 182 Japanese patients with type 2 diabetes who switched to tirzepatide, the steatosis index fell in both risk groups [3]. The fibrosis index fell significantly only in the high-risk group. Nobody stayed on the original drug, so there is no comparison arm, and the switching cohort sets out what that costs.
Monitoring is part of the indication
The panel devotes substantial attention to on-treatment monitoring and response assessment. That includes what counts as non-response, and when to switch or combine. It is a treatment relationship with a clinician who is tracking something over time.
It is also the part of the framework a website transaction is least equipped to supply. A drug with a monitoring protocol, sold without one, is not the same treatment the approval describes. What a remote prescriber should actually be doing is set out in the standard of care.
What to take from it
Risk factors for fatty liver disease include type 2 diabetes, obesity and high triglycerides. If you have them, there is now a reason to ask about fibrosis staging that did not exist three years ago. The tests are non-invasive. That is a conversation with a clinician, not a purchase.
And if you are already on one of these drugs for weight, the panel addresses that case too. Somebody who started for one reason and turns out to qualify for another is a case the specialists have now written down. The answer is not the same as continuing unchanged. The eligibility question for weight itself is a different threshold again, read in the BMI cut-off.