MASH: where the field is heading,
and where primary care starts

Fibrosis stage on the NASH CRN scale, mapped against UK licensed indications and phase 3 programmes

F0
None
F1
Portal only
F2
Periportal
F3
Bridging
F4c
Compensated
cirrhosis
increasing fibrosis →
ResmetiromUK licence, June 2026
LICENSED, NON-CIRRHOTIC
phase 3 in cirrhosis
SemaglutideUK licence, July 2026, conditional
LICENSED, NON-CIRRHOTIC
phase 2, endpoint not met
Tirzepatideno MASH licence
phase 3, pre-cirrhotic
Licensed UK indication Phase 3 in progress Studied, not pursued
At least eight investigational agents are in phase 3 for MASH, and several are recruiting in compensated cirrhosis, where nothing is yet licensed.
Where primary care starts
1

FIB-4, from bloods you already have. Age, AST, ALT and platelets. Worth repeating every one to two years in type 2 diabetes.

Below 1.3advanced fibrosis excluded in around 99%
1.3 to 2.67indeterminate
2.67 or aboveadvanced fibrosis likely
2

Above 1.3, a second test decides it. Elastography or ELF. FIB-4 alone should not determine treatment candidacy.

FIB-4 performs less well in type 2 diabetes, and in over 65s a higher cut-off of 2.0 applies.

Licensed indications, both non-cirrhotic MASH with F2 to F3 fibrosis: resmetirom, MHRA 3 June 2026; semaglutide (injection only), MHRA 3 July 2026, conditional. Current at 16 August 2026.
Cirrhosis programmes: MAESTRO-NASH OUTCOMES, phase 3, Child-Pugh A, enrolment complete (NCT05500222). Semaglutide phase 2 in cirrhosis did not meet its primary endpoint (Lancet Gastroenterol Hepatol 2023). Tirzepatide: SYNERGY-OUTCOMES phase 3 (NCT07165028), entry by ELF and elastography, cirrhosis largely excluded.
FIB-4 thresholds: AASLD Practice Guidance; EASL–EASD–EASO Guidelines on MASLD, J Hepatol 2024;81:492–542. Chart: Medicine Central. For UK healthcare professionals.