MASH Treatment Enters 2.0 Era: GSK’s Once-Monthly Efimosfermin Alfa Receives CDE Clinical Trial Approval

(Source: Antibody Circle)

CDE Official Website Announces Today,GlaxoSmithKline (China) Investment Co., Ltd.Class 1 Biological New Drug ApplicationEfimosfermin alfa for Injection(CDE acceptance shows as Elimfermin alfa) The clinical trial application has been officially accepted (Acceptance No.:CXSL2600632）。

This GSK-fundedUp to $2 billionAcquisition of a potential best-in-class drug, currently the most advanced long-acting FGF21 analog globally, marks the official arrival of an innovative once-monthly therapy in China’s MASH (metabolic dysfunction-associated steatohepatitis) treatment landscape.

Technical Breakthrough: Addressing the Clinical Pain Points of FGF21

Efimosfermin alfa is an engineeredLong-acting FGF21 analog, with its core innovation lying in the optimization of the amino acid sequence of native FGF21, successfully addressing two major clinical pain points of the native protein:

1.Significantly Prolonged Half-Life

Natural FGF21 is highly susceptible to degradation in vivo, with a half-life of only a few hours. Efimosfermin alfa achieves, through structural modification,Once monthlyThe convenient administration significantly improves patient compliance.

2.Triple Mechanism of Action

Compared with existing MASH drugs, Efimosfermin alfa possesses unique"Triple Efficacy: Fat Reduction + Anti-Inflammation + Anti-Fibrosis"：

✅Reduce Liver Fat: Rapidly Reduce Liver Fat Content

✅Improve Liver Inflammation: Modulate metabolic pathways and alleviate hepatic inflammatory response

✅Reversal of Liver Fibrosis: Directly acts on fibrotic pathways to halt disease progression

Stunning Phase II Clinical Data Published in The Lancet

Phase II clinical trial data presented at the 2025 DDW conference and published in The Lancet Gastroenterology & Hepatology demonstrated encouraging results:

Key Data at 24 Weeks of Treatment:

MASH Resolution Rate: 68% (vs. placebo group), without worsening of fibrosis

Hepatic fat reduction ≥30%: 89% of patients met this criterion

Normalization of Liver Fat: 32% of patients achieved hepatic fat content ≤5% (complete normalization)

Improvement in Fibrosis: Significantly superior fibrosis reversal efficacy compared to existing treatments

Safety: Well tolerated, with no serious treatment-related adverse events

Particularly important is the efficacy of this drugIndependent of GLP-1 Background Therapy, which means that even if patients are using weight-loss medications such as semaglutide, Efimosfermin alfa can still provide additional liver protection.

Market Landscape: MASH Enters a Golden Age

MASH (formerly NASH), as one of the largest unmet medical needs globally, affects hundreds of millions of people worldwide. In China, there are approximately200-300 millionAmong patients with non-alcoholic fatty liver disease, approximately 10–20% will progress to MASH, which may ultimately lead to cirrhosis and hepatocellular carcinoma.

The global MASH pipeline has now entered the harvest phase:

Launched: Intercept’s obeticholic acid, Madrigal’s semaglutide (MASH indication)

Late-stage clinical trials: Efimosfermin alfa, Efruxifermin, and other FGF21-based drugs lead the way

China Market: Currently, no biologic drugs specifically targeting MASH have been approved.

The unique advantages of Efimosfermin alfa lie in:

Convenient Administration: Once monthly vs. weekly/daily dosing

Comprehensive Mechanism: Simultaneously targets the three major pathological processes of adiposity, inflammation, and fibrosis

Combination Potential: Can complement and enhance the efficacy of GLP-1 drugs

Capital Perspective: The Strategic Logic Behind a $2 Billion Acquisition

In May 2025, GSK announced that$1.2 billion upfront payment + up to $800 million in milestones, acquiring Boston Pharmaceuticals for a total of $2 billion, with Efimosfermin alfa as the core asset. This transaction set a record for the largest single deal in the MASH field.

The logic behind GSK’s heavy investment is clear:

Vast Market Potential: The global market size for MASH is projected to exceed $30 billion

Differentiated Competition: Long-acting delivery + comprehensive mechanism, with best-in-class potential

Pipeline Synergy: Strategically complements GSK’s existing immunology and metabolism pipeline

It is worth noting that this drug was initially developed byNovartisR&D, later licensed to Boston Pharmaceuticals; after GSK's acquisition, tiered royalties are still payable to Novartis.

Clinical Significance in China: Filling the Treatment Gap

The clinical trial application for Efimosfermin alfa in China carries multiple significances:

Patient Benefits: Bringing cutting-edge international treatment options to tens of millions of MASH patients in China

Market Education: Promoting Awareness and Screening for MASH

Accelerated Competition: Promote domestic pharmaceutical companies' R&D investment in the FGF21 target

Currently, GSK has launched two large-scale Phase III clinical trials (ZENITH-1 and ZENITH-2) globally, planning to enroll more than 1,250 patients with MASH and F2/F3 fibrosis. The initiation of the clinical trial in China means that Chinese patients are expected to participate in this international multicenter study concurrently.

Industry Observation

From Novartis to Boston Pharma, and then to GSK, the development journey of Efimosfermin alfa has witnessed a revaluation of value in the MASH field. As this $2 billion blockbuster drug officially enters China, the FGF21 track, once questioned, is now ushering in its golden moment.

For Chinese patients, a once-monthly long-acting treatment regimen not only signifies improved adherence but also represents a novel model for chronic disease management—transforming MASH, the "silent killer," into a truly preventable, controllable, and treatable chronic condition.