Ervogastat and Clesacostat in stage II-III MASH

### Ervogastat and Clesacostat in Stage II–III MASH: Detailed Overview

**Metabolic dysfunction-associated steatohepatitis (MASH)** is a progressive form of fatty liver disease characterized by inflammation, liver cell injury, and fibrosis. In patients with stage II–III fibrosis, the condition is particularly concerning due to its potential to progress to cirrhosis and liver failure. The phase 2 clinical trial of **ervogastat** (a DGAT2 inhibitor) and **clesacostat** (an ACC inhibitor) explored the potential of these investigational drugs to address the unmet therapeutic needs in this patient population.

---

### **Key Findings from the Trial**

#### **1. Investigational Drugs and Mechanism of Action**

• **Ervogastat**: Inhibits diacylglycerol acyltransferase 2 (DGAT2), a key enzyme in triglyceride synthesis, to reduce liver fat production.
• **Clesacostat**: Inhibits acetyl-CoA carboxylase (ACC), an enzyme critical for lipogenesis, to further suppress fat synthesis in the liver.
• The combination of these agents was designed to synergistically reduce liver fat and inflammation, targeting the root causes of MASH.

---

#### **2. Trial Design and Patient Population**

• **Participants**: 255 adults with biopsy-confirmed MASH and stage II–III fibrosis.
• **Randomization**: Patients were assigned to receive:
• **Ervogastat monotherapy** (25, 75, 150, or 300 mg twice daily),
• **Combination therapy** (ervogastat 150 mg + clesacostat 5 mg or ervogastat 300 mg + clesacostat 10 mg twice daily),
• **Placebo**.
• **Duration**: 48 weeks.
• **Primary Endpoint**: Success was defined as achieving at least one of the following:
• Resolution of MASH without worsening of fibrosis,
• ≥1-stage fibrosis improvement without worsening of MASH,
• Both outcomes.

---

#### **3. Efficacy Results**

• **Combination Therapy**:
• Achieved the primary endpoint in **66%** (ervogastat 150 mg + clesacostat 5 mg) and **63%** (ervogastat 300 mg + clesacostat 10 mg) of patients.
• These results were significantly better than the placebo group (38%).
• **Placebo-adjusted benefit**: Absolute differences were 27% and 25% for the low- and high-dose combination groups, respectively.
• Efficacy was consistent across doses, suggesting a **ceiling effect** in MASH resolution.
• **Monotherapy**:
• None of the ervogastat monotherapy groups met the composite primary endpoint.
• This indicates that the combination strategy is critical for therapeutic efficacy.

---

#### **4. Mechanism of Benefit**

• Improvements were driven primarily by **MASH resolution without fibrosis worsening**, underscoring the liver fat–lowering effects of the drugs.
• However, no treatment arm (including the combination groups) demonstrated superiority over placebo in achieving **≥1-stage fibrosis improvement without MASH worsening**. This highlights the persistent challenge of reversing fibrosis with current therapies.

---

#### **5. Safety and Adverse Events**

• **General Tolerability**:
• Most side effects were mild to moderate.
• The most common adverse events included **diarrhea** and **inadequate diabetes control**.
• **Lipid Profile Concerns**:
• Combination therapy was associated with unfavorable changes in lipid parameters:
• Increased **serum triglycerides**, **apolipoprotein C3**, and **apolipoprotein E**.
• These changes raise concerns about potential **cardiovascular risks**, particularly for patients with pre-existing cardiovascular conditions.
• **Safety Reassurance**:
• No unexpected safety signals were observed.
• However, careful monitoring of metabolic and cardiovascular profiles is essential.

---

#### **6. Implications for DGAT2 and ACC Inhibition**

• **DGAT2 Inhibition Alone**:
• Ervogastat monotherapy did not achieve significant efficacy, suggesting that DGAT2 inhibition alone is insufficient for treating MASH.
• **Synergy with ACC Inhibition**:
• The addition of clesacostat (ACC inhibitor) significantly enhanced the effectiveness of ervogastat, particularly in resolving steatohepatitis.
• This supports the hypothesis that targeting multiple steps in lipid synthesis may be necessary for meaningful therapeutic outcomes in MASH.

---

### **Editorial Perspective and Clinical Implications**

• **Hepatic Benefits vs Cardiovascular Risks**:
• The trial demonstrated significant improvements in liver histology, particularly in resolving MASH without worsening fibrosis.
• However, the unfavorable lipid changes linked to combination therapy temper enthusiasm, especially for patients at high cardiovascular risk.
• **Patient Selection**:
• Ervogastat plus clesacostat may be most suitable for patients with MASH and fibrosis who do not have significant cardiovascular comorbidities.
• **Dose Optimization**:
• The similar efficacy observed across low- and high-dose combination regimens suggests that lower doses may be sufficient, potentially minimizing side effects.

---

### **Future Research Directions**

1. **Longer-Term Studies**:

• Extended trials are needed to determine whether fibrosis improvement emerges with prolonged therapy.
• The durability of MASH resolution should also be evaluated.

2. **Cardiovascular Risk Mitigation**:

• Strategies to address the lipid-related side effects of combination therapy must be developed.
• This could involve co-administration of lipid-lowering agents or identifying subpopulations less prone to adverse lipid changes.

3. **Exploration of Additional Combinations**:

• Combining DGAT2 and ACC inhibitors with other therapeutic agents (e.g., anti-inflammatory or antifibrotic drugs) may yield better results.

---

### **Conclusion**

The combination of **ervogastat** and **clesacostat** represents a promising therapeutic approach for patients with stage II–III MASH. While the combination therapy demonstrated significant efficacy in resolving steatohepatitis, its inability to reverse fibrosis and the unfavorable lipid profile changes highlight the need for careful patient selection and further research. This dual-drug regimen may ultimately play a role in the treatment landscape for MASH, but its clinical utility must be balanced against potential cardiovascular safety concerns.