Understanding MET Exon 14 Skipping Mutations

MET exon 14 skipping mutations occur in approximately 3-4% of non-small cell lung cancers (NSCLC). These mutations disrupt normal MET gene regulation, leading to uncontrolled protein production. Targeted MET inhibitors like tepotinib and capmatinib offer significantly better outcomes than traditional chemotherapy.

3-4%

of NSCLC patients

MET Exon 14

Emerging biomarker

2 FDA-approved

MET inhibitors

50-70% response

Rates with MET inhibitors

What is MET Exon 14 Skipping?

MET exon 14 skipping is a specific type of MET mutation where the 14th exon of the MET gene is removed during splicing. This deletion removes the critical degradation signal for the MET protein, causing abnormal accumulation and constant activation. Unlike some other oncogenic mutations, MET exon 14 skipping is relatively straightforward to target therapeutically.

How It Works

Normal MET protein is tightly regulated. Exon 14 skipping removes the "off switch," causing uncontrolled MET signaling that drives cancer cell growth.

Testing

MET exon 14 is detected via next-generation sequencing (NGS) or RT-PCR. It's often missed on standard FISH testing, so NGS panels are essential for accurate diagnosis.

Prevalence

More common in older patients and smokers. Can co-occur with other mutations in some cases.

Treatment Pathways for MET Exon 14+ NSCLC

First-Line Therapy

Tepotinib (Tepotrectinib, Rybrevant) - FDA approved first-line
Capmatinib (Tabrecta) - Selective MET inhibitor
Response rates 50-70% in clinical trials
Well-tolerated with manageable side effects

Post-MET Inhibitor

Switching between tepotinib and capmatinib
Next-generation MET inhibitors in development
Chemotherapy for resistant disease
Immunotherapy combinations being explored

Resistance Strategies

Secondary MET mutations detected via NGS
D1228V and other resistance mutations
Next-generation MET inhibitors for resistant mutations
Combination approaches to overcome resistance

Special Considerations

Cardiovascular monitoring recommended
Hepatic function assessment
Drug-drug interactions awareness
CNS penetration varies by drug

Frequently Asked Questions

How is MET exon 14 skipping detected? +

MET exon 14 skipping is best detected through next-generation sequencing (NGS) with RNA component or RT-PCR. Standard FISH testing, which works well for detecting other MET alterations, may miss exon 14 skipping. This is why comprehensive NGS panels are important for accurate diagnosis and biomarker-driven treatment selection.

What is the difference between tepotinib and capmatinib? +

Both tepotinib and capmatinib are selective MET inhibitors approved for MET exon 14 skipping NSCLC. Tepotinib has FDA approval for first-line use, while capmatinib is approved for previously treated patients. They have similar efficacy but differ in selectivity profiles and handling of resistant mutations. Your oncologist can help determine which is better for your situation.

What happens if I develop resistance to MET inhibitors? +

Some patients develop secondary MET mutations (like D1228V) that confer resistance. Switching to the alternative MET inhibitor may still be effective. Next-generation MET inhibitors in clinical trials are being tested specifically for resistant mutations. Your oncologist may also recommend combination therapy approaches.

Can MET inhibitors treat brain metastases? +

MET inhibitors have variable blood-brain barrier penetration. While some activity against brain metastases is seen, patients with significant CNS disease may require additional CNS-directed therapy like radiation. Clinical trials are investigating combinations of MET inhibitors with radiation for optimal brain control.

MET Exon 14 Lung Cancer