Prolonged Disease Control Despite ALK Inhibitor Discontinuation in Advanced ALK-Positive NSCLC.

Area of Science:

• Oncology
• Molecular Biology

Background:

• EML4-ALK fusion is an oncogenic driver in approximately 5% of advanced non-small-cell lung cancer (NSCLC).
• Anaplastic lymphoma kinase tyrosine kinase inhibitors (TKI) are effective treatments for ALK-positive NSCLC.
• Disease flare, a rapid worsening of cancer upon TKI discontinuation, is associated with poor survival.

Purpose of the Study:

• To review literature on EML4-ALK NSCLC patients experiencing disease flare upon TKI discontinuation.
• To contrast these cases with patients who safely discontinued TKI and achieved prolonged survival.

Main Methods:

• Literature review of published cases of disease flare in EML4-ALK NSCLC patients.
• Case series of three ALK-positive NSCLC patients with EML4-ALK variant 1 translocation.
• Analysis of patient outcomes after TKI discontinuation.

Main Results:

• Three patients with advanced ALK-positive NSCLC and EML4-ALK variant 1 translocation safely discontinued TKI therapy without disease flare.
• These patients experienced prolonged survival despite TKI cessation.
• Factors influencing flare risk include time to progression, symptoms, metastasis, tumor response, line of therapy, disease burden, fusion variant, and co-alterations.

Conclusions:

• Identifying patients at risk for disease flare upon TKI discontinuation is crucial for improving outcomes.
• Advanced ALK-positive NSCLC with EML4-ALK variant 1 and wild-type TP53 may be suitable for intermittent TKI dosing strategies.
• Intermittent TKI dosing warrants further investigation to avoid resistance and toxicity.