A novel MYO5C-ALK fusion in lung adenocarcinoma: limited alectinib response and durable lorlatinib benefit.
Tai-Yun Wu, Nien-Tzu Liu, Yu-Cheng Wu et al.
✦ AI-curated · Sources linked
Case in brief
A 72-year-old never-smoker with stage IVB lung adenocarcinoma was found to have a novel MYO5C-ALK fusion. Despite initial treatment with alectinib, the tumor progressed after approximately seven months without any detected mutations contributing to resistance. However, the patient achieved a durable partial response to lorlatinib, with progression-free survival exceeding 15 months.
What made this case unusual
This case presents the first reported MYO5C-ALK fusion in lung adenocarcinoma, highlighting its unique pharmacologic behavior compared to the more common EML4-ALK fusion.
Diagnostic / clinical pearl
Clinicians should consider the potential for atypical ALK fusions, such as MYO5C-ALK, to exhibit distinct responses to targeted therapies like lorlatinib.
Why it matters
Understanding the mechanisms behind differential responses to ALK inhibitors can guide treatment strategies for patients with rare fusions and mutation-negative resistance.