"This case challenges current paradigms, demonstrating that amivantamab monotherapy can effectively target rare EGFR mutations, achieve durable extracranial and CNS disease control, and potentially overcome blood-brain barrier limitations."
BUFFALO, NY – June 11, 2025 – A new research paper was published in Volume 16 of Oncotarget on May 29, 2025, titled " Durable complete response in leptomeningeal disease of EGFR mutated non-small cell lung cancer to amivantamab, an EGFR-MET receptor bispecific antibody, after progressing on osimertinib. "
A team led by first author Jinah Kim, from the University of Vermont Medical Center , and corresponding author Young Kwang Chae, from the Feinberg School of Medicine , reports a clinical case in which a patient with advanced non-small cell lung cancer (NSCLC) carrying rare EGFR mutations responded remarkably to amivantamab after other treatments had failed. The patient experienced a complete resolution of brain and spinal fluid metastases, suggesting that amivantamab may be a viable option for patients with uncommon genetic profiles and limited therapy options.
Lung cancer remains one of the leading causes of cancer-related deaths worldwide. Patients with NSCLC who have rare mutations in the EGFR gene often face limited treatment options and poor outcomes, especially when the disease spreads to the brain or spinal fluid. This case involved a 67-year-old man diagnosed with NSCLC who had two rare EGFR mutations—G719A and A289V. After disease progression on osimertinib and other therapies, the patient began amivantamab monotherapy.
Within six weeks, his lung tumor shrank by over 30 percent. By six months, imaging confirmed the disappearance of brain metastases and leptomeningeal disease, a serious condition affecting the membranes of the brain and spinal cord. Blood tests showed no detectable cancer-related mutations, and the patient, previously wheelchair-bound, regained the ability to walk and perform daily activities. This response has been sustained for more than 19 months.
"Treatment produced a durable response over 19 months, including a 32.2% reduction in tumor size at six weeks, and complete resolution of brain metastases and LMD by six months."
Amivantamab is a bispecific antibody that targets EGFR and MET, two key drivers of tumor growth. While it is approved in combination regimens for common EGFR mutations, its effectiveness as a single agent in rare mutations or in treating brain metastases remains largely unproven. This case challenges the assumption that large antibody drugs cannot cross the blood-brain barrier and suggests that amivantamab may have potential in managing central nervous system involvement. Further research is needed to clarify how the drug achieves these effects and to explore its broader use in patients with rare EGFR mutations and limited treatment options.
This case highlights three key findings: amivantamab may be effective against rare EGFR mutations, can be used as monotherapy, and may overcome the challenges of the blood-brain barrier. Although based on a single patient, the results provide encouraging evidence to support further investigation of amivantamab in treating difficult-to-manage forms of NSCLC.
Continue reading: DOI: https://doi.org/10.18632/oncotarget.28730
