Triple administration of osimertinib followed by chemotherapy for advanced lung adenocarcinoma: A case report

Area of Science:

• Oncology
• Pharmacology

Background:

• Osimertinib is a first-line treatment for EGFR-mutation positive advanced or metastatic non-small cell lung cancer (NSCLC).
• Acquired resistance to EGFR-tyrosine kinase inhibitors (EGFR-TKIs) like osimertinib is a significant clinical challenge.
• Discontinuation of the TKI is the current standard of care upon resistance development.

Observation:

• A 57-year-old female with lung adenocarcinoma and EGFR exon 21 L858R mutation presented with brain metastases.
• The patient initially responded to osimertinib but developed progressive disease.
• Following resistance, the patient underwent re-challenge and tri-challenge with osimertinib after two cycles of resensitization chemotherapy.

Findings:

• The patient achieved long-term survival of 31 months.
• Successful re-challenge and tri-challenge with osimertinib demonstrated efficacy despite prior resistance.
• Resensitization chemotherapy prior to osimertinib re-challenge may overcome acquired resistance.

Implications:

• This case suggests that osimertinib re-challenge can be a viable strategy for NSCLC patients who develop acquired resistance.
• Selective therapeutic options may exist for patients previously controlled on osimertinib.
• Further investigation into re-challenge strategies for EGFR-TKI resistance is warranted.