First-Line Lorlatinib in Striatin-Anaplastic Lymphoma Kinase-Positive Lung Adenocarcinoma: A Case Report and Literature Review.

Striatin-anaplastic lymphoma kinase (STRN-ALK) is a rare fusion variant in non-small cell lung cancer (NSCLC), and the efficacy of first-line lorlatinib for this subgroup is poorly defined. We report a 45-year-old treatment-naïve male with STRN-ALK-positive lung adenocarcinoma and symptomatic brain metastases. Following stereotactic radiosurgery for intracranial lesions, the patient initiated lorlatinib at 100 mg once daily as the first systemic therapy. After starting treatment, neuropsychiatric side effects necessitated a gradual reduction in dosage to 75 mg and then to 50 mg. The patient achieved a durable partial response with sustained intracranial disease control for over 1 year. Adjusting the dosage improved tolerability without compromising efficacy, allowing for ongoing treatment. This case demonstrates that first-line lorlatinib can achieve durable systemic and intracranial disease control in STRN-ALK-positive NSCLC, including in patients presenting with brain metastases, while maintaining antitumor efficacy despite dose reduction.