Alectinib Pharmacokinetic in Patients With NSCLC

Inclusion Criteria: * Both sexes * ≥ 18 years old * Pathologically confirmed diagnosis of NSCLC * Stage IIIB - IV by the American Joint Committee of Cancer Version 8. * Recurrent disease (at least 180 days from curative intent treatment) * ALK rearrangements tested by FDA-approved tests (IHQ or FISH) * Karnofsky PS scale ≥ 70% * Having received first-line treatment with anti-ALK inhibitors and one previous line of platinum-based chemotherapy. * Measurable disease as referred by RECIST version 1.1 * Symptomatic brain metastases could receive prior treatment with radiotherapy or surgery for at least two weeks before treatment initiation. * Asymptomatic brain metastases could not receive local therapy before study inclusion. * Negative highly sensitive pregnancy test (serum or urine) within 72 days before first dose intervention. * Sexually active patients should use a contraceptive method with a failure rate of less than 1% per year. * Signed written informed consent * Adequate organ function (hematological, liver, and renal function) * Life expectancy of at least 12 weeks Exclusion Criteria: * Carcinomatous meningitis confirmed by a positive CRL cytology or highly suspicious brain MRI. * Previous malignancies except for any carcinoma in-situ * Treatment with other anti-cancer therapy * Participating in other clinical trials in the former four weeks * Any other serious condition or uncontrolled active infection, altered mental status, or psychiatric condition that, in the investigator´s opinion, would limit the ability of an individual to meet the requirements of the study or which affects the interpretability of the results. * Active hepatitis virus infection (any serotype) or chronic infection with a potential risk of reactivation evaluated through a serological panel. * Active HIV infection. * Breastfeeding.