Brigatinib Post Definitive Chemo-radiotherapy in Patients with ALK-fusion Non-small Cell Lung Cancer

Inclusion Criteria: Inclusion criteria for enrolment * Pathologically documented, treatment naïve unresectable stage III NSCLC * Documented ALK-fusion, tested locally on tumour tissue by a validated method (DNA NGS, RNA NGS, FISH, IHC, or ctDNA) * ECOG Performance Status 0-1 * Age ≥18 years * Patient is a candidate to receive chemo-radiotherapy, as per investigator's assessment (including adequate haematological, renal and liver function as per local guidelines). * Women of childbearing potential, including women who had their last menstruation in the last 2 years, must have a negative urinary or serum pregnancy test within 5 weeks before enrolment. * Ability to comply with the trial protocol, in the investigator's judgment. * Written IC for trial participation must be signed and dated by the patient and the investigator prior to any trial-related intervention, including the submission of mandatory biomaterial. Eligibility criteria for randomisation Randomisation of eligible patients must occur within 8 weeks after the last radiotherapy fraction. * Completion of thoracic radiotherapy * Non-PD at restaging * Adequate haematological function * Adequate renal function * Adequate liver and pancreatic function * Women of childbearing potential, including women who had their last menstruation in the last 2 years, must have a negative urinary or serum pregnancy test before randomisation and should be repeated within 3 days before the first dose of brigatinib. * No radiation-pneumonitis of grade ≥2 * All other AEs from previous chemo-radiotherapy resolved to grade \<2 (except for alopecia) * ECOG 0-2 * No major surgery as defined by the investigator within 4 weeks of the the first planned dose of brigatinib. Minor surgical procedures such as catheter placement or minimally invasive biopsies are allowed. * No systemic treatment with strong cytochrome p-450 (cyp)3a inhibitors, strong cyp3a inducers, or moderate cyp3a inducers within 14 days before randomisation. Exclusion Criteria: * Diagnosis of another primary malignancy other than NSCLC. With the exception of adequately treated non-melanoma skin cancer or cervical cancer in situ; definitively treated non-metastatic prostate cancer; or patients with another primary malignancy who are definitively relapse-free with at least 3 years since the diagnosis of the other primary malignancy. * Prior treatment for NSCLC * Any evidence of stage IV NSCLC * Significant, uncontrolled, or active cardiovascular disease * Uncontrolled hypertension Patients with hypertension should be under treatment on study entry to control blood pressure. * History or the presence at baseline of pulmonary interstitial disease, drug-related pneumonitis. * Ongoing or active infection, including, but not limited to, the requirement for intravenous antibiotics. * Malabsorption syndrome or other GI illness that could affect oral absorption of brigatinib. * Known or suspected hypersensitivity to brigatinib or its excipients. * Any concurrent medical condition which, in the opinion of the investigator, would compromise patient safety or interfere with the evaluation of brigatinib. * Judgment by the investigator that the patient should not participate in the study if the patient is unlikely to comply with study procedures, restrictions and requirements. * Women who are pregnant or in the period of lactation. * Sexually active men and women of childbearing potential who are not willing to use an effective contraceptive method during the trial until at least 4 months after the last dose of protocol treatment.