Efficacy and Safety of Radiotherapy Compared to Everolimus in Somatostatin Receptor Positive Neuroendocrine Tumors of the Lung and Thymus.

The LEVEL Trial is a randomized, prospective, international, open-label, phase III study comparing everolimus and 177Lu-edotreotide in advanced somatostatin receptor positive (SSTR+) lung and thymic well differentiated neuroendocrine tumors with high expression of somatostatin receptors confirmed by positron emission tomography somatostatin receptor imaging.

In the investigator's opinion, patients recruited into the trial must be eligible to receive everolimus. Patients with both functional and nonfunctional lung and thymus neuroendocrine tumors (NETs) will be included in this trial. In total, 170 patients will be randomized in a 3:2 proportion to either experimental or control arms, respectively.

Randomization will be stratified according to prior medical therapy (tumor treatment-naïve \[patients who have not received any prior systemic anticancer therapy\] versus non-treatment- naïve \[patients who have received one or two prior line of systemic anticancer therapy, including somatostatin analogs (SSAs) as anti-tumor treatment\]) and histological differentiation (typical versus atypical / well versus moderately differentiated). Stratification according to the functional status is not foreseen considering the poor predictive and prognostic relevance of this criteria on PRRT in the literature.

Diagnosis of progression and tumor burden will be established based on radiological information from morphological imaging (magnetic resonance imaging \[MRI\] and/or computed tomography \[CT\]) according to RECIST v1.1. Tumors assessments will be scheduled every 12 ± 2 weeks from randomization (the first scan will be performed after Cycle 2 for the 177Lu-edotreotide until radiologically confirmed progression of the disease, initiation of new subsequent anticancer therapy, or death (whichever comes first). The scanning modality and protocol should be consistent with the baseline scan. Diagnosis of RECIST v1.1 progression will be made by the local investigator. The confirmatory scans should be performed preferably at the next scheduled imaging visit and no less than 4 weeks after the prior assessment of progression (PD) (in the absence of clinically significant deterioration). Additional MRI/CT scans may be performed at any other time if, in the investigator's clinical judgment, PD is suspected. For equivocal findings of progression, treatment may continue until the next scheduled assessment.

In both arms, for a given patient, trial treatment dosing should be discontinued if there is evidence of RECIST v1.1 progression, in case of persistent toxicities or if the patient withdraws consent to continue with treatment. In all cases, if possible, all other protocol scheduled assessments should be continued until the end of the long-term follow-up period, unless the patient explicitly withdraws consent to all trial procedures and follow-up.