IMMUNOtherapy and Stereotactic ABlative Radiotherapy (IMMUNOSABR) a Phase II Study

Inclusion criteria Oligometastatic disease (≤5 metastases) * Histological confirmed limited metastatic adult NSCLC patients, regardless of the PD-L1 status. * Maximum of 5 metastatic lesions, maximum two brain lesion with a total cumulative diameter of 5cm is allowed. SOC baseline imaging e.g MRI and/or PET-CT and CT-brain or MRI brain and/or CT-scan with at least covering thorax-upper abdomen-brain, within 6 weeks prior to randomisation. If a patient has unclear lesions in the liver or brain an MRI would be advised following the ESMO guidelines. o In patients with 2 lung tumours, it can be unclear if the patient has 2 concurrent primary tumours or a primary lung tumour with 1 metastasis. In this case, the local multidisciplinary tumour board will decide whether the patient has an M1 disease or not. • Previous treatment: Prior cancer treatments are allowed but must be discontinued for at least 4 weeks before randomisation. In case of maintenance chemotherapy, this therapy will only be started after the end of the L19-IL2 treatment or only in case of Anti-PD(L)1 treatment, during L19-IL2 therapy. * Age of 18 years or older. * WHO performance status 0-1; * Adequate bone marrow function, evaluated in the local laboratory (Lab): Absolute Neutrophil Count (ANC) of ≥ 1.0 x 109 /L, platelet count ≥ 100 x 109/L, Haemoglobin (Hb) ≥ 6.0 mmol/L (or 9.67 g/dL) (it is allowed to give a blood transfusion if Hb is initially too low); * Adequate hepatic function (evaluated in the local lab): total bilirubin ≤ 1.5 x upper limit of normal (ULN) for the institution; ALT, AST, and alkaline phosphatase ≤ 2.5 x ULN for the institution or ≤ 5 in case of liver metastasis); * Adequate renal function (evaluated in the local lab): creatinine clearance of at least 40 ml/min; * Adequate endocrine (TSH, FT4) function, local guidelines * The patient is capable of complying with study procedures; * Life expectancy of at least 12 weeks; * Negative serum pregnancy test for females of childbearing potential. * Signed and dated written informed consent. * Ability to comply with contraception requirements: Non-sterilised, sexually active male patient with a female partner who is of child-bearing age, must use two acceptable birth control methods like a condom combined with spermicidal cream or gel from the first dose of study medicine, during the study and at least up to 12 weeks after the last administration of the study medicine and up to 5 months after the last dose of the medicine with anti-PDL)1 as an action mechanism (if you get this product besides the study medicine), as an addition to the use, by the female partner, of as described in the following section: Women of childbearing potential (WOCBP) and WOCBP partners of male patients must be using, from the screening to three months following the last study drug administration and 4 5 months after last dose of anti-PD(L)1 maintenance treatment, effective contraception methods ((a) IUD (IUD) or intrauterine hormone delivery system (IUS), b) combined (with estrogen and progesterone) hormonal contraception associated with ovulation inhibition (oral, intravaginal, transdermal), c) hormonal contraception with progesterone only associated with ovulation inhibition (oral, injectable, implantable), as defined by the "Recommendations for contraception and pregnancy testing in clinical trials" issued by the Head of Medicine Agencies' Clinical Trial Facilitation Group (www.hma.eu/ctfg.html). Poly-metastatic disease (6 to 10 metastases) • Histological confirmed limited metastatic adult NSCLC patients, regardless of the PD-L1 status. A minimum of 6 and maximum of 10 metastatic lesions, maximum two brain lesion with a total cumulative diameter of 5cm is allowed. At least one measurable lesion (according to RECIST 1.1) that has no overlap with the PTV of the lesion subjected to radiotherapy. • Previous treatment: The time between the last administration of chemotherapy and the randomisation must be at least 4 weeks. In case of maintenance chemotherapy, this therapy will only be started after the study if e-arm, allowed during c-arm. In case of Anti-PD(L)1 treatment, this is allowed in both arms, so also during L19-IL2 therapy. * Age of 18 years or older; * WHO performance status 0-1; * Adequate bone marrow function (evaluated in the local lab): Absolute Neutrophil Count (ANC) of ≥ 1.0 x 109 /L, platelet count ≥ 100 x 109/L, Hb ≥ 6.0 mmol/L (or 9.67 g/dL) (it is allowed to give a blood transfusion if Hb is initially too low); * Adequate hepatic function (evaluated in the local lab): total bilirubin ≤ 1.5 x upper limit of normal (ULN) for the institution; ALT, AST, and alkaline phosphatase ≤ 2.5 x ULN for the institution or ≤ 5 in case of liver metastasis); * Adequate renal function (evaluated in the local lab): creatinine clearance of at least 40 ml/min; * Adequate endocrine (TSH, FT4) function, local guidelines; * The patient is capable of complying with study procedures; * Life expectancy of at least 12 weeks; * Negative serum pregnancy test for females of childbearing potential; * Ability to comply with contraception requirements (see oligo) * Signed and dated written informed consent. Exclusion criteria * More than 10 metastatic lesions. * More than 2 brain metastatic lesions. * 2 brain metastases with a cumulative diameter larger than 5 cm. * Patients with non-infectious pneumonitis, uncontrolled thyroid disease, pleuritis, pericarditis and peritonitis carcinomatosis. * Patients who received live vaccines 30 days or fewer prior to enrolment. * Patients who are already actively participating in another study. * Patients who need simultaneous radiation on the primary tumour and metastatic lesion(s). For these patients it might be an option to treat the primary tumour first although this is not mandatory for this study. There must be minimal four weeks between last treatment and randomisation. * Whole brain radiotherapy (WBRT) is not allowed, although it is accepted when given at least 4 weeks prior to randomisation or after the treatment period. Patients with stable brain metastases are not excluded. * Previous radiotherapy to an area that would be re-treated by (SAB)R, resulting in overlap of the high dose areas. * Maintenance therapy with Anti-PD(L)1 treatment combined with chemotherapy is not allowed during treatment ((SAB)R and L19-IL2 cycles). * Other active malignancy or malignancy within the last 2 years (except localised skin basal/squamous cell carcinoma, non-muscle invasive carcinoma of the bladder or in situ carcinoma from any site). * Concomitantly administered glucocorticoids may decrease the activity of IL2 and therefore should be avoided. However, patients who develop life-threatening signs or symptoms may be treated with dexamethasone until toxicity resolves or reduces to an acceptable level (generally grade 1 and 2, however must be based at the research physician's discretion). * History of allergy to intravenously administered proteins/peptides/antibodies/ radiographic contrast media. * HIV positive; active HIV infection, or active hepatitis B or C (assessed in local lab). * Systemic treatment with either corticosteroid (\>10 mg daily prednisone equivalents) or Interferon alpha or immunosuppressive medications within 14 days prior to randomisation. Topical or inhalation steroids are allowed. If a patient needs to take unexpectedly immunosuppressive medication during the trial, it will be allowed but decreasing the dose as soon as possible is strongly advised. * Prior history of organ transplant, including autologous stem cell transplant. * Acute or sub-acute coronary syndromes within the last year, acute inflammatory heart disease, heart insufficiency NYHA \> 2, or irreversible cardiac arrhythmias. * A known impaired cardiac function defined as left ventricular ejection fraction (LVEF) \< 50 % (or below the study site's lower limit of normal) as measured by MUGA or ECHO. * Uncontrolled hypertensive disease; (systolic blood pressure (SBP) ≥160 or diastolic blood pressure (DBP) ≥100 mm Hg during two measurements). * History or evidence of active autoimmune disease. * Severe diabetic retinopathy (neoangiogenesis targeted by L19 outside the tumour). * Major trauma, including oncologic surgery, but excluding smaller procedures like the placement of porth-à-cath or surgical biopsy, within 4 weeks prior to randomisation (neoangiogenesis targeted by L19 outside a tumour). * Any underlying mental, medical or psychiatric condition which in the opinion of the investigator will make administration of study drug hazardous or hinder the interpretation of study results. Unstable or serious concurrent uncontrolled medical conditions. * Pregnancy or breast feeding; it is well known that ED-B, the target of both L19IL2, is expressed in a variety of fetal tissues. Furthermore, anti-PD(L)1 treatment may increase the risk of immune-mediated disorders. Therefore, it will be contra-indicated for pregnant or lactating women.