Inclusion Criteria:

          -  Signed informed consent form by patients and/or patients' parents/legal guardians and
             age appropriate assent form by the patients obtained before any study specific
             procedure

          -  Male or female patients from 6 months to ≤ 21 years old at the time of study
             enrollment

          -  Confirmation of diagnosis:

               -  Phase I: Patients must have histologic verification of a solid tumor or lymphoma
                  malignancy at diagnosis, with measurable or evaluable disease, for which there is
                  no standard curative anti-cancer treatment or treatment is no longer effective
                  and must have received ≥ 1 prior line of therapy.

               -  Phase II: patients must have histologically verified tumor at initial diagnosis
                  and radiologically or histologically confirmed status at inclusion as indicated
                  in the following: neuroblastoma, osteosarcoma, rhabdomyosarcoma or Ewing sarcoma.

               -  In Phase II, patients with solid tumors must have measurable disease (evaluable
                  disease is acceptable for neuroblastoma and Ewing sarcoma). Tumor assessment will
                  be done via computed tomography (CT), magnetic resonance imaging (MRI) or
                  positron emission tomography-computed tomography (PET-CT). Tumor lesions situated
                  in a previously irradiated area, or in an area subjected to other loco-regional
                  therapy, may be considered measurable if there has been demonstrated progression
                  in the lesion. Bone scans (if clinically indicated) should be obtained within ≤ 4
                  weeks prior to the start of treatment.

          -  Performance level: Lansky ≥ 50% for patients ≤ 16 years of age and Karnofsky ≥ 50% for
             patients > 16 years of age.

          -  Adequate bone marrow, renal and liver function.

        Exclusion Criteria:

          -  Active or uncontrolled infection (National Cancer Institute (NCI)-CTCAE Grade ≥ 2).

          -  History or concurrent condition of interstitial lung disease of any severity and/or
             severely impaired lung function (as judged by the investigator).

          -  Diabetes mellitus.

          -  Uncontrolled arterial hypertension despite optimal medical management (per
             institutional guidelines).

          -  Patients with central nervous system (CNS) malignancies.