Cohorts 1, 2B, 3A, and 3B: Number of Participants With Best Overall Response (BOR)

Cohort 1, Single-agent Dose-finding: Lenvatinib 11 mg/m^2

Participants (age group 2 to \<6 years \[following completion of run-in period\] and 6 to \<18 years) with relapsed or refractory solid malignant tumors received lenvatinib 11 mg/m\^2 (per BSA, daily dose capped at 24 mg/day) as capsules or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 28 of each treatment cycle as single agent until PD, intolerable toxicity, participant noncompliance with safety or efficacy assessments, initiation of another anticancer therapy, voluntary discontinuation by participant at any time, or study termination by sponsor, whichever occurred first. Duration of each treatment cycle in Cohort 1=28 days.

Cohort 1, Single-agent Dose-finding: Lenvatinib 14 mg/m^2

Participants (age group 2 to \<6 years \[following completion of run-in period\] and 6 to \<18 years) with relapsed or refractory solid malignant tumors received lenvatinib 14 mg/m\^2 (per BSA, daily dose capped at 24 mg/day) as capsules or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 28 of each treatment cycle as a single agent until PD, intolerable toxicity, participant noncompliance with safety or efficacy assessments, initiation of another anticancer therapy, voluntary discontinuation by participant at any time, or study termination by sponsor, whichever occurred first. Duration of each treatment cycle in Cohort 1=28 days.

Cohort 1, Single-agent Dose-finding: Lenvatinib 17 mg/m^2

Participants (of age group 6 to \<18 years) with relapsed or refractory solid malignant tumors received dose of lenvatinib 17 mg/m\^2 (administered per BSA, daily dose capped at 24 mg/day) as capsules or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 28 of each treatment cycle as a single agent until PD, intolerable toxicity, participant noncompliance with safety or efficacy assessments, initiation of another anticancer therapy, voluntary discontinuation by the participant at any time, or study termination by the sponsor, whichever occurred first. Duration of each treatment cycle in Cohort 1=28 days.

Cohort2B,Single-agentExpansion,Osteosarcoma:Lenvatinib14mg/m^2

Participants with relapsed or refractory osteosarcoma received lenvatinib 14 mg/m\^2 (administered per BSA with daily dose capped at 24 mg/day) as capsule or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 28 of each treatment cycle as a single agent until PD, intolerable toxicity, participant noncompliance with safety or efficacy assessments, initiation of another anticancer therapy, voluntary discontinuation by the participant at any time, or study termination by the sponsor, whichever occurred first. Duration of each treatment cycle in Cohort 2B=28 days.

Cohort 3A, Combination Dose-finding: Lenvatinib 11 mg/m^2

Participants with relapsed or refractory osteosarcoma received lenvatinib 11 mg/m\^2 (20% lower than the RD from Cohort 1; administered per BSA with daily dose capped at 24 mg/day) as capsules or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 21 of each treatment cycle in combination with ifosfamide 3000 mg/m\^2/day intravenously and etoposide 100 mg/m\^2/day intravenously on Days 1 to 3 of each treatment cycle for up to a total of 5 cycles as a combination therapy. Duration of each treatment cycle in Cohort 3A=21 days.

Cohort 3A, Combination Dose-finding: Lenvatinib 14 mg/m^2

Participants with relapsed or refractory osteosarcoma received lenvatinib 14 mg/m\^2 (administrated per BSA with daily dose capped at 24 mg/day) as capsules or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 21 of each treatment cycle in combination with ifosfamide 3000 mg/m\^2/day intravenously and etoposide 100 mg/m\^2/day intravenously on Days 1 to 3 of each treatment cycle for up to a total of 5 cycles as a combination therapy. Duration of each treatment cycle in Cohort 3A=21 days.

Cohort 3B, Combination Expansion: Lenvatinib 14 mg/m^2

Participants with relapsed or refractory osteosarcoma received lenvatinib 14 mg/m\^2 (administrated per BSA with daily dose capped at 24 mg/day) as capsules or suspension (lenvatinib capsules were dissolved in water or apple juice for participants who were unable to swallow capsules and given as suspension), orally, once daily on Days 1 to 21 of each treatment cycle in combination with ifosfamide 3000 mg/m\^2/day intravenously and etoposide 100 mg/m\^2/day intravenously on Days 1 to 3 of each treatment cycle for up to a total of 5 cycles as a combination therapy. Duration of each treatment cycle in Cohort 3B=21 days.

Analysis denominator · Participants