A Study to Evaluate the Safety and Pharmacokinetics of Eflapegrastim in Pediatric Participants With Solid Tumors or Lymphomas and Treated With Myelosuppressive Chemotherapy

The purpose of this study is to evaluate the safety and pharmacokinetics of eflapegrastim in pediatric participants with solid tumors or lymphoma and treated with myelosuppressive chemotherapy.

Inclusion Criteria: 1. Participant must have a pathologic/histologic confirmed newly diagnosed/relapsed/recurrent solid tumor or lymphoma without bone marrow involvement. 2. Participant must be a candidate to receive myelosuppressive chemotherapy, with a febrile neutropenia rate of at least 20% as outlined in the National Comprehensive Cancer Network (NCCN) guidelines. 3. Participant has adequate hematological, renal, and hepatic function. 4. Participant must have an echocardiogram (ECHO) or multigated acquisition (MUGA) within 14 days of Screening if receiving a cardiotoxic therapy and have a cardiac ejection fraction of \>50%. 5. Participant must have a lumbar puncture, if clinically indicated, to rule out central nervous system (CNS) involvement within 14 days of study entry. 6. Participant has a Karnofsky performance level ≥50% for patients ≥16 years of age or a Lansky performance level ≥50 for children \