Study Evaluating the Safety and Efficacy of Eribulin Mesilate in Combination With Irinotecan Hydrochloride in Children With Refractory or Recurrent Solid Tumors

Participants must be

• >=12 months to less than or equal to ( 6 months and =12 months participant in order to maximize safety for infant participants. In Phase 2, participants aged >6 months and =50% Karnofsky (for participants >16 years of age) or Lansky (for participants =50% radiation of pelvis.
• At least 84 days must have elapsed after stem cell infusion prior to study drug administration
• No evidence of active graft-versus-host disease (GVHD) and at least 100 days must have elapsed after allogeneic bone marrow transplant or stem cell infusion prior to study drug administration
• Participants must have adequate bone marrow function, defined as:
• Peripheral absolute neutrophil count (ANC) >=1.0*10^9/liter (L).
• Platelet count >=100*10^9/L (not receiving platelet transfusions within a 7-day period prior to study drug administration).
• Hemoglobin (Hb) at least 8.0 grams per deciliter (g/dL) at baseline (blood transfusions are allowed during the screening period to correct Hb values =50 milliliters/minute/1.73 m^2, based on a 12 or 24 hours (h) urine creatinine collection.
• Participants must have adequate liver function, defined as:
• Bilirubin (sum of conjugated + unconjugated) =2 g/dL.
• All participants and/or their parents or guardians must sign a written informed consent.
• Participants must be willing to comply with all aspects of the protocol.

Exclusion Criteria

• Females who are breastfeeding or pregnant at Screening or Baseline. A separate baseline assessment is required if a negative screening pregnancy test was obtained more than 72 h before the first dose of study drug.
• Females of childbearing potential who:
• Do not agree to use a highly effective method of contraception for the entire study period and for 6 months after study drug discontinuation, that is:
• Total abstinence (if it is their preferred and usual lifestyle)
• An intrauterine device (IUD) or intrauterine system (IUS)
• A contraceptive implant
• An oral contraceptive OR
• Do not have a vasectomized partner with confirmed azoospermia.
• Males who have not had a successful vasectomy (confirmed azoospermia) or they and their female partners do not meet the criteria above (that is, not of childbearing potential or practicing highly effective contraception throughout the study period or for 3 months after study drug discontinuation). No sperm donation is allowed during the study period or for 3 months after study drug discontinuation.
• Concomitant Medications:
• Participants receiving corticosteroids who have not been on a stable dose for at least 7 days prior to study drug administration.
• Participants who are currently receiving other anticancer agents.
• Participants who are receiving cyclosporine, tacrolimus or other agents to prevent GVHD post bone marrow transplant.
• Participants who are receiving strong cytochrome P450 3A4 (CYP3A4) inhibitors and inducers including traditional herbal medicinal products (example, St. John's Wort).
• Phase 1: Received prior therapy with eribulin mesilate within 6 months prior to study drug administration.
• Phase 2: Received prior therapies with eribulin mesilate or irinotecan hydrochloride (for prior irinotecan hydrochloride, participants can be included if there was no tumor progression during irinotecan therapy).
• Any other malignancy that required treatment (except non-melanoma skin cancer, or histologically confirmed complete excision of carcinoma in situ), within 2 years prior to study drug administration.
• Has hypersensitivity to either study drug or any of the excipients.
• Has a known prior history of viral hepatitis (B or C) as demonstrated by positive serology (presence of antigens) or have an uncontrolled infection requiring treatment
• Has >Grade 1 peripheral sensory neuropathy or >Grade 1 peripheral motor neuropathy graded according to the Modified ("Balis") Pediatric Scale of Peripheral Neuropathies.
• Has cardiac pathology, defined as:
• Participants with known congestive heart fa