Rolapitant Plus Olanzapine in Multiday Cisplatin Chemotherapy

Inclusion Criteria: * Written informed consent and HIPAA authorization for release of personal health information prior to registration. NOTE: HIPAA authorization may be included in the informed consent or obtained separately. * Age ≥ 15 years at the time of consent. * Must be able to take oral medications (swallow pills) * ECOG Performance Status of 0-2 within 14 days prior to registration. * Histological or serological confirmation of germ cell tumor planning on receiving a standard 5 day cisplatin based chemotherapy regimen. * Patients must have had no nausea or vomiting for 24 hours and no antiemetic use for 72 hours prior to starting protocol therapy. * No active central nervous system (CNS) metastases. Patients with neurological symptoms must undergo a head CT scan or brain MRI to exclude brain metastasis. A subject with prior brain metastasis may be considered if they have completed their treatment for brain metastasis at least 4 weeks prior to study registration, have been off of corticosteroids for ≥ 2 weeks, and are asymptomatic. * Prior cancer treatments are not allowed. Patients have to be chemotherapy naïve. * Absolute Neutrophil Count (ANC) ≥ 1 K/mm3 * Hemoglobin (Hgb) ≥ 10 g/dL * Platelets (Plt) ≥ 100 K/mm3 * Creatinine ≤ 2 mg/dL * Bilirubin ≤ 1.5 × upper limit of normal (ULN) * Aspartate aminotransferase (AST) ≤ 2.5 × ULN * Alanine aminotransferase (ALT) ≤ 2.5 × ULN * No concurrent use of thioridazine or pimozide. No use of agents expected to induce the metabolism of rolapitant which include: Rifampin, Rifabutin, Phenytoin, Carbamazepine, and Barbiturates. * As determined by the enrolling physician or protocol designee, ability of the subject to understand and comply with study procedures for the entire length of the study * Patients and their partners must agree to use a highly effective method of birth control from the signing of the informed consent form until 90 days following the last dose of rolapitant. Exclusion Criteria: * Any untreated central nervous system (CNS) metastases. * Treatment with any investigational drug within 30 days prior to registration. * Concurrent participation in a clinical trial which involves another investigational agent.