Study With Palonosetron Alone in Preventing Chemotherapy-induced Nausea and Vomiting in Untreated Patients With Aggressive Non Hodgkin's Lymphomas Who Underwent Moderately Emetogenic Chemotherapy

Inclusion Criteria: * Male or female, \>18 years of age; * Histologically or cytologically confirmed aggressive NHL (any stage in accordance with the REAL Classification); * Patients candidates to a initial chemotherapy treatment; * ECOG performance status of 0-1; * Scheduled to receive a single intravenous dose of at least one of the moderately emetogenic agents (according to the modified Hesketh classification) on Day 1; * Written informed consent; * Female of childbearing potential must be using reliable contraceptive measures; * Acceptable hepatic and renal functions; * Willing and able to complete the patient diary. Exclusion Criteria: * Highly emetogenic chemotherapy (containing cisplatin, mechlorethamine, streptozotocin, cyclophosphamide \>1500 mg/sqm; carmustine; dacarbazine; hexamethylmelamine; procarbazine), or single-agent chemotherapy with drugs having low/minimal emetogenic potential according to the Hesketh classification); * Diagnosis of Hodgkin's Disease or Leukemia; * Candidates to High-Dose Chemotherapy or Bone Marrow/Peripheral Blood Stem Cells Transplantation; * Chemotherapy schedules considering the administration of emetogenic drugs in more than two consecutive days; * Have received any investigational drugs within 30 days before study entry; * Have received any drug with potential anti-emetic efficacy (with the exception of specific corticosteroids foreseen in the chemotherapy combination) within 24 hours of treatment initiation); * Prior treatment with Palonosetron; * Have a seizure disorder requiring anticonvulsant medication unless clinically stable and free of seizure activity; * Experienced or ongoing vomiting or nausea from any organic etiology, in the screening phase; * Clinical evidence of current or impending bowel obstruction, peritonitis, infection, uremia, severe mucositis; * Clinically relevant electrolyte abnormalities; * Have a known hypersensitivity to 5HT3 receptor antagonists; * Radiotherapy within 30 days before chemotherapy administration, or scheduled to receive radiotherapy within two weeks after chemotherapy; * Female patients who are pregnant or breast feeding; * Inability to understand or cooperate with the study procedures.