• response rate [ Time Frame: Jan 2010 ] [ Designated as safety issue: No ]
  

• progression-free survival [ Time Frame: Jan 2010 ] [ Designated as safety issue: No ]
  
• overall survival [ Time Frame: Jan 2010 ] [ Designated as safety issue: No ]
  
• safety profile of pemetrexed (Alimta) treatment [ Time Frame: Jan 2010 ] [ Designated as safety issue: Yes ]
  
• pharmacokinetic analysis of half-life, maximum plasma concentration (Cpmax), clearance (CL), area under the curve (AUC), and apparent volume of distribution [ Time Frame: Jan 2010 ] [ Designated as safety issue: No ]
  
• evaluate the relationship between the expression of alpha folate receptor protein, TS and clinical response [ Time Frame: Jan 2010 ] [ Designated as safety issue: No ]
  

Inclusion Criteria:

• Histologic diagnosis of nasopharyngeal carcinoma.
• Locally recurrent or metastatic disease.
• Patients must have previously received one platinum based chemotherapy regimen for palliative therapy of locally advanced or metastatic disease.
• Prior platinum based chemotherapy completed at least 3 months prior to study enrollment and the patient must have recovered from toxic effects of the treatment.
• Previous radiation therapy is allowed, but should have been limited and must not have included whole pelvis radiation. Patients must have recovered from the toxic effects of the treatment prior to study enrollment (except for alopecia). Prior radiotherapy must be completed 30 days before study entry. Lesions that have been radiated cannot be included as sites of measurable disease unless clear tumor progression has been documented in these lesions since the end of radiation therapy.
• Disease status must be that of measurable disease as defined by Response Evaluation Criteria in Solid Tumors (RECIST) criteria.
• Performance status of 0 to 1 on the Eastern Cooperative Oncology Group (ECOG) Scale.
• Estimated life expectancy of at least 8 weeks.
• Patient compliance and geographic proximity that allow adequate follow-up.
• Adequate organ function including the following: Bone marrow: absolute neutrophil count (ANC) >or= 1.5x10^9/L, platelets >or= 100x10^9/L, hemoglobin >or= 9g/dL. Hepatic: bilirubin <1.5 x ULN, alkaline phosphatase, aspartate transaminase (AST) and alanine transaminase (ALT) < 2.5 x ULN (alkaline phosphatase, AST, ALT < 5 x ULN is acceptable if liver has tumor involvement). Renal: calculated creatinine clearance > 45 ml/min.
• Men or women of at least 18 years of age.
• For women: Must be surgically sterile, post-menopausal, or compliant with a medically approved contraceptive regimen during and for 3 months after the treatment period; must have a negative serum or urine pregnancy test and must not be lactating. For men: Must be surgically sterile, or compliant with a contraceptive regimen during and for 3 months after the treatment period.
• Signed informed consent from patient.

Exclusion Criteria:

• Known or suspected brain metastasis. Patients who have clinical signs or symptoms that are suspicious of brain metastasis must have a pretreatment computed tomography (CT) or magnetic resonance imaging (MRI) of the brain. A patient with documented brain metastasis, at the time of consideration for study entry or in the past, will be excluded from entering in the study.
• Have previously completed or withdrawn from this study, or received Alimta previously outside this study.
• Concurrent administration of any other tumor therapy.
• Active infection (at the discretion of the investigator).
• Serious concomitant disorders that would compromise the safety of the patient or compromise the patient's ability to complete the study, at the discretion of the investigator.
• Pregnancy or breast feeding.
• History of significant neurological or mental disorder, including seizures or dementia.
• Second primary malignancy that is clinically detectable at the time of consideration for study enrollment.
• Have received treatment within the last 30 days with a drug that has not received regulatory approval for any indication at the time of study entry.
• Inability to interrupt aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) 2 days before, the day of, and 2 days after the dose of Alimta. If a patient is taking a NSAID (Cox-2 inhibitors included) or salicylate with a long half-life, it should not be taken 5 days before, the day of, and 2 days after the dose of Alimta.
• Presence of clinically relevant third-space fluid collections that cannot be controlled by drainage or other procedures prior to study entry.
• Inability or unwillingness to take folic acid, vitamin B12 supplementation, or dexamethasone.