Pemetrexed for the Treatment of Chordoma

Inclusion Criteria:

1. Participant has the ability to understand and the willingness to provide a signed and dated informed consent form.
2. Participant has the willingness to comply with all study procedures and availability for the duration of the study.
3. Participant has a diagnosis of chordoma.
4. Participant is male or female, 18 years of age or older.
5. Participant has a Karnofsky Performance Status of 50% or greater.
6. Participant has adequate organ function:

   1. ANC at least 1.5 x 10\^9/L or higher
   2. Platelets at least 100 x 10\^9/L or higher
   3. Hemoglobin at least 8 g/dL or higher.
   4. Total bilirubin 1.5 x upper limit of normal (ULN) or lower.
   5. ALT and AST 3 x ULN or lower.
   6. Serum creatinine 1.5 x ULN or lower.
7. Participant has the ability to interrupt non-steroidal anti-inflammatory drugs (NSAIDS) 2 days before (5 days for long-acting NSAIDs), the day of, and 2 days following administration of Pemetrexed.
8. Participant has the ability to take folic acid, Vitamin B12, and dexamethasone according to protocol.
9. Participant has recovered from any previous therapy-related toxicity to CTCAE Grade 1 or to their clinical baseline at study entry.

Exclusion Criteria:

1. Participant is less than 28 days from any investigational agent.
2. Participant has third space fluid which cannot be controlled by drainage.
3. Participant has a severe or uncontrolled medical disorder that would, in the investigator's opinion, impair ability to receive study intervention, including, but not limited to:

   1. Uncontrolled diabetes;
   2. Renal disease that requires dialysis;
   3. Pulmonary disorder requiring supplemental oxygen to keep saturation \>95% and the situation is not expected to resolve within 2 weeks;
   4. Severe dyspnea at rest or requiring oxygen therapy;
   5. Interstitial lung disease;
   6. History of major surgical resection involving the stomach or small bowel;
   7. Preexisting Crohn's disease;
   8. Ulcerative colitis;
   9. Uncontrolled vasculitis and/or disease with known vasculitis;
   10. Preexisting chronic condition resulting in baseline Grade 2 or higher diarrhea;
   11. Psychiatric illness/social situations that would limit compliance with study requirements.
4. Participant has an active bacterial infection requiring intravenous \[IV\] antibiotics at time of initiating study treatment, fungal infection, or detectable viral infection (such as known human immunodeficiency virus positivity or with known active hepatitis B or C).
5. Participant has a personal history or presence of any of the following cardiovascular conditions:

   1. Syncope of cardiovascular etiology;
   2. Ventricular arrhythmia of pathological origin (including, but not limited to, ventricular tachycardia and ventricular fibrillation);
   3. Myocardial infraction within 6 months of investigational product administration;
   4. Unstable angina;
   5. Sudden cardiac arrest;
   6. Congestive heart failure (NYHA classification ≥ 3).
6. Participant is a female of childbearing potential who is pregnant or nursing.