Pemetrexed Maintenance in Patients With Urothelial Carcinoma Who Completed First Line Platinum-based Chemotherapy

Inclusion Criteria: 1. Histologically or cytologically confirmation urothelial cancer of bladder, ureter, or renal pelvis. 2. Patients must present with locally advanced, recurrent or metastatic disease not amenable to surgery, radiotherapy, or combined modality therapy with curative intent. 3. Patients who were administered 4-6 cycles of cisplatin-based first line chemotherapy \[GP (gemcitabine/cisplatin), classic MVAC (methotrexate/vinblastine/doxorubicin/cisplatin), or dose-dense MVAC\] and were planned to undergo regular surveillance 4. ce after confirmation of absence of disease progression on CT taken within 3 week after the administration of the last cycle of 1st line chemotherapy. 5. For patients with recurrent disease who received prior adjuvant or neoadjuvant chemotherapy with cisplatin-containing regimen, the last administration of previous treatment should be administered at least 6 months before start date of 1st line chemotherapy. 6. Measurable disease according RECIST criteria v 1.1. 7. Age 20 years or older 8. ECOG performance status 2 or better 9. Adequate bone marrow, hepatic, and renal function 10. Signed and dated informed consent of document indicating that the patient (or legally acceptable representative) has been informed of all pertinent aspects of the trial prior to enrollment Exclusion Criteria: 1. Prior systemic chemotherapy or immunotherapy for palliative aim before or after 1st line cisplatin-based chemotherapy. However, prior intravesical chemotherapy or immunotherapy is allowed. 2. Disease progression during or after 1st line cisplatin-based chemotherapy 3. Known CNS metastasis 4. Diagnosis of any serious secondary malignancy within the last 2 years, except for adequately treated basal cell or squamous cell carcinoma of skin, early gastric carcinoma, early stage thyroid carcinoma, insignificant prostate carcinoma, or in situ carcinoma of cervix uteri 5. Pregnancy or breast feeding. 6. Serious hypersensitivity reaction to pemetrexed. 7. Severe renal function impairment with creatinine clearance \<45 mL/min by standard Cockcroft-Gault formula or GFR measured by Tc99m-DPTA serum clearance method. 8. Other severe acute or chronic medical or psychiatric condition