Pemetrexed Disodium in Treating Patients With Ovarian Epithelial Cancer or Primary Peritoneal Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed ovarian epithelial or primary peritoneal cancer * Recurrent or persistent disease * Measurable disease * At least 1 unidimensionally measurable target lesion ≥ 20 mm by conventional techniques (e.g., palpation, plain x-ray, CT scan, or MRI) OR ≥ 10 mm by spiral CT scan * Tumors within a previously irradiated field are considered non-target lesions * Must have received 1 prior platinum-based (carboplatin, cisplatin, or another organoplatinum compound) chemotherapy regimen for primary disease * Initial treatment may have included high-dose therapy, consolidation, or extended therapy administered after surgical or non-surgical assessment * Patients who had not received prior paclitaxel may have received a second regimen that included paclitaxel * Platinum-resistant or refractory disease * Treatment-free interval \< 6 months after prior platinum-based therapy OR progressed during platinum-based therapy * Not eligible for a higher priority GOG protocol (i.e., any active phase III GOG protocol for the same patient population) PATIENT CHARACTERISTICS: Age * Any age Performance status * GOG 0-2 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 9 g/dL Hepatic * Bilirubin ≤ 1.5 times upper limit of normal (ULN) * Alkaline phosphatase ≤ 3 times ULN\* * AST and ALT ≤ 3 times ULN\* NOTE: \* ≤ 5 times ULN if due to hepatic metastases Renal * Creatinine clearance ≥ 45 mL/min Other * No other malignancy within the past 5 years except nonmelanoma skin cancer * No neuropathy (sensory or motor) \> grade 1 * No active infection requiring antibiotics * Not pregnant * Negative pregnancy test * Fertile patients must use effective contraception during and for at least 3 months after study treatment PRIOR CONCURRENT THERAPY: Biologic therapy * One prior noncytotoxic (biologic or cytostatic) regimen allowed for management of recurrent or refractory disease, including, but not limited to, the following: * Monoclonal antibodies * Cytokines * Small-molecule inhibitors of signal transduction * At least 3 weeks since prior biologic or immunologic therapy * At least 24 hours since prior growth factors * No concurrent routine colony-stimulating factors Chemotherapy * See Disease Characteristics * Recovered from prior chemotherapy * No prior cytotoxic chemotherapy for recurrent or persistent disease, including retreatment with initial chemotherapy regimens * No prior pemetrexed disodium Endocrine therapy * At least 1 week since prior hormonal therapy for the malignant tumor * Concurrent hormone replacement therapy allowed Radiotherapy * See Disease Characteristics * No prior radiotherapy to \> 25% of bone marrow * At least 2 weeks since prior radiotherapy and recovered Surgery * Recovered from prior surgery Other * No prior cancer treatment that would preclude study participation * No non-steroidal anti-inflammatory drugs (NSAIDs) for 2-5 days before, during, and for 1-2 days after study drug administration * Concurrent low-dose (≤ 325 mg/day) aspirin allowed * At least 3 weeks since other prior therapy for the malignant tumor