DISEASE CHARACTERISTICS:

• Histologically confirmed ovarian epithelial or primary peritoneal carcinoma
• Recurrent or persistent disease

• Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan

  • Must have ≥ 1 target lesion to assess response

    • Tumors within a previously irradiated field are designated as "nontarget" lesions unless progression is documented or a biopsy is obtained to confirm persistence ≥ 90 days after completion of radiotherapy

• Must have received 1 prior platinum-based chemotherapy regimen containing carboplatin, cisplatin, or another organoplatinum compound for management of primary disease

  • Initial treatment may have included high-dose therapy, consolidation therapy, or extended therapy administered after surgical or nonsurgical assessment

  • Must meet any 1 of the following criteria for platinum-based therapy:

    • Disease progression during therapy
    • Treatment-free interval after completion of treatment < 12 months
    • Disease persistence after completion of therapy
• Ineligible for a higher priority GOG clinical trial

PATIENT CHARACTERISTICS:

• GOG performance status 0-1 (for patients who received 2 prior treatment regimens) OR 0-2 (for patients who received 1 prior treatment regimen)
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Hemoglobin ≥ 9 g/dL (transfusions allowed)
• Creatinine < 1.5 times upper limit of normal (ULN)
• Bilirubin ≤ 2 times ULN
• Alkaline phosphatase ≤ 3 times ULN (5 times ULN if liver metastases are present)
• AST and ALT ≤ 3 times ULN (5 times ULN if liver metastases are present)
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after completion of study treatment
• Able to swallow tablets
• No sensory or motor neuropathy > grade 1
• No active infection requiring antibiotics
• No other invasive malignancies or evidence of cancer within the past 5 years except nonmelanoma skin cancer
• No serious systemic disorders that would preclude study compliance, including an abnormal ECG indicative of cardiac disease

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from prior surgery, radiotherapy, or chemotherapy
• At least 1 week since prior anticancer hormonal therapy
• No more than 1 additional cytotoxic regimen for management of recurrent or persistent disease
• At least 4 weeks since other prior anticancer therapy, including immunotherapy
• At least 30 days since prior investigational drugs
• No prior enzastaurin hydrochloride
• No prior radiotherapy to > 25% of marrow-bearing areas
• No prior noncytotoxic therapy, including bevacizumab, for recurrent or persistent disease
• No prior treatment that would preclude treatment on this protocol
• No concurrent chemotherapy, immunotherapy, or other experimental medications
• No concurrent enzyme-inducing antiepileptic drugs, including carbamazepine, phenobarbital, or phenytoin
• No other concurrent systemic anticancer therapy
• No concurrent radiotherapy, including palliative radiotherapy
• No concurrent agents that stimulate thrombopoiesis
• No concurrent amifostine or other protective reagents
• Concurrent hormone replacement therapy allowed
• Concurrent bisphosphonates allowed provided bony metastases are present