Inclusion Criteria:

- Patients must have recurrent or persistent epithelial ovarian or primary peritoneal
carcinoma.

- All patients must have measurable disease.

- Patients must have at least one "target lesion" to be used to assess response on this
protocol.

- Patients must not be eligible for a higher priority GOG protocol, if one exists.

- Patients who have received one prior regimen must have a GOG Performance Status of 0,
1, or 2. Patients who have received two prior regimens must have a GOG Performance
Status of 0 or 1.

- Any hormonal therapy directed at the malignant tumor must be discontinued at least
one week prior to registration. Continuation of hormone replacement therapy is
permitted.

- Any other prior therapy directed at the malignant tumor, including immunologic
agents, must be discontinued at least four weeks prior to registration.

- Patients must have had one prior platinum-based chemotherapeutic regimen for
management of primary disease containing carboplatin, cisplatin, or another
organoplatinum compound.

- Patients must NOT have received any non-cytotoxic therapy for management of recurrent
or persistent disease.

- Patients of child-bearing potential must have a negative serum pregnancy test prior
to study entry and be practicing an effective form of contraception (for example,
intrauterine device [IUD], birth control pills, or barrier device) during and for 3
months after discontinuation of study treatment.

Exclusion Criteria:

- Patients with previous enzastaurin treatment.

- Patients who have received radiation to more than 25% of marrow-bearing areas

- Patients with other invasive malignancies, with the exception of non-melanoma skin
cancer, who had (or have) any evidence of other cancer present within the last 5
years or whose previous cancer treatment contraindicates this protocol therapy.

- Patients who 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.

- Patients who are unable to discontinue use of carbamazepine, phenobarbital, and
phenytoin (refer to Concomitant Medications for a discussion of enzyme inducing
anti-epileptic drugs [EIAEDs]).

- Patients who are receiving concurrent administration of any other systemic anticancer
therapy except for a biphosphonate if patient has bony metastases.

- Patients who have received prior therapy with non-cytotoxic agents (i.e.
bevacizumab).

- Patients with serious concomitant systemic disorders (for example, active infection
or abnormal electrocardiogram (ECG) indicative of cardiac disease) that, in the
opinion of the investigator, would compromise the safety of the patient and his/her
ability to complete the study.