Inclusion Criteria:

- Histologically confirmed ovarian epithelial cancer or primary peritoneal cancer

- Recurrent or persistent disease

- Platinum AND taxane-resistant or refractory disease

- Progressed during therapy

- Refractory disease within 6 months of therapy

- Measurable disease

- At least 20 mm by conventional techniques

- At least 10 mm by spiral CT scan

- Tumor lesions located within a previously irradiated field are not considered
measurable disease unless there is documented tumor progression in these lesions
or biopsy confirmation ≥ 90 days following completion of radiotherapy

- Ineligible for higher priority GOG protocol

- No active brain metastases

- Performance status - GOG 0-2

- Absolute neutrophil count ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- Bilirubin ≤ 1.5 times upper limit of normal (ULN)

- SGOT ≤ 2.5 times ULN

- Alkaline phosphatase ≤ 2.5 times ULN

- Creatinine ≤ 1.5 times ULN

- No sensory or motor neuropathy > grade 1

- No dementia or altered mental status

- No other serious uncontrolled medical disorder

- No active infection requiring antibiotics

- No prior hypersensitivity reaction to paclitaxel or other therapy containing
Cremophor EL

- No other malignancy within the past 5 years except nonmelanoma skin cancer

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- At least 3 weeks since prior biologic therapy

- At least 3 weeks since prior immunotherapy

- Must have received:

- 1 prior combination taxane-based and platinum-based chemotherapy regimen

- 1 prior platinum-based chemotherapy regimen AND 1 prior taxane-based
chemotherapy regimen

- Initial treatment may include high-dose therapy, consolidation, or extended therapy

- At least 3 weeks since prior chemotherapy and recovered

- No prior ixabepilone

- No other prior cytotoxic chemotherapy for recurrent or persistent disease, including
treatment with initial regimen

- At least 1 week since prior hormonal anticancer therapy

- Concurrent hormone replacement therapy allowed

- At least 3 weeks since prior radiotherapy and recovered

- No prior radiotherapy to site(s) of measurable disease

- No radiotherapy to > 25% of marrow-containing areas

- Recovered from recent surgery

- At least 3 weeks since other anticancer therapy

- No prior anticancer therapy that precludes study participation

- No concurrent food supplements (e.g., St. John's wort)

- No concurrent amifostine or other protective agents