Inclusion Criteria:

- Unresectable, residual, recurrent or persistent ATC, histologically or cytologically
confirmed

- Prior cytotoxic therapeutic regimen as primary therapy for curative intent or prior
targeted therapies (TKIs) are eligible (Prior taxane or platinum therapy is allowed)

- Untreated ATC following biopsy, surgery for curative intent, palliation, or after
radiation therapy has been considered or administered with or without
radiosensitizing chemotherapy

- Disease present on clinical exam (measurable or non-measurable)

- Distant metastases (Stage IVC) only must have histologic confirmation of ATC either
from the original primary lesion or a metastatic site

- Neoadjuvant therapy with radiation and either radiosensitizing chemotherapy followed
by surgery for curative intent, palliation, or biopsy are eligible if residual or
persistent ATC is present

- Subjects with tracheostomy are eligible

- ECOG PS 2 or less

- Adequate bone marrow, renal, and hepatic function, electrolytes WNL for the
institution

Exclusion Criteria:

- Disease that is able to be completely resected with negative microscopic margins and
without any residual disease in the body

- Active brain metastases, including symptomatic involvement, evidence of cerebral
edema by prior CT or MRI, radiographic evidence of brain metastasis since definitive
therapy, or continued requirement for corticosteroids for cerebral edema

- History of malignancies other than ACT except prior lower grade thyroid malignancy,
curatively treated basal cell carcinoma and in-situ melanoma of the skin, cervical
intra-epithelial neoplasia,localized prostate cancer, in-situ carcinoma of the breast

- Known intolerance or hypersensitivity to fosbretabulin, paclitaxel, carboplatin or
any of their components

- Receiving concurrent investigational therapy or have received investigational therapy
for any indication within 28 days of the first scheduled day of dosing

- Grade 3 or greater peripheral neuropathy

- History of prior cerebrovascular event,including transient ischemic attack within the
past 6 months

- Uncontrolled hypertension defined as blood pressure >150/100 mm Hg despite medication

- Symptomatic vascular disease (e.g. intermittent claudication)

- History of unstable angina pectoris pattern, myocardial infarction (including non-Q
wave) within the past 6 months, or NYHA Class III or IV congestive heart failure

- History of torsade de pointes, ventricular tachycardia, ventricular fibrillation or
congenital long QT syndrome.

- Pathologic bradycardia (<60 b/m or heart block(excluding 1st degree block, consisting
of PR interval prolongation only)

- ECG findings of clinically significant ventricular arrhythmia, new ST segment
elevation or depression, or new Q wave on ECG (PVCs are not excluded).

- QTc interval 480 ms or more

- Requirement of concurrent treatment with any drugs know to prolong the QTc interval,
including anti-arrhythmic medications

- Potassium and/or magnesium concentrations below normal range for the reference
laboratory

- History of solid organ or bone marrow transplant