A Rollover Protocol to Allow Continued Access to Tivozanib (AV 951) for Subjects Enrolled in Other Tivozanib Protocols

Inclusion Criteria: 1. The subject must have received tivozanib while enrolled in another protocol, must be tolerating study drug and must currently display clinical benefit. The length of time that a subject must be on the parent protocol before rolling over to this protocol will be dictated by the parent protocol. 2. If female and of childbearing potential, documentation of negative pregnancy test prior to enrollment. 3. Ability to give written informed consent. Exclusion Criteria: 1. \> 4 weeks since discontinuation of tivozanib treatment on a previous protocol 2. If female, pregnant or lactating 3. Sexually active male and pre-menopausal female subjects (and their partners) unless they agree to use adequate contraceptive measures, while on study and for 30 days after the last dose of study drug. All fertile male and female subjects (and their partners) must agree to use a highly effective method of contraception. Highly effective birth control includes (a) intrauterine device plus one barrier method; or (b) 2 barrier methods. Effective barrier methods are male or female condoms, diaphragms, and spermicides (creams or gels that contain a chemical to kill sperm). (Note: Oral, implantable, or injectable contraceptives may be affected by cytochrome P450 interactions, and are not considered effective for this study.) 4. Uncontrolled hypertension: systolic blood pressure \> 140 mmHg or diastolic blood pressure \>90 mmHg on 2 or more antihypertensive medications, documented on 2 consecutive measurements taken at least 24 hours apart. 5. Newly identified central nervous system (CNS) malignancies or documented progression of CNS metastases; subjects will be allowed only if the CNS metastases have been adequately treated with radiotherapy or surgery. For subjects receiving steroid therapy please refer to Section 6.3 for allowed steroid maintenance therapy. 6. Unhealed wounds (including active peptic ulcers) 7. Serious/active infection or infection requiring parenteral antibiotics 8. Life-threatening illness or organ system dysfunction compromising safety evaluation 9. Psychiatric disorder, altered mental status precluding informed consent or necessary testing 10. Inability to comply with protocol requirements