Inclusion Criteria

-INCLUSION CRITERIA:

1. Pathologic confirmation of cancer by the Laboratory of Pathology, NCI

2. Phase I: Diagnosis of recurrent, metastatic or primary unresectable solid tumor that
does not have curative standard treatment.

Phase II: Diagnosis of recurrent, metastatic or primary unresectable medullary
thyroid cancer (MTC).

3. Measurable disease at presentation: Either by RECIST or by measurement of serum
markers (calcitonin, CEA, PSA or CA-125) in the dose-finding portion of the study;
with disease measurable by RECIST required only in the phase II cohort.

4. A life expectancy of at least 3 months and ECOG performance status 0 - 1.

5. Age greater than or equal to 18 years

6. Last dose of chemotherapy or experimental therapy more than 4 weeks (6 weeks in the
case of nitrosourea) prior to enrollment date; unless the last therapy consisted of
an oral agent whose average half life is known to be less than 48 hours in which case
only 2 weeks need to have elapsed. Regardless of the therapy, any toxicity greater
than CTCAE grade 1 from previous anti-cancer therapy must have been resolved.

7. Last radiotherapy treatment 4 weeks prior to starting treatment with this protocol -
with the exception of palliative radiotherapy - and there must be sites of measurable
disease that did not receive radiation.

8. Organ and marrow function as defined:

- total bilirubin less than 1.5 times the upper limit of reference range (ULRR),
unless the patient meets the criteria for Gilbert's Syndrome

- alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline
phosphatase (ALP) all three less than 2.5 times the ULRR, or less than 5 times
the ULRR if judged by the investigator to be related to liver metastases

- serum creatinine less than 1.5 times the ULRR or creatinine clearance greater
than or equal to 30 mL/minute (calculated by Cockcroft-Gault formula or measured
in a timed urine collection)

- serum calcium below the CTCAE grade 1 upper limit (11.5mg/dL or 2.9 mmol/L). In
cases where the serum calcium is below the normal range, the calcium adjusted
for albumin is calculated and substituted for the measured value.

- serum potassium greater than the LLN and less than 5.5 mmol/L.

- serum magnesium greater than the LLN and less than 3.0 mg/dL or 1.23 mmol/L.

- absolute neutrophil count greater than or equal to 1000/mm(3)

- platelet count greater than or equal to 100,000/mm(3)

- PT less than or equal to 4 seconds above ULN and PTT less than or equal to 10
seconds above ULN.

9. Ability to understand and sign an informed consent document.

10. Provision of informed consent prior to any study-related procedures

11. Negative pregnancy test for women of childbearing potential

12. Ability and willingness to follow the guidelines of the clinical protocol including
visits to NCI, Bethesda, Maryland for treatment and follow up visits.

13. Because the effects of chemotherapy on the developing human fetus are potentially
harmful, female patients must be one year post-menopausal, surgically sterile, or
using an acceptable method of contraception during and continued after the last dose
of study medications (oral contraceptives, barrier methods, approved contraceptive
implant, long-term injectable contraception, intrauterine device or tubal ligation).
Male patients must be surgically sterile or using an acceptable method of
contraception during their participation in this study. Contraceptive use will
continue for at least two months, five half-lives, after the last dose of study
medication.

EXCLUSION CRITERIA:

1. Patients with cancer potentially curable by surgical excision alone or patients who
have not received therapy that might be considered standard and potentially curable.

2. Evidence of severe or uncontrolled systemic disease or any concurrent condition -
including, but not limited to symptomatic congestive heart failure, unstable angina
pectoris, unstable hypertension, seizure disorder, or psychiatric illness - which in
the Investigator's opinion makes it undesirable for the patient to participate in the
trial or which would jeopardize compliance with the protocol.

3. Untreated brain metastases (or local treatment of brain metastases within the last 6
months) due to the poor prognosis of these patients and difficulty ascertaining the
cause of neurologic toxicities.

4. During Phase II enrollment: Prior therapy with vandetanib.

5. Women who are currently pregnant or breast-feeding, due to the possible adverse
effects on the developing fetus and infants.

6. The presence of a second malignancy within the last 2 years, other than squamous cell
carcinoma of the skin or in situ cervical cancer because it will complicate the
primary objective of the study. Cancer survivors who have been free of disease for at
least two years can be enrolled in this study.

- There is one other exception to the exclusion of secondary malignancies: MEN2
patients with concurrent medullary thyroid cancer and pheochromocytoma may be
enrolled at the discretion of the Principal Investigator.

7. Patients with evidence of a bleeding diathesis that cannot be corrected with standard
therapy or factor replacement.

8. Any unresolved toxicity greater than CTCAE grade 1 (except alopecia) from previous
anticancer therapy. Patients with grade 1 neuropathy will be evaluated on a case by
case basis for entry into study. Baseline conditions will be taken into
consideration.

9. Major surgery within 4 weeks, or incompletely healed surgical incision before
starting study therapy.

10. Clinically significant cardiovascular event (e.g. myocardial infarction, superior
vena cava syndrome (SVC), New York Heart Association (NYHA) classification of heart
disease greater than or equal to 2 within 3 months before entry; or presence of
cardiac disease that, in the opinion of the Investigator, increases the risk of
ventricular arrhythmia.

11. History of arrhythmia (multifocal premature ventricular contractions PVCs, bigeminy,
trigeminy, ventricular tachycardia, or uncontrolled atrial fibrillation) which is
symptomatic or requires treatment (CTCAE grade 3) or asymptomatic sustained
ventricular tachycardia. Atrial fibrillation controlled on medication is not
excluded.

12. History (within the last 6 months) or presence of stroke/cerebrovascular accident.

13. QTc prolongation with other medications. If the medication can be discontinued and an
alternative medication started that does not cause QTc prolongation, the patient
would be eligible. If no alternative medication is available and the medication
cannot be discontinued for medical reasons, then the patient would not be eligible.

14. Congenital long QT syndrome, or 1st degree relative with unexplained sudden death
under 40 years of age.

15. Presence of left bundle branch block (LBBB).

16. QTc with Bazett's correction that is not measurable, or greater than or equal to 480
msec on screening ECG. (Note: If a patient has a QTc interval greater than or equal
to 480 msec on screening ECG, the screen ECG may be repeated twice (at least 24 hours
apart). The average QTc from the three screening ECGs must be less than 480 msec in
order for the patient to be eligible for the study). Patients who are receiving a
drug that has a risk of QTc prolongation are excluded if QTc is greater than or equal
to 460 msec.

17. Concurrent medication that may cause QTc prolongation or induce Torsades de Pointes:
Those medications in Group One will not be allowed. Those medications in Group Two
will be allowed.

18. Hypertension not controlled by medical therapy (systolic blood pressure greater than
160 mm Hg or diastolic blood pressure greater than 100 mm Hg)

19. Currently active (uncontrolled) diarrhea greater than or equal to CTCAE Grade 2 that
may affect the ability of the patient to absorb the vandetanib or tolerate diarrhea.
Antidiarrhea medications are allowed in patients with chronic diarrhea.

20. Concomitant medications that are potent inducers (rifampicin, rifabutin, phenytoin,
carbamazepine, phenobarbital and St. John's Wort) of CYP3A4 function.

21. Major surgery within 4-weeks, or incompletely healed surgical incision before
starting study medications. Biopsies, port placements, and dental work are examples
of acceptable (nonmajor) surgery within the 4 week time frame.

22. Inability to take oral medications for whatever reason.