Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed solid tumor

- Metastatic or unresectable disease

- Standard curative or palliative measures do not exist OR are no longer effective

- Measurable disease by radiography (for patients treated at the maximum tolerated dose
[MTD] only)

- Tumor accessible for serial biopsies (for patients treated at the MTD only)

- No known brain metastases

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2 OR

- Karnofsky 60-100%

Life expectancy

- More than 12 weeks

Hematopoietic

- WBC ≥ 3,000/mm^3

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

- Platelet count ≥ 100,000/mm^3

- No bleeding diathesis or coagulopathy

Hepatic

- Bilirubin normal

- AST and ALT ≤ 2.5 times ULN

- PT INR ≤ 1.5 unless on full-dose warfarin

Renal

- Creatinine normal OR

- Creatinine clearance ≥ 60 mL/min

Cardiovascular

- No uncontrolled hypertension (i.e., systolic blood pressure [BP] > 140 mm Hg or
diastolic BP > 90 mm Hg despite medication)

- No symptomatic congestive heart failure

- No unstable angina pectoris

- No cardiac arrhythmia

Ophthalmic

- No abnormalities of the cornea, including any of the following:

- Dry eye syndrome

- Sjögren's syndrome

- Congenital abnormalities (e.g., Fuch's dystrophy)

- Abnormal slit-lamp examination using a vital dye (e.g., fluorescein or
Bengal-Rose)

- Abnormal corneal sensitivity test (e.g., Schirmer test or similar tear
production test)

Gastrointestinal

- No active peptic ulcer disease that would impair the ability to swallow pills

- No gastrointestinal tract disease resulting in an inability to take oral medication
or a requirement for IV alimentation

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- Willing to undergo serial biopsies, positron emission tomography, and CT scanning
(for patients treated at the MTD only)

- No ongoing or active infection

- No significant traumatic injury within the past 3 weeks

- No history of allergic reaction to drugs of similar chemical or biological
composition to study drugs

- No psychiatric illness or social situation that would preclude study compliance

- No other condition that would impair the ability to swallow pills

- No other uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

- No concurrent prophylactic hematopoietic colony-stimulating factors

Chemotherapy

- More than 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)
and recovered

Endocrine therapy

- Not specified

Radiotherapy

- More than 4 weeks since prior radiotherapy (except for low dose, non-myelosuppressive
radiotherapy) and recovered

Surgery

- More than 3 weeks since prior major surgery

- No prior surgical procedure affecting absorption

Other

- No prior sorafenib or erlotinib

- No other prior agents targeting Raf, vascular endothelial growth factor (VEGF), VEGF
receptor, or epidermal growth factor receptor

- No other concurrent investigational agents

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No concurrent enzyme-inducing antiepileptic drugs (e.g., phenytoin, carbamazepine, or
phenobarbital)

- No concurrent CYP3A4 inducers (e.g., rifampin or Hypericum perforatum [St. John's
wort])

- No other concurrent anticancer therapy

- Concurrent prophylactic anticoagulation therapy (e.g., low-dose warfarin) allowed
provided PT INR < 1.1 times upper limit of normal (ULN)

- Concurrent full-dose anticoagulants (e.g., warfarin) with PT INR > 1.5 allowed
provided both of the following criteria are met:

- Patient has an in range INR (between 2-3) while on a stable-dose of oral
anti-coagulant OR a stable-dose of low molecular weight heparin

- No active bleeding OR pathological condition that would confer a high risk of
bleeding (e.g., tumor involving a major vessel or known varices)