Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of systemic mastocytosis

- Aggressive or borderline (smoldering) disease (in first line or more)

- Relapsed or progressive disease

- Measurable or evaluable disease

- Presence of c-Kit D816V mutation in the skin, spine, or infiltrated organs

- No nonsymptomatic mastocytosis

PATIENT CHARACTERISTICS:

- Life expectancy > 3 months

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception for 1 month prior to, during, and
until first menstrual cycle after completion of study treatment

- Bilirubin < 2 times normal (unrelated to disease)

- Liver enzymes < 2 times normal (unrelated to disease)

- Creatinine ≤ 300 mmol/L

- No central or peripheral neuropathy leading to psychiatric concerns

- No HIV positivity

- No active infection or other serious underlying illness that would preclude treatment

- No history of thromboembolism or deep vein thrombosis

- No geographical, social, or psychological reasons preventing medical monitoring

PRIOR CONCURRENT THERAPY:

- More than 4 weeks since prior antitumor therapy (e.g., chemotherapy, radiotherapy)

- No other concurrent treatment specific for this disease

- No concurrent participation in another experimental drug trial