DISEASE CHARACTERISTICS:

• Histologically confirmed myelodysplastic syndromes including the following:

  • Refractory anemia (RA)
  • RA with ringed sideroblasts
  • RA with excess blasts (RAEB)
  • RAEB in transformation
  • Chronic myelomonocytic leukemia
  • Refractory cytopenia with multilineage dysplasia

• Patients with International Prognostic Scoring System score of 0 must have significant cytopenias of at least 4 weeks duration comprising at least one of the following:

  • Hematocrit no greater than 26%
  • Absolute neutrophil count less than 1,000/mm^3
  • Platelet count no greater than 50,000/mm^3
• Ineligible for allogeneic bone marrow transplantation (i.e., less than 60 years old, with a histocompatible donor, and no contraindications for transplantation)

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• More than 12 weeks

Hematopoietic:

• See Disease Characteristics

Hepatic:

• Bilirubin no greater than 1.5 mg/dL

Renal:

• Creatinine no greater than 1.5 mg/dL

Cardiovascular:

• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Other:

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No other uncontrolled illness
• No prior allergic reactions attributed to compounds of similar chemical or biological composition to tipifarnib (e.g., imidazoles)
• No allergy to imidazoles (e.g., clotrimazole, ketoconazole, miconazole, or econazole)
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 2 weeks since prior growth factors (except filgrastim [G-CSF])
• At least 4 weeks since prior immunotherapy and recovered
• No concurrent immunotherapy
• No concurrent growth factors except G-CSF

Chemotherapy:

• At least 4 weeks since prior chemotherapy (3 months for UCN-01) and recovered
• At least 24 hours since prior hydroxyurea
• No other concurrent chemotherapy

Endocrine therapy:

• At least 4 weeks since prior hormonal therapy and recovered
• No concurrent hormonal therapy
• No concurrent steroids

Radiotherapy:

• At least 4 weeks since prior radiotherapy and recovered
• No concurrent radiotherapy

Surgery:

• Not specified

Other:

• No more than 2 prior therapies
• No other concurrent agents known to influence the course of myelodysplastic syndromes
• No other concurrent investigational or commercial agents or therapies for the malignancy