• Progression-free survival at 1 year [ Designated as safety issue: No ]
  
• Rate of molecular complete remission [ Designated as safety issue: No ]
  

• Time to Philadelphia chromosome (Ph) negativity as measured by polymerase chain reaction [ Designated as safety issue: No ]
  
• Disease-free survival [ Designated as safety issue: No ]
  
• Percent molecular complete remission [ Designated as safety issue: No ]
  
• Toxicity [ Designated as safety issue: Yes ]
  
• Time to progression [ Designated as safety issue: No ]
  

OBJECTIVES:

Primary

• Compare clinical response, in terms of 1-year progression-free survival and rate of molecular complete remission, in patients with Philadelphia chromosome-positive chronic myelogenous leukemia (Ph+ CML) in chronic phase who have achieved a complete cytogenetic remission to single-agent imatinib mesylate treated with imatinib mesylate, interferon alfa, and sargramostim (GM-CSF) vs imatinib mesylate and GM-K562 cell vaccine.

Secondary

• Compare time to Ph-negativity by polymerase chain reaction after randomization.
• Compare disease-free survival and percent molecular complete remissions.
• Determine the toxicity of these treatment regimens in these patients.

OUTLINE: This is a multicenter, randomized, crossover, study. Patients are randomized to 1 of 2 treatment arms.

All patients continue to receive their standard dose of imatinib mesylate in addition to 1 of the following treatment arms:

• Arm I : Patients receive interferon alfa subcutaneously (SC) and GM-CSF SC once daily for 6 months. Patients who achieve a molecular complete remission (CR) (defined as BCR-ABL-negative disease confirmed by 2 PCR assays separated by 1 month) at the end of the 6-month period, discontinue study therapy and are monitored for disease recurrence by blood tests every 4 weeks. Patients who do not achieve a molecular CR (defined as BCR-ABL-positive disease) after completion of the initial 6 months of therapy, receive an additional 6 months of therapy as above. Patients who achieve BCR-ABL-negative disease during the additional 6 months of therapy, discontinue study therapy and are monitored for disease recurrence by blood tests every 4 weeks. Patients who remain BCR-ABL-positive by PCR after an additional 6 months of therapy, are eligible to cross over to arm II.

If at any time after stopping study therapy blood tests show disease recurrence, patients restart imatinib mesylate and are eligible to cross over to arm II. Patients are also eligible to cross over to arm II in the presence of unacceptable toxicity.

• Arm II: Patients receive GM-K562 cell vaccine intradermally once every 3 weeks for a minimum of 6 months. Patients with BCR-ABL-negative disease at the end of the 6-month period discontinue study therapy and are monitored for disease recurrence by blood tests every 4 weeks. Patients with BCR-ABL-positive disease after the completion of the initial 6 months of therapy, receive an additional 6 months of therapy as above. Patients who achieve BCR-ABL-negative disease during the additional 6 months of therapy, discontinue study therapy and are monitored every 4 weeks for disease recurrence. Patients who remain BCR-ABL-positive after the additional 6 months of therapy, are eligible to cross over to arm I.

If at any time after stopping study therapy blood tests show disease recurrence, patients restart imatinib mesylate and are eligible to cross over to arm I. Patients are also eligible to cross over to arm I in the presence of unacceptable toxicity.

After completion of study therapy, patients are followed periodically for up to 1 year.

PROJECTED ACCRUAL: A total of 56 patients will be accrued for this study.