Trial Information

A Randomized Phase II Trial of Interferon + GM-CSF Versus K562/GM-CSF Vaccination in CML Patients Achieving a Complete Cytogenetic Response to Frontline Tyrosine Kinase Inhibitor Therapy

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 tyrosine kinase inhibitor treated with interferon
alfa and sargramostim (GM-CSF) vs tyrosine kinase inhibitor 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 tyrosine kinase inhibitor 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 tyrosine kinase inhibitor 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 tyrosine kinase inhibitor 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.