Validation of Digital-PCR Analysis Through Programmed Imatinib Interruption in PCR Negative CML Patients

This study will recruit approximately 100 CML patients under imatinib therapy in complete molecular remission with a history of at least 18 months of consecutive negative standard Q-RT-PCR as performed in their own centers. After signing the informed consent form (ICF), the patients will be tested for dPCR and will discontinue imatinib therapy. Then they will be monitored by standard Q-RT-PCR to assess the maintenance of the molecular remission; collection of data will be prospective as each center will collect the data for 36 months. At the end of this period, a peripheral blood sample for dPCR analysis will be obtained from those patients who will still have undetectable BCR-ABL transcripts by Q-RT-PCR to verify CML eradication. The maintenance of molecular remission by Q-RT-PCR and the survival will be monitored every six months during an additional follow-up of 24 months. Patients found to be positive to BCR-ABL transcripts by standard Q-RTPCR will repeat the test every 2 to 4 weeks until the loss of molecular remission, defined as two consecutive BCR-ABL positive tests with at least one with BCR-ABL/BCR value above 0.1%, or until the end of the study, whichever come first.

Inclusion criteria

• Signed and dated IRB/IEC-approved Informed Consent
• Age>=18 years
• Male or female patients with CML diagnosed in chronic or accelerated phase and who have been treated for more than 2 consecutive years with imatinib therapy
• Sustained Complete Molecular Response (as defined by the treating center) for at least 18 months with imatinib treatment
• A minimum of 3 CMR determined by Q-RT-PCR analysis to support disease status, with the list one performed within 3 calendar months prior to enrollment date
• Willingness and ability to comply with scheduled visits laboratory tests and other study procedures

Exclusion criteria

• Allogenic hematopoietic stem cell transplantation
• Known active infections including human immunodeficiency virus (HIV) positivity
• Current enrollment another clinical trial
• Other severe acute or chronic medical or psychiatric condition or laboratory abnormality that may increase the risk associated with study participation or study drug administration or may interfere with the interpretation of study results