Months Of Imatinib Research Articles

Effect of a p210 multipeptide vaccine associated with imatinib or interferon in patients with chronic myeloid leukaemia and persistent residual disease: a multicentre observational trial

Although imatinib is the standard treatment for chronic myeloid leukaemia, not all patients reach complete cytogenetic remission (CCR) and most maintain detectable disease at the molecular level. We investigated whether a vaccine targeting the BCR-ABL-derived p210 fusion protein was an active and specific immunotherapy. We recruited 16 patients who had chronic myeloid leukaemia (with the b3a2 fusion point of p210), stable residual disease, a minimum treatment of 12 months of imatinib or 24 months of interferon alfa, and no further reduction of residual disease for at least 6 months preceding enrollment. They were given six vaccinations with a peptide vaccine derived from the sequence p210-b3a2 plus molgramostim and QS-21 as adjuvants (CMLVAX100) before assessment of immunological and disease response, which included detecting amounts of b3a2 transcripts by standardised quantitative real-time reverse-transcriptase PCR. Of ten patients on imatinib, nine started CMLVAX100 having had a median of 10 months' stable cytogenetic disease (median 10% Philadelphia-chromosome-positive metaphases), whereas one started in stable CCR. All patients' cytogenetic responses improved after six vaccinations, with five reaching CCR. Notably, three of these five patients also had undetectable amounts of b3a2 transcript (BCR-ABL:beta2 microglobulin ratio <0.00001). Six patients on interferon alfa treatment with a median of 17 months' stable residual disease (median 13% Philadelphia-chromosome-positive cells) were also vaccinated. All but one had improved cytogenetic responses, and two reached CCR. Overall, we recorded peptide-specific delayed-type hypersensitivity (in 11 of 16 patients), CD4 cell proliferation (13 of 14 assessed), and interferon gamma production (five of five assessed). Addition of CMLVAX100 to conventional treatment in patients with chronic myeloid leukaemia might favour further reduction of residual disease and increase the number of patients reaching a molecular response.

Morphological effects of imatinib mesylate (STI571) on the bone marrow and blood of patients with Philadelphia chromosome (Ph) positive chronic myeloid leukaemia

There have been few reports on the morphological findings in patients with chronic myeloid leukaemia (CML) undergoing treatment with imatinib mesylate. We examined morphological changes in the marrow and peripheral blood of 27 patients with chronic phase (CP), accelerated phase (AP) and blastic phase (BP) CML, 3 and 6 months after treatment with imatinib. At 3 months there was a significant clearance of leukaemic cells as evidenced by a complete haematological response (CHR) in the peripheral blood in 25 patients, together with reduced marrow cellularity in 25 (median reduction CP 42%; AP/BP 68%) and a reduction in the number of megakaryocytes (13 of 18 CP: five of six AP/BP; three patients did not have an assessable marrow) with an increase in the amount of normal megakaryopoiesis. After 6 months, there was continued morphological improvement in eight of 17 CP patients (one patient died after 3 months) with continued cytogenetic response (7 out of 15 patients with assessable metaphases had no abnormal Ph+ cells and three had <35% Ph+ cells) and maintenance of haematologic response in all patients. After an initial response to treatment at 3 months in the AP/BP group, with CHR and a reduction in cellularity in all patients, we found morphological evidence of a loss of response to treatment, with an increase in leukaemic cells, as evidenced by loss of CHR in three of nine and an increase in median cellularity in five patients. No patient in this group achieved a complete cytogenetic response. In summary, in CML-CP patients treated with 6 months of imatinib, there was a significant reduction in leukaemic cells as evidenced by a haematolological response in the peripheral blood, together with reduced marrow cellularity, restoration of morphologically normal haemopoiesis and a meaningful cytogenetic response. Maintaining a response to treatment appeared less likely to occur in the AP/BP group patients, especially those who did not achieve any cytogenetic response to treatment.