In:
Blood, American Society of Hematology, Vol. 108, No. 11 ( 2006-11-16), p. 4794-4794
Abstract:
Peripheral blood samples from 70 patients treated with imatinib were regularly sent to us for the determination of bcr-abl transcript levels by a standardized quantitative real-time PCR (TaqMan®). 45 patients with early chronic phase CML were treated with imatinib as a first line therapy and 25 patients in late chronic phase received imatinib as a second line therapy after hydroxyurea plus interferon. The median pre-treatment time with hydroxyurea plus interferon in these late chronic patients was 43 months (6 – 130). The median follow-up was 18.4 months (1–51) for first line patients and 18.0 months (1–48) for second line patients. Patients received a median dosage between 400–600 mg imatinib in both groups. At the time of diagnosis the median bcr-abl/abl ratio was 248 % (26–460%, SD: 148%) in patient receiving imatinib as a first line treatment. Patients receiving imatinib as second line treatment had a median bcr-abl/abl ratio of 24,84% (1–256%, SD: 78%) just before the imatinib treatment was initiated. Early chronic phase CML patients treated with imatinib as a first line therapy showed a strong biphasic decay of their bcr-abl transcript with a fast reduction between 1-2-log during the first 6–9 months followed by a slower rate of reduction afterwards. A bcr-abl/abl ratio & lt;0.1% could be observed in 19/51 (37%) patients and in 12/51 (23%) patients a bcr-abl/abl ratio & lt; 0.01% was found. After 18 months of therapy the median reduction of bcr-abl was about 2.5-log, after 36 months about 3-log. 12/51 (23%) patients showed a suboptimal response or had a subsequent increase of their bcr-abl transcript levels. Best responding patients could be identified by a & gt;2-log reduction after 6 months and & gt; 3-log reduction after 18 months of therapy. In late chronic phase CML patients pre-treated with hydroxyurea and interferon the overall median decrease of bcr-abl transcript levels was about 1-log after a median follow-up of 18 as well as after 36–48 months. Obviously, there are at least three subgroups of patients with a different molecular response. We identified 7/25 (28%) patients with no significant reduction of bcr-abl transcripts after 18 months as well as after 36 months of imatinib therapy. In contrast, another group of 4/25 (16%) patients showed a 2-log reduction of bcr-abl/abl ratio after 18 months with a subsequent reduction of 3-log after 36 months. Within the largest group of 14/25 (56%) patients a 1-log reduction after 18 months and a 1-2-log reduction after 36 months was observed. No patient had & gt; 3-log reduction within the whole group of 25 late chronic phase patients. The reduction of bcr-abl transcript levels as a result of imatinib therapy is significantly superior in CML patients receiving imatinib as first line treatment for CML in early chronic phase compared to patients treated with imatinib after a long term pre-treatment with hydroxyurea and interferon.
Type of Medium:
Online Resource
ISSN:
0006-4971
,
1528-0020
DOI:
10.1182/blood.V108.11.4794.4794
Language:
English
Publisher:
American Society of Hematology
Publication Date:
2006
detail.hit.zdb_id:
1468538-3
detail.hit.zdb_id:
80069-7
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