Autografting for chronic myeloid leukaemia

A review of imatinib mesilate in the treatment of patients with gastrointestinal stromal tumours and chronic myeloid leukaemia

Context. Imatinib mesylate (GlivecÒ, GleevecÒ, Novartis) has made a dramatic impact on the treatment available for both chronic myeloid leukaemia (CML) and gastrointestinal stromal tumours (GISTs). Both are rare diseases that have possibly been unfamiliar to many pharmacists until now.

Objective. To provide readers with a structured overview of CML and GISTs and the trial data available to support the role imatinib is playing in the treatment of these diseases.

Data sources. Published reviews and primary trial results were sourced via Medline to prepare the review. Articles published up to and including August 2002 were considered. Additionally, pertinent books were used to prepare the text and Novartis kindly supplied information currently only available on file at the company. As imatinib has only been available for a short time, all types and sizes of trials were considered for inclusion. The authors made the final decision as to the relevance and therefore subsequent inclusion of data.

Conclusions. Imatinib is a new molecularly targeted therapy for the treatment of CML and GISTs. It has provided an efficacious alternative therapy choice for physicians managing the care of patients suffering from these diseases. In the future there is the possibility that imatinib may demonstrate activity in other disease states characterized by the genetic changes targeted by imatinib. The results of randomized controlled trials in new and existing indications are awaited.

Flow cytometric analysis of aneuploidy and S-phase fraction in chronic myeloid leukemia patients: role in early detection of accelerated phase

We studied S-phase fraction (SPF) and aneuploidy in peripheral blood leucocytes of patients with chronic myeloid leukemia (CML) in chronic phase (CML-CP, n=41), accelerated phase (CML-AP, n=6), and control subjects (n=12) with an aim to find out their role in early detection of accelerated phase. The SPF and aneuploidy were studied through flow-cytometry using LT-Mod. Fit software. Mean SPF value in CML-AP (9.28+/-3.46%) and in CML-CP (4.76+/-2.30%) were significantly higher than in normal controls (0.28+/-0.21%), (P<0.005, P<0.001). CML-CP patients having higher SPF (>7%) converted to accelerated phase within 18 months of follow-up while those with lower SPF (<7%) did not. Aneuploidy was present in 34.14% of CML-CP and all patients of CML-AP whereas no control subjects showed aneuploidy. Among CML-CP patients having SPF >7%, 86% developed aneuploidy during follow-up as compared to 18.50% of CML-CP with less than 7% SPF. We conclude that peripheral blood SPF and aneuploidy could be important parameters for prediction of evolution to accelerated phase in CML patients.

Evaluation at single cell level of residual Philadelphia negative hemopoietic stem cells in chronic phase CML patients

In chronic myeloid leukemia, accurate determination of Ph(-) Hemopoietic stem cells (HSC) in peripheral blood (PB), bone marrow (BM) and leukapheresis products is important for the selection of patients for whom mobilization, collection, and autografting of Ph(-) HSC are envisaged. To this effect, the BCR/ABL fusion was assessed at the single cell level in 25 sets of PB and BM samples using dual-color I-FISH in immunophenotyped CD34(+) cells and RT-PCR of individual CFU-GM colonies. In 15 cases found to be 100% Ph(+), the respective BCR/ABL gene was absent in 30% of CD34(+) cells, while the respective transcripts could not be identified in 17% of CFU-GM. The mean percentage of BCR/ABL(-) CD34(+) cells and CFU-GM cells was higher (38% and 29%, respectively) in untreated patients than in treated patients (24% and 7%, respectively). In eight cases with cytogenetic response (CgR), the percentage of Ph(-) metaphases correlated with the level of BCR/ABL(-) colonies in BM and PB and with the proportion of BCR/ABL(-) CD34(+) cells in the BM. Immunophenotyping and FISH was fast, easy, always informative, and quantitative for the BCR/ABL(-) CD34(+) cells. Our results show that (a) at early diagnosis a high frequency of BCR/ABL(-) HSC circulate in the PB and that Ph(-) hematopoiesis is not completely suppressed; (b) although normal clonogenic cells decline rapidly within a few months after diagnosis, appreciable numbers of normal CD34(+) cells survive in chronic phase, especially in patients with CgR.

Mobilisation of haemopoietic progenitors in CML: a second course of intensive chemotherapy does not improve Ph-negativity in stem cell harvests

We collected peripheral blood stem cells (PBSC) in 19 early chronic phase CML patients following each of two consecutive cycles of intensive chemotherapy (CT) to evaluate whether an additional cycle of CT would increase Philadelphia (Ph)-negativity of the PBSC harvest. Autologous SCT (autoSCT) was performed if a major cytogenetic response (MCR) of the PBSC harvest was obtained. CT consisted of cytarabine 200 mg/ m2/day (days 1-7)/idarubicin 12 mg/m2/day (days 1-2) (cycle one) and cytarabine 2000 mg/m2/day (days 1-6)/amsacrine 120 mg/m2/day (days 1-3) (cycle two). One patient died of fungal pneumonia after the first cycle. Stem cells were harvested in 18 patients after cycle one and in 16 patients after cycle two. After the first cycle, all patients showed a cytogenetic response of their graft (MCR in eight patients: three complete, five partial), after cycle two, seven patients obtained an MCR (one complete, six partial). Seven patients became eligible for autoSCT. All patients proceeded with IFNalpha maintenance. Currently, 16 patients are alive. At the latest cytogenetic examination of bone marrow, four patients showed an MCR and four a minor response. In conclusion, although a second cycle of CT may contribute to elimination of leukemia residing in the patient, it appeared to be ineffective in improving the Ph-negativity of the PBSC graft.