Andrew Peniket

Allogeneic Stem-Cell Transplantation Using a Reduced-Intensity Conditioning Regimen Has the Capacity to Produce Durable Remissions and Long-Term Disease-Free Survival in Patients With High-Risk Acute Myeloid Leukemia and Myelodysplasia

PURPOSE The toxicity of allogeneic stem-cell transplantation can be substantially reduced using a reduced-intensity conditioning (RIC) regimen. This has increased the proportion of patients with myeloid malignancies eligible for allogeneic transplantation. However, the capacity of RIC allografts to produce durable remissions in patients with acute myeloid leukemia (AML) and myelodysplasia (MDS) has not yet been defined, and consequently, the role of RIC allografts in the management of these diseases remains conjectural. PATIENTS AND METHODS Seventy-six patients with high-risk AML or MDS received an allograft using a fludarabine/melphalan RIC regimen incorporating alemtuzumab. The median age of the cohort was 52 years (range, 18 to 71 years). RESULTS The 100-day transplantation-related mortality rate was 9%, and no patient developed greater than grade 2 graft-versus-host disease. With a median follow-up of 36 months (range, 13 to 70 months), 27 patients were alive and in remission, with 3-year actuarial overall survival (OS) and disease-free survival (DFS) rates of 41% and 37%, respectively. The 3-year OS and DFS rates of patients with AML in complete remission at the time of transplantation were 48% and 42%, respectively. Disease relapse was the most common cause of treatment failure and occurred at a median time of 6 months after transplantation. All but one patient destined to relapse did so within 24 months of transplantation. CONCLUSION The extended follow-up in this series identifies a high risk of early disease relapse but provides evidence that RIC allografts can produce sustained DFS in a significant number of patients with AML who would be ineligible for allogeneic transplantation with myeloablative conditioning.

Back-up bone marrow is frequently ineffective in patients with poor peripheral-blood stem-cell mobilization.

PURPOSE To assess hematologic recovery and procedure-related mortality in patients who received high-dose therapy with stem-cell support, in whom the peripheral-blood stem-cell (PBSC) collection fails (CD34+ cells < 1 x 10(6)/kg). The predictive value of granulocyte-monocyte colony-forming cell (GM-CFC) measurements and the value of bone marrow obtained after PBSC collection failure was assessed. PATIENTS AND METHODS The study group comprised 324 consecutive patients mobilized with granulocyte colony-stimulating factor (G-CSF) and cyclophosphamide (273 patients), G-CSF with other chemotherapy (37 patients), and G-CSF alone (14 patients). Between one and four aphereses were performed. RESULTS In 51 of 324 patients, there was failure to obtain 1 x 10(6)/kg CD34+ cells. Twenty-three patients had greater than 1 x 10(5)/kg GM-CFC; 22 patients proceeded to high-dose therapy. Neutrophil recovery occurred within 21 days, but platelet independence was delayed (> 28 days) in eight patients. Of 28 patients with less than 1 x 10(5)/kg GM-CFC, six received high-dose therapy with PBSC alone and five had delayed engraftment. Twelve patients with less than 1 x 10(5)/kg GM-CFC received high-dose therapy supported by bone marrow collected after PBSC collection failure. Eleven patients were assessable for engraftment; four patients had slow (> 21 days) or delayed (> 28 days) neutrophil recovery and eight patients had delayed platelet recovery. In the group of patients who received less than 1 x 10(5)/kg GM-CFC, there were five procedure-related deaths. CONCLUSION This study shows that delayed hematologic recovery is frequent if less than 1 x 10(6)/kg CD34+ cells are infused after high-dose therapy, particularly with GM-CFC less than 1 x 10(5)/kg. The procedure-related mortality in this latter group is high. In most patients whose PBSC collection contains less than 1 x 10(5)/kg GM-CFC, the use of bone marrow cells does not improve engraftment, which suggests that poor PBSC mobilization usually indicates poor marrow function.

Telomere length shortening is associated with disease evolution in chronic myelogenous leukemia.

We studied telomere length in the peripheral blood leukocyte samples of a large group of patients with chronic myelogenous leukemia (CML) by Southern blot hybridization using the (TTAGGG)4 probe. The average telomere length expressed as the peak telomere repeat array (TRA) of the peripheral blood samples obtained from a group of 34 healthy age‐matched controls ranged between 7.6 and 10.0 kb and the mean peak TRA was 8.7 kb. Forty‐one patients in the chronic phase of CML were studied; 32/41 (78%) showed telomere reduction (<7.6 kb) relative to age‐matched controls and the mean peak TRA was 6.4 kb (range 4.0–10.6 kb). Serial samples were analysed from 12 patients at both chronic phase and during disease progression. The leukocyte DNA of all 12 patients in accelerated phase and/or blast crisis showed telomere reduction relative to age‐matched controls and the mean peak TRA was 4.1 kb (range 3.0–5.4 kb). The peak TRA in the accelerated or blast phase was reduced compared with the corresponding paired sample in the chronic phase in all cases studied. These data show that a marked reduction in telomere length is associated with disease progression in CML. Am. J. Hematol. 61:5–9, 1999.

Factors predicting long-term survival after T-cell depleted reduced intensity allogeneic stem cell transplantation for acute myeloid leukemia

Background Reduced intensity conditioning regimens permit the delivery of a potentially curative graft-versus-leukemia effect in older patients with acute myeloid leukemia. Although T-cell depletion is increasingly used to reduce the risk of graft-versus-host disease its impact on the graft-versus-leukemia effect and long-term outcome post-transplant is unknown. Design and Methods We have characterized pre- and post-transplant factors determining overall survival in 168 patients with acute myeloid leukemia transplanted using an alemtuzumab based reduced intensity conditioning regimen with a median duration of follow-up of 37 months. Results The 3-year overall survival for patients transplanted in CR1 or CR2/CR3 was 50% (95% CI, 38% to 62%) and 44% (95% CI, 31% to 56%), respectively compared to 15% (95% CI, 2% to 36%) for patients with relapsed/refractory disease. Multivariate analysis demonstrated that both survival and disease relapse were influenced by status at transplant (P=0.008) and presentation cytogenetics (P=0.01). Increased exposure to cyclosporine A (CsA) in the first 21 days post-transplant was associated with an increased relapse risk (P<0.0001) and decreased overall survival (P<0.0001). Conclusions Disease stage, presentation karyotype and post-transplant CsA exposure are important predictors of outcome in patients undergoing a T-cell depleted reduced intensity conditioning allograft for acute myeloid leukemia. These data confirm the presence of a potent graft-versus-leukemia effect after a T-cell depleted reduced intensity conditioning allograft in acute myeloid leukemia and identify CsA exposure as a manipulable determinant of outcome in this setting.

Delineation of the minimal commonly deleted segment and identification of candidate tumor-suppressor genes in del(9q) acute myeloid leukemia

Deletion of the long arm of chromosome 9, del(9q), is a recurring chromosomal aberration in acute myeloid leukemia (AML) that is frequently associated with t(8;21). The critical gene products affected by del(9q) are unknown but likely cooperate with the AML1/ETO fusion gene created by t(8;21) in leukemogenesis. In 43 AML samples with del(9q), we used high‐density microsatellite markers to define the commonly deleted region (CDR) to less than 2.4 Mb. We found no homozygous loss at any locus tested. The CDR contains 7 known genes, FRMD3, UBQLN1, GKAP42, KIF27, HNRPK, SLC28A3, and NTRK2, and 4 novel genes, RASEF, C9orf103, C9orf64, and C9orf76. In addition, TLE1 and TLE4 are adjacent to the CDR. We performed a comprehensive mutational analysis of the coding regions of all these genes. No sequence variations absent in normal controls were seen in more than a single del(9q) AML sample. Expression of 7 of the 10 genes examined was significantly down‐regulated in del(19q)AML as compared with the CD34‐purified progenitors from normal individuals, a pattern distinct from that seen in AML samples with a normal karyotype. The results of our studies are consistent with a model of tumor suppression mediated by haploinsufficiency of critical genes in del(9q) AML.

Efficacy of bimonthly extracorporeal photopheresis in refractory chronic mucocutaneous GVHD

Extracorporeal photopheresis (ECP) has become a recognised treatment for steroid-refractory chronic GVHD (cGVHD), but the optimal frequency and duration of treatment are yet to be established. We report on 82 consecutive patients with mucocutaneous cGVHD who received a bimonthly regimen of ECP treatment for two consecutive days, which could be subsequently tapered to a monthly regimen depending on response. Patients were steroid-refractory, steroid-dependent or steroid-intolerant, and 29 (35%) had multiorgan involvement. The median duration of treatment was 330 days (42–987). The median number of ECP cycles was 15 (1.5–32). Response was assessed by clinical assessment and reduction in immunosuppression after 6 months. 69/82 (84%) had completed 6 months of ECP and 65/69 (94%) had ⩾50% improvement in symptoms and signs of cGVHD. A total of 77% of patients who completed 6 months of ECP had a reduction in immunosuppression dose and 80% had decreased their steroid dose (27.5% stopped, 30% had ⩾75% reduction, 17.5% had ⩾50% reduction and 25% had <50% reduction). OS at 3 years from the start of ECP was 69%. This study reports the largest series of patients receiving bimonthly ECP treatment for cGVHD, and confirms that ECP allows successful reduction of immunosuppression.

A case of EBV-associated lymphoproliferative disease following high-dose therapy and CD34-purified autologous peripheral blood progenitor cell transplantation.

A fatal case of EBV-associated lymphoproliferative disorder arising after a CD34-selected autologous peripheral blood stem cell transplant is reported in a patient with multiple myeloma in first plateau phase. It is suggested that this is likely to be a consequence of the accessory cell depletion associated with the CD34+ cell purification and it is recommended that a source of autologous T cells is stored before transplantation to be used if a severe opportunistic infection or EBV lymphoma arises post-transplantation.

Del (9q) AML: clinical and cytological characteristics and prognostic implications.

Del (9q) is a recurrent cytogenetic abnormality in acute myeloid leukaemia (AML). We report an analysis of 81 patients with del(9q) as a diagnostic karyotypic abnormality entered into the Medical Research Council AML trials 10, 11 and 12. Patients were divided into three groups: (i) Sole del (9q), 21 patients; (ii) Del(9q) in association with t(8;21), 29 patients; (iii) Del(9q) in association with other cytogenetic abnormalities, 31 patients. Sole del(9q) was associated with a characteristic bone marrow phenotype at diagnosis: a single Auer rod was found in all cases examined. There was also an association with erythroid dysplasia (74%) and granylocytic lineage vacuolation (90%). The incidence of all three of these features was significantly higher (P < 0·05) in the sole del(9q) group compared with control cases lacking del(9q). The overall survival (OS) of all 81 patients was compared with a control group of 1738 patients with normal cytogenetics entered in the same trials over the period of investigation. The 5‐year OS for patients with del(9q) was 45%, compared with 35% for the control group (P = 0·09). Patients with del(9q) in association with t(8;21) had a 5‐year OS of 75%, which was significantly better than the groups with either sole del(9q) (40%) and del(9q) with other abnormalities (26%; P = 0·008). Karyotyping indicated a common area of deletion in the region 9q21–22, which was present in 94% of cases. It is likely that the deletion of single or multiple tumour suppressor genes located in this region may underlie the pathogenesis of del (9q) AML.

Episomal amplification of NUP214-ABL1 fusion gene in B-cell acute lymphoblastic leukemia

To the editor: The NUP214-ABL1 fusion gene is found amplified as multiple (5-50) episomal copies in 6% of T-cell acute lymphoblastic leukemia (T-ALL).[1][1],[2][2] Alterations of the TLX1 , TLX3 , CDKN2A/B , and NOTCH1 genes are commonly associated with NUP214-ABL1 T-ALL. Recently, the NUP214-ABL1

Alemtuzumab markedly reduces chronic GVHD without affecting overall survival in reduced-intensity conditioning sibling allo-SCT for adults with AML

By retrospective analysis of 88 patients from the British Society of Blood and Marrow Transplantation registry, we investigated the effect of in vivo T-cell depletion in HLA-identical sibling reduced-intensity conditioning (RIC) allografts for adult AML by comparing patients who received alemtuzumab with those without alemtuzumab conditioning. Both groups were equivalent for age, sex, karyotype and disease status at transplant. With a median follow-up of 27 months (3–72 months) and 48 months (7–72 months), the 2- and 5-year overall survival, with or without alemtuzumab, is 60 and 60% (P=0.80) and 61 and 53%, respectively (P=0.85). The 2-year non-relapse mortality is 12% with alemtuzumab, and 17% without alemtuzumab (P=0.49). The 2-year relapse rate is 35% with alemtuzumab compared with 19% without alemtuzumab (P=0.28). Grades II–IV acute GVHD occurred in 22% (8/37) without alemtuzumab compared with 14% (7/51) given alemtuzumab (P=0.25). Extensive chronic GVHD occurred in 47% (14/30) not given alemtuzumab compared with 4% (2/45) who were given alemtuzumab (P=0.001). Among evaluable patients, the risk of infections was higher in those treated with alemtuzumab compared with those not treated with alemtuzumab (79 vs 57%, respectively, P=0.02). In conclusion, alemtuzumab has a beneficial effect by reducing chronic GVHD without affecting overall survival. Further studies are warranted before alemtuzumab can be recommended as standard in RIC allografts for AML.