Abstract 3763
Ponatinib is a potent pan-BCR-ABL inhibitor that is active against native and mutated forms of BCR-ABL, including the TKI resistant T315I mutant. The efficacy and safety of ponatinib ...(45 mg orally once daily) in patients with chronic phase (CP), accelerated phase (AP), or blast phase (BP) chronic myeloid leukemia (CML), or Ph+ acute lymphoblastic leukemia (Ph+ ALL) were evaluated in a pivotal phase 2, international, open-label clinical trial (PACE).
To evaluate the patterns of molecular response in patients treated with ponatinib in the PACE trial.
The PACE trial enrolled 449 patients resistant or intolerant (R/I) to dasatinib or nilotinib or with the T315I BCR-ABL mutation. Patients were assigned to 1 of 6 cohorts according to disease phase (CP-CML, AP-CML, or BP-CML/Ph+ ALL), R/I to dasatinib or nilotinib, and presence of T315I. Mutation and molecular response analyses were performed at a single central laboratory. Molecular responses are reported on the International Scale (BCR-ABLIS; b2a2/b3a2 p210 transcript only): major molecular response (MMR), ≤0.1%; MR4, ≤0.01%; MR4.5, ≤0.0032%. The trial is ongoing. Data as of 23 July 2012 are reported, with a minimum follow-up of 9 months (median 12 0.1 to 21 months).
The median age was 59 (18 to 94) years. The median time from initial diagnosis to start of ponatinib was 6 (0.3 to 28) years. 96% had received prior imatinib, 84% dasatinib, 65% nilotinib; 8% received 1, 39% received 2, and 53% received all 3 prior approved TKIs. In patients previously treated with dasatinib or nilotinib (N=427), 88% had a history of resistance and 12% were purely intolerant to dasatinib or nilotinib. BCR-ABL mutations were detected in 55% of all patients at baseline: 22.9% T315I only, 26.5% mutations other than T315I, 5.8% mutations in addition to T315I. The most common mutations were T315I (29%), F317L (8%), E255K (4%), F359V (4%), and G250E (3%). Baseline BCR-ABL transcript levels were >10% in 74% (74% in CP-CML) and >1% to ≤10% in 14% (20% in CP-CML). No patients entered the study in MMR. The best response to the most recent dasatinib or nilotinib containing regimen was MMR or better in 4% (3% in CP-CML).
Molecular response rates by cohort are shown below for CP-CML and AP-CML. Deep molecular responses, including MR4.5, were observed in both disease phases. Of 16 BP-CML and 3 Ph+ ALL patients with the b2a2/b3a2 transcript and baseline and post-baseline bone marrow assessments, 5 BP-CML and 0 Ph+ ALL patients achieved MMR. In CP-CML, MMR rates for the most frequent mutations other than T315I were 41% F317L, 50% E255K, 31% F359V, 38% G250E. Subgroup analyses in CP-CML indicated significant differences in the MMR rate for patients with T315I only (56%; p<0.001) and mutations in addition to T315I (50%; p=0.0216) vs. no mutation (21%), and for T315I only vs. mutations other than T315I (34%; p=0.0237). These differences are likely due to younger age (median 51 vs. 61 years) and exposure to fewer prior TKIs (median 2 vs. 3) in CP-CML patients with T315I vs. those without T315I. In CP-CML, 53% maintained or achieved BCR-ABLIS ≤10% by 3 months, with a trend towards higher rates in patients receiving fewer prior approved TKIs (1: 81%; 2: 61%; 3: 45%). The MMR rate (cumulative) in CP-CML improved over time: 13% by 3 months, 24% by 6 months, 28% by 9 months. The median time to MMR for CP-CML patients achieving MMR was 6 (2 to 17) months. CP-CML patients with MMR had an estimated probability of remaining in MMR at 6 months and 1 year of 87% and 84%, respectively (Kaplan-Meier). Ponatinib was generally well-tolerated. Data with a minimum follow-up of 12 months will be presented.
Ponatinib treatment led to significant and deep molecular responses in this heavily pretreated population. In CP-CML, the MMR rate was ∼10-fold higher than that reported with the most recent dasatinib or nilotinib treatment.Molecular response in peripheral bloodCP-CMLa,bAP-CMLaR/I N=203T315I N=64R/I N=65T315I N=18MMR25%55%14%17%MR416%33%6%0%MR4.510%17%5%0%aExcludes 3 CP-CML and 2 AP-CML patients post-imatinib and without T315IbThe MMR rate in CP-CML patients previously treated with dasatinib or nilotinib was 79/256 (31%)
Hochhaus:ARIAD, Novartis, Bristol Myers-Squibb, Pfizer, and MSD: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kim:Novartis, Bristol Myers-Squibb, Pfizer, ARIAD, and Il-Yang: Consultancy, Employment, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau. Pinilla-Ibarz:Novartis, BMS: Research Funding, Speakers Bureau. le Coutre:Novartis and BMS: Honoraria. Paquette:ARIAD: Consultancy. Chuah:Novartis and Bristol Myers-Squibb: Honoraria. Nicolini:Novartis, Bristol Myers Squibb, Pfizer, ARIAD: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Apperley:Novartis, Bristol Myers-Squibb, and ARIAD: Honoraria, Research Funding. Talpaz:Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; BMS: Membership on an entity's Board of Directors or advisory committees, Research Funding; Incyte: Research Funding; Sanofi: Membership on an entity's Board of Directors or advisory committees, Research Funding; Millenium: Research Funding; Celgene: Research Funding; ARIAD: Research Funding; Deciphera: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees. Abruzzese:BMS: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees. Rea:Bristol Myers-Squibb, Novartis, and Teva: Honoraria. Baccarani:ARIAD, NOVARTIS PHARMA, BRISTOL MYERS SQUIBB, PFIZER: Consultancy, Honoraria, Speakers Bureau. Muller:ARIAD: Consultancy. Wong:MolecularMD Corp: Employment, Equity Ownership. Lustgarten:ARIAD Pharmaceuticals, Inc.: Employment, Equity Ownership. Rivera:ARIAD Pharmaceuticals, Inc.: Employment, Equity Ownership. Clackson:ARIAD: Employment, Equity Ownership. Turner:ARIAD: Employment, Equity Ownership. Haluska:ARIAD: Employment, Equity Ownership. Guilhot:ARIAD: Honoraria. Hughes:Novartis, BMS, ARIAD: Honoraria, Research Funding. Goldman:Novartis, Bristol Myers-Squibb, and Amgen: Honoraria. Shah:ARIAD: Consultancy, Research Funding; Bristol-Myers Squibb: Consultancy, Research Funding; Novartis: Consultancy. Kantarjian:Novartis: Consultancy; Pfizer: Research Funding; ARIAD: Research Funding; BMS: Research Funding; Novartis: Research Funding. Cortes:Novartis, BMS, ARIAD, Pfizer, and Chemgenex: Consultancy, Research Funding.
There is little information published on the long-term outcomes in recipients of T-cell depleted (TCD) unrelated donor (UD) transplants comparing Peripheral Blood Stem Cells (PBSC) with Bone Marrow ...(BM). We present retrospective outcome data on 306 recipients of myeloablative, HLA-matched UD allografts using pre-transplant in-vivo Alemtuzumab. Transplants were performed between 2000-2007 for CML (CP1) and acute leukaemia (CR1/2) and 184 patients received BM and 122 PBSC. The median age was 28.9 years (<1-58years) and the median follow-up was 48 months. Overall survival at 8 years is 53%. The incidence of acute GvHD was significantly higher in PBSC (65%) than BM recipients (49%; p=0.012). This represented only grade 1 GVHD with no difference in grade II-IV aGvHD (BM 23% PBSC 24%). The incidence of chronic GvHD, either overall (BM 47%, PBSC 49%) or extensive (BM 15%, PBSC 13%) was not increased with PBSC. The incidence of relapse, non-relapse mortality and survival were not significantly different. Whilst accepting the limitations of retrospective analyses, we suggest the increased risk of GvHD in recipients of PBSC in T-replete transplants is offset by in-vivo Alemtuzumab, and that either stem cell source can be used with good outcomes in this setting.
We identified 103 consecutive patients who, 5 years after allogeneic transplantation for chronic myeloid leukaemia (CML), were in molecular remission (MR). The 103 patients were divided into three ...groups on the basis of reverse transcription–polymerase chain reaction (RT–PCR) studies for BCR‐ABL transcripts in the first 5 years post transplant: Group A comprised 63 patients who had been continuously PCR negative; Group B comprised 20 patients with one or more positive PCR result but only at a low level; and Group C comprised 20 patients who had fulfilled the criteria for molecular relapse, been treated with donor lymphocyte infusions (DLI) and had thereafter regained complete MR within the 5‐year post‐transplant period. The median follow‐up for all 103 patients was 8·4 years from transplant (range 5–17·6 years). In group A only one patient relapsed at 9·2 years. In group B eight patients (40%) relapsed: six at molecular, one at cytogenetic and one haematological levels. The actuarial probabilities of survival at 10 years for patients in Groups A, B and C were 97·4%, 92·9% and 100% respectively; the probabilities of relapse were 3%, 54% and 0% respectively. We conclude that molecular studies during the first 5 years post transplant can help to predict long‐term leukaemia‐free survival and, possibly, cure of CML.
Abstract 1205
Poster Board I-227
The use of GSCF-mobilised Peripheral Blood Stem Cells (PBSC) for unrelated donor (UD) transplantation has increased dramatically since 2000. The association of PBSC ...with more rapid engraftment and with an increase in chronic Graft versus Host Disease (GvHD), compared to bone marrow (BM) has been reported in a number of studies. More recently the use of PBSC has been associated with an increase in non relapse mortality (NRM) and decrease in survival (OS) in T-cell replete transplants.
We have previously reported outcome data in 145 patients who received an unrelated donor transplant for leukaemia. In that study we reported an increase in mild acute GvHD using PBSC, but no other significant differences in outcome. We have now doubled the cohort and report our findings on 320 patients here. In this group all of the patients received pre-transplant serotherapy (Alemtuzumab = 306, ATG = 14) as part of myeloablative conditioning prior to an HLA-matched UD allograft. Patients were transplanted between January 2000 and August 2007: CML in 1CP (n=102) and acute leukaemia in CR1/2 (AML in 105, ALL in 144). 190 patients received BM and 130 PBSC. The median age of the recipients was 28.9 years (10months - 58years). There was no significant difference in age between those receiving BM or PBSC.98% and 96% of patients receiving PBSC and BM achieved neutrophil engraftment (NS), with a significantly faster time to engraftment in recipients of PBSC compared to BM (14 vs 20 days; p<0.001). The incidence of acute GvHD was significantly higher in recipients of PBSC (64%) compared to BM (51%; p=0.022), however there was no increase in grade III/IV (p=0.420) disease in PBSC recipients. The incidence of chronic GvHD at 6 years was 61% in the BM recipients and 55% in the PBSC recipients (NS), with no difference in the incidence of extensive disease.
The 5-years OS was 55% in BM recipients, with a median follow-up of 59 months, compared to 54% in PBSC recipients at a median follow-up of 38 months (NS). The incidence of neither disease relapse nor NRM was significantly different between groups (relapse at 5 years: BM 44%, PBSC 36%; p=0.112, and NRM at 5 years: BM 22%, PBSC 24%; p=0.751).
In view of the fact that there were more CML patients in the BM group and more AML patients who received PBSC (the distribution of ALL patients was similar) (p=0.051), we performed a subgroup analysis. The pattern of results for each outcome, dependant on the use of BM or PBSC, in patients with CML and those with acute leukaemia were similar to those reported in the group overall. In conclusion, we have confirmed the results of our previous smaller study, showing the only significant difference in clinical outcome between PBSC and BM to be a higher incidence in the occurrence (but not grade) of acute GvHD. We found no association between the use of PBSC and an increased risk of chronic GVHD or of a worse transplant outcome, when compared to BM. We suggest that either stem cell source can be used with a similar outcome in adult and paediatric recipients of T-cell depleted allografts for standard risk leukaemia.
Apperley:Novartis: Consultancy, Honoraria.
Patients with Ph+ chronic myelogenous leukemia who relapse after a first allogeneic stem cell transplant still have a possibility of long-term survival. To assess the value of the individual ...therapeutic options, the factors predicting outcome should be identified. We investigated data from 500 patients who relapsed before July 1996; follow-up was updated during 1998. The actuarial survival from relapse was 34.2% (95% confidence interval CI: 29.9%-38.5%) at 5 years and 23.4% (95% CI: 18.9%-27.9%) at 10 years. Survival after relapse was significantly related to 5 factors: time from diagnosis to transplant (< 2 years vs ≥ 2 years), disease phase at transplant (first chronic phase vs other), disease stage at relapse (cytogenetic or chronic phase vs advanced phase), time from transplant to relapse (< 1 year vs ≥ 1 year), and donor type (HLA-identical sibling vs volunteer unrelated donor). The effects of individual adverse risk factors were cumulative: The probability of survival at 10 years decreased stepwise from 42% (0 factors), 32% (1 factor), 14% (2 factors), 3% (3 factors), to 0% (4 or 5 factors). Novel strategies for high-risk patients are warranted. We conclude that these 5 factors should be taken into account when comparing results of salvage therapies in patients with Ph+ chronic myeloid leukemia relapsing after allogeneic stem cell transplant.
Non-HLA polymorphisms (NHP) influence risk of GVHD and outcome of allogeneic hematopoietic stem cell transplants (HSCT) however their influence on GvHD vs GvL remains to be defined. A cohort of 291 ...CML HLA matched sibling transplants with known clinical risk factors; eg stage of disease, gender mismatch (female donor/male recipient), patient age and time from diagnosis to transplant as defined by the EBMT risk score, were typed via SNPs or microsatellites for cytokines (IL-1Ra, IL-4, IL-6, IL-10, IFNγ, TNFα, TNFR 11), steroid hormone receptors (VDR and ERα) and NOD2/CARD15 mutations. TNFRII-196 allele R; IL-10 ATC/ACC; IL-1 Ra (allele 2) and IL-4T were significantly associated with survival using univariate analysis. Two clinical Cox proportional hazards models were generated for the statistical analysis and used as a basis for further development: (i) using the EBMT risk score as a single variable on an ordinal scale or (ii) using the individual clinical factors of the EBMT risk score as categorical variables. After step-wise variable selection using the significant genetic factors as candidates, the resulting multivariate models indicated that absence of TNFRII-196 R, i.e. down regulation of TNF in the recipient, absence of IL-10 ATC/ACC, i.e. intermediate IL-10 production in the donor and presence of IL-1Ra (allele 2) i.e. down regulation of IL-1 in the donor were associated with poor outcome. The addition of the genetic variables significantly improved the preferred model containing the EBMT risk score as a single variable. The Goodness of Fit of the models was assessed by Kaplan-Meier curves showing clinically relevant differences between good, intermediate and poor prognostic groups. The worst prognostic scores included the absence of ATA/ACC in the donor, evidenced by a steep change in survival probability. Relapse was associated with clinical factors; absence of female to male transplants; absence of bone marrow transplants and presence of T cell depletion but no significant association was found with genetic factors. This study suggests that distinct high risk patterns of NHP of patients and donors can be defined, which influences survival due to factors associated with an increased risk of GvHD without the potential benefit of increased GvL response. Data add to the clinical factors (eg age, sex, multiparity of the donor) where an unrelated donor might be the preferred choice compared to a high risk sibling donor.
From the discovery of the Ph-chromosome, there has been an extraordinary progress in our understanding of chronic myeloid leukemia (CML). During the last three decades, new findings arising from ...dissection of the genetic abnormalities at a molecular level have received the most attention, but there have also been important new observations arising from studies of the biologic behaviour of normal and leukemic stem cells and, more recently, from clinical investigations. In this review we first report the most important observations relevant to understanding the oncogenic potential of the BCR-ABL chimeric gene, and the behaviour and the relationships of normal and leukemic stem cells. From a clinical point of view, allogeneic stem cell transplantation is the only procedure able to cure CML. The main issues are: who can receive this procedure, and when and how it can be given. The situation is more complex in unrelated transplants. In patients without HLA compatible donors, many large trials in different countries have demonstrated that interferon alpha therapy is indicated and effective in the majority of patients. On the other hand, autologous stem cell transplantation is still an experimental procedure. These aspects will be analyzed in detail and, at the end, a therapeutic algorithm of a possible approach to the patients with untreated CML is provided.
The method used for preparing this review was an informal consensus development. All the authors of the present review have been working in the field of chronic myeloid leukemia, and have contributed original papers in peer-reviewed journals. In addition, the material examined in the present review includes articles and abstracts published in journals covered by the Science Citation Index and Medline.
The oncogenic potential of BCR-ABL has been demonstrated in a number of in vitro and in vivo model systems. Current research efforts are focused on defining the mechanism by which BCR-ABL transforms primary hematopoietic cells. The fact that BCR-ABL contains tyrosine residues, an SH2 domain, an SH3 domain, and proline-rich sequences raises the possibility of multiple protein-protein interactions. Indeed, BCR-ABL is reported to bind and/or phosphorylate more than 20 proteins. The insights into the signal transduction pathways activated by BCR-ABL will hopefully provide a new basis for the treatment of CML patients. Clinical evidence of the existence of a transplantable CML stem cell population has recently been extended to xenogeneic recipients of transplanted CML cells and by retroviral marking to autograft recipients. The potential of using immunodeficient mice as recipients of CML stem cells to create an in vivo model of chronic phase CML should be invaluable for testing novel therapies designed to eliminate residual disease in the patient. Current therapeutic options include conventional chemotherapy, IFN-a and allogeneic stem cell transplantation as established procedures, and autografting as an experimental procedure. While IFN-a as a first line therapy does not seem to jeopardize further treatments, autografting, according to the Genoa approach or other procedures, i.e. Ph-positive cells collected at diagnosis without mobilization therapy, raises the question of an ideal sequential strategy in the management of CML patients. There seems to be a general agreement that a patient less than 50 years old, with an HLA identical sibling, should receive an allogeneic stem cell transplant. This approach should be offered also to younger patients (< or = 40 years) who are able to find an unrelated matched donor. Since it seems that the normal hematopoietic reservoir declines with time, it may be desiderable to mobilize and collect peripheral stem cells in order to store Ph-negative progenitors as soon after diagnosis as possible when the WBC count has been controlled by hydroxyurea while searchin
We treated 14 patients with Ph-chromosome-positive chronic myeloid leukaemia still in chronic phase by autografting with blood-derived haemopoietic stem cells. Eleven patients were autografted ...electively after cytoreductive treatment with busulphan (16 mg/kg) and melphalan (60 mg/m2) and three were autografted after marrow cells from HLA-identical sibling donors had failed to engraft. In 13 patients haemopoiesis recovered; one failed to engraft and died 114 d after autografting. Two other patients became pancytopenic and received further stem cell transfusions at 3 and 40 months respectively after first autografting. One patient entered lymphoid transformation and died 14 months after autografting. Twelve patients survive at a median of 41 months (range 24-53) after autografting. Nine of the survivors have required further chemotherapy after autografting and four of the nine were electively autografted on a second occasion. Three patients surviving after autografting for 28, 43 and 53 months respectively have not required further chemotherapy. In two of these patients haemopoiesis is now predominantly Ph-negative. We conclude that autografting in chronic phase might prolong survival in some cases by reducing the size of the leukaemic stem cell population. The fact that initially successful grafts failed in two patients suggests that blood-derived stem cells may have a finite potential for self-replication.
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