Imatinib therapy prior to myeloablative allogeneic stem cell transplantation

The prevalence of hepatic and thyroid toxicity associated with imatinib treatment of chronic myeloid leukaemia: a systematic review

BACKGROUND

Imatinib, a potent inhibitor of targeted protein tyrosine kinases, treats chronic myeloid leukaemia (CML). Data on imatinib-associated changes in hepatic and thyroid functions are limited and conflicting.

AIM

To report the prevalence of hepatic and thyroid toxicity associated with the use of imatinib in CML patients.

METHOD

Articles for the systematic review were selected from electronic databases (PubMed, CINALH, Web of Science). Readily accessible peer-reviewed full articles in English published 1st January 2000 to 18th July 2023 were included. The search terms included combinations of: imatinib, CML, liver toxicity, hepatic toxicity, thyroid toxicity. Screening of titles, abstracts, full text articles was conducted independently by two reviewers. Inclusions and exclusions were recorded following PRISMA guidelines. Detailed reasons for exclusion were recorded. Included articles were critically appraised.

RESULTS

Ten thousand one hundred and twenty-three CML patients were reported in the 82 included studies corresponding to 21 case reports, 2 case series, 39 clinical trials and 20 observational studies were selected. Excluding case studies/reports, 1268 (12.6%; n = 1268/10046) hepatotoxicity adverse events were reported, of which 64.7% were rated as mild grade I & II adverse events, 363 (28.6%) as severe, grade III and IV adverse events; some led to treatment discontinuation, liver transplantation and fatal consequences. Twenty (35.1%) studies reported discontinuation of imatinib treatment due to the severity of hepatic toxicity. Fourteen (8.4%, n = 14/167) thyroid dysfunction adverse events were reported.

CONCLUSION

High frequency of mild and severe hepatotoxicity, associated with imatinib in CML patients, was reported in the published literature. Low numbers of mild and manageable thyroid toxicity events were reported.

Outcomes and toxicity of allogeneic hematopoietic cell transplantation in chronic myeloid leukemia patients previously treated with second-generation tyrosine kinase inhibitors: a prospective non-interventional study from the Chronic Malignancy Working Party of the EBMT

Allogeneic hematopoietic cell transplantation (allo-HCT) remains a treatment option for patients with chronic myeloid leukemia (CML) who fail to respond to tyrosine kinase inhibitors (TKIs). While imatinib seems to have no adverse impact on outcomes after transplant, little is known on the effects of prior use of second-generation TKI (2GTKI). We present the results of a prospective non-interventional study performed by the EBMT on 383 consecutive CML patients previously treated with dasatinib or nilotinib undergoing allo-HCT from 2009 to 2013. The median age was 45 years (18-68). Disease status at transplant was CP1 in 139 patients (38%), AP or >CP1 in 163 (45%), and BC in 59 (16%). The choice of 2GTKI was: 40% dasatinib, 17% nilotinib, and 43% a sequential treatment of dasatinib and nilotinib with or without bosutinib/ponatinib. With a median follow-up of 37 months (1-77), 8% of patients developed either primary or secondary graft failure, 34% acute and 60% chronic GvHD. There were no differences in post-transplant complications between the three different 2GTKI subgroups. Non-relapse mortality was 18% and 24% at 12 months and at 5 years, respectively. Relapse incidence was 36%, overall survival 56% and relapse-free survival 40% at 5 years. No differences in post-transplant outcomes were found between the three different 2GTKI subgroups. This prospective study demonstrates the feasibility of allo-HCT in patients previously treated with 2GTKI with a post-transplant complications rate comparable to that of TKI-naive or imatinib-treated patients.

Allogeneic transplantation for CML in the TKI era: striking the right balance

The management of chronic myeloid leukaemia (CML) has changed extensively over the past 15 years. Prior to the development of targeted therapies and in the absence of allogeneic haematopoetic stem-cell transplantation (HSCT), the median survival was 5-7 years. HSCT was quickly established as the standard of care for eligible patients through the 1980s and 1990s, when considerable advances were made in the optimization of conditioning regimens and supportive care. Exploiting a deeper understanding of the molecular basis of CML, the development of tyrosine kinase inhibitors (TKIs) in the late 1990s revolutionized the management of the disease. TKIs offer the prospect of long-term disease control with a simple oral therapy, and are the first-line treatment in the 21(st) century. The majority of patients treated with TKIs achieve excellent responses with sustained treatment, and some even continue to have undetectable or exceptionally low level disease upon TKI withdrawal; however, for an almost equal number of patients, an adequate response cannot be achieved with any of the currently available TKIs. For those patients who fail to respond adequately to TKIs, HSCT offers the best prospect of long-term survival.

Pretransplantation use of the second-generation tyrosine kinase inhibitors has no negative impact on the HCT outcome

Introduction

Allogeneic hematopoietic cell transplantation (HCT) was a standard therapy in chronic phase (CP) chronic myeloid leukemia (CML). As a result of the effective therapy with tyrosine kinase inhibitors (TKI), HCT was shifted to defined clinical situations. We present the results of observational prospective analysis of 28 CML patients undergoing HCT after exposure to, at least, two lines of TKI (including dasatinib and/or nilotinib), with respect to response, overall survival (OS), treatment toxicity, graft versus host disease (GVHD), and progression/relapse incidence.

Results

All the patients but one engrafted with median time 19 days. OS for patients in CP1 and CP2/accelerated phase (AcP) were 92.9 and 85.7 %, respectively. Six patients allotransplanted in blast crisis (BC) CML died early after HCT.

Eighteen patients achieved deep molecular remission (MR^4.5 or MR^4.0). Relapse incidence was 29.6 %. Median time to progression (TTP) differs significantly depending on the CML phase prior to HCT, the best response achieved after HCT and development of chronic GvHD.

NRM yielded the values 7.1, 12.5, and 50 % in CP1, CP2/AcP, and BC, respectively. Fatal outcome, due to veno-occlusive disease (VOD), was observed in two (7 %) patients. In five (17.9 %) patients, mild or moderate VOD was observed with no negative impact of preceding therapy with TKI2. Acute GvHD was diagnosed in 25.9 % of patients, while chronic GvHD developed in 42.9 % of individuals.

Conclusion

Pretransplantation therapy with TKI2 in CP CML is safe and reasonable. In BC, the optimal approach before HCT is to reduce the leukemic burden and achieve subsequent CP.

Allogeneic transplant for chronic myeloid leukemia in 2010

Tyrosine kinase inhibitor (TKI) therapy has revolutionized the therapy of chronic myeloid Leukemia (CML). Thus, while in the near past allogeneic transplantation was the curative option for CML, imatinib, nilotinib, and dasatinib have pushed transplantation to the role of salvage therapy in CML. Still, TKI therapy still fails some patients, and so the clinical challenge is to integrate transplantation in a safe and sane manner. This manuscript reviews the data on the variables that have an influence on outcome following transplantation, and discusses the variables to consider in determining who and when patients should receive transplantation.

Chronic myelogenous leukemia: role of stem cell transplant in the imatinib era

In the pre-tyrosine kinase (TKI) era, allogeneic stem cell transplant (allo-SCT) was the front-line treatment of choice for young patients with chronic myelogenous leukemia (CML). Today, imatinib is well established as front-line therapy for CML, with excellent long-term outcomes. This has changed the role of allo-SCT and the number of patients undergoing allo-SCT has declined dramatically. Allo-SCT is currently recommended for patients in accelerated/blast phase disease, those who have failed a second-generation TKI and those with TKI-resistant mutations such as T315I. The role of allo-SCT in the management of CML will require continual reappraisal as medical therapies continue to evolve.

Prognostic factors for outcomes in allogeneic transplantation for CML in the imatinib era: a CIBMTR analysis

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative treatment, albeit in a minority of patients with accelerated (AP) or blast phase (BP) chronic myeloid leukemia (CML). Imatinib (IM) has transient but significant activity in advanced phases of CML, which may permit early allografting for responding patients. To identify prognostic factors in allograft recipients previously treated with IM, we analyzed 449 allogeneic HSCT performed between 1999–2004 in advanced phase CML using data reported to the Center for International Blood and Marrow Transplant Research. CML patients in second chronic phase (CP2, n=184), AP (n=185), and BP (n=80) received HLA-identical sibling (27%), related (3%), or matched or mismatched unrelated donor (70%), peripheral blood (47%) or bone marrow (53%) HSCT after myeloablative (78%) or non-myeloablative (22%) conditioning. 52% in CP2, 49% in AP, and 46% in BP received IM pre-HSCT. Disease-free survival was 35–40% for CP2, 26–27% for AP and 8–11% for BP. Cumulative incidence of acute and chronic GVHD and TRM were not affected by stages of CML or pre-HSCT IM exposure. Multivariate analyses showed that conventional prognostic indicators remain the strongest determinants of transplant outcomes. In conclusion, there are no new prognostic indicators of outcomes of allogeneic HSCT for advanced phase CML in the IM era.

Stem cell transplant for chronic myeloid leukemia in the imatinib era

Tyrosine kinase inhibitor (TKI) therapy has revolutionized the therapy of chronic myeloid leukemia (CML). Thus, while in the near past allogeneic transplantation was the curative option for CML, imatinib, nilotinib, and dasatinib have pushed transplantation to the role of salvage therapy in CML. Still, TKI therapy still fails some patients, and so the clinical challenge is to integrate transplantation in a safe and sane manner. This article reviews the data on the variables that influence outcome following transplantation, and discusses the variables to consider in determining which patients should receive transplantation and when.

Challenges for allogeneic hematopoietic stem cell transplantation in chronic myeloid leukemia in the era of tyrosine kinase inhibitors

Following the introduction of the tyrosine kinase inhibitor (TKI) imatinib in the treatment of chronic myeloid leukemia (CML) patients, the allogeneic hematopoietic stem cell transplantation (HSCT) scene in CML has changed dramatically. The number of patients receiving HSCT in first chronic phase (CP) has declined rapidly, as allogeneic HSCT in CP is now performed in these patients only in case of failure or intolerance of TKIs. Second, those CML patients who undergo allogeneic HSCT represent a selection of high-risk patients due to more advanced disease with high rates of accelerated or blast phase (being associated with an increased relapse risk), advanced age and relevant co-morbidities. Efforts at meeting these special challenges are being developed: treatment with TKIs aims to improve the pre-transplant remission status before HSCT. Dose-reduced conditioning protocols were introduced to decrease transplant-related mortality in patients with co-morbidities or older age. In the post-transplant period, TKIs may be administered for prophylaxis and for treatment of post-transplant relapse. Still, the outcome of patients in advanced CML phases remains guarded, and requires an improvement in current transplant strategies.

Tyrosine kinase inhibitors and allogeneic hematopoietic cell transplantation for chronic myeloid leukemia: targeting both therapeutic modalities

BACKGROUND

Due to its curative potential, allogenic hematopoietic transplantation (HCT) was a mainstay of treatment for chronic myeloid leukemia (CML), but the advent of tyrosine kinase inhibitors (TKIs) has markedly altered the use of allogeneic HCT.

METHODS

The authors reviewed their experiences as well as the published data regarding the impact of TKIs on the natural history of CML and thus on the application and timing of TKIs in the management of CML.

RESULTS

Most patients with CML respond well to TKIs given as up-front therapy. Available retrospective data suggest that allogenic HCT is safe after TKI therapy. Work is ongoing regarding salvage of postallogeneic HCT failures using TKIs with and without donor lymphocyte infusion.

CONCLUSIONS

While allogeneic HCT therapy remains useful, the timing of its application in CML has changed, and it is now considered as second- or third-line therapy.

Nilotinib: a second-generation tyrosine kinase inhibitor for the treatment of chronic myelogenous leukemia

BACKGROUND

Nilotinib, a second-generation tyrosine kinase inhibitor (TKI) formerly known as AMN107, was approved by the US Food and Drug Administration (FDA) on October 29, 2007, for the treatment of adult patients with chronic-phase (CP) and accelerated-phase (AP) Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) resistant to or intolerant of prior treatment that included imatinib.

OBJECTIVE

The purpose of this review was to evaluate the pharmacology, pharmacokinetic properties, and pharmacodynamic properties of nilotinib; results of clinical trials in patients with CML, Ph+ acute lymphoblastic leukemia (ALL), and gastrointestinal stromal tumors (GISTs); and potential drug interactions.

METHODS

Literature was identified and reviewed using searches of MEDLINE (1966-April 1, 2008), the American Society of Hematology and American Society of Clinical Oncology abstracts databases (2002-2008 annual meetings/symposia), the European Hematology Association abstracts database (2006-2007 annual meetings), and the American Association for Cancer Research symposia (2000-2007). Search terms included, but were not limited to, nilotinib, AMN107, chronic myelogenous leukemia, acute lymphoblastic leukemia, bcr-abl, imatinib resistance, adverse events, pharmacology, and clinical trials.

RESULTS

Nilotinib is an orally bioavailable derivative of imatinib with improved specificity toward the breakpoint cluster region-Abelson murine leukemia (bcr-abl) viral protooncogene. In preclinical studies, nilotinib was found to have activity against 32 of 33 imatinib-resistant bcr-abl mutations, but not against the T3151 mutation. On pharmacokinetic analysis, T(max) was 3 hours. The calculated t((1/2)) following multiple daily dosing was approximately 17 hours. The main metabolic pathways identified were oxidation and hydroxylation. The parent compound is the circulating component found in serum; the metabolites were not found to contribute to pharmacologic activity. Nilotinib is a competitive inhibitor of cytochrome P450 (CYP) 3A4, CYP2C8, CYP2C9, and CYP2D6. In 2 Phase II, open-label, single-arm clinical studies, nilotinib was found to be beneficial in patients with CML that was imatinib resistant or intolerant. Overall, 58% of patients with CML-CP achieved a major cytogenetic response; 42%, a complete cytogenetic response; and 77%, a complete hematologic response (CHR). At 18 months, the estimated overall survival rate was 91%. Of patients whose disease had progressed to AP, nilotinib was associated with major cytogenetic response in 32%; complete cytogenetic response in 19%; and CHR in 30%. At 12 months, an estimated 56% of patients lacked progression of disease, and the estimated overall survival rate was 82%. Concurrent use of CYP3A4 inhibitors should be avoided. The most common toxicities attributable to nilotinib include rash, pruritus, nausea, fatigue, headache, constipation, diarrhea, and vomiting. Grade 3/4 toxicities (> or = 10%) have included thrombocytopenia, neutropenia, elevated lipase, hyperglycemia, and hypophosphatemia. Nilotinib has been associated with a prolonged QT interval, and sudden death has been reported. The FDA-approved regimen of nilotinib is 400 mg PO BID on an empty stomach.

CONCLUSIONS

Nilotinib is an oral second-generation bcr-abl TKI indicated for the treatment of imatinib resistant or -intolerant Ph+ CML-CP and -AP in adults. Positive clinical activity and tolerability have been reported in clinical trials. Clinical data on off-label indications and in patients with Ph+ ALL and GIST continue to emerge.

Impact of prior imatinib mesylate on the outcome of hematopoietic cell transplantation for chronic myeloid leukemia

Imatinib mesylate (IM, Gleevec) has largely supplanted allogeneic hematopoietic cell transplantation (HCT) as first line therapy for chronic myeloid leukemia (CML). Nevertheless, many people with CML eventually undergo HCT, raising the question of whether prior IM therapy impacts HCT success. Data from the Center for International Blood and Marrow Transplant Research on 409 subjects treated with IM before HCT (IM(+)) and 900 subjects who did not receive IM before HCT (IM(-)) were analyzed. Among patients in first chronic phase, IM therapy before HCT was associated with better survival but no statistically significant differences in treatment-related mortality, relapse, and leukemia-free survival. Better HLA-matched donors, use of bone marrow, and transplantation within one year of diagnosis were also associated with better survival. A matched-pairs analysis was performed and confirmed a higher survival rate among first chronic phase patients receiving IM. Among patients transplanted with advanced CML, use of IM before HCT was not associated with treatment-related mortality, relapse, leukemia-free survival, or survival. Acute graft-versus-host disease rates were similar between IM(+) and IM(-) groups regardless of leukemia phase. These results should be reassuring to patients receiving IM before HCT.

Novel tyrosine kinase inhibitor therapy before allogeneic stem cell transplantation in patients with chronic myeloid leukemia: no evidence for increased transplant-related toxicity

BACKGROUND

Patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) for chronic myeloid leukemia (CML) are increasingly likely to have received a novel tyrosine kinase inhibitor (NTKI) after failing imatinib mesylate. It is unknown whether the use of these NTKIs before HSCT increases transplant-related toxicity.

METHODS

The outcome of 12 patients with CML (1 in chronic phase, 6 in the accelerated phase, and 5 in the blastic phase) who received dasatinib (n = 2), nilotinib (n = 7), or both (n = 3) before HSCT were retrospectively analyzed.

RESULTS

The median time on treatment was 134 days, and the median time from the end of NTKI therapy to HSCT was 34 days. The preparative regimen was ablative in 8 patients and nonablative in 4. All patients engrafted within 13 days. There was no significant early transplant-related toxicity. One patient developed secondary graft failure after 6 months from the first HSCT that required a second HSCT. Acute and chronic graft-versus-host disease (GVHD) was observed in 7 and 6 patients, respectively. Nine patients achieved a molecular response: 4 complete and 5 major (quantitative reverse transcriptase-polymerase chain reaction <0.05%). Three patients had disease progression by Day 30 after HSCT. Two patients developed disease recurrence after a median of 12 months. After a median follow-up of 10 months, 7 patients were alive in molecular response and 5 patients had died, 4 of disease progression and 1 of extensive chronic GVHD.

CONCLUSIONS

Previous treatment with NTKI did not increase transplant-related toxicity in this preliminary experience. Further follow-up and a larger number of patients will be necessary to confirm these observations.

Long-term follow-up of allogeneic hematopoietic stem-cell transplantation with reduced-intensity conditioning for patients with chronic myeloid leukemia

Allogeneic hematopoietic stem-cell transplantation (HSCT) remains an effective strategy for inducing durable remission in chronic myeloid leukemia (CML). Reduced-intensity conditioning (RIC) regimens extend HSCT to older patients and those with comorbidities who would otherwise not be suitable candidates for HSCT. The long-term efficacy of this approach is not established. We evaluated outcomes of 64 CML patients with advanced-phase disease (80% beyond first chronic phase), not eligible for myeloablative preparative regimens due to older age or comorbid conditions, who were treated with fludarabine-based RIC regimens. Donor type was matched related (n =30), 1 antigen-mismatched related (n =4), or matched unrelated (n =30). With median follow-up of 7 years, overall survival (OS) and progression-free survival (PFS) were 33% and 20%, respectively, at 5 years. Incidence of treatment-related mortality (TRM) was 33%, 39%, and 48% at 100 days, and 2 and 5 years after HSCT, respectively. In multivariate analysis, only disease stage at time of HSCT was significantly predictive for both OS and PFS. RIC HSCT provides adequate disease control in chronic-phase CML patients, but alternative treatment strategies need to be explored in patients with advanced disease. TRM rates are acceptable in this high-risk population but increase over time.

The effects of imatinib mesylate treatment before allogeneic transplantation for chronic myeloid leukemia

The impact of imatinib mesylate (IM) treatment for chronic myeloid leukemia (CML) on subsequent allogeneic transplantation is uncertain. To better understand this relationship, we retrospectively compared 145 patients with CML receiving IM for a minimum of 3 months before allogeneic hematopoietic cell transplantation (HCT) to 231 patients with CML who did not. IM treatment was associated with no increase in early hepatotoxicity or engraftment delay after HCT compared with the historical cohort. In addition, there was no statistically significant difference in the IM-treated cohort compared with the historical cohort with regard to overall survival, disease-free survival, relapse, and nonrelapse mortality. For chronic-phase (CP) patients, IM response prior to HCT was associated with post-HCT outcome. Patients who underwent transplantation in CP with a suboptimal response or a loss of response on IM had a statistically significant higher hazard of mortality when compared with CP patients who achieved a complete cytogenetic response (CCR) or major cytogenetic response (MCR) on IM (HR=5.31, 95% confidence interval [CI] 1.13-25.05, P=.03). These data indicate that pre-HCT IM is not associated with increased transplant-related morbidity (TRM) or poorer outcomes. However, patients with a suboptimal or loss of IM response before HCT do worse, suggesting a more aggressive disease course for these patients.

Allogeneic stem cell transplantation for patients with chronic myeloid leukemia and acute lymphocytic leukemia after Bcr-Abl kinase mutation-related imatinib failure

Resistance to imatinib mesylate is an emerging problem in the treatment of chronic myeloid leukemia (CML), often associated with point mutations in the Bcr-Abl kinase domain. Outcome of patients with such mutations after allogeneic stem cell transplantation (Allo-SCT) is unknown. Ten imatinib-resistant patients with Bcr-Abl kinase mutations received a transplant: 9 had CML (3 in chronic phase, 4 in accelerated phase, and 2 in blast phase) and 1 had Philadelphia-positive acute lymphocytic leukemia (ALL). Patients harbored 9 different protein kinase mutations (T315I mutation, n = 2). Preparative regimens were ablative (n = 7) and nonablative (n = 3). All patients engrafted; there were no treatment-related deaths. Disease response was complete molecular (CMR; n = 7), major molecular (n = 2), and no response (n = 1). Three patients (mutations Q252H, E255K, and T315I) died of relapse after Allo-SCT. Seven patients are alive (6 in CMR) for a median of 19 months. Allo-SCT remains an important salvage option for patients who develop resistance to imatinib through Bcr-Abl mutations.

[Hematological side effects of tyrosine kinase inhibition using imatinib]

Imatinib (STI571, Gleevec/Glivec) and other small-molecule tyrosine kinase inhibitors are highly effective in the treatment of chronic myeloid leukemia (CML), gastrointestinal stromal tumors and, for example, eosinophilia-associated chronic myeloproliferative disorders. This molecularly targeted approach disrupts abnormal tyrosine kinase dependent signalling pathways, thus providing a preferred treatment option for selected neoplastic disorders with activating mutations of Abelson-, Abl-related-, Kit-, and platelet-derived growth factor receptor A and B genes. Loss of response to imatinib may be due to an acquired resistance of emerging mutant tumor cell clones. Therapy is generally well tolerated. However, toxicities including edema, skin rashes, fatigue, nausea and myelosuppression have been reported. Philadelphia/Bcr-Abl-negative clonal chromosomal abnormalities may develop. Bone marrow trephines obtained from CML patients in complete remission with prolonged pancytopenia secondary to imatinib generally show marrow hypoplasia. Morphological features may be in keeping with either aplastic anemia or myelodysplasia developing in Philadelphia-negative hematopoiesis. Single or multilineage myelodysplasia may be accompanied by an excess of blasts and rarely evolves into acute leukemia in CML patients. Severe adverse hematological effects of imatinib are extremely rare. Current questions involve the molecular mechanisms of hematological side effects of tyrosine kinase inhibitors with special regard to the emergence of distinct aberrant clones.