Reversible lymph node follicular hyperplasia associated with dasatinib treatment of chronic myeloid leukemia in chronic phase

Epstein-Barr virus-associated lymphoproliferative disease during remission after induction therapy with dasatinib in Philadelphia chromosome-positive acute lymphoblastic leukemia: a case report

Dasatinib, a second-generation tyrosine kinase inhibitor, has been reported to have immunomodulatory effects. Epstein-Barr virus (EBV)-associated lymphoproliferative disorders (EBV-LPD) occur in immunocompromised patients, such as those receiving methotrexate or other immunosuppressive drugs or after allogenic transplantation. EBV-LPD is also reported to be a rare side effect in patients receiving long-term dasatinib or imatinib. The present report describes a 60-year-old woman with Philadelphia chromosome-positive acute lymphoblastic leukemia who was treated with dasatinib and prednisolone for induction of remission. Fever, enlargement of the tonsils, multiple cervical lymphadenopathies and a splenic mass emerged after 1 month of treatment. Histopathological analysis of tonsil biopsy specimens showed diffuse proliferation of CD20-positive atypical cells with large, irregular nuclei. Some of these cells were positive for EBV-encoded small RNA, and her peripheral blood was positive for EBV-DNA (4.9 Log IU/mL), leading to a diagnosis of EBV-LPD. After discontinuation of dasatinib, her high fever and cervical lymphadenopathies disappeared without recurrence. The subsequently removed splenic mass was largely composed of non-neoplastic cytotoxic T cells resulting from a reaction to EBV-infected B cells. EBV-LPD should be included in the differential diagnosis of patients who develop lymphadenopathy during dasatinib treatment, regardless of its duration.

Dasatinib-associated follicular lymphoma in a patient with B-cell acute lymphoblastic leukaemia

The tyrosine kinase inhibitor dasatinib is approved for the treatment of chronic myeloid leukaemia and Philadelphia chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL). Patients on dasatinib can rarely develop a form of benign reversible reactive lymphadenopathy termed follicular lymphoid hyperplasia (FLH). Here, we describe a patient with Ph+ ALL who developed follicular lymphoma (FL) after prolonged treatment with dasatinib and who had complete remission of FL after discontinuation of dasatinib. This case suggests that dasatinib-associated FLH could be a premalignant condition that can transform into FL. Moreover, withdrawal of dasatinib may be sufficient for remission of dasatinib-associated FL.

Dasatinib plus Peg-Interferon alpha 2b combination in newly diagnosed chronic phase chronic myeloid leukaemia: Results of a multicenter phase 2 study (DASA-PegIFN study)

Superior rates of deep molecular response (DMR) have been reported with the combination of tyrosine kinase inhibitors and pegylated-interferon-alpha (Peg-IFN) in patients with newly diagnosed chronic phase-chronic myeloid leukaemia (CP-CML). In this setting, this study investigated the efficacy and safety of dasatinib combined to Peg-IFN-α2b (Dasa-PegIFN, NCT01872442). A total of 79 patients (age ≤65 years) started dasatinib; 61 were eligible for Peg-IFNα-2b add-on therapy at month 3 for a maximum 21-months duration. Dasatinib was continued thereafter. The primary endpoint was the cumulative rate of molecular response 4.5 log (MR^4.5 ) by 12 months. The results are reported for the 5-year duration of the study. Grade 3 neutropenia was frequent with the combination but did not induce severe infection (one of grade 3). Other adverse events were generally low grade (4% of grade 3-4) and expected. Seventy-nine per cent and 61% of patients continued the Peg-IFN until months 12 and 24, respectively. Overall, at these time points, MR^4.5 rates were 25% and 38%, respectively. Thereafter, 32% and 46% of patients achieved a sustained (≥2 years) MR^4.5 or MR⁴ , respectively. This work established the feasibility and high rates of achievement of early and sustained DMR (a prerequisite for treatment-free-remission) with dasatinib and Peg-IFNα-2b combination as initial therapy.

[Dasatinib-induced follicular lymphoid hyperplasia, an entity to know]

Follicular lymphoid hyperplasia induced by dasatinib is an entity recently described. It is sometimes difficult to rule out the diagnostic of small B-cell lymphoma. Usually, the node is swollen, with follicular architecture conserved, composed by germinal centers with variable size and shape, with a hight number of mitoses and tingible bodies macrophages inside. Follicular lymphoid hyperplasia is isolated or associated with multiple reactive patterns. The immunohistochemical profil of germinal centers is CD20+, CD10+, BCL6+, BCL2-. Swollen node disappears in a short time after dasatinib discontinuation. Clinicians and pathologists need to be aware of this entity, so as not to avoid mistakenly suspect lymphoma when lymphadenopathy occurs in a patient with chronic myeloid leukemia treated with dasatinib.

The incidence and natural history of dasatinib complications in the treatment of chronic myeloid leukemia

Dasatinib has shown superiority over imatinib in achieving molecular responses (MRs) in chronic phase chronic myeloid leukemia but with a different toxicity profile, which may impact its overall benefit. Reported toxicities include pleural effusions and pulmonary hypertension, and although the incidence of these events is well described, response to therapy and impact of dose modifications on toxicity has not been comprehensively characterized in a real-world setting. We retrospectively reviewed the incidence of dasatinib adverse events in 212 chronic phase chronic myeloid leukemia patients at 17 Australian institutions. Adverse events were reported in 116 patients (55%), most commonly pleural effusions (53 patients, 25%), which was the predominant cause of permanent drug cessation. Age and dose were risk factors for pleural effusion (P < .01 and .047, respectively). Recurrence rates were higher in those who remained on 100 mg compared with those who dose reduced (P = .041); however, recurrence still occurred at 50 mg. Patients who developed pleural effusions were more likely to have achieved MR4.5 after 6 months of dasatinib than those without effusions (P = .008). Pulmonary hypertension occurred in 5% of patients, frequently in association with pleural effusion, and was reversible upon dasatinib cessation in 6 of 7 patients. Dose reductions and temporary cessations had minimal impact on MR rates. Our observations suggest that by using the lowest effective dose in older patients to minimize the effusion risk, dose modification for cytopenias, and care with concomitant antiplatelet therapy, the necessity for permanent dasatinib cessation due to toxicity is likely to be minimal in immunologically competent patients.

EBV-Positive B-Cell Proliferations of Varied Malignant Potential: 2015 SH/EAHP Workshop Report-Part 1

OBJECTIVES

The 2015 Workshop of the Society for Hematopathology/European Association for Haematopathology aimed to review B-cell proliferations of varied malignant potential associated with immunodeficiency.

METHODS

The Workshop Panel reviewed all cases of B-cell hyperplasias, polymorphic B-lymphoproliferative disorders, Epstein-Barr virus (EBV)-positive mucocutaneous ulcer, and large B-cell proliferations associated with chronic inflammation and rendered consensus diagnoses. Disease definitions, boundaries with more aggressive B-cell proliferations, and association with EBV were explored.

RESULTS

B-cell proliferations of varied malignant potential occurred in all immunodeficiency backgrounds. Presentation early in the course of immunodeficiency and in younger age groups and regression with reduction of immunosuppression were characteristic features. EBV positivity was essential for diagnosis in some hyperplasias where other specific defining features were absent.

CONCLUSIONS

This spectrum of B-cell proliferations show similarities across immunodeficiency backgrounds. Localized forms of immunodeficiency disorders arise in immunocompetent patients most likely due to chronic immune stimulation and, despite aggressive histologic features, often show indolent clinical behavior.

Dasatinib for the treatment of chronic myeloid leukemia: patient selection and special considerations

Dasatinib is one of the second-generation tyrosine kinase inhibitors used in imatinib resistance and/or intolerance, as well as in the frontline setting in patients with chronic myeloid leukemia-chronic phase, and also in patients with advanced disease. It is also utilized in Philadelphia chromosome-positive acute lymphocytic leukemia. While choosing the appropriate tyrosine kinase inhibitor (ie, dasatinib) for each individual patient, comorbidities and BCR-ABL1 kinase domain mutations should always be taken into consideration, among other things. This review mainly focuses on patient selection prior to dasatinib administration in the treatment of chronic myeloid leukemia.

Dasatinib-related Follicular Hyperplasia: An Underrecognized Entity With Characteristic Morphology

Dasatinib, a second-generation tyrosine kinase inhibitor with activity against BCR-ABL1 and other Src family tyrosine kinases, is approved as a first-line treatment option for Philadelphia chromosome-positive chronic myelogenous leukemia (CML) in the chronic phase. Recently, lymphadenopathy with morphologic features of reactive follicular hyperplasia was described in a cohort of patients with CML on long-term dasatinib therapy. However, the complete morphologic and immunophenotypic features of this previously underappreciated adverse effect have not been fully described. Herein, we report 3 cases of unexplained lymphadenopathy resulting in multiple diagnostic procedures in patients with CML and a history of long-term dasatinib therapy. Morphologic examination demonstrated preserved nodal architecture showing hybrid features of progressive transformation of germinal centers and Castleman-type changes in a background of florid follicular hyperplasia. Large germinal centers were disrupted by complex infolding of IgD+ mantle zones arranged as cuffs surrounding perforating capillaries. Other abnormalities variably present included decreased CD20 expression among polytypic B cells and increased Epstein-Barr virus reactivity in scattered paracortical cells and/or individual germinal centers. B-cell clonality studies showed no predominant clonal rearrangements. Consideration of dasatinib-related lymphadenopathy may pre-empt unnecessary repeat diagnostic procedures in patients with CML or other dasatinib-susceptible malignancies and persistent lymphadenopathy.

Vascular safety issues in CML patients treated with BCR/ABL1 kinase inhibitors

Vascular safety is an emerging issue in patients with chronic myeloid leukemia (CML) treated with tyrosine kinase inhibitors (TKIs). Whereas imatinib exhibits a well-documented and favorable long-term safety profile without obvious accumulation of vascular events, several types of vascular adverse events (VAEs) have been described in patients receiving second- or third-generation BCR/ABL1 TKIs. Such VAEs include pulmonary hypertension in patients treated with dasatinib, peripheral arterial occlusive disease and other arterial disorders in patients receiving nilotinib, and venous and arterial vascular occlusive events during ponatinib. Although each TKI interacts with a unique profile of molecular targets and has been associated with a unique pattern of adverse events, the mechanisms of drug-induced vasculopathy are not well understood. Here, recent data and concepts around VAEs in TKI-treated patients with CML are discussed, with special reference to potential mechanisms, event management, and strategies aimed at avoiding occurrence of such events in long-term treated patients.