Allogeneic hematopoietic cell transplant for prolymphocytic leukemia

An effective treatment and suspicious adverse reaction to Ibrutinib in a patient diagnosed with splenic B-cell lymphoma/leukaemia with prominent nucleoli: A first case report

RATIONALE

Splenic B-cell lymphoma/leukemia with prominent nucleoli (SBLPN) is a new classification, which is so rare that it lacks clinical data.

PATIENT CONCERNS

An increased proportion of prolymphocytes (84%) in the bone marrow smear. Whole exon sequence analysis revealed a TP53 mutation.

DIAGNOSES

Combining the clinical features with laboratory test results led to a diagnosis of SBLPN which was made according to the 5th edition of the WHO classification of hematolymphoid tumors, although the patient was diagnosed with B-PLL when guided by the 4th edition of the WHO classification.

INTERVENTIONS

The use of Ibrutinib as an effective treatment.

OUTCOMES

The patient was in complete remission after 5 months of Ibrutinib and then died of sudden aortic dissection.

LESSONS

Ibrutinib was an effective regimen for SBLPN. Aortic dissection might be considered as a suspicious adverse reaction to Ibrutinib.

The role of allogeneic hematopoietic cell transplantation for chronic lymphocytic leukemia: A review

Although the use of allogeneic hematopoietic cell transplantation (HCT) for chronic lymphocytic leukemia (CLL) has declined with the development of novel targeted agents, it continues to play an important role for eligible patients with high-risk or heavily pretreated CLL who lack other treatment options. CLL is susceptible to a potent graft-versus-leukemia (GVL) effect which produces long-lasting remissions in 30-50% of transplanted patients. While allogeneic HCT is associated with significant risks of graft-versus-host disease (GVHD), infection, and non-relapse mortality (NRM), improvements in patient and donor selection, reduced intensity conditioning (RIC), GVHD prophylaxis, and supportive care have rendered this an increasingly safe and effective procedure in the current era. In this review, we discuss recent advances in allogeneic HCT for CLL, with a focus on the optimal evidence-based strategies to maximize benefit and minimize toxicity of this potentially curative cellular therapy.

Advances in Cellular Therapy for T-Cell Prolymphocytic Leukemia

T-cell prolymphocytic leukemia (T-PLL) is a rare, aggressive hematologic malignancy with a poor prognosis. Alemtuzumab (Campath) remains the cornerstone for treatment, with an 80% complete response (CR). Hematopoietic stem cell transplant (HSCT) is considered the standard of care as consolidative therapy in eligible patients. However, allogeneic stem cell transplant is also complicated by increased rates of infections from chemotherapy, acute graft-versus-host disease (GVHD), and chronic GVHD. This review aims to report the available literature on the efficacy and complications of consolidative HSCT. It also discusses the importance of patient selection and pre- and post-transplant complications including atypical infections and GVHD.

Outcomes of Allogeneic Hematopoietic Cell Transplantation in T-cell Prolymphocytic Leukemia: A Contemporary Analysis from the Center for International Blood and Marrow Transplant Research

T cell prolymphocytic leukemia (T-PLL) is a rare, aggressive malignancy with limited treatment options and poor long-term survival. Previous studies of allogeneic hematopoietic cell transplantation (alloHCT) for T-PLL are limited by small numbers, and descriptions of patient and transplantation characteristics and outcomes after alloHCT are sparse. In this study, we evaluated outcomes of alloHCT in patients with T-PLL and attempted to identify predictors of post-transplantation relapse and survival. We conducted an analysis of data using the Center for International Blood and Marrow Transplant Research database on 266 patients with T-PLL who underwent alloHCT between 2008 and 2018. The 4-year rates of overall survival (OS), disease-free survival (DFS), relapse, and treatment-related mortality (TRM) were 30.0% (95% confidence interval [CI], 23.8% to 36.5%), 25.7% (95% CI, 20% to 32%), 41.9% (95% CI, 35.5% to 48.4%), and 32.4% (95% CI, 26.4% to 38.6%), respectively. In multivariable analyses, 3 variables were associated with inferior OS: receipt of a myeloablative conditioning (MAC) regimen (hazard ratio [HR], 2.18; P < .0001), age >60 years (HR, 1.61; P = .0053), and suboptimal performance status, defined by Karnofsky Performance Status (KPS) <90 (HR, 1.53; P = .0073). Receipt of an MAC regimen also was associated with increased TRM (HR, 3.31; P < .0001), an elevated cumulative incidence of grade II-IV acute graft-versus-host disease (HR, 2.94; P = .0011), and inferior DFS (HR, 1.86; P = .0004). Conditioning intensity was not associated with relapse; however, stable disease/progression was correlated with increased risk of relapse (HR, 2.13; P = .0072). Both in vivo T cell depletion (TCD) as part of conditioning and KPS <90 were associated with worse TRM and inferior DFS. Receipt of total body irradiation had no significant effect on OS, DFS, or TRM. Our data show that reduced-intensity conditioning without in vivo TCD (ie, without antithymocyte globulin or alemtuzumab) before alloHCT was associated with long-term DFS in patients with T-PLL who were age ≤60 years or who had a KPS >90 or chemosensitive disease.

T-Cell Prolymphocytic Leukemia: An Overview of Current and Future Approaches

T-cell prolymphocytic leukemia (T-PLL) is a rare mature T-cell hematologic neoplasm with a very poor prognosis and limited treatment options to date. Single-agent alemtuzumab remains the first line of therapy for the treatment-naive and relapsed/refractory patients. Prospective clinical trials are difficult to conduct given that these patients have a short life expectancy after the initial diagnosis. As a result, researchers are implementing the use of targeted therapies in vitro and ex vivo followed by in vivo trials on a small subset of patients which are reviewed here. Newer approaches in the treatment of T-PLL are developing based on recognizing the cytogenetic phenotype of each patient and targeting the identified defective genes that are usually involved in the cell cycle regulation such as protooncogenes, tumor suppressors, and deoxyribonucleic acid (DNA) repair genes. These could potentially redirect the management in the near future and improve the overall survival (OS) and the progression-free survival (PFS) for these patients. 

Advances and Perspectives in the Treatment of T-PLL

PURPOSE OF REVIEW

T cell prolymphocytic leukemia (T-PLL) is a rare mature T cell tumor. Available treatment options in this aggressive disease are largely inefficient and patient outcomes are highly dissatisfactory. Current therapeutic strategies mainly employ the CD52-antibody alemtuzumab as the most active single agent. However, sustained remissions after sole alemtuzumab-based induction are exceptions. Responses after available second-line strategies are even less durable. More profound disease control or rare curative outcomes can currently only be expected after a consolidating allogeneic hematopoietic stem cell transplantation (allo-HSCT) in best first response. However, only 30-50% of patients are eligible for this procedure. Major advances in the molecular characterization of T-PLL during recent years have stimulated translational studies on potential vulnerabilities of the T-PLL cell. We summarize here the current state of "classical" treatments and critically appraise novel (pre)clinical strategies.

RECENT FINDINGS

Alemtuzumab-induced first remissions, accomplished in ≈ 90% of patients, last at median ≈ 12 months. Series on allo-HSCT in T-PLL, although of very heterogeneous character, suggest a slight improvement in outcomes among transplanted patients within the past decade. Dual-action nucleosides such as bendamustine or cladribine show moderate clinical activity as single agents in the setting of relapsed or refractory disease. Induction of apoptosis via reactivation of p53 (e.g., by inhibitors of HDAC or MDM2) and targeting of its downstream pathways (i.e., BCL2 family antagonists, CDK inhibitors) are promising new approaches. Novel strategies also focus on inhibition of the JAK/STAT pathway with the first clinical data. Implementations of immune-checkpoint blockades or CAR-T cell therapy are at the stage of pre-clinical assessments of activity and feasibility. The recommended treatment strategy in T-PLL remains a successful induction by infusional alemtuzumab followed by a consolidating allo-HSCT in eligible patients. Nevertheless, long-term survivors after this "standard" comprise only 10-20%. The increasingly revealed molecular make-up of T-PLL and the tremendous expansion of approved targeted compounds in oncology represent a "never-before" opportunity to successfully tackle the voids in T-PLL. Approaches, e.g., those reinstating deficient cell death execution, show encouraging pre-clinical and first-in-human results in T-PLL, and urgently have to be transferred to systematic clinical testing.

Current understandings on T-cell prolymphocytic leukemia and its association with TCL1 proto-oncogene

T-cell prolymphocytic leukemia (T-PLL) is a rare mature T cell leukemia with aggressive clinical course, poor response to conventional therapies and high mortality rates. Classical cytogenetics and various genetic techniques have observed complex karyotypes and associated genes involved in the molecular pathogenesis of T-PLL, among which the proto-oncogene T-cell leukemia/lymphoma 1 (TCL1) as a hallmark of malignancy is hyper-activated and abnormally expressed in many T-PLL cases. Progress has been made to identify the presence of chromosomal rearrangements and subsequent changes in key molecular pathways typically involving Akt, which may hint cytogenetic mechanisms underlying the pathogenesis of T-PLL and indicate new treatment targets. In this article, we describe current insights of T-PLL with an emphasis on the potential role of TCL1 gene disorders and TCL1-Akt interactions in cell transformation and disease progression, followed by discussion on current treatment options and novel therapeutic approaches based on cytogenetics, which still remains to be explored for the effective management of T-PLL and other TCL1-driven hematological malignancies.

B and T cell prolymphocytic leukaemia

Prolymphocytic leukaemias B-PLL and T-PLL are rare disorders, typically with an aggressive clinical course and poor prognosis. Combining morphology, immunophenotyping, cytogenetic and molecular diagnostics reliably separates B-PLL and T-PLL from one another and other disorders. In T-PLL discovery of frequent mutations in the JAK-STAT pathway have increased understanding of disease pathogenesis. Alemtuzumab (anti-CD52) produces excellent response rates but long-term remissions are only achieved in a minority following consolidation with allogeneic stem cell transplant. Molecular abnormalities in B-PLL are less understood. Disruption of TP53 is a key finding, conveying chemotherapy resistance requiring novel therapies such as B-cell receptor inhibitors (BCRi). Both conditions require improved pathobiological knowledge to identify new treatment targets and guide therapy with novel pathway inhibitors.

EBMT prospective observational study on allogeneic hematopoietic stem cell transplantation in T-prolymphocytic leukemia (T-PLL)

Preliminary data suggest that allogeneic stem cell transplantation (allo-SCT) may be effective in T-prolymphocytic leukemia (T-PLL). The purpose of the present observational study was to assess the outcome of allo-SCT in patients aged 65 years or younger with a centrally confirmed diagnosis of T-PLL. Patients were consecutively registered with the EBMT at the time of transplantation and followed by routine EBMT monitoring but with an extended dataset. Between 2007 and 2012, 37 evaluable patients (median age 56 years) were accrued. Pre-treatment contained alemtuzumab in 95% of patients. Sixty-two percent were in complete remission (CR) at the time of allo-SCT. Conditioning contained total body irradiation with 6 Gy or more (TBI6) in 30% of patients. With a median follow-up of 50 months, the 4-year non-relapse mortality, relapse incidence, progression-free (PFS) and overall survival were 32, 38, 30 and 42%, respectively. By univariate analysis, TBI6 in the conditioning was the only significant predictor for a low relapse risk, and an interval between diagnosis and allo-SCT of more than 12 months was associated with a lower NRM. This study confirms for the first time prospectively that allo-SCT can provide long-term disease control in a sizable albeit limited proportion of patients with T-PLL.

Advances in the understanding and management of T-cell prolymphocytic leukemia

T-prolymphocytic leukemia (T-PLL) is a rare T-cell neoplasm with an aggressive clinical course. Leukemic T-cells exhibit a post-thymic T-cell phenotype (Tdt-, CD1a-, CD5+, CD2+ and CD7+) and are generally CD4+/CD8-, but CD4+/CD8+ or CD8+/CD4- T-PLL have also been reported. The hallmark of T-PLL is the rearrangement of chromosome 14 involving genes for the subunits of the T-cell receptor (TCR) complex, leading to overexpression of the proto-oncogene TCL1. In addition, molecular analysis shows that T-PLL exhibits substantial mutational activation of the IL2RG-JAK1-JAK3-, STAT5B axis. T-PLL patients have a poor prognosis, due to a poor response to conventional chemotherapy. Monoclonal antibody therapy with antiCD52-alemtuzumab has considerably improved outcomes, but the responses to treatment are transient; hence, patients who achieve a response to therapy are considered for stem cell transplantation (SCT). This combined approach has extended the median survival to four years or more. Nevertheless, new approaches using well-tolerated therapies that target growth and survival signals are needed for most patients unable to receive intensive chemotherapy.

Prolymphocytic Leukemia: New Insights in Diagnosis and in Treatment

PURPOSE OF REVIEW

We aimed to produce a comprehensive update on clinical and biological data regarding two rare lymphoid neoplasms, B and T prolymphocytic leukemias, and assess therapeutic management in the light of new molecular insights and the advent of targeted therapies.

RECENT FINDINGS

B cell prolymphocytic leukemia (B-PLL) diagnosis remains challenging in the absence of clear immunophenotypic or cytogenetic signature and overlap with mantle cell lymphoma. New molecular defects have been identified in T cell prolymphocytic leukemia (T-PLL), especially in the JAK STAT pathway. Like in chronic lymphocytic leukemia (CLL), B-PLL treatment depends on the presence of TP53 dysfunction. In T-PLL, alemtuzumab still remains the standard of care. Allogeneic transplantation is the only curable option. Thanks to reduced intensity conditioning regimens, it has become accessible to a larger number of patients. PLL prognosis remains poor with conventional therapies. However, great advances in the understanding of both T- and B-PLL pathogenesis lead to promising new therapeutic agents.

Management of prolymphocytic leukemia

B-cell (B-PLL) and T-cell (T-PLL) prolymphocytic leukemias are rare, poor-prognosis lymphoid neoplasms with similar presentation characterized by symptomatic splenomegaly and lymphocytosis. They can be distinguished from each other and from other T- and B-cell leukemias by careful evaluation of morphology, immunophenotyping, and molecular genetics. The clinical behavior is typically aggressive, although a subset of patients may have an indolent phase of variable length. First-line therapy for T-PLL is with intravenous alemtuzumab and for B-PLL is with combination purine analog-based chemo-immunotherapy. New B-cell receptor inhibitors, such as ibrutinib and idelalisib, may have a role in the management of B-PLL, especially for the patients harboring abnormalities of TP53. Allogenic stem cell transplantation should still be considered for eligible patients and may be the only current therapy capable of delivering a cure. In the past few years, many of the molecular mechanisms underlying disease pathogenesis and progression have been revealed and are likely to lead to the development of novel targeted approaches.

Impact of Alemtuzumab Therapy and Route of Administration in T-Prolymphocytic Leukemia: A Single-Center Experience

OBJECTIVE

We conducted a single-center retrospective analysis to determine the impact of the anti-CD52 monoclonal antibody alemtuzumab including route of administration compared to non-alemtuzumab-containing regimens in T-prolymphocytic leukemia (T-PLL).

PATIENTS AND METHODS

The study was a retrospective analysis of a consecutive cohort of adult patients diagnosed with T-PLL at Mayo Clinic Rochester from January 1, 1997, through September 30, 2014.

RESULTS

A total of 41 patients were diagnosed with T-PLL per the World Health Organization 2008 classification. The median age was 66 years, and 23 (56%) were male. After a median follow-up of 18 months (range, 0.4-66.1 months), 32 patients (78%) had died, with a median overall survival of 16.9 months. Approximately half the cohort was treated with alemtuzumab, almost exclusively after 2004. Median survival for patients receiving intravenous alemtuzumab-based therapy was 40.5 versus 10.3 months for all other therapies (P = .0004). A significant survival difference between intravenous versus subcutaneous alemtuzumab administration of 40.5 versus 13.7 months was noted (P = .0014). Only 4 (14%) of 28 patients aged < 70 years underwent hematopoietic stem cell transplantation, with a median survival after transplantation of 4 months.

CONCLUSION

In this large series of T-PLL patients treated at a single tertiary-care center, we confirmed the prior observation of the superiority of intravenous alemtuzumab over other therapies. Hematopoietic stem cell transplantation was feasible in a minority of potentially eligible patients. Early transplant referral should be considered for all eligible patients.

T-Cell Prolymphocytic Leukemia, Small Cell Variant, Possibly at the Stage of Intracytoplasmic Expression of CD3 in T-Cell Ontogenesis

T-cell prolymphocytic leukemia, small cell variant (T-PLL-s), is a rare lymphoid neoplasm associated with a poor prognosis. We encountered a case of T-PLL-s with a characteristic phenotype. A 67-year-old female was referred to our hospital because of lymphocytosis in August 2013. Hepatosplenomegaly, lymphadenopathy, and skin lesions were absent. Hematologic examination revealed a white blood cell count of 17.9 × 10(9)/L with 81.2% mature lymphocytes, which were small with a high nuclear/cytoplasmic ratio, lacking a nucleolus and cytoplasmic granules. Anemia and thrombocytopenia were not observed. Flow cytometric analysis showed that these lymphocytes were positive for CD2, cyCD3, CD4, CD5, CD7, CD21, and CD38 (partially), but negative for smCD3, smTCR-αβ and -γδ, cyTCR-β, CD1a, CD8, CD25, HLA-DR, and terminal deoxynucleotidyl transferase. Polymerase-chain reaction analysis of cells from both the peripheral blood and the bone marrow demonstrated monoclonal rearrangement of TCR-γ. A possible rearranged band of the TCR-β gene was observed by Southern blot analysis. The karyotype of the marrow cells was 46, XX. A diagnosis of T-PLL-s, possibly at the stage of cytoplasmic CD3 expression in the ontogenesis of T-cells, was made. The patient has been asymptomatic, and the white blood cell count has gradually increased during one-year observation, being 69.0 × 10(9)/L with 89.7% lymphocytes in August 2014.

A pediatric case of T-cell prolymphocytic leukemia

T-cell Prolymphocytic Leukemia (T-PLL) is a rare entity, and to date has never been reported in children. Here, we describe the first pediatric case of T-PLL in a 16-year old male and review his clinical course through treatment. He underwent therapy with alemtuzumab and pentostatin, which was successful in inducing initial remission. He then underwent an allogeneic matched sibling stem cell transplant following a myeloablative conditioning regimen and remains disease-free 1.5 years after diagnosis.

Management of prolymphocytic leukemia

B-cell (B-PLL) and T-cell (T-PLL) prolymphocytic leukemias are rare, poor-prognosis lymphoid neoplasms with similar presentation characterized by symptomatic splenomegaly and lymphocytosis. They can be distinguished from each other and from other T- and B-cell leukemias by careful evaluation of morphology, immunophenotyping, and molecular genetics. The clinical behavior is typically aggressive, although a subset of patients may have an indolent phase of variable length. First-line therapy for T-PLL is with intravenous alemtuzumab and for B-PLL is with combination purine analog-based chemo-immunotherapy. New B-cell receptor inhibitors, such as ibrutinib and idelalisib, may have a role in the management of B-PLL, especially for the patients harboring abnormalities of TP53. Allogenic stem cell transplantation should still be considered for eligible patients and may be the only current therapy capable of delivering a cure. In the past few years, many of the molecular mechanisms underlying disease pathogenesis and progression have been revealed and are likely to lead to the development of novel targeted approaches.

Allogeneic hematopoietic stem cell transplantation for T-prolymphocytic leukemia: a report from the French society for stem cell transplantation (SFGM-TC)

T-prolymphocytic leukemia (T-PLL), a rare aggressive mature T-cell disorder, remains frequently resistant to conventional chemotherapy. Studies have suggested that allogeneic hematopoietic stem cell transplantation (HSCT) might possibly serve to consolidate the response to initial chemotherapy. The current report summarizes the outcome of 27 T-PLL cases identified in the registry in French Society for stem cell transplantation (SFGM-TC). Prior to HSCT, 14 patients were in complete remission (CR), 10 in partial response, three refractory, or in progression. Following HSCT, 21 patients achieved CR as best response. With a median follow-up for surviving patients of 33 (range, 6-103) months, 10 patients are still alive in continuous CR. Overall survival and progression-free survival estimates at 3 yr were 36% (95% CI: 17-54%) and 26% (95% CI: 14-45%), respectively. The relapse incidence after HSCT was 47% occurring at a median of 11.7 (range, 2-24) months. Overall cumulative incidence of transplant-related mortality was 31% at 3 yr. These results suggest that HSCT may allow long-term survival in patients with T-PLL following induction treatment; however, it is associated with a significant rate of toxicity.

B- and T-cell prolymphocytic leukemia: antibody approaches

B- and T-cell subtypes of prolymphocytic leukemia (PLL) are rare, aggressive lymphoid malignancies with characteristic morphologic, immunophenotypic, cytogenetic, and molecular features. Prognosis for these patients remains poor, with short survival times and no curative therapy. The advent of mAbs has improved treatment options. In B-PLL, rituximab-based combination chemoimmunotherapy is effective in fitter patients. TP53 abnormalities are common and, as for chronic lymphocytic leukemia, these patients should generally be managed using an alemtuzumab-based therapy. Currently, the best treatment for T-PLL is IV alemtuzumab, which has resulted in very high response rates of more than 90% when given as frontline treatment and a significant improvement in survival. Consolidation of remissions with autologous or allogeneic stem cell transplantation further prolongs survival times, and the latter may offer potential cure. The role of allogeneic transplantation with nonmyeloablative conditioning needs to be explored further in both T- and B-PLL to broaden the patient eligibility for what may be a curative treatment.

B-cell prolymphocytic leukemia and hairy cell leukemia: new advances in biology and treatment

SUMMARY B-cell prolymphocytic leukemia and hairy cell leukemia are mature lymphoid neoplasms recognized by WHO classification as distinct entities. The diagnosis relies on a constellation of clinical and laboratory features. B-cell prolymphocytic leukemia is a rare disease that lacks a genetic signature and represents a challenge to clinicians, due to the limited information on its pathogenesis, the difficulty of setting up prospective clinical trials and its refractoriness to treatments used in other chronic lymphoid neoplasms. By contrast, major advances have taken place in the understanding of the pathogenesis of hairy cell leukemia, as well as in the therapeutic armamentarium available for this disease. In this review, data will be presented on the natural history, pathogenesis, diagnosis and current therapies for these two leukemias.

How I treat prolymphocytic leukemia

T- and B-cell subtypes of prolymphocytic leukemia (PLL) are rare, aggressive lymphoid malignancies with characteristic morphologic, immunophenotypic, cytogenetic, and molecular features. Recent studies have highlighted the role of specific oncogenes, such as TCL-1, MTCP-1, and ATM in the case of T-cell and TP53 mutations in the case of B-cell prolymphocytic leukemia. Despite the advances in the understanding of the biology of these conditions, the prognosis for these patients remains poor with short survival and no curative therapy. The advent of monoclonal antibodies has improved treatment options. Currently, the best treatment for T-PLL is intravenous alemtuzumab, which has resulted in very high response rates of more than 90% when given as first-line treatment and a significant improvement in survival. Consolidation of remissions with autologous or allogeneic stem cell transplantation further prolongs survival, and the latter may offer potential cure. In B-PLL, rituximab-based combination chemo-immunotherapy is effective in fitter patients. TP53 abnormalities are common and, as for chronic lymphocytic leukemia, these patients should be managed using an alemtuzumab-based therapy. The role of allogeneic transplant with nonmyeloablative conditioning needs to be explored further in both T- and B-cell PLL to broaden the patient eligibility for what may be a curative treatment.

A case report of T cell prolymphocytic leukemia and Kaposi sarcoma and a review of T cell prolymphocytic leukemia

T cell prolymphocytic leukemia (T-PLL) is a rare mature T cell lymphoproliferative disease. It has been associated with an aggressive course, a poor response to conventional chemotherapy and a short median survival. Here we present a rare case of concurrent T-PLL and Kaposi sarcoma who achieved a complete hematologic and cytogenetic remission after a very short course of treatment with alemtuzumab. A review of T-PLL was done. In this review, clinical features, laboratory features and current therapeutic strategies of T-PLL are presented.