Rituximab plus cladribine with or without cyclophosphamide in patients with relapsed or refractory chronic lymphocytic leukemia

OBJECTIVES: The aim of our study was to determine the feasibility, effectiveness and toxicity of combined regimens consisting of rituximab and cladribine (2-CdA) (RC) and RC plus cyclophosphamide (RCC) in the treatment of patients with recurrent or refractory chronic lymphocytic leukemia (CLL). METHODS: The RC regimen consisted of rituximab given on day 1 and 2-CdA (days 2-6). The RCC protocol included rituximab (day 1), 2-CdA (days 2-4) and cyclophosphamide given on days 2-4. The courses were re-administered at time intervals of 4 weeks or longer if severe myelosuppression occurred. RESULTS: Forty-six patients with CLL entered the study. Eighteen patients were treated with RC and 28 with RCC regimen. The median number of courses administered were three cycles (range 1-6). Three (6.5%) patients (95% CI: 1-14%) achieved a complete response and 31 (67%) patients (95% CI: 50-83%) a partial response. According to the particular regimen, the overall response rate was obtained in 12 (67%) patients treated with RC (95% CI: 45-89%) and in 22 patients (78%) treated with RCC (95% CI: 62-93%). The median progression free survival of responders to RC/RCC regimens was 12 months (range 4-46). Hypersensitivity to rituximab occurred in 16 (33%) patients, mostly during the first infusion of the drug. Grade 3/4 neutropenia was seen in six (13%) patients, grade 3/4 thrombocytopenia in three (9%) patients and grade 3/4 infections were observed in ten (28%) patients. CONCLUSIONS: These data indicate that both RC and RCC regimens are feasible in heavily pretreated patients with CLL, showing also distinct therapeutic activity and relatively low toxicity, even in patients previously treated with cladribine-based protocols.     

The successful treatment of refractory autoimmune hemolytic anemia with rituximab in a patient with chronic lymphocytic leukemia

The most frequent autoimmune complication in chronic lymphocytic leukemia (CLL) is autoimmune hemolytic anemia (AIHA). There are various treatment modalities; however, there is not much experience with the use of the chimeric anti-CD20 monoclonal antibody rituximab in the autoimmune complications of CLL. Here, we present our patient with CLL and AIHA whose AIHA was unresponsive to various treatment modalities. The administration of 375 mg/m(2)/day rituximab weekly for four cycles halted hemolysis and resulted in resolution of the patient's anemia. One year after therapy, the patient is well with a normal blood count. Rituximab might be preferred over other treatment modalities in the autoimmune complications of CLL because it is effective and has fewer side effects than other therapies.     

Abnormal T cell function in early-stage chronic lymphocytic leukemia (CLL) patients

Significant alterations in T cell subpopulations and function occur in chronic lymphocytic leukemia (CLL) patients. We studied whether abnormalities in peripheral blood T cell parameters were present in 15 untreated early stage CLL patients (ie, Rai stage 0, 1, 2). Seven of the nine patients showed decreased T helper support as compared to control T cells for pokeweed mitogen (PWM)-induced control B cell proliferation (ie, patient 6,063 +/- 1,434 cpm vs control 14,894 +/- 121 cpm). All stage 0 and 1 patients showed a marked impairment of T helper activity for control B cell proliferation (patient T = 7,752 +/- 1,137 cpm vs control T = 14,894 +/- 121 cpm). In a separate assay system, six of nine CLL patients showed T suppressor activity for control B cell proliferation greater than control T cell suppressor activity. Four patients were stage 0 and 1. CLL patients demonstrated markedly impaired T cell support for control B cell immunoglobulin synthesis compared to control T cells (188 +/- 28 vs 869 +/- 56 hemolytic plaque-forming cells (HePFC)/culture, respectively). Control T cells showed increasing support for control B cell immunoglobulin synthesis with increasing T:B cell ratios (869 +/- 56 vs 1,265 +/- 48 HePFC/culture, at 1:1 and 2:1 T:B cell ratios, respectively). In contrast, five of eight CLL patients' T cells showed no improvement in control B cell immunoglobulin synthesis with increasing T:B cell ratios (795 +/- 56 vs 569 +/- 48 HePFC/culture, at 1:1 and 2:1 T:B cell ratios, respectively). There was no direct correlation with CLL T cell-mediated suppression of B cell proliferation and suppression of B cell immunoglobulin synthesis. These studies suggest there is a complex array of abnormal immunoregulatory T cell function in early stage CLL. These include a prominent T helper dysfunction and more variable excessive suppressor activity. The relationship of these findings to the basic disease process remains to be elucidated.     

Bendamustine + rituximab chemoimmunotherapy and maintenance lenalidomide in relapsed,refractory chronic lymphocytic leukaemia and small lymphocytic lymphoma: A Wisconsin Oncology Network Study

Bendamustine + rituximab (BR) has demonstrated high response rates in relapsed/refractory (R/R) chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL). However, progression‐free survival (PFS) after BR is <18 months. This study was designed to determine if maintenance lenalidomide after BR induction could improve PFS in R/R CLL/SLL. Thirty‐four patients with R/R CLL/SLL who had received 1–5 prior chemotherapy regimens were treated with 6 cycles of BR induction. Patients achieving at least a minor response received twelve 28‐d cycles of lenalidomide 5–10 mg/d. The primary endpoint was PFS. The median age was 67 years, with a median of 2 prior therapies. Eleven patients had confirmed presence of 17p and/or 11q deletions. Twenty‐five (74%) completed 6 cycles of induction BR (response rate 56%). Nineteen (56%) patients received maintenance lenalidomide; only 6 patients completed the intended 12 cycles, highlighting the limited feasibility of lenalidomide in this setting, primarily due to haematological and infectious toxicities. The observed median PFS of 18·3 months is not significantly different from that of BR induction in R/R CLL/SLL without maintenance therapy (15·2 months). It is possible that lenalidomide maintenance may be more feasible and effective in the front‐line setting, which is being tested in an ongoing trial (NCT01754857).     

Simultaneous manifestation of chronic lymphocytic leukemia (CLL) and hairy cell leukemia (HCL)

We report a unique case of 83-year-old Caucasian male with the initial simultaneous manifestation of chronic lymphocytic leukemia (CLL) and hairy cell leukemia (HCL). The patient presented with absolute lymphocytosis in the blood, asymptomatic generalized lymphadenopathy, and mild splenomegaly. The diagnosis of CLL was suggested from the blood film, but subsequent flow cytometric (FC) analysis on peripheral blood mononuclear cells (PBMNC) revealed two distinct abnormal clones of mature B cells. A small subpopulation (7%) of lymphoid cells expressed CD20, CD11c, FMC-7, CD103, CD25, and kappa surface light chain, consistent with HCL. The larger subpopulation (75%) of lymphoid cells expressed CD19, CD20, CD23, CD5, and lambda light chain, consistent with CLL. The expression of different immunoglobulin light chains on the circulating CLL (lambda) and HCL (kappa) cells suggested two, independent, malignant B-cell clones. Interestingly, FC analysis of bone marrow (BM) cells done 6 months later revealed bright lambda light chain expression on the HCL cells. Despite administration of several different courses of chemotherapy, the HCL subpopulation was not eliminated from the BM but remained stable between 7% and 10% of total BM lymphoid cells. The CLL, responsible for most of clinical symptoms in our patient, responded to combination chemotherapy with fludarabine and cytoxan, and later to monotherapy with rituximab.     

Spleen irradiation in chronic lymphocytic leukemia (CLL): palliation in patients unfit for splenectomy

In 22 patients with CLL given 30 courses of spleen irradiation, 23 responses were observed (77%, 95% confidence limits, 58-90%). Response was defined as reduction in palpable spleen size accompanied by relief of symptoms (pain, abdominal discomfort, and sweating) or improvement in hypersequestration or hemolytic anemia. Reduction in leukocyte count alone was not regarded as response. All responses were partial. The median response duration was 1 year. Subsequently, three patients underwent splenectomy. The median survival from the beginning of spleen irradiation was 2.5 years (range: 1 month-greater than 5 years). Only six patients had minor side effects from the gastrointestinal tract. The hematologic effect was most pronounced on the white blood cell count, but also the platelet count was affected. It is concluded that spleen irradiation is a gentle and effective alternative in CLL patients suffering from splenomegaly (pain and hypersplenism), refractory to chemotherapy and glucocorticosteroids and unfit for splenectomy. Splenic irradiation may also be used with benefit preoperatively before splenectomy in patients with excessive splenomegaly and hypersplenism.     

Chronic lymphocytic leukemia‐associated immune thrombocytopenia treated with rituximab: a retrospective study of 21 patients

Introduction: There are no standard therapies for chronic lymphocytic leukemia (CLL)‐associated immune thrombocytopenia (IT) so far. Patients and methods: We report the results of therapy with single agent rituximab in 21 patients with CLL‐associated IT. The mean age at CLL and IT diagnosis was 64 and 68 yr, respectively. IT developed at a mean time of 44 months from the diagnosis of CLL. In four cases, IT was diagnosed at the same time as CLL. For three patients, IT was considered fludarabine‐related and two patients showed autoimmune hemolysis also. All patients but one received steroids as first‐line treatment for IT. Some patients received intravenous high‐dose Ig, vincristine, and Cytoxan also, without beneficial effect. After a mean time of 43 d from the diagnosis of IT, all patients were scheduled to receive rituximab at a dosage of 375 mg/mq/weekly. Results: Eighteen (86%) patients completed the scheduled four cycles of rituximab. Irrelevant first infusion side effects were seen only in one patient. Twelve (57%) patients showed a complete response (CR), six (29%) patients a partial response (PR), and three (14%) patients did not respond. In responding patients, the mean duration of response was 21 months (4–49 months). At a mean follow‐up of 28 months, 14 (66%) patients were still alive, 10 (48%) of them in CR and three (14%) in PR. Conclusions: This retrospective analysis prove that rituximab is an effective and well‐tolerated alternative treatment for CLL‐associated IT.     

Fractionated subcutaneous rituximab is well-tolerated and preserves CD20 expression on tumor cells in patients with chronic lymphocytic leukemia

A pilot study previously demonstrated that thrice-weekly, fractionated-dose intravenous rituximab (RTX) limits CD20 loss from chronic lymphocytic leukemia (CLL) B cells, thereby enhancing immunotherapeutic targeting. Here, we investigated the feasibility of giving 20 mg rituximab subcutaneously thrice weekly for up to 12 weeks in 4 previously treated CLL patients. Subcutaneous rituximab was well-tolerated with minimal injection site reactions; a variable degree of efficacy was observed, likely influenced by the size of the patients’ B cell/CD20 burden. Subcutaneous RTX largely preserved CD20 expression on leukemic cells but the most effective therapeutic dosing regimen needs to be established (ClinicalTrials.gov Identifier: NCT00366418).     

A randomized phase II trial of fludarabine, cyclophosphamide and mitoxantrone (FCM) with or without rituximab in previously treated chronic lymphocytic leukaemia

Combination fludarabine (F), cyclophosphamide (C) and rituximab (R) is the standard front-line therapy in chronic lymphocytic leukaemia (CLL), but appropriate treatment of relapsed/refractory CLL is less clear. Combined FC and mitoxantrone (M) has been reported to be effective in a single arm study, and rituximab when added to chemotherapy in CLL is synergistic. A randomized, two-stage, Phase II trial of FCM and FCM-R was conducted in relapsed CLL. The primary endpoint was response rate 2 months after therapy, assessed according to the 2008 International Workshop CLL criteria. In addition, minimal residual disease (MRD) in the marrow was studied 2 months after therapy, with MRD negativity defined as <0·01% CLL cells. Fifty-two patients were entered, 26 in each arm. The overall response rates to FCM and FCM-R were 58% and 65% respectively. Combined complete response (CR) and CR with incomplete marrow recovery [CR(i)] was 15% (95% confidence interval [CI]:4-35%) for FCM and 42% (95%CI:23-63%) for FCM-R, with eight patients achieving MRD negativity (3 FCM; 5 FCM-R). The toxicity of both regimens was acceptable. In conclusion, the addition of rituximab to FCM improves the response rates in relapsed CLL, resulting in more complete remissions and without additional safety concerns. Efficacy and safety should be fully tested in a randomized Phase III trial.     

Successful labor in the course of chronic lymphocytic leukemia (CLL) and management of CLL during pregnancy with leukapheresis

We describe the successful management of a 30-year-old woman in the second trimester of her pregnancy with chronic lymphocytic leukemia (CLL) in stage IV by using only leukapheresis. We applied three sessions (courses) of leukapheresis throughout the pregnancy. The procedure did not have any significant adverse effect on the patient and the fetus. The patient gave birth vaginally to a healthy boy, weighing 3100 g, at 39 weeks of gestation. Seven months after delivery, Richter's syndrome developed in the patient. We conclude that leukapheresis may provide an alternative for palliative treatment to chemotherapy in pregnant patients with CLL. To our knowledge, this is the fourth reported case of CLL in pregnancy, and the first management of CLL during pregnancy with leukapheresis.     

CCR4 expression in a case of cutaneous Richter's transformation of chronic lymphocytic leukemia (CLL) to diffuse large B-cell lymphoma (DLBCL) and in CLL patients with no skin manifestations

Objective: Richter’s transformation of B‐cell chronic lymphocytic leukemia (CLL) to cutaneous diffuse large B‐cell lymphoma (DLBCL) is very rare. We took the advantage of one of these cases to test the hypothesis that the chemokine receptor CCR4 is involved in the homing of CLL cells to skin. Patients and Methods: We evaluated CCR4 expression by flow cytometry in both circulating and skin CD19⁺ leukemic cells from a patient with cutaneous DLBCL. As controls, we used peripheral blood samples from CLL patients without skin manifestations and from elderly healthy donors. Results: We found that both DLBCL cells derived from the original CLL clone and circulating CLL cells from this patient expressed CCR4. Although it was previously reported that CCR4 is not expressed in CLL cells, we found that a low but significant proportion of leukemic cells from CLL patients with no skin manifestations do express CCR4. There was a positive correlation between the expression of CCR4 and the percentage of ZAP‐70 of each sample. Moreover, we consistently observed a higher expression of CCR4 within CD19⁺CD38⁺ and CD19⁺Ki67⁺ subsets compared to CD19⁺CD38^? and CD19⁺Ki67^? lymphocytes from the same sample, respectively. Conclusion: We conclude that the chemokine receptor CCR4 is not a special feature of CLL cells with skin manifestation, but rather it is expressed in a low but significant proportion of peripheral blood CLL cells.     

Recombinant interferon-alpha 2A as maintenance treatment for patients with advanced stage chronic lymphocytic leukemia responding to chemotherapy.

Forty-five patients suffering from advanced B-CLL were randomized to receive interferon-alpha (IFN alpha) or no treatment after achieving complete remission or partial response, following a chemotherapy protocol called MiNa. The two groups were fully comparable in terms of clinical characteristics and level of response obtained by chemotherapy. IFN alpha was given at a dose of 3 megaunits three times a week intramuscularly for 1 year. The IFN-treated patient group showed a significantly longer duration of response and a less frequent incidence of infections as compared to the no treatment group. A minority of patients who had had partial response to chemotherapy obtained complete remission while on therapy with IFN alpha. Toxicity was mild and patient compliance was excellent. We conclude that IFN alpha may have a role as maintenance therapy in CLL for patients responding to chemotherapy.     

Prognostic value of CD20 antigen mediated immune checkpoint inhibition in patients with acute or chronic lymphocytic leukemia: A protocol for systematic review

Background:The addition of rituximab to standard chemotherapy has been shown to improve response rates in patients with acute or chronic lymphocytic leukemia. However, the prognostic factors associated with progression-free survival in rituximab treated patients with lymphocytic leukemias remains unclear. We will perform a comprehensive systematic review and meta-analysis on available data on prognostic factors associated with the clinical outcomes of patients with acute and chronic lymphocytic leukemia.Methods and analysis:This protocol for a systematic review and meta-analysis of prognostic factors has been prepared following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015 guidelines. Electronic databases will be searched using keywords related to the objectives of this review. This systematic review and meta-analysis will include published randomized clinical trials, observational, prospective, and retrospective comparative cohorts. Two reviewers (ZAM and SAM) will independently screen studies, with a third reviewer consulted in cases of disagreements using a defined inclusion and exclusion criteria. Data items will be extracted using a predefined data extraction sheet. Moreover, the risk of bias and the quality of evidence were independently assessed using the quality in prognostic studies tool (QUIPS). The I2 and chi squared statistical tests will be used to analyze statistical heterogeneity across studies. An I2 values of > 50% will be considered substantial. All data analysis will be performed using STATA 16.0 (StataCorp LP, TX, USA). The outcomes examined will be progression-free and overall survival.Ethics and dissemination:No ethical approval will be required and the findings of this meta-analysis will be published in a peer-reviewed journal.Systematic review registration:International prospective Register of Systematic Reviews (PROSERO) number: CRD42021218997.     

CD5-negative chronic lymphocytic leukemia with indolent clinical course and autoimmune thrombocytopenia, successfully treated with rituximab

A 59-year-old male with lymphocytosis and thrombocytopenia was asymptomatic without lymphadenopathy or hepatosplenomegaly over 10 years. He was admitted to our hospital because his thrombocytopenia had worsened. The clonal lymphocytes appeared as regular small mature lymphocytes on blood films, and bone marrow biopsy showed diffuse infiltration of mature lymphocytes. However, megakaryocytes also presented. The immunophenotypic analysis by flow cytometry revealed that the lymphocytes were positive for CD19, CD20, CD22, and surface membrane immunoglobulin (SmIg) M and D-lambda and were negative for CD5, CD10, CD11c, CD23, and other lineage markers. Expression levels of CD20 and SmIg were strong. The markers were consistent with CD5- CLL with autoimmune thrombocytopenia. He received rituximab, and a rapid decrease of lymphocytes with concomitant increase of platelets was observed. A few cases of CD5- CLL with a stable clinical course have been reported, thought to be B lymphocytosis of undetermined significance (MLUS). This is the first report of CD5- CLL with indolent clinical course associated with autoimmune thrombocytopenia, successfully treated with rituximab.     

Clinical efficacy of immunochemotherapy with fludarabine, epirubicin and rituximab in the treatment for chronic lymphocytic leukaemia and prolymphocytic leukaemia

Despite some considerable progress in the therapy for chronic lymphocytic leukaemia (CLL) owing to fludarabine-based regimens and rituximab, no curative treatment is available so far. We conducted an explorative phase II study in patients with CLL, prolymphocytic leukaemia (PLL) and leukaemic lymphoplasmacytic lymphoma (LL) with the combination of fludarabine, epirubicin and rituximab (FER) to improve the complete remission (CR) rate and progression-free survival (PFS). Fludarabine 25 mg/m(2) was administered i.v. on days 1-5 and epirubicin 25 mg/m(2) i.v. on days 4 and 5, and rituximab was added at a dose of 375 mg/m(2) i.v. day 1 in the first cycle and at a dose of 500 mg/m(2) in all consecutive cycles. Patients exhibiting responsive disease after FER were eligible to receive maintenance therapy of up to 12 cycles of rituximab 375 mg/m(2) bimonthly. Forty-four patients (38 CLL, 4 PLL and 2 LL) with a median age of 65 yrs (43-84 yrs) were evaluable. Seventeen patients with CLL had stage Binet C, 14 Binet B and seven symptomatic or rapid progressive stage Binet A. Cytogenetic features showed normal karyotype in nine cases, an isolated deletion (del) 13q in 12 patients, trisomy 12 in 7, del 11 in two and del 17p in 4. Half of the patients (48%) had mutated IgVH genes. Treatment with FER achieved an overall response rate of 95%, including 63% CRs and 32% PRs. Haematological toxicity was considerable. After a median follow-up period of 34 months (range: 8-84 months), median PFS was 61 months and overall survival was yet not reached. All patients with PLL and LL achieved CR. The data support the high efficacy of the combination of rituximab with chemotherapy (FE) and are suggestive of possible benefit with rituximab maintenance therapy for PFS and DFS.     

HLA ligandome analysis identifies the underlying specificities of spontaneous antileukemia immune responses in chronic lymphocytic leukemia (CLL)

The breakthrough development of clinically effective immune checkpoint inhibitors illustrates the potential of T-cell–based immunotherapy to effectively treat malignancies. A remaining challenge is to increase and guide the specificities of anticancer immune responses, e.g., by therapeutic vaccination or by adoptive T-cell transfer. By analyzing the landscape of naturally presented HLA class I and II ligands of primary chronic lymphocytic leukemia (CLL), we delineated a novel category of tumor-associated T-cell antigens based on their exclusive and frequent representation in the HLA ligandome of leukemic cells. These antigens were validated across different stages and mutational subtypes of CLL and found to be robustly represented in HLA ligandomes of patients undergoing standard chemo-/immunotherapy. We demonstrate specific immune recognition of these antigens exclusively in CLL patients, with the frequencies of representation in CLL ligandomes correlating with the frequencies of immune recognition by patient T cells. Moreover, retrospective survival analysis revealed survival benefits for patients displaying immune responses to these antigens. These results directly imply these nonmutant self-peptides as pathophysiologically relevant tumor antigens and encourages their implementation for cancer immunotherapy.For a long time peptide-based immunotherapy fell short of its potential to achieve meaningful responses in the clinical setting of cancer therapy (1, 2). A disequilibrium between proposed tumor-associated antigens on the input side (3) and functional vaccines on the output side (4–6) became strikingly apparent. This might in part have been due to the distorted relationship of gene expression and HLA restricted presentation of the corresponding gene product (7, 8). In contrast, a recent study on vaccination with naturally presented tumor-associated peptides identified by direct analysis of primary tumor-derived HLA ligands reported specific, nontoxic vaccine-induced immune responses, which were associated with improved clinical outcome (6). On the other hand, experimental cancer immunotherapy using adoptive transfer of antigen-specific T cells showed high efficiency but also severe toxicity in some patients due to presence of target antigens on normal tissues (7). Both situations underscore the importance and potential of identifying (patho-)physiologically relevant targets by direct differential analysis of the entire landscape of HLA-presented peptides, termed the HLA ligandome.Here, we mapped the nonmutant HLA ligandome of chronic lymphocytic leukemia (CLL) with the aim of developing a CLL-specific multipeptide vaccine. The immunogenicity of CLL, as revealed in GvL-effects and cases of spontaneous remissions (8–10), as well as favorable immune effector-to-target cell ratios present in situations with minimal residual disease (MRD) suggest that CLL might be effectively targeted by T-cell–based immunotherapy (11, 12). Furthermore, the highly variable and in some patients prolonged course of disease indicates an underlying mechanism of tumor control (13). However, so far only very few CLL-associated antigens that are able to elicit specific T-cell responses have been described (14–16).We identified a novel category of ligandome-defined tumor-associated antigens (LiTAAs; source proteins of HLA ligands on tumor cells), which were frequently and exclusively detected in CLL patients. Specific immune recognition of the corresponding HLA ligands (LiTAPs) was observed exclusively in CLL patients, remarkably showing a direct correlation with the frequency of HLA restricted presentation. Furthermore, retrospective survival analysis points to an association of LiTAP-specific immune responses with improved overall survival in CLL patients.