Proteomic markers with prognostic impact on outcome of chronic lymphocytic leukemia patients under chemo-immunotherapy: results from the HOVON 109 study.

Despite recent identification of several prognostic markers, there is still a need for new prognostic parameters able to predict clinical outcome in chronic lymphocytic leukemia (CLL) patients. Here, we aimed to validate the prognostic ability of known (proteomic) markers measured pretreatment and to search for new proteomic markers that might be related to treatment response in CLL. To this end, baseline serum samples of 51 CLL patients treated with chemo-immunotherapy were analyzed for 360 proteomic markers, using Olink technology. Median event-free survival (EFS) was 23 months (range: 1.25-60.9). Patients with high levels of sCD23 (>11.27, p = 0.026), sCD27 (>11.03, p = 0.04), SPINT1 (>1.6, p = 0.001), and LY9 (>8.22, p = 0.0003) had a shorter EFS than those with marker levels below the median. The effect of sCD23 on EFS differed between immunoglobulin heavy chain variable gene-mutated and unmutated patients, with the shortest EFS for unmutated CLL patients with sCD23 levels above the median. Taken together, our results validate the prognostic impact of sCD23 and highlight SPINT1 and LY9 as possible promising markers for treatment response in CLL patients.

Feasibility and efficacy of addition of individualized-dose lenalidomide to chlorambucil and rituximab as first-line treatment in elderly and FCR-unfit patients with advanced chronic lymphocytic leukemia.

Lenalidomide has been proven to be effective but with a distinct and difficult to manage toxicity profile in the context of chronic lymphocytic leukemia, potentially hampering combination treatment with this drug. We conducted a phase 1-2 study to evaluate the efficacy and safety of six cycles of chlorambucil (7 mg/m2 daily), rituximab (375 mg/m2 cycle 1 and 500 mg/m2 cycles 2-6) and individually-dosed lenalidomide (escalated from 2.5 mg to 10 mg) (induction-I) in first-line treatment of patients with chronic lymphocytic leukemia unfit for treatment with fludarabine, cyclophosphamide and rituximab. This was followed by 6 months of 10 mg lenalidomide monotherapy (induction-II). Of 53 evaluable patients in phase 2 of the study, 47 (89%) completed induction-I and 36 (68%) completed induction-II. In an intention-to-treat analysis, the overall response rate was 83%. The median progression-free survival was 49 months, after a median follow-up time of 27 months. The 2- and 3-year progression-free survival rates were 58% and 54%, respectively. The corresponding rates for overall survival were 98% and 95%. No tumor lysis syndrome was observed, while tumor flair reaction occurred in five patients (9%, 1 grade 3). The most common hematologic toxicity was grade 3-4 neutropenia, which occurred in 73% of the patients. In conclusion, addition of lenalidomide to a chemotherapy backbone followed by a fixed duration of lenalidomide monotherapy resulted in high remission rates and progression-free survival rates, which seem comparable to those observed with novel drug combinations including novel CD20 monoclonal antibodies or kinase inhibitors. Although lenalidomide-specific toxicity remains a concern, an individualized dose-escalation schedule is feasible and results in an acceptable toxicity profile. EuraCT number: 2010-022294-34.

Clonal diversity predicts adverse outcome in chronic lymphocytic leukemia.

Genomic analyses of chronic lymphocytic leukemia (CLL) identified somatic mutations and associations of clonal diversity with adverse outcomes. Clonal evolution likely has therapeutic implications but its dynamic is less well studied. We studied clonal composition and prognostic value of seven recurrently mutated driver genes using targeted next-generation sequencing in 643 CLL patients and found higher frequencies of mutations in TP53 (35 vs. 12%, p < 0.001) and SF3B1 (20 vs. 11%, p < 0.05) and increased number of (sub)clonal (p < 0.0001) mutations in treated patients. We next performed an in-depth evaluation of clonal evolution on untreated CLL patients (50 "progressors" and 17 matched "non-progressors") using a 404 gene-sequencing panel and identified novel mutated genes such as AXIN1, SDHA, SUZ12, and FOXO3. Progressors carried more mutations at initial presentation (2.5 vs. 1, p < 0.0001). Mutations in specific genes were associated with increased (SF3B1, ATM, and FBXW7) or decreased progression risk (AXIN1 and MYD88). Mutations affecting specific signaling pathways, such as Notch and MAP kinase pathway were enriched in progressive relative to non-progressive patients. These data extend earlier findings that specific genomic alterations and diversity of subclones are associated with disease progression and persistence of disease in CLL and identify novel recurrently mutated genes and associated outcomes.

Rituximab maintenance improves overall survival of patients with follicular lymphoma-Individual patient data meta-analysis.

BACKGROUND: Randomised trials of rituximab maintenance (MR) for patients with follicular lymphoma support improved progression-free survival (PFS), but the effect on overall survival has been inconclusive. To evaluate the effect of MR on overall survival according to patient and disease characteristics, and to explore certain adverse events, we performed an individual patient data (IPD) meta-analysis. METHODS: All investigators of randomised controlled trials that compared MR therapy with observation or treatment only at relapse (no MR) for patients with follicular lymphoma were invited to participate in an IPD meta-analysis. We obtained baseline patient and disease characteristics and time to progression and death for each patient. All analyses took into account the trial and original randomised treatment group. We analysed data in two ways: a two-stage analysis and a multivariate model including patient and disease characteristics. FINDINGS: Seven trials including 2315 patients were analysed. Overall survival of patients improved with MR compared with no MR (hazard ratio [HR] 0.79, 95% CI 0.66-0.96). We could not detect any patient or disease characteristics that were associated with a survival benefit with MR. In all of the models, MR had a beneficial effect on overall survival compared with observation for all types of patients, which was not shown in a particular subgroup in which the patient had already received rituximab in the induction phase and received first-line therapy. MR improved PFS compared with observation (HR 0.57, 95% CI 0.51-0.64). The risk of adverse events was higher with MR, specifically infection of any grade and grade 3-4 infections. INTERPRETATION: Based on IPD from randomised controlled trials, MR improves overall survival consistently in all patients, regardless of patient and disease characteristics when compared with observation, and should be prescribed after a successful induction with R-CVP or R-CHOP for patients with follicular lymphoma. It is still uncertain if that holds when the patient has already received rituximab in his/hers first induction. The effect of MR after bendamustine-rituximab induction compared with rituximab at progression should be further explored.

Soluble CD52 is an indicator of disease activity in chronic lymphocytic leukemia.

CD52 is a glycoprotein expressed on normal as well as leukemic immune cells and shed as soluble CD52 (sCD52). We studied sCD52 levels in three CLL cohorts: the 'early', the 'high-risk', and the 'ibrutinib-treated'. The 'high-risk' patients had significantly higher sCD52 levels than the 'early' patients. For the 'early' patients, high sCD52 levels were associated with a significantly shorter time to first treatment. Regarding prognostic factors, no clear correlations with stage, IGHV, or beta-2-microglobulin were found; in a cox multivariate analysis of the 'early' patients, sCD52 and IGHV both had independent prognostic value. Following chemo-immunotherapy, sCD52 decreased in parallel with leukocytes while during ibrutinib treatment and ibrutinib-induced ymphocytosis, sCD52 decreased along with lymph node reductions. In vitro IgM stimulation of CLL cells led to increased sCD52 levels in the medium. Our findings indicate that sCD52 reflects disease activity and potentially treatment efficacy in CLL.

The HOVON68 CLL trial revisited: performance status and comorbidity affect survival in elderly patients with chronic lymphocytic leukemia.

In the HOVON68 CLL trial, patients 65 to 75 years of age had no survival benefit from the addition of low-dose alemtuzumab to fludarabine and cyclophosphamide (FC) in contrast to younger patients. The reasons are explored in this 5-year trial update using both survival analysis and competing risk analysis on non-CLL-related mortality. Elderly FCA patients died more frequently from causes not related to CLL, and more often related to comorbidity (mostly cardiovascular) than to infection. In a Cox multivariate analysis, del(17p), performance status >0, and comorbidity were associated with a higher non-CLL-related mortality in the elderly independent of the treatment modality. Thus, while the 'fit' elderly with no comorbidity or performance status of 0 might potentially benefit from chemo-immunotherapy with FC, caution is warranted, when considering alemtuzumab treatment in elderly patients with cardiovascular comorbidity.

Ofatumumab maintenance versus observation in relapsed chronic lymphocytic leukaemia (PROLONG): an open-label, multicentre, randomised phase 3 study.

BACKGROUND: Ofatumumab is a human anti-CD20 monoclonal antibody that has proven efficacy as monotherapy in refractory chronic lymphocytic leukaemia. We assessed the efficacy and safety of ofatumumab maintenance treatment versus observation for patients in remission after re-induction treatment for relapsed chronic lymphocytic leukaemia. METHODS: This open-label, multicentre, randomised phase 3 study enrolled patients aged 18 years or older from 130 centres in 24 countries who had chronic lymphocytic leukaemia in complete or partial remission after second-line or third-line treatment. Eligible patients had a WHO performance status of 0-2, had a response assessment within the previous 3 months, did not have refractory disease, autoimmune haemolytic anaemia requiring treatment, chronic or active infection requiring treatment, and had not previously received maintenance treatment or autologous or allogeneic stem-cell transplant. Using a randomisation list generated by a central computerised system and an interactive voice recognition system, we randomly assigned (1:1) patients to receive ofatumumab (300 mg followed by 1000 mg 1 week later and every 8 weeks for up to 2 years) or undergo observation. Randomisation was stratified by number and type of previous treatment and remission status after induction treatment (block size of four). Treatment assignment was open label. The primary endpoint was investigator-assessed progression-free survival in the intention-to-treat population. We report the results of a prespecified interim analysis after two-thirds of the planned study events (disease progression or death) had happened. This trial is closed to accrual but follow-up is ongoing. This trial is registered with ClinicalTrials.gov, number NCT00802737. FINDINGS: Between May 6, 2010, and June 19, 2014, we enrolled 474 patients: 238 patients were randomly assigned to receive ofatumumab maintenance treatment and 236 to undergo observation. One (<1%) patient in the ofatumumab group did not receive the allocated intervention (withdrawal of consent). The median follow-up was 19·1 months (IQR 10·3-28·8). Progression-free survival was improved in patients assigned to the ofatumumab group (29·4 months, 95% CI 26·2-34·2) compared with those assigned to observation (15·2 months, 11·8-18·8; hazard ratio 0·50, 95% CI 0·38-0·66; p<0·0001). The most common grade 3 or higher adverse events up to 60 days after last treatment were neutropenia (56 [24%] of 237 patients in the ofatumumab group vs 23 [10%] of 237 in the observation group) and infections (31 [13%] vs 20 [8%]). 20 (8%) of 237 patients in the ofatumumab group and three (1%) of 237 patients in the observation group had adverse events that led to permanent discontinuation of treatment. Up to 60 days after last treatment, two deaths related to adverse events occurred in the ofatumumab treatment group and five deaths related to adverse events occurred in the observation group; no deaths were attributed to the study drug. INTERPRETATION: These data are important for the development of optimum maintenance strategies in patients with relapsed chronic lymphocytic leukaemia, notably in the present era of targeted drugs, many of which are to be used until progression.

Early discharge after high dose chemotherapy is safe and feasible: a prospective evaluation of 6 years of home care.

A single-center, prospective, non-randomized clinical study was performed to examine the safety and feasibility of early discharge in patients undergoing consolidation chemotherapy for acute leukemia, or autologous stem cell transplant for lymphoma or multiple myeloma. Patients were discharged into ambulatory care the day after the last chemotherapy administration and were subsequently seen at the ambulatory care unit three times a week. One hundred and one of 224 patients were ineligible for the program, mostly because of their medical situation, the lack of a caregiver or the travel time to the hospital. The remaining 123 patients were able to spend more than 70% of the time at home. In 44% of cycles they were never readmitted. This study demonstrates the safety, feasibility and benefits of managing carefully selected patients. Patients and their caregivers felt safe and comfortable at home, and the vast majority preferred home care to in-hospital treatment.

Induction of TAp73 by platinum-based compounds to overcome drug resistance in p53 dysfunctional chronic lymphocytic leukemia.

In chronic lymphocytic leukemia (CLL), strategies to overcome drug resistance due to p53 dysfunction are highly needed. Platinum-based compounds such as cisplatinum (CDDP) are active in fludarabine-refractory CLL through a largely unknown mechanism. We analyzed the mechanism of action of CDDP in the context of p53 dysfunctionality. In vitro treatment with CDDP did not induce death in quiescent CLL cells, but did induce apoptosis in CD40-ligand (and CpG) stimulated and proliferating cells, irrespective of p53 function. In the p53 dysfunctional prolymphocytic cell-line MEC1, CDDP treatment resulted in apoptosis, cell cycle arrest and ABL1-dependent expression of TAp73, CDKN1A, PUMA and BID. TAp73 RNA-interference decreased sensitivity to CDDP. Finally, both in vitro stimulated CLL cells and lymph node (LN) derived CLL cells showed increased TAp73 expression in comparison with quiescent peripheral blood derived cells. Activity of CDDP may therefore be mediated by TAp73, especially in the context of activation such as occurs in the LN microenvironment.

Activated innate lymphoid cells are associated with a reduced susceptibility to graft-versus-host disease.

Allogeneic hematopoietic stem cell transplantation (HSCT) is widely used to treat hematopoietic cell disorders but is often complicated by graft-versus-host disease (GVHD), which causes severe epithelial damage. Here we have investigated longitudinally the effects of induction chemotherapy, conditioning radiochemotherapy, and allogeneic HSCT on composition, phenotype, and recovery of circulating innate lymphoid cells (ILCs) in 51 acute leukemia patients. We found that reconstitution of ILC1, ILC2, and NCR(-)ILC3 was slow compared with that of neutrophils and monocytes. NCR(+) ILC3 cells, which are not present in the circulation of healthy persons, appeared both after induction chemotherapy and after allogeneic HSCT. Circulating patient ILCs before transplantation, as well as donor ILCs after transplantation, expressed activation (CD69), proliferation (Ki-67), and tissue homing markers for gut (α4ß7, CCR6) and skin (CCR10 and CLA). The proportion of ILCs expressing these markers was associated with a decreased susceptibility to therapy-induced mucositis and acute GVHD. Taken together, these data suggest that ILC recovery and treatment-related tissue damage are interrelated and affect the development of GVHD.

Frontline low-dose alemtuzumab with fludarabine and cyclophosphamide prolongs progression-free survival in high-risk CLL.

The randomized Haemato Oncology Foundation for Adults in The Netherlands 68 phase 3 trial compared front-line chemotherapy with chemotherapy plus the CD52 monoclonal antibody alemtuzumab for high-risk chronic lymphocytic leukemia, defined as at least 1 of the following: unmutated immunoglobulin heavy chain genes, deletion 17p or 11q, or trisomy 12. Fit patients were randomized to receive either 6 28-day cycles of oral FC chemotherapy (days 1 through 3: fludarabine 40 mg/m(2) per day and cyclophosphamide 250 mg/m(2) per day: n = 139) or FC plus subcutaneous alemtuzumab 30 mg day 1 (FCA, n = 133). FCA prolonged the primary end point, progression-free survival (3-year progression-free survival 53 vs 37%, P = .01), but not the secondary end point, overall survival (OS). However, a post hoc analysis showed that FCA increased OS in patients younger than 65 years (3-year OS 85% vs 76%, P = .035). FCA also increased the overall response rate (88 vs 78%, P = .036), and the bone marrow minimal residual disease-negative complete remission rate (64% vs 43%, P = .016). Opportunistic infections were more frequent following FCA, but without an increase in treatment related mortality (FCA: 3.8%, FC: 4.3%). FCA improves progression-free survival in high-risk chronic lymphocytic leukemia. As anticipated, FCA is more immunosuppressive than FC, but with due vigilance, does not lead to a higher treatment-related mortality. This study was registered at www.trialregister.nl as trial no. NTR529.

Dasatinib in combination with fludarabine in patients with refractory chronic lymphocytic leukemia: a multicenter phase 2 study.

Resistance to chemotherapy-induced apoptosis in CLL is associated with overexpression of antiapoptotic proteins induced by signals from the microenvironment. In vitro, dasatinib effectively inhibits expression of anti-apoptotic regulators and restores fludarabine sensitivity in activated CLL. The aim of this study was to evaluate efficacy of one cycle of dasatinib monotherapy (100mg/day, days 1-28) followed by combination of dasatinib with fludarabine (40mg/m²/day, days 1-3 every 28 day) for a total of 6 cycles in fludarabine-refractory CLL. The primary endpoint was overall response rate according to the IWCLL'08 criteria. 20 patients were enrolled: 18 completed at least one cycle of treatment of which 67% finished at least 2 cycles of combination treatment. 3 of these 18 patients reached a formal PR (16.7%). Majority of patients obtained some reduction in lymph node (LN) size. Most frequent toxicity was related to myelosuppression. NF-κB RNA expression levels of circulating CLL cells decreased whereas the levels of pro-apoptotic NOXA increased during treatment. In conclusion, dasatinib/fludarabine combination has modest clinical efficacy in fludarabine-refractory patients.

CMV-specific CD8+ T-cell function is not impaired in chronic lymphocytic leukemia.

In chronic lymphocytic leukemia (CLL), CD8(+) T cells exhibit features of exhaustion and impaired functionality. Yet, reactivations of latent viruses such as cytomegalovirus (CMV) are uncommon in untreated CLL, suggesting that antiviral responses are uncompromised. We analyzed phenotypical and functional characteristics of CMV-specific CD8(+) T cells in CLL patients in comparison with age-matched healthy controls (HCs). Despite increased expression of the inhibitory receptors PD1, CD160, and CD244 on total CD8(+) T cells in CLL, expression levels of these markers were decreased on CMV-tetramer(+)CD8(+) T cells. Second, cytokine production upon stimulation with both phorbol 12-myristate 13-acetate/ionomycin and CMV-peptide-loaded antigen-presenting cells was intact in CMV-tetramer(+)CD8(+) T cells. Third, CMV-tetramer(+)CD8(+) T cells of CLL patients and HCs were equally effective in killing CMV-peptide-loaded target cells. Finally, quantitative imaging flow cytometry revealed that the proportion of CD8(+) T cells forming immunologic synapses with CMV-peptide-loaded B cells was intact. In conclusion, despite evidence for global T-cell dysfunction in CLL, we show here that CLL-derived CMV-specific CD8(+) T cells display lower expression of exhaustion markers and are functionally intact. These data indicate that the changes in the T-cell compartment in CLL may be more heterogeneous than presently assumed.

Chronic lymphocytic leukemia disease progression is accelerated by APRIL-TACI interaction in the TCL1 transgenic mouse model.

Although in vitro studies pointed to the tumor necrosis factor family member APRIL (a proliferation-inducing ligand) in mediating survival of chronic lymphocytic leukemia (CLL) cells, clear evidence for a role in leukemogenesis and progression in CLL is lacking. APRIL significantly prolonged in vitro survival of CD5(+)B220(dull) leukemic cells derived from the murine Eµ-TCL1-Tg (TCL1-Tg [transgenic]) model for CLL. APRIL-TCL1 double-Tg mice showed a significantly earlier onset of leukemia and disruption of splenic architecture, and survival was significantly reduced. Interestingly, clonal evolution of CD5(+)B220(dull) cells (judged by BCR clonality) did not seem to be accelerated by APRIL; both mouse strains were oligoclonal at 4 months. Although APRIL binds different receptors, APRIL-mediated leukemic cell survival depended on tumor necrosis factor receptor superfamily member 13B (TACI) ligation. These findings indicate that APRIL has an important role in CLL and that the APRIL-TACI interaction might be a selective novel therapeutic target for human CLL.

IL-21 and CD40L signals from autologous T cells can induce antigen-independent proliferation of CLL cells.

Chronic lymphocytic leukemia (CLL) cells multiply in secondary lymphoid tissue, but the mechanisms leading to their proliferation are still uncertain. In addition to B-cell receptor (BCR)-triggered signals, other microenvironmental factors might well be involved. In proliferation centers, leukemic B cells are in close contact with CD4(+)CD40L(+) T cells. Therefore, we here dissected the signals provided by autologous activated T cells (Tact) to CLL cells. Although the gene expression profile induced by Tact was highly similar to that induced by sole CD40 signaling, an obvious difference was that Tact induced proliferation of CLL cells. We determined that stimulation with only CD40L+IL-21 was sufficient to induce robust proliferation in CLL cells. We then defined an interleukin (IL)-21-induced gene signature in CLL, containing components of Janus kinase/signal transducer and activator of transcription and apoptosis pathways, and this signature could be detected in lymph node (LN) samples from patients. Finally, we could detect IL-21 RNA and protein in LN, and IL-21 production ex vivo by LN CD4(+)CXCR5(+) follicular helper T cells. These results indicate that in addition to BCR signaling, activated T cells might contribute to CLL cell proliferation via CD40 and IL-21. Targeting these signaling pathways might offer new venues for treatment of CLL.