Enduring undetectable MRD and updated outcomes in relapsed/refractory CLL after fixed-duration venetoclax-rituximab.

The MURANO trial (A Study to Evaluate the Benefit of Venetoclax Plus Rituximab Compared With Bendamustine Plus Rituximab in Participants With Relapsed or Refractory Chronic Lymphocytic Leukemia [CLL]; ClinicalTrials.gov identifier #NCT02005471) reported superior progression-free survival (PFS) and overall survival (OS) with venetoclax-rituximab (VenR) vs bendamustine-rituximab (BR) in relapsed/refractory (R/R) CLL. Patients were randomized to 2 years of VenR (n = 194; rituximab for the first 6 months) or 6 months of BR (n = 195). Although undetectable minimal residual disease (uMRD) was achieved more often with VenR, the long-term implications of uMRD with this fixed-duration, chemotherapy-free regimen have not been explored. We report MRD kinetics and updated outcomes with 5 years' follow-up. Survival benefits with VenR vs BR were sustained (median PFS [95% confidence interval]: 53.6 [48.4, 57.0] vs 17.0 [15.5, 21.7] months, respectively, P < .0001; 5-year OS [95% confidence interval]: 82.1% [76.4, 87.8] vs 62.2% [54.8, 69.6], P < .0001). VenR was superior to BR, regardless of cytogenetic category. VenR-treated patients with uMRD at end of treatment (EOT; n = 83) had superior OS vs those with high-MRD+ (n = 12): 3-year post-EOT survival rates were 95.3% vs 72.9% (P = .039). In those with uMRD at EOT, median time to MRD conversion was 19.4 months. Of 47 patients with documented MRD conversion, 19 developed progressive disease (PD); median time from conversion to PD was 25.2 months. A population-based logistic growth model indicated slower MRD median doubling time post-EOT with VenR (93 days) vs BR (53 days; P = 1.2 × 10-7). No new safety signals were identified. Sustained survival, uMRD benefits, and durable responses support 2-year fixed-duration VenR treatment in R/R CLL.

ALPINE: zanubrutinib versus ibrutinib in relapsed/refractory chronic lymphocytic leukemia/small lymphocytic lymphoma.

Treatment standards for chronic lymphocytic leukemia (CLL) have been transformed with the advent of effective inhibitors of B-cell receptor signaling such as ibrutinib - a first-in-class inhibitor of BTK. Off-target kinase inhibitions by ibrutinib are thought to contribute to its adverse events. Zanubrutinib is a next-generation BTK inhibitor with minimal off-target effects, sustained BTK occupancy in peripheral blood mononuclear cells and lymph nodes from patients with B-cell malignancies and promising responses in patients with CLL. Described here is a head-to-head Phase III study comparing the efficacy and safety of zanubrutinib with those of ibrutinib in patients with CLL/small lymphocytic lymphoma in the relapsed/refractory setting.

CLL2-BIG: sequential treatment with bendamustine, ibrutinib and obinutuzumab (GA101) in chronic lymphocytic leukemia.

Obinutuzumab (GA101) and ibrutinib show excellent efficacy for treatment of chronic lymphocytic leukemia (CLL). Preclinical investigations and a complementary safety profile were in support of testing their combined use. The exploratory CLL2-BIG-trial evaluated a sequential combination therapy following a recently proposed strategy. Two courses of bendamustine were used for debulking in patients with a high tumor load, followed by six courses of induction therapy with ibrutinib and GA101, followed by an MRD-triggered maintenance phase. The results of a pre-planned analysis at the end of the induction phase are presented. 61 patients were included, 30 previously untreated and 31 with relapsed/refractory CLL. 44 patients received bendamustine. During induction, neutropenia (14.8%) and thrombocytopenia (13.1%) were the most common CTC grade 3 and 4 events. One fatality (duodenitis) occurred. The overall response rate was 100%. 54.1% of patients achieved a partial remission, 41% a clinical complete remission (cCR) without confirmation by CT scan or bone marrow (BM) biopsy according to protocol and 4.9% a cCR with incomplete recovery of the BM. 29 patients (47.5%) had no detectable (<10-4) minimal residual disease assessed by flow cytometry in peripheral blood. In conclusion, the BIG regimen is a safe and highly effective therapy for CLL.

Alemtuzumab consolidation in chronic lymphocytic leukaemia: a phase I/II multicentre trial.

OBJECTIVE: Despite high rates of long-lasting remissions in patients with chronic lymphocytic leukaemia (CLL) treated with chemoimmunotherapy, none of the current therapeutic approaches is curative with the exception of allogeneic transplantation. One strategy to extend progression-free survival and long-term survival might be the establishment of consolidation therapies. METHODS: In this trial, patients with complete or partial second remission after fludarabine-based treatment received consolidation therapy with alemtuzumab. The aim of this phase I/II trial was to determine the maximal tolerable dose (MTD) of alemtuzumab consolidation and to evaluate safety and efficacy in patients who responded to second-line fludarabine-based treatment. Thirteen patients in complete (CR) or partial remission (PR) received alemtuzumab dose escalation starting with 10 mg intravenously (iv) once weekly for 8 wk and increasing in 10-mg intervals per dose level. RESULTS: The main dose-limiting toxicities (DLTs) were infectious complications, and the MTD was determined at 10 mg. After alemtuzumab consolidation, seven of 13 patients (53%) were in CR, and four of these patients (30.7%) achieved minimal residual disease (MRD) negativity (<1 × 10E-4). At a median follow-up of 71.5 months, four patients were progression-free, with a median progression-free survival (PFS) of 28.5 months after the end of second-line treatment. CONCLUSION: The results provide a safe and efficient schedule with weekly intravenous application of 10 mg of alemtuzumab as a consolidation regime in patients with CLL.

Development of a comprehensive prognostic index for patients with chronic lymphocytic leukemia.

In addition to clinical staging, a number of biomarkers predicting overall survival (OS) have been identified in chronic lymphocytic leukemia (CLL). The multiplicity of markers, limited information on their independent prognostic value, and a lack of understanding of how to interpret discordant markers are major barriers to use in routine clinical practice. We therefore performed an analysis of 23 prognostic markers based on prospectively collected data from 1948 CLL patients participating in phase 3 trials of the German CLL Study Group to develop a comprehensive prognostic index. A multivariable Cox regression model identified 8 independent predictors of OS: sex, age, ECOG status, del(17p), del(11q), IGHV mutation status, serum ß2-microglobulin, and serum thymidine kinase. Using a weighted grading system, a prognostic index was derived that separated 4 risk categories with 5-year OS ranging from 18.7% to 95.2% and having a C-statistic of 0.75. The index stratified OS within all analyzed subgroups, including all Rai/Binet stages. The validity of the index was externally confirmed in a series of 676 newly diagnosed CLL patients from Mayo Clinic. Using this multistep process including external validation, we developed a comprehensive prognostic index with high discriminatory power and prognostic significance on the individual patient level. The studies were registered as follows: CLL1 trial (NCT00262782, http://clinicaltrials.gov), CLL4 trial (ISRCTN 75653261, http://www.controlled-trials.com), and CLL8 trial (NCT00281918, http://clinicaltrials.gov).

Bendamustine in combination with rituximab for previously untreated patients with chronic lymphocytic leukemia: a multicenter phase II trial of the German Chronic Lymphocytic Leukemia Study Group.

PURPOSE: We investigated the safety and efficacy of bendamustine and rituximab (BR) in previously untreated patients with chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: In all, 117 patients, age 34 to 78 years, 46.2% of patients at Binet stage C, and 25.6% of patients age 70 years or older received BR chemoimmunotherapy for first-line treatment of CLL. Bendamustine was administered at a dose of 90 mg/m(2) on days 1 and 2 combined with 375 mg/m(2) rituximab on day 0 of the first course and 500 mg/m(2) on day 1 during subsequent courses for up to six courses. RESULTS: Overall response rate was 88.0% (95% CI, 80.7% to 100.0%) with a complete response rate of 23.1% and a partial response rate of 64.9%. Ninety percent of patients with del(11q), 94.7% with trisomy 12, 37.5% with del(17p), and 89.4% with unmutated IGHV status responded to treatment. After a median observation time of 27.0 months, median event-free survival was 33.9 months, and 90.5% of patients were alive. Grade 3 or 4 severe infections occurred in 7.7% of patients. Grade 3 or 4 adverse events for neutropenia, thrombocytopenia, and anemia were documented in 19.7%, 22.2%, and 19.7% of patients, respectively. CONCLUSION: Chemoimmunotherapy with BR is effective and safe in patients with previously untreated CLL.

Minimal residual disease quantification is an independent predictor of progression-free and overall survival in chronic lymphocytic leukemia: a multivariate analysis from the randomized GCLLSG CLL8 trial.

PURPOSE: To determine the clinical significance of flow cytometric minimal residual disease (MRD) quantification in chronic lymphocytic leukemia (CLL) in addition to pretherapeutic risk factors and to compare the prognostic impact of MRD between the arms of the German CLL Study Group CLL8 trial. PATIENTS AND METHODS: MRD levels were prospectively quantified in 1,775 blood and bone marrow samples from 493 patients randomly assigned to receive fludarabine and cyclophosphamide (FC) or FC plus rituximab (FCR). Patients were categorized by MRD into low- (< 10(-4)), intermediate- (≥ 10(-4) to <10(-2)), and high-level (≥ 10(-2)) groups. RESULTS: Low MRD levels during and after therapy were associated with longer progression-free survival (PFS) and overall survival (OS; P < .0001). Median PFS is estimated at 68.7, 40.5, and 15.4 months for low, intermediate, and high MRD levels, respectively, when assessed 2 months after therapy. Compared with patients with low MRD, greater risks of disease progression were associated with intermediate and high MRD levels (hazard ratios, 2.49 and 14.7, respectively; both P < .0001). Median OS was 48.4 months in patients with high MRD and was not reached for lower MRD levels. MRD remained predictive for OS and PFS in multivariate analyses that included the most important pretherapeutic risk markers in CLL. PFS and OS did not differ between treatment arms within each MRD category. However, FCR induced low MRD levels more frequently than FC. CONCLUSION: MRD levels independently predict OS and PFS in CLL. Therefore, MRD quantification might serve as a surrogate marker to assess treatment efficacy in randomized trials before clinical end points can be evaluated.

Bendamustine combined with rituximab in patients with relapsed and/or refractory chronic lymphocytic leukemia: a multicenter phase II trial of the German Chronic Lymphocytic Leukemia Study Group.

PURPOSE: The objective of this trial was to evaluate safety and efficacy of bendamustine combined with rituximab (BR) in patients with relapsed and/or refractory chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Seventy-eight patients, including 22 patients with fludarabine-refractory disease (28.2%) and 14 patients (17.9%) with deletion of 17p, received BR chemoimmunotherapy. Bendamustine was administered at a dose of 70 mg/m(2) on days 1 and 2 combined with rituximab 375 mg/m(2) on day 0 of the first course and 500 mg/m(2) on day 1 during subsequent courses for up to six courses. RESULTS: On the basis of intent-to-treat analysis, the overall response rate was 59.0% (95% CI, 47.3% to 70.0%). Complete response, partial response, and nodular partial response were achieved in 9.0%, 47.4%, and 2.6% of patients, respectively. Overall response rate was 45.5% in fludarabine-refractory patients and 60.5% in fludarabine-sensitive patients. Among genetic subgroups, 92.3% of patients with del(11q), 100% with trisomy 12, 7.1% with del(17p), and 58.7% with unmutated IGHV status responded to treatment. After a median follow-up time of 24 months, the median event-free survival was 14.7 months. Severe infections occurred in 12.8% of patients. Grade 3 or 4 neutropenia, thrombocytopenia, and anemia were documented in 23.1%, 28.2%, and 16.6% of patients, respectively. CONCLUSION: Chemoimmunotherapy with BR is effective and safe in patients with relapsed CLL and has notable activity in fludarabine-refractory disease. Major but tolerable toxicities were myelosuppression and infections. These promising results encouraged us to initiate a further phase II trial evaluating the BR regimen in patients with previously untreated CLL.

Limited clinical relevance of imaging techniques in the follow-up of patients with advanced chronic lymphocytic leukemia: results of a meta-analysis.

The clinical value of imaging is well established for the follow-up of many lymphoid malignancies but not for chronic lymphocytic leukemia (CLL). A meta-analysis was performed with the dataset of 3 German CLL Study Group phase 3 trials (CLL4, CLL5, and CLL8) that included 1372 patients receiving first-line therapy for CLL. Response as well as progression during follow-up was reassessed according to the National Cancer Institute Working Group1996 criteria. A total of 481 events were counted as progressive disease during treatment or follow-up. Of these, 372 progressions (77%) were detected by clinical symptoms or blood counts. Computed tomography (CT) scans or ultrasound were relevant in 44 and 29 cases (9% and 6%), respectively. The decision for relapse treatment was determined by CT scan or ultrasound results in only 2 of 176 patients (1%). CT scan results had an impact on the prognosis of patients in complete remission only after the administration of conventional chemotherapy but not after chemoimmunotherapy. In conclusion, physical examination and blood count remain the methods of choice for staging and clinical follow-up of patients with CLL as recommended by the International Workshop on Chronic Lymphocytic Leukemia 2008 guidelines. These trials are registered at http://www.isrctn.org as ISRCTN 75653261 and ISRCTN 36294212 and at http://www.clinicaltrials.gov as NCT00281918.

First-line therapy with fludarabine compared with chlorambucil does not result in a major benefit for elderly patients with advanced chronic lymphocytic leukemia.

Although chronic lymphocytic leukemia (CLL) is a disease of elderly patients, subjects older than 65 years are heavily underrepresented in clinical trials. The German CLL study group (GCLLSG) initiated a multicenter phase III trial for CLL patients older than 65 years comparing first-line therapy with fludarabine with chlorambucil. A total of 193 patients with a median age of 70 years were randomized to receive fludarabine (25 mg/m(2) for 5 days intravenously, every 28 days, for 6 courses) or chlorambucil (0.4 mg/kg body weight [BW] with an increase to 0.8 mg/kg, every 15 days, for 12 months). Fludarabine resulted in a significantly higher overall and complete remission rate (72% vs 51%, P = .003; 7% vs 0%, P = .011). Time to treatment failure was significantly shorter in the chlorambucil arm (11 vs 18 months; P = .004), but no difference in progression-free survival time was observed (19 months with fludarabine, 18 months with chlorambucil; P = .7). Moreover, fludarabine did not increase the overall survival time (46 months in the fludarabine vs 64 months in the chlorambucil arm; P = .15). Taken together, the results suggest that in elderly CLL patients the first-line therapy with fludarabine alone does not result in a major clinical benefit compared with chlorambucil. This trial is registered with www.isrctn.org under identifier ISRCTN 36294212.

Consolidation with alemtuzumab improves progression-free survival in patients with chronic lymphocytic leukaemia (CLL) in first remission: long-term follow-up of a randomized phase III trial of the German CLL Study Group (GCLLSG).

Alemtuzumab has shown considerable activity in untreated and relapsed chronic lymphocytic leukaemia. We report our long-term experience in 21 patients within a randomized phase III trial investigating the role of alemtuzumab for consolidation therapy after first-line fludarabine +/- cyclophosphamide, which was stopped prematurely due to severe infections. However, after a median follow-up of 48 months, progression-free survival was significantly prolonged for patients receiving alemtuzumab consolidation compared to those with no further treatment (P = 0.004). Minimal residual disease (MRD) levels were persistently reduced after consolidation. Therefore, despite toxicity, MRD reduction by alemtuzumab consolidation translates into a significantly improved long-term clinical outcome.

Use of alemtuzumab and rituximab consolidation in CLL: Pros and cons.

As new therapeutic approaches have improved responses and outcomes in the treatment of chronic lymphocytic leukemia (CLL), the scientific community focuses now on diagnostic procedures and definitions of response in CLL. The use of monoclonal antibodies in particular has made it possible to treat CLL more effectively. The success of these new therapeutic tools can be traced back to the eradication of detectable disease in a significant number of patients. Therefore, the evaluation of minimal residual disease has become an important end point within clinical trials. This article describes various methods of assessing minimal residual disease and presents data demonstrating that new therapeutic approaches can eliminate residual malignant cells at the highest levels of sensitivity currently available. Although initial evidence suggests that the use of alemtuzumab induces a survival benefit when used in the consolidation setting, important safety issues remain to be resolved before this approach can be introduced in routine practice.

Health-related quality of life in younger patients with chronic lymphocytic leukemia treated with fludarabine plus cyclophosphamide or fludarabine alone for first-line therapy: a study by the German CLL Study Group.

PURPOSE: To date, only a few studies have evaluated the health-related quality of life (HRQOL) of patients with chronic lymphocytic leukemia (CLL) receiving chemotherapy. Therefore, the German CLL Study Group assessed HRQOL in younger patients with advanced CLL receiving first-line chemotherapy with fludarabine or fludarabine plus cyclophosphamide (FC). PATIENTS AND METHODS: Three hundred seventy-five patients younger than 66 years with advanced CLL were randomly assigned to receive either fludarabine alone (fludarabine 25 mg/m2/d for 5 days intravenously [IV], repeated every 28 days) or FC (fludarabine 30 mg/m2/d for 3 days IV plus cyclophosphamide 250 mg/m2/d for 3 days, repeated every 28 days). Six courses of treatment were planned to be administered. The European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 was sent to all patients at baseline and after 6, 12, and 24 months. RESULTS: Eighty-nine percent of 362 included patients completed at least one questionnaire (163 fludarabine- and 158 FC-treated patients). Comparing the baseline levels of 249 CLL patients with the general German population, significant differences in nearly all HRQOL scales were assessed between the two groups. A multivariate analysis showed no significant differences in all HRQOL scales between both arms. In both treatment arms, symptoms such as fatigue, insomnia, and appetite loss improved to lower levels after the end chemotherapy. Except for lower physical status, no significant difference in HRQOL between male and female patients was evaluated. CONCLUSION: Fludarabine-based treatment seems to improve HRQOL little to moderately in younger patients with advanced CLL. No significant difference between fludarabine- and FC-treated patients was observed.

Due to low infection rates no routine anti-infective prophylaxis is required in younger patients with chronic lymphocytic leukaemia during fludarabine-based first line therapy.

The impact of the combination therapy fludarabine plus cyclophosphamide (FC) in comparison with fludarabine alone regarding the incidence and severity of infections among previously untreated patients with chronic lymphocytic leukaemia (CLL) was evaluated within a multicentre phase III study. A total of 375 patients, up to 65 years old, were randomised between fludarabine or FC for first line therapy. No routine anti-infective prophylaxis was provided. A total of 196 infectious episodes, including 33 severe infections, were documented. In the fludarabine arm, 32.9% of the patients developed an infectious complication compared with 39.9% in the FC arm (P = 0.2). No difference was observed in the rate of severe infections (Common Toxicity Criteria grades III and IV) between both treatment arms. Dose reductions were performed more frequently in FC-treated patients. Granulocyte colony-stimulating factor (G-CSF) was administered due to leucopenia in 5% of all patients. A multivariate regression model identified only elevated thymidine kinase, but not the treatment arm, as a statistically independent risk factor for infections. In summary, FC was not associated with a higher rate of infections compared with fludarabine alone. No routine antibiotic or virostatic prophylaxis, or preemptive treatment with G-CSF, is necessary in first line therapy with fludarabine-based regimens in younger patients with CLL, if adequate dose reduction is performed. The combination therapy FC is not associated with a higher rate of infections compared with fludarabine alone. No routine antibiotic or virostatic prophylaxis as well as preemptive treatment with G-CSF is necessary in first line therapy with fludarabine-based regimen in younger patients with CLL, if adequate dose reductions due to cytopenia or previous infections are performed.

Fludarabine plus cyclophosphamide versus fludarabine alone in first-line therapy of younger patients with chronic lymphocytic leukemia.

Combination chemotherapy with fludarabine plus cyclophosphamide (FC) was compared with the standard regimen of fludarabine monotherapy in first-line treatment of younger patients with chronic lymphocytic leukemia (CLL). Between 1999 and 2003, a total of 375 patients younger than 66 years who predominantly had advanced CLL were randomly assigned to receive either fludarabine (25 mg/m(2) for 5 days intravenously, repeated every 28 days) or FC combination therapy (fludarabine 30 mg/m(2) plus cyclophosphamide 250 mg/m(2) for 3 days intravenously, repeated every 28 days). Both regimens were administered to a maximum of 6 courses. FC combination chemotherapy resulted in significantly higher complete remission rate (24%) and overall response rate (94%) compared with fludarabine alone (7% and 83%; P < .001 and P = .001). FC treatment also resulted in longer median progression-free survival (48 vs 20 months; P = .001) and longer treatment-free survival (37 vs 25 months; P < .001). Thus far, no difference in median overall survival has been observed. FC caused significantly more thrombocytopenia and leukocytopenia but did not increase the number of severe infections. In summary, first-line treatment with FC increases the response rates and the treatment-free interval in younger patients with advanced CLL.

Chemotherapy combination treatment regimens with fludarabine in chronic lymphocytic leukemia.

Fludarabine monotherapy is an established treatment for chronic lymphocytic leukemia (CLL), achieving superior remission rates compared with other treatment regimens containing alkylating agents or corticosteroids. However, CLL remains incurable and research continues into finding new treatments for this, the most common leukemia in the Western world. Recent research has focused on the use of fludarabine in combination with other chemotherapeutic agents. Studies published to date indicate that regimens containing fludarabine plus cyclophosphamide, with or without mitoxantrone, achieve overall response (OR) rates of 64-100% and complete response (CR) rates of up to 50%. Administration of cyclophosphamide at a lower dosage (< or =300 mg) appears to reduce the risk of myelosuppression without compromising efficacy. Combinations of fludarabine with prednisone or chlorambucil have been shown to be no more effective than fludarabine monotherapy (OR 27-79% with these combinations), while the combination of fludarabine plus cytarabine proved to be less effective than fludarabine monotherapy. Further studies are needed to evaluate the combinations of fludarabine plus doxorubicin and fludarabine plus epirubicin, as results to date have been inconclusive. More trials are also needed to examine a fludarabine, cytarabine, mitoxantrone and dexamethasone combination that has achieved a promising CR rate of 60% in the one trial reported thus far. Taken together, the results obtained so far with fludarabine plus cyclophosphamide suggest that this combination is more potent than fludarabine monotherapy and is able to increase the CR rate, the OR rate, event-free survival and progression-free survival in patients with CLL.