Venetoclax inhibits BCL2, an antiapoptotic protein that is pathologically overexpressed and that is central to the survival of chronic lymphocytic leukemia cells. We evaluated the efficacy of ...venetoclax in combination with rituximab in patients with relapsed or refractory chronic lymphocytic leukemia.
In this randomized, open-label, phase 3 trial, we randomly assigned 389 patients to receive venetoclax for up to 2 years (from day 1 of cycle 1) plus rituximab for the first 6 months (venetoclax-rituximab group) or bendamustine plus rituximab for 6 months (bendamustine-rituximab group). The trial design did not include crossover to venetoclax plus rituximab for patients in the bendamustine-rituximab group in whom progression occurred. The primary end point was investigator-assessed progression-free survival.
After a median follow-up period of 23.8 months, the rate of investigator-assessed progression-free survival was significantly higher in the venetoclax-rituximab group (32 events of progression or death in 194 patients) than in the bendamustine-rituximab group (114 events in 195 patients); the 2-year rates of progression-free survival were 84.9% and 36.3%, respectively (hazard ratio for progression or death, 0.17; 95% confidence interval CI, 0.11 to 0.25; P<0.001 by the stratified log-rank test). The benefit was maintained across all clinical and biologic subgroups, including the subgroup of patients with chromosome 17p deletion; the 2-year rate of progression-free survival among patients with chromosome 17p deletion was 81.5% in the venetoclax-rituximab group versus 27.8% in the bendamustine-rituximab group (hazard ratio, 0.13; 95% CI, 0.05 to 0.29), and the 2-year rate among those without chromosome 17p deletion was 85.9% versus 41.0% (hazard ratio, 0.19; 95% CI, 0.12 to 0.32). The benefit of venetoclax plus rituximab over bendamustine plus rituximab was confirmed by an independent review committee assessment of progression-free survival and other secondary efficacy end points. The rate of grade 3 or 4 neutropenia was higher in the venetoclax-rituximab group than in the bendamustine-rituximab group, but the rates of grade 3 or 4 febrile neutropenia and infections or infestations were lower with venetoclax than with bendamustine. The rate of grade 3 or 4 tumor lysis syndrome in the venetoclax-rituximab group was 3.1% (6 of 194 patients).
Among patients with relapsed or refractory chronic lymphocytic leukemia, venetoclax plus rituximab resulted in significantly higher rates of progression-free survival than bendamustine plus rituximab. (Funded by Genentech and AbbVie; ClinicalTrials.gov number, NCT02005471 .).
The previous edition of the consensus guidelines of the International Workshop on Chronic Lymphocytic Leukemia (iwCLL), published in 2008, has found broad acceptance by physicians and investigators ...caring for patients with CLL. Recent advances including the discovery of the genomic landscape of the disease, the development of genetic tests with prognostic relevance, and the detection of minimal residual disease (MRD), coupled with the increased availability of novel targeted agents with impressive efficacy, prompted an international panel to provide updated evidence- and expert opinion–based recommendations. These recommendations include a revised version of the iwCLL response criteria, an update on the use of MRD status for clinical evaluation, and recommendations regarding the assessment and prophylaxis of viral diseases during management of CLL.
The approval of Bruton's tyrosine kinase (BTK) inhibitors such as ibrutinib and acalabrutinib and the Bcl-2 inhibitor venetoclax have revolutionized the treatment of chronic lymphocytic leukemia ...(CLL). While these novel agents alone or in combination induce long lasting and deep remissions in most patients with CLL, their use may be associated with the development of clinical resistance. In this review, we elucidate the genetic basis of acquired resistance to BTK and Bcl-2 inhibition and present evidence on resistance mechanisms that are not linked to single genomic alterations affecting these target proteins. Strategies to prevent resistance to novel agents are discussed in this review with a special focus on new combination therapies.
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.
•Two-year fixed-duration VenR offers sustained PFS, OS, and MRD benefits over BR in R/R CLL, regardless of presence of high-risk biomarkers.•Median MRD doubling time post-VenR EOT was 93 days, with 19 months from uMRD to MRD conversion and another 25 months from conversion to PD.
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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.
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.
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.
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.
The MURANO study demonstrated significant progression-free survival (PFS) benefit for fixed-duration venetoclax-rituximab compared with bendamustine-rituximab in relapsed/refractory chronic ...lymphocytic leukemia. With all patients off treatment, we report minimal residual disease (MRD) kinetics and updated outcomes.
Patients were randomly assigned to 2 years of venetoclax plus rituximab during the first six cycles, or six cycles of bendamustine-rituximab. Primary end point was PFS. Safety and peripheral blood (PB) MRD status-at cycle 4, 2 to 3 months after end of combination therapy (EOCT), and every 3 to 6 months thereafter-were secondary end points.
Of 194 patients, 174 (90%) completed the venetoclax-rituximab phase and 130 (67%) completed 2 years of venetoclax. With a median follow-up of 36 months, PFS and overall survival remain superior to bendamustine-rituximab (hazard ratio, 0.16 95% CI, 0.12 to 0.23; and hazard ratio, 0.50 95% CI, 0.30 to 0.85, respectively). Patients who received venetoclax-rituximab achieved a higher rate of PB undetectable MRD (uMRD; less than 10
) at EOCT (62% v 13%) with superiority sustained through month 24 (end of therapy). Overall, uMRD status at EOCT predicted longer PFS. Among those with detectable MRD, low-level MRD (10
to less than 10
) predicted improved PFS compared with high-level MRD (10
or greater). At a median of 9.9 months (range, 1.4 to 22.5 months) after completing fixed-duration venetoclax-rituximab, overall only 12% (16 of 130) of patients developed disease progression (11 high-level MRD, three low-level MRD). At the end of therapy, 70% and 98% of patients with uMRD remained in uMRD and without disease progression, respectively.
With all patients having finished treatment, continued benefit was observed for venetoclax-rituximab compared with bendamustine-rituximab. uMRD rates were durable and predicted longer PFS, which establishes the impact of PB MRD on the benefit of fixed-duration, venetoclax-containing treatment. Low conversion to detectable MRD and sustained PFS after completion of 2 years of venetoclax-rituximab demonstrate the feasibility of this regimen.
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).
...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.
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.
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.
We investigated the safety and efficacy of bendamustine and rituximab (BR) in previously untreated patients with chronic lymphocytic leukemia (CLL).
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.
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.
Chemoimmunotherapy with BR is effective and safe in patients with previously untreated CLL.
Chemoimmunotherapy has been the standard of care for patients with chronic lymphocytic leukemia for a long time. However, over the last few years, novel agents have produced unprecedented outcomes in ...treatment-naïve and relapsed/refractory chronic lymphocytic leukemia. With the advent of these targeted agents, treatment options have diversified very considerably and new questions have emerged. For example, it is unclear whether these novel agents should be used as sequential monotherapies until disease progression or whether they should preferably be combined in time-limited treatment regimens aimed at achieving deep and durable remissions. While both approaches yield high response rates and long progression-free and overall survival, it remains challenging to identify patients individually for the optimal concept. This review provides guidance in this decision process by presenting evidence on sequential and combined use of novel agents and discussing the advantages and drawbacks of these two approaches.
To define the efficacy of venetoclax with extended follow-up and identify clinical or biological treatment effect modifiers, updated data for previously treated patients with chronic lymphocytic ...leukemia (CLL) or small lymphocytic lymphoma (SLL) enrolled in 4 early-phase trials were pooled. Rates of response, complete remission (CR/CRi), and undetectable minimal residual disease (U-MRD) were analyzed for all patients (n = 436) and for those patients who were planned to receive 400 mg/day monotherapy (n = 347). Univariate and multiple regression analyses were performed to identify the pretreatment factors associated with response rates and duration of response (DoR). Objective responses were documented in 75% of all patients, including 22% CR/CRi. Overall, 27% and 16% of the patients achieved U-MRD in blood and marrow, respectively. Estimated median progression-free survival (PFS), DoR, and time to progression were 30.2, 38.4, and 36.9 months, respectively. Similar efficacy outcomes were observed within the 400 mg/day monotherapy subset. For those who achieved CR/CRi, the 3-year PFS estimate was 83%. DoR was superior for patients achieving CR/CRi or U-MRD in landmark analyses. In multiple regression analyses, bulky lymphadenopathy (≥5 cm) and refractoriness to B-cell receptor inhibitor (BCRi) therapy were significantly associated with lower CR rate and shorter DoR. Fewer prior therapies were associated with higher CR rate, but not DoR. Chromosome 17p deletion and/or TP53 mutation and NOTCH1 mutation were consistently associated with shorter DoR, but not probability of response. Thus, both pretreatment factors and depth of response correlated with DoR with venetoclax. Patients without bulky lymphadenopathy, BCRi-refractory CLL, or an adverse mutation profile had the most durable benefit.
•Patients with relapsed CLL achieving complete remission or undetectable MRD on venetoclax treatment have the most durable responses.•Less durable responses are associated with bulky adenopathy, TP53 aberrations, NOTCH1 mutations, and prior refractoriness to BCRis.
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