Acalabrutinib, venetoclax, and obinutuzumab in relapsed/refractory CLL: final efficacy and ctDNA analysis of the CLL2-BAAG trial.

ABSTRACT: The phase 2 CLL2-BAAG trial tested the measurable residual disease (MRD)-guided triple combination of acalabrutinib, venetoclax, and obinutuzumab after optional bendamustine debulking in 45 patients with relapsed/refractory chronic lymphocytic leukemia (CLL). MRD was measured by flow cytometry (FCM; undetectable MRD <10-4) in peripheral blood (PB) and circulating tumor DNA (ctDNA) using digital droplet polymerase chain reaction of variable-diversity-joining (VDJ) rearrangements and CLL-related mutations in plasma. The median number of previous treatments was 1 (range, 1-4); 18 patients (40%) had received a Bruton tyrosine kinase inhibitor (BTKi) and/or venetoclax before inclusion, 14 of 44 (31.8%) had TP53 aberrations, and 34 (75.6%) had unmutated immunoglobulin heavy-chain variable region genes. With a median observation time of 36.3 months and all patients off-treatment for a median of 21.9 months, uMRD <10-4 in PB was achieved in 42 of the 45 patients (93.3%) at any time point, including 17 of 18 (94.4%) previously exposed to venetoclax/BTKi and 13 of 14 (92.9%) with TP53 aberrations. The estimated 3-year progression-free and overall survival rates were 85.0% and 93.8%, respectively. Overall, 585 paired FCM/ctDNA samples were analyzed and 18 MRD recurrences (5 with and 13 without clinical progression) occurred after the end of treatment. Twelve samples were first detected by ctDNA, 3 by FCM, and 3 synchronously. In conclusion, time-limited MRD-guided acalabrutinib, venetoclax, and obinutuzumab achieved deep remissions in almost all patients with relapsed/refractory CLL. The addition of ctDNA-based analyses to FCM MRD assessment seems to improve early detection of relapses. This trial was registered at www.clinicaltrials.gov as #NCT03787264.

Reassessing the chronic lymphocytic leukemia International Prognostic Index in the era of targeted therapies.

ABSTRACT: We evaluated the chronic lymphocytic leukemia International Prognostic Index (CLL-IPI) in patients with CLL treated first line with targeted drugs (n = 991) or chemoimmunotherapy (n = 1256). With a median observation time of 40.5 months, the 3-year progression-free survival (PFS) rates for targeted drug-treated patients varied by CLL-IPI risk group: 96.5% (low), 87.6% (intermediate), 82.4% (high), and 78.7% (very high). Differences between consecutive CLL-IPI risk groups were observed for intermediate vs low and high vs intermediate, but not very high vs high. CLL-IPI factors ß2-microglobulin, immunoglobulin heavy variable (IGHV) status, and TP53 status each retained prognostic value for PFS. The 3-year overall survival (OS) rates by CLL-IPI risk groups were 100%, 96%, 93.9%, and 89.4%, respectively, with no differences between consecutive risk groups. Age, Binet stage, ß2-microglobulin, and TP53 status each retained prognostic value for OS. In chemoimmunotherapy patients (median observation time, 66.9 months), 3-year PFS rates for CLL-IPI risk groups were 78.1%, 51.4%, 40.1%, and 16.5%, respectively; corresponding 3-year OS rates were 97.4%, 93.1%, 81.8%, and 57.3%. In a matched-pair analysis, PFS differences in targeted therapies (n = 812) vs chemoimmunotherapy (n = 812) across all risk groups and OS differences in all but patients at low risk were demonstrated. The CLL-IPI maintains its prognostic value in predicting PFS outcomes with targeted drugs, but its impact in predicting survival appears diminished. Targeted therapies showed enhanced outcomes over chemoimmunotherapy, highlighting their effectiveness across various risk groups. Our findings support ongoing assessment of prognostic tools in CLL treatment evolution. These trials were registered at www.ClinicalTrials.gov as #NCT02345863, #NCT02401503, #NCT02689141, #NCT02445131, #NCT02758665, #NCT02950051, #NCT02242942, #NCT00262782, #NCT00281918, and #NCT01010061.

Venetoclax-Obinutuzumab for previously untreated chronic lymphocytic leukemia: 6-year results of the phase 3 CLL14 study.

Venetoclax-obinutuzumab (Ven-Obi) is a standard-of-care for patients with previously untreated chronic lymphocytic leukemia (CLL). In the CLL14 study, patients with previously untreated CLL and coexisting conditions were randomized to 12 cycles of Ven-Obi (n=216) or chlorambucil-obinutuzumab (Clb-Obi, n=216). Progression-free survival (PFS) was the primary endpoint. Key secondary endpoints included time-to-next-treatment (TTNT), rates of undetectable minimal residual disease (uMRD), overall survival (OS) and rates of adverse events. Patient reported outcomes (PROs) of time until definitive deterioration (TUDD) in quality of life (QoL) were analyzed. At a median observation time of 76.4 months, PFS remained superior for Ven-Obi compared to Clb-Obi (median 76.2 vs 36.4 months; HR 0.40[95%CI 0.31-0.52], p<0.0001). Likewise, TTNT was longer after Ven-Obi (6-year-TTNT 65.2% vs 37.1%; HR 0.44, 95%CI 0.33-0.58, p<0.0001). In the Ven-Obi arm, presence of del(17p), unmutated-IGHV and lymph node size ≥5 cm were independent prognostic factors for shorter PFS. Five years after treatment, 17 patients (7.9% of intention-to-treat-population) in the Ven-Obi arm had uMRD (<10-4 in peripheral blood) compared to 4 (1.9%) in the Clb-Obi arm. 6-year-OS rate was 78.7% in the Ven-Obi and 69.2% in the Clb-Obi arm (HR 0.69[95%CI 0.48-1.01], p=0.052). A significantly longer TUDD in global health status/QoL was observed in the Ven-Obi compared to the Clb-Obi arm (median 82.1 vs 65.1 months; HR 0.70[95%CI 0.51-0.97]). Follow-up adjusted SPM incidence rates were 2.3 and 1.4/1000 patient-months in the Ven-Obi and Clb-Obi arm, respectively. The sustained long-term survival, uMRD and QoL benefits support the use of one-year fixed-duration Ven-Obi in CLL. NCT02242942, EudraCT 2014-001810-24.

Chronic Lymphocytic Leukemia: Time-Limited Therapy in the First-Line Setting and Role of Minimal Residual Disease.

PURPOSE OF REVIEW: In this review, we provide an overview of different time-limited combination therapies of chronic lymphocytic leukemia (CLL) and summarize the data of pivotal clinical studies. Furthermore, we discuss the relevance of MRD in clinical trials and summarize the challenges that arise in routine clinical care. Finally, we provide an outlook on studies and datasets needed to optimize the use of time-limited treatment strategies and MRD assessments in modern CLL management. RECENT FINDINGS: In recent years, first-line treatment of CLL has undergone a considerable transformation, with targeted substances having largely replaced chemoimmunotherapy (CIT) as a time-limited strategy in the frontline setting. BTK inhibitors were the first class of targeted agents introduced in CLL, which achieved longer progression-free survival (PFS) and in some cases also overall survival (OS) than CIT. However, this required an indefinite drug intake until disease progression, while CIT is generally administered over the course of few months. In contrast to BTK inhibitors, BCL2 inhibitors, another class of targeted agents, can achieve high rates of undetectable minimal residual disease (uMRD) levels and induce deep molecular remissions with the potential to stop treatment while maintaining remissions. Combinations of BCL2 inhibitors with CD20 antibodies or with BTK inhibitors have been explored to establish time-limited treatment strategies with targeted agents. In this context, one of the strongest predictors of long-term outcomes is MRD status at the end of treatment, which has been shown to correlate closely with PFS and OS in most cases.

The prognostic significance of genomic complexity in patients with CLL.

Chromosomal aberrations are a common feature of cancer and can fuel cancer progression and treatment resistance. In chronic lymphocytic leukemia (CLL), the presence of multiple chromosomal aberrations is commonly referred to as "genomic complexity" or "complex karyotype"- (CKT). In the context of chemo- and chemoimmunotherapy, genomic complexity is associated with poor response to treatment and short survival, while some targeted therapies are able to mitigate its adverse prognostic impact. This article reviews currently available data and literature on the role of genomic complexity in CLL. The currently established tools to measure genomic complexity in patients with CLL are summarized and their strengths and weaknesses for routine diagnostics are evaluated. Moreover, possible definitions of CKT as an indicator for genomic complexity are discussed. Finally, data on the impact of CKT on clinical outcomes of patients with CLL are reviewed and the implications for patient stratification are presented.

Realizing precision medicine in chronic lymphocytic leukemia: Remaining challenges and potential opportunities.

Patients with chronic lymphocytic leukemia (CLL) exhibit diverse clinical outcomes. An expanding array of genetic tests is now employed to facilitate the identification of patients with high-risk disease and inform treatment decisions. These tests encompass molecular cytogenetic analysis, focusing on recurrent chromosomal alterations, particularly del(17p). Additionally, sequencing is utilized to identify TP53 mutations and to determine the somatic hypermutation status of the immunoglobulin heavy variable gene. Concurrently, a swift advancement of targeted treatment has led to the implementation of novel strategies for patients with CLL, including kinase and BCL2 inhibitors. This review explores both current and emerging diagnostic tests aimed at identifying high-risk patients who should benefit from targeted therapies. We outline existing treatment paradigms, emphasizing the importance of matching the right treatment to the right patient beyond genetic stratification, considering the crucial balance between safety and efficacy. We also take into consideration the practical and logistical issues when choosing a management strategy for each individual patient. Furthermore, we delve into the mechanisms underlying therapy resistance and stress the relevance of monitoring measurable residual disease to guide treatment decisions. Finally, we underscore the necessity of aggregating real-world data, adopting a global perspective, and ensuring patient engagement. Taken together, we argue that precision medicine is not the mere application of precision diagnostics and accessibility of precision therapies in CLL but encompasses various aspects of the patient journey (e.g., lifestyle exposures and comorbidities) and their preferences toward achieving true personalized medicine for patients with CLL.