TP53 Clonal and Subclonal Architecture in Chronic Lymphocytic Leukemia Patients Under Ibrutinib Treatment

Abstract Introduction. Ibrunitib (IBR) is active in chronic lymphocytic leukemia (CLL) patients (pts) with TP53 aberrations. Few data describing the dynamics of TP53 mutated clones under IBR are available. We analyzed a cohort of 40 treatment-naïve and relapsed CLL pts treated with IBR to investigate the dynamics of clonal and subclonal TP53 mutations (TP53-mut). Methods. Forty pts (Table) underwent a longitudinal TP53 monitoring (117 samples) by ultra-deep sequencing (UDS): 26 received IBR + rituximab (IBR+RTX) in first line as part of the GIMEMA LLC 1114 protocol (IBR exposition: 8 months in 7 pts and 14 months in 19 pts) (cohort 1), while 14 received IBR single agent after a median of 1.5 (range: 1-4) chemo-immunotherapy lines (IBR exposition: 2.1 to 4 years in 12 pts) (cohort 2). Samples were analyzed by UDS on a MiSeq sequencer (Illumina, Inc.) to obtain a 5000X coverage/base. For variant calling, the MiSeq Reporter software and an in-house bioinformatics pipeline were applied. All mutations were checked on the IARC TP53 database and those with a variant allele frequency (VAF) <10% (i.e. subclonal) were confirmed in an independent UDS run. VAF was corrected to cancer cell fraction (CCF) by the proportion of CD19+/CD5+ cells. Results. In cohort 1, 12/26 pts were evaluated at 3 time-points: baseline (T0), +8 (T8) and +14 (T14) months from IBR+RTX, and 14 at T0 and either T8 or T14. At T0, 19/26 pts showed a mean number of 1.5 (range: 1-5) clonal/subclonal TP53-mut/pt, for a total of 28 mutations. Of those, 20/28 (71.4%) were clonal (mean VAF: 57.8%; range: 18-94.8%) and 8/28 (27.6%) were subclonal (mean VAF: 4.4%; range: 1.2-9.2%; VAF≤5% in 6). Seven/26 pts resulted wild-type (WT). Under IBR+RTX, of the 28 TP53-mut corrected to CCF (21 clonal and 7 subclonal), 12 (9 clonal + 3 subclonal) (42.8%) persisted stable, 9 (32.1%) clonal mutations decreased, 6 (21.4%) were lost, one evolved to clonal. No novel clonal or subclonal TP53-mut arose during IBR+RTX. According to CCF, the pts followed 5 patterns: 1) clonal TP53-mut present from T0 and persisting clonal with a stable (n=6) or decreasing CCF (n=7); 2) clonal TP53-mut disappearing during treatment (n=1); 3) subclonal TP53-mut evolving to clonal (n=1, CCF 8% at T0 and 17.5% at T14); 4) subclonal TP53-mut persisting subclonal (n=1); 5) absence of any detectable TP53-mut in all time-points (n=7). In addition, 3 cases showed coexisting clonal and subclonal TP53-mut at T0: in one case 3 TP53-mut remained stable; in another one, 4 TP53-mut, including one clonal, were lost, and one clonal decreased in CCF; in the last case, 1 TP53-mut decreased, 1 remained stable and 1 subclonal disappeared. In cohort 2, before IBR, 10/14 pts showed a mean of 3.1 (range: 1-11) clonal/subclonal TP53-mut/pt, for a total of 31 mutations. Of those, 11/31 (35.5%) were clonal (mean VAF: 31.9%; range: 10.5-78.8%) and 20/31 (64.5%) were subclonal (mean VAF: 2.9%; range: 0.9-6.8%). Four/14 pts were WT. Under IBR, 16/31 (6 clonal+10 subclonal) (51.5%) TP53-mut persisted stable, 2 (6.5%) clonal decreased, 11 (2 clonal+9 subclonal) (35.5%) were lost, 2 (6.5%) subclonal evolved to clonal; 2 novel subclonal mutations emerged. No mutation was identified in the 4 WT pts over time. In both cohorts, most of TP53-mut remained stable (42.8% vs 51.5% in cohort 1 and 2, respectively) or decreased (32.1% vs 6.5%) and 17 (5 clonal and 12 subclonal) were lost (21.4% vs 35.5%) (p=NS). Although the lymphocyte count significantly decreased during IBR+RTX/IBR exposure (cohort 1: 47.1 x 109/L vs 7.5 x 109/L, p<0.0001; cohort 2: 48.5 x 109/L vs 15.3 x 109/L, p=0.015), the mean CCF of the existing mutations remained stable on treatment (cohort 1: 48.1% vs 40.1%, p=0.42; cohort 2: 16.9 % vs 13.02%; p=0.5). Conclusions. Both when used front-line or as a subsequent line of therapy, IBR appears to decrease the TP53 clonal and subclonal numerosity and complexity. Clonal evolution and the occurrence of novel mutations are rare and occur mostly in pre-treated pts. The significant decrease of lymphocytosis with stable CCF, prove the IBR effectiveness both on TP53 mutated and WT CLL cells, regardless of previous therapies. A longer follow-up will better clarify the dynamics of clonal and subclonal TP53-mut and whether the persistent clones may survive over time and give rise to subsequent relapses. Figure. Figure. Disclosures Mauro: abbvie: Other: board member; janssen: Other: board member. Foà:GILEAD: Speakers Bureau; CELTRION: Other: ADVISORY BOARD; INCYTE: Other: ADVISORY BOARD; ROCHE: Other: ADVISORY BOARD, Speakers Bureau; JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; NOVARTIS: Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; AMGEN: Other: ADVISORY BOARD; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau.

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Mechanisms of Adaptation to Ibrutinib in High Risk Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood-2018-99-116739 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 585-585 ◽

Cited By ~ 4

Author(s):

Valeria Spina ◽

Gabriela Forestieri ◽

Antonella Zucchetto ◽

Alessio Bruscaggin ◽

Tamara Bittolo ◽

...

Keyword(s):

High Risk ◽

Chronic Lymphocytic Leukemia ◽

Nuclear Localization ◽

Peripheral Blood ◽

Research Funding ◽

Clonal Evolution ◽

Lymphocytic Leukemia ◽

Adaptation Process ◽

Over Time ◽

Stimulation Of

Abstract Introduction. Ibrutinib inhibits the BTK molecule downstream the B-cell receptor (BCR). Though highly active in high risk chronic lymphocytic leukemia (CLL), the most typical response achievable in patients is a minimal residual disease (MRD) positive partial remission (PR) which is maintained until the development of genetically driven resistance caused by the acquisition of mutations in the BTK or PLCG2 genes. The study aims at characterizing the adaptation process allowing residual CLL cells to persist despite BTK inhibition. Methods. The IOSI-EMA-001 study (NCT02827617) is an observational study consisting in the prospective and longitudinal collection of peripheral blood samples and clinical data from high risk CLL patients treated with ibrutinib. Peripheral blood CLL cells longitudinally drawn from patients before treatment start and at fixed timepoints under ibrutinib were monitored by: i) next generation flow cytometry approaches for changes in proliferation rate, surfaceome, and pathway activation; and ii) CAPP-seq targeted deep next generation (sensitivity ~10-3) for clonal evolution. Results. The study cohort comprised 31 high risk CLL patients, including 15 treatment naïve, 16 relapsed, 80% IGHV unmutated, 42% 17p deleted and 55% TP53 mutated. Median duration of ibrutinib treatment was 45 weeks (24-72 weeks). All patients obtained a MRD positive PR that was maintained in all but one who progressed with a PLCG2 mutation (VAF 3%). Compared to baseline, under ibrutinib therapy CLL cells slowed down their proliferation, as suggested by the decreased expression of Ki-67, the reduction of the proliferating fraction (CXCR4dimCD5bright), and the increase of the resting fraction (CXCR4brightCD5dim). Compared to baseline, under ibrutinib therapy CLL cells also upregulated BCR and adhesion/homing proteins, and decreased the expression of BCR inhibitor proteins. Upon stimulation of the BCR with anti-IgM, the downstream path through pBTK and pPLCG2 was inhibited by ibrutinib, while conversely the downstream path through pAKT and pERK was still inducible throughout all the assessed timepoints. The proportion of CLL cells harboring nuclear localization of NF-kB progressively increased over time under ibrutinib. NF-kB nuclear localization was inducible throughout all the assessed timepoints by CD40L stimulation of the non-canonical NF-kB pathway, but not by anti-IgM stimulation of the BCR/canonical NF-kB pathway. Overall, 880 individual mutations were longitudinally discovered and monitored across a total of 121 sequential timepoints collected during ibrutinib treatment. Clonal evolution was observed in (67.7%) cases, a proportion rate previously documented in CLL treated with chemoimmunotherapy. Clonal evolution appeared to be heterogeneous involving different genes without a stereotypic targeting. Consistently, none of the main driver gene mutations was homogeneously selected or suppressed by ibrutinib suggesting that the biological adaptation of CLL cells under ibrutinib is not genetically driven. Clonal evolution propensity was not associated with any of the biomarkers of the disease, and it did not decrease over time under ibrutinib. Conclusions. Taken together these results suggest that residual CLL cells persisting under ibrutinib therapy adapt their phenotype by upregulating adhesion molecules, chemokine receptors and BCR molecules, and by maintaining a competence of BCR signaling through the PI3K/AKT/ERK pathway. The progressive selection of CLL cells having NF-kB in the nucleus, likely due to the BTK independent non-canonical NF-kB pathway, might explain their survival despite ibrutinib therapy. Finally, clonal evolution is not suppressed by ibrutinib chemotherapy, and despite does not seem to be directly involved in such adaptation process, may ultimately favor the acquisition of BTK and PLCG2 ibrutinib resistance mutations. Disclosures Zucca: Celltrion: Consultancy; AstraZeneca: Consultancy. Ghia:Sunesis: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; AbbVie, Inc: Honoraria, Research Funding; Acerta: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; Gilead: Honoraria, Research Funding; BeiGene: Honoraria, Research Funding. Montillo:Janssen: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Speakers Bureau; AbbVie: Consultancy, Honoraria, Speakers Bureau; Roche: Consultancy, Honoraria, Research Funding. Tedeschi:Janssen: Consultancy, Speakers Bureau; Gilead: Consultancy; AbbVie: Consultancy. Gaidano:AbbVie: Consultancy, Honoraria; Gilead: Consultancy, Honoraria; Amgen: Consultancy, Honoraria; Janssen: Consultancy, Honoraria; Morphosys: Honoraria; Roche: Consultancy, Honoraria.

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Five-Year Experience with Single-Agent Ibrutinib in Patients with Previously Untreated and Relapsed/Refractory Chronic Lymphocytic Leukemia/Small Lymphocytic Leukemia

Blood ◽

10.1182/blood.v128.22.233.233 ◽

2016 ◽

Vol 128 (22) ◽

pp. 233-233 ◽

Cited By ~ 53

Author(s):

Susan M. O'Brien ◽

Richard R. Furman ◽

Steven E. Coutre ◽

Ian W. Flinn ◽

Jan Burger ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Board Of Directors ◽

Research Funding ◽

Single Agent ◽

Lymphocytic Leukemia ◽

Advisory Committees ◽

Equity Ownership ◽

Grade 3 ◽

Over Time

Abstract Background: Ibrutinib (ibr), a first-in-class, once-daily Bruton's tyrosine kinase inhibitor, is approved by the US FDA for treatment of patients (pts) with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) including pts with del17p. The phase 1b/2 PCYC-1102 trial showed single-agent efficacy and tolerability in treatment-naïve (TN; O'Brien, Lancet Oncol 2014) and relapsed/refractory (R/R) CLL/SLL (Byrd, N Engl J Med 2013). We report efficacy and safety results of the longest follow-up to date for ibr-treated pts. Methods: Pts received 420 or 840 mg ibr QD until disease progression (PD) or unacceptable toxicity. Overall response rate (ORR) including partial response (PR) with lymphocytosis (PR-L) was assessed using updated iwCLL criteria. Responses were assessed by risk groups: unmutated IGVH, complex karyotype (CK; ≥3 unrelated chromosomal abnormalities by stimulated cytogenetics assessed by a reference lab), and in hierarchical order for del17p, then del11q. In the long-term extension study PCYC-1103, grade ≥3 adverse events (AEs), serious AEs, and AEs requiring dose reduction or discontinuation were collected. Results: Median age of the 132 pts with CLL/SLL (31 TN, 101 R/R) was 68 y (range, 37-84) with 43% ≥70 y. Baseline CK was observed in 41/112 (37%) of pts. Among R/R pts, 34 (34%) had del17p, 35 (35%) del11q, and 79 (78%) unmutated IGVH. R/R pts had a median of 4 prior therapies (range, 1-12). Median time on study was 46 m (range, 0-67) for all-treated pts, 60 m (range, 0-67.4) for TN pts, and 39 m (range, 0-67) for R/R pts. The ORR (per investigator) was 86% (complete response [CR], 14%) for all-treated pts (TN: 84% [CR, 29%], R/R: 86% [CR, 10%]). Median progression-free survival (PFS) was not reached (NR) for TN and 52 m for R/R pts with 60 m estimated PFS rates of 92% and 43%, respectively (Figure 1). In R/R pts, median PFS was 55 m (95% confidence intervals [CI], 31-not estimable [NE]) for pts with del11q, 26 m (95% CI,18-37) for pts with del17p, and NR (95% CI, 40-NE) for pts without del17p, del11q, trisomy 12, or del13q. Median PFS was 33 m (95% CI, 22-NE) and NR for pts with and without CK, and 43 m (95% CI, 32-NE) and 63 m (95% CI, 7-NE) for pts with unmutated and mutated IGVH, respectively(Figure 2). Among R/R pts, median PFS was 63 m (95% CI, 37-NE) for pts with 1-2 prior regimens (n=27, 3 pts with 1 prior therapy) and 59 m (95% CI, 22-NE) and 39 m (95% CI, 26-NE) for pts with 3 and ≥4 prior regimens, respectively. Median duration of response was NR for TN pts and 45 m for R/R pts. Pts estimated to be alive at 60 m were: TN, 92%; all R/R, 57%; R/R del17p, 32%; R/R del 11q, 61%; R/R unmutated IGVH, 55%. Among all treated pts, onset of grade ≥3 treatment-emergent AEs was highest in the first year and decreased during subsequent years. With about 5 years of follow-up, the most frequent grade ≥3 AEs were hypertension (26%), pneumonia (22%), neutropenia (17%), and atrial fibrillation (9%). Study treatment was discontinued due to AEs in 27 pts (20%) and disease progression in 34 pts (26%). Of all treated pts, 38% remain on ibr treatment on study including 65% of TN pts and 30% of R/R pts. Conclusions: Single-agent ibrutinib continues to show durable responses in pts with TN or R/R CLL/SLL including those with del17p, del11q, or unmutated IGVH. With extended treatment, CRs were observed in 29% of TN and 10% of R/R pts, having evolved over time. Ibrutinib provided better PFS outcomes if administered earlier in therapy than in the third-line or beyond. Those without CK experienced more favorable PFS and OS than those with CK. Ibrutinib was well tolerated with the onset of AEs decreasing over time, allowing for extended dosing for 65% of TN and 30% of R/R pts who continue treatment. Disclosures O'Brien: Janssen: Consultancy, Honoraria; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding. Furman:Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Speakers Bureau. Coutre:Janssen: Consultancy, Research Funding; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Research Funding; AbbVie: Research Funding. Flinn:Janssen: Research Funding; Pharmacyclics LLC, an AbbVie Company: Research Funding; Gilead Sciences: Research Funding; ARIAD: Research Funding; RainTree Oncology Services: Equity Ownership. Burger:Pharmacyclics, LLC, an AbbVie Company: Research Funding; Gilead: Research Funding; Portola: Consultancy; Janssen: Consultancy, Other: Travel, Accommodations, Expenses; Roche: Other: Travel, Accommodations, Expenses. Sharman:Gilead: Research Funding; TG Therapeutics: Research Funding; Acerta: Research Funding; Seattle Genetics: Research Funding; Pharmacyclics: Research Funding; Celgene: Research Funding. Wierda:Abbvie: Research Funding; Genentech: Research Funding; Novartis: Research Funding; Acerta: Research Funding; Gilead: Research Funding. Jones:Janssen: Membership on an entity's Board of Directors or advisory committees, Research Funding; AbbVie: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pharmacyclics, LLC, an AbbVie Company: Membership on an entity's Board of Directors or advisory committees, Research Funding. Luan:AbbVie: Equity Ownership; Pharmacyclics, LLC, an AbbVie Company: Employment, Other: Travel, Accommodations, Expenses. James:AbbVie: Equity Ownership; Pharmacyclics, LLC, an AbbVie Company: Employment. Chu:Pharmacyclics, LLC, an AbbVie Company: Employment; AbbVie: Equity Ownership.

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The Combination of Complex Karyotypes' Subtypes and IGHV Mutational Status Provides Prognostic and Predictive Information in Chronic Lymphocytic Leukemia

Blood ◽

10.1182/blood-2018-99-114721 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 1844-1844

Author(s):

Andrea Visentin ◽

Laura Bonaldi ◽

Gian Matteo Rigolin ◽

Francesca Romana Mauro ◽

Annalisa Martines ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Research Funding ◽

Board Member ◽

Advisory Board ◽

Lymphocytic Leukemia ◽

Rank Test ◽

Predictive Information ◽

Excellent Outcome ◽

Mutational Status

Abstract INTRODUCTION. Complex karyotype (CK), defined by the presence of at least 3 chromosomal abnormalities, is a heterogeneous cytogenetic category associated with adverse prognosis in several hematologic malignancies. Recently, Rigolin et al. provided evidence that CK with major structural abnormalities (CK2) at chronic lymphocytic leukemia (CLL) diagnosis negatively impact on the time to first treatment (TTFT) and overall survival (OS) (Rigolin GM, BJH 2018). However, it is unknown whether the prognostic strength of CK could be implemented when combined with stable markers such as the IGHV mutational status. In the present study, we assessed the prognostic and predictive role of the combination of CK subtypes and IGHV status in a large CLL series. METHODS. Stimulated cytogenetics with CpG+IL2 was performed in 736 CLL patients in 3 referenced Italian hematological centers. According to Rigolin et al, CK2 cases included unbalanced translocations, addition, insertion, derivative and marker chromosomes. All other CK were classified as type 1 (CK1). An IGHV gene sequence homology >98% was considered as unmutated (U-IGHV), as opposed to mutated (M-IGHV). Treatment was initiated according to the iwCLL guidelines. TTFT and OS were calculated from diagnosis to first treatment or death, respectively, or last known follow-up. Survival curves were compared with the log-rank test and p<.05 was considered as significant. Harrell concordance index (c-index) was used to compare our prognostic model with Dohner's and FISH-IGHV models. RESULTS. We focused on 520 out of the 736 patients with cytogenetic and IGHV status assessed within 12 months from diagnosis. The median age at diagnosis was 63 years, 322 (62%) were males, 68% at Binet A stage, 45% U-IGHV, 48 harbored TP53 abnormalities, 99 a CK (28 CK1 and 71 CK2), 232 received at least one line of therapy (31% FCR, 16% BR, 8% ibrutinib, 5% chlorambucil-antiCD20, 40% other treatments) and 80 died over a median follow-up of 5.8 years. 71 (14%) harbored CK2, 214 (41%) CK1 or U-IGHV and 235 (45%) M-IGHV without CK2. The former group were characterized by a higher prevalence TP53 (38% vs 8% vs 3%, p<0.0001) and cytogenetics abnormalities but lower cases with low-risk FISH (i.e. 13q or normal; 38% vs 54% vs 91%, p<0.0001) as compared with others two groups. We observed that subjects with CK2 had a shorter TTFT (median years 1.97, 3.40 and 19.1, p<0.0001) and 5 years OS (67%, 85%, 93%, p<0.0001) compared to cases with CK1/U-IGHV, or M-IGHV without CK. These data were confirmed in multivariate analysis. The worse prognosis of CK2 patients was independent of TP53 status (p values 0.0770 and 0.8122 for TTFT and OS, respectively). The c-indexes for our model were 69% and 68% for TTFT and OS, respectively, and were not inferior to those calculated with Dohner's (64% and 61%) and FISH-IGHV (69% and 63%) models. The combination of these two markers also provides predictive information after first-line therapy (p<0.0001 for both TTFT and OS). In particular, among 107 patients treated with FCR or BR just one of the M-IGHV cases relapsed but none died after a median follow-up of 43 months as compared with the other two subgroups (3-year PFS 92%, 69% and 23%, p<0.0001; 3-year OS: 100%, 94%, 62%, p<0.0001). CONCLUSIONS. In this study, we demonstrated that the combination of CK subtypes and IGHV status provides important prognostic and predictive data in CLL. Moreover, our model was not inferior to other commonly used prognostic scores. While patients with M-IGHV without any subtypes of CK showed an excellent outcome with chemoimmunotherapy, new alternative therapies should be explored for patients with CK2. Disclosures Visentin: janssen: Consultancy, Honoraria. Rigolin:Gilead: Research Funding. Mauro:abbvie: Other: board member; janssen: Other: board member. Foà:JANSSEN: Other: ADVISORY BOARD, Speakers Bureau; NOVARTIS: Speakers Bureau; INCYTE: Other: ADVISORY BOARD; CELTRION: Other: ADVISORY BOARD; ABBVIE: Other: ADVISORY BOARD, Speakers Bureau; AMGEN: Other: ADVISORY BOARD; GILEAD: Speakers Bureau; CELGENE: Other: ADVISORY BOARD, Speakers Bureau; ROCHE: Other: ADVISORY BOARD, Speakers Bureau. Cuneo:Roche: Other: advisory board, Speakers Bureau; Gilead: Other: advisory board, Speakers Bureau; Abbvie: Other: advisory board, Speakers Bureau; janssen: Other: advisory board, Speakers Bureau. Trentin:Gilead: Research Funding; Janssen: Research Funding; Abbvie: Honoraria; Roche: Membership on an entity's Board of Directors or advisory committees.

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High Surface IgM Levels Associate with Shorter Response Duration and Bypass of the BTK Blockade during Ibrutinib Therapy in CLL Patients

Blood ◽

10.1182/blood-2019-128899 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1752-1752 ◽

Cited By ~ 1

Author(s):

Giorgia Chiodin ◽

David Dutton ◽

Enrica Antonia Martino ◽

Samantha Drennan ◽

Ian Tracy ◽

...

Keyword(s):

Research Funding ◽

High Surface ◽

Single Agent ◽

Advisory Board ◽

Lymphocytic Leukemia ◽

Educational Support ◽

Time Points ◽

Board Membership ◽

Duration Of Response ◽

The University

The circulating tumor cells of chronic lymphocytic leukemia (CLL) are characterized by variably low surface IgM (sIgM) levels and signaling capacity, consequent to stimulation by tissue-based antigen. The variability is evident in both CLL subsets with unmutated and mutated immunoglobulin genes and affects tumor cell survival and proliferation. This appears clinically important because CLL with relatively higher sIgM levels/signaling capacity progress more rapidly than those with lower sIgM levels/signaling capacity (D'Avola, Blood 2016), likely due to a larger proliferative component at tissue sites. B-cell receptor (BCR)-signaling inhibitor ibrutinib exerts its therapeutic activity in CLL by irreversibly binding the Bruton's tyrosine kinase (BTK) at Cys481 in the active site. This leads to redistribution of CLL cells from tissue sites into peripheral blood and to a selective recovery of sIgM levels and function, consequent to release from antigen drive at tissue sites (Drennan, Clin Cancer Res 2019). We have now investigated the hypothesis that sIgM levels on the CLL cells affect duration of response to ibrutinib therapy possibly consequent to circumvention of the pharmacological BTK inhibition. Seventy CLL patients participating in the "real-world" observational study at the University of Southampton (NIHR/UKCRN ID: 31076) were investigated for phenotypic, molecular and functional characteristics associated with response to single-agent ibrutinib. Time to progression requiring a new treatment from ibrutinib start (TTNT) was used as primary endpoint to measure duration of response. The levels of sIgM were measured by flow cytometry. Anti-IgM induced signaling was determined by immunoblotting or iCa2+ mobilization. BTK and PLCγ2 mutations were determined using the Illumina NexteraXT kit and a MiSeq at the University of Southampton and validated independently at Karolinska Institutet. Our previous cut-offs of 50 (MFI) or 5 (iCa2+ % mobilization) were used to distinguish patients with high/low sIgM levels or signaling capacity, respectively. Median follow-up from ibrutinib start was 42 months (range 12-70). Pre-ibrutinib sIgM levels (range 7-618, median 65; high sIgM MFI 46/70, 66%) and sIgM signaling capacity (range 1-98; median 45; high sIgM signalers 56/70, 80%) were broadly heterogeneous. However, median values were significantly higher than the general CLL population at diagnosis, as expected in progressive CLL. By univariate analyses of clinical, phenotypic, FISH and immunogenetic characteristics for TTNT, high sIgM was the only parameter predicting shorter duration of response to ibrutinib (p=0.02). Only 2/24 CLL with low sIgM levels (CLLIgM_lo) had progressed (median TTNT not reached) compared to 15/46 CLL with high sIgM (CLLIgM_hi, 14% at 12 months, 18% at 24 months, 34% at 36 months, 44% at 42 months) during therapy. The levels of sIgM correlated significantly with sIgM signaling capacity prior to treatment (r= 0.68; p<0.0001) and were selectively maintained during ibrutinib therapy. From in vitro analysis of 13 therapy-naive CLL samples, the degree of inhibition by ibrutinib of anti-IgM induced signals downstream to BTK correlated negatively with sIgM levels (r=-0.68,p=0.01) and signaling (r=-0.71,p=0.009). Anti-IgM induced signals were then measured in 12 patients (7 CLLIgM_hi, 5 CLLIgM_lo) after 1, 4 and 12 weeks of ibrutinib therapy. These patients had not acquired BTK or PLCγ2 mutations and BTK phosphorylation appeared completely inhibited at all time-points. Mean anti-IgM induced iCa2+ mobilization and ERK1/2 phosphorylation were significantly reduced but not abolished during therapy and degree of inhibition was variable between individuals. Remarkably, degree of inhibition of anti-IgM-induced iCa2+ mobilization and pERK1/2 was significantly lower in CLLIgM_hi than in CLLIgM_lo (p<0.05 at all time-points). These results confirm that sIgM signaling is dependent on sIgM levels and that it can circumvent BTK blockade when sIgM levels are high. They suggest that high sIgM signaling can drive ibrutinib resistance despite ability of ibrutinib to fully occupy the BTK phosphorylation pocket. A possibility is that those CLL cells with high sIgM represent a potentially dangerous subpopulation equipped to migrate to tissue and to receive proliferative stimuli. These cells might be targeted by a combinatorial therapeutic approach with ibrutinib. Disclosures Johnson: Takeda: Honoraria; Kite: Honoraria; Bristol-Myers Squibb: Honoraria; Genmab: Honoraria; Incyte: Honoraria; Celgene: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; Novartis: Honoraria; Epizyme: Honoraria, Research Funding; Boehringer Ingelheim: Honoraria. Duncombe:Abbvie: Other: Advisory Board membership;Educational support; Gilead: Other: Advisory Board membership; Janssen: Other: Advisory Board membership;Educational support; Novartis: Other: Advisory Board membership. Scarfo:Janssen: Honoraria; AstraZeneca: Honoraria; AbbVie: Honoraria. Sutton:Gilead: Honoraria; Janssen: Honoraria; Abbvie: Honoraria. Ghia:Pharmacyclics LLC, an AbbVie Company: Consultancy; AbbVie: Consultancy, Honoraria, Research Funding; ArQule: Consultancy, Honoraria; Dynamo: Consultancy, Honoraria; Gilead: Consultancy, Honoraria, Research Funding; Janssen: Consultancy, Honoraria, Research Funding; Juno/Celgene: Consultancy, Honoraria; BeiGene: Consultancy, Honoraria; Acerta/AstraZeneca: Consultancy, Honoraria; Novartis: Research Funding; Sunesis: Consultancy, Honoraria, Research Funding. Forconi:Roche: Honoraria; Janssen-Cilag: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Menarini: Consultancy; Novartis: Honoraria; Abbvie: Consultancy, Honoraria, Other: Travel, Accommodations, Expenses, Speakers Bureau; Gilead Sciences: Research Funding.

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XPO1 Mutations May Identify Binet Α Chronic Lymphocytic Leukemia Patients with Shorter Time to First Treatment

Blood ◽

10.1182/blood-2019-126054 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 1743-1743 ◽

Cited By ~ 1

Author(s):

Riccardo Moia ◽

Chiara Favini ◽

Sruthi Sagiraju ◽

Valeria Spina ◽

Alessio Bruscaggin ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Board Of Directors ◽

Variant Calling ◽

Advisory Board ◽

Lymphocytic Leukemia ◽

Advisory Committees ◽

Scientific Advisory Board ◽

Scientific Advisory ◽

Trisomy 12 ◽

Time To First Treatment

Background. Chronic lymphocytic leukemia (CLL) is the most common leukemia of adults in western countries. CLL is a highly heterogeneous disease; some patients may never require treatment, whereas other relapse early after frontline therapy. In approximately 70% of newly diagnosed cases, CLL presents at an early clinical stage and is managed with a watch & wait strategy. Until now, few clinical and molecular predictors inform on the risk of treatment requirement and the impact of CLL gene mutations is not completely understood. Purpose. We aimed at identifying new molecular markers that may predict early treatment requirement and may help clinicians to better plan the watch & wait strategy in asymptomatic early stage CLL patients. Methods. This study includes 295 Binet A CLL patients referring at our institution who did not require treatment for at least 3 months after diagnosis. Tumor genomic DNA (gDNA) was isolated from peripheral blood mononuclear cells at the time of diagnosis. gDNA was analyzed in the coding exons plus splice sites of the most frequently mutated genes in CLL with a next-generation-sequencing (NGS) approach. NGS analysis was performed on the Illumina MiSeq instrument (coverage >2000x in >80% of the target region). The somatic function of VarScan2 was used for variant calling and a stringent bioinformatic pipeline was developed to protect against the false call of polymorphisms and sequencing errors. A threshold of 5% of variant allele frequency was set for variant calling. The primary endpoint was time to first treatment (TTFT) defined as the timeinterval between the date of CLL diagnosis and the date of first CLL treatment. Statistical analysis was performed using SPSS version 24.0. Results. The median age of the study cohort was 70.8 years old, 136 (46.1%) patients were female, 71 (24.1%) harbored unmutated IGHV genes, 44 (14.9%) had trisomy 12, 12 (4.1%) had 17p deletion, 15 (5.1%) had 11q deletion and 150 (50.8%) had 13q deletion. NGS mutational analysis showed that NOTCH1 was the most frequently mutated gene occurring in 25 (8.5%) patients, followed by ATM in 18 (6.1%), TP53 in 17 (5.8%), MYD88 in 12 (4.1%), SF3B1 in 10 (3.4%), XPO1 in 7 (2.4%), EGR2 in 6 (2.0%), NFKBIE in 4 (1.4%), POT1 in 2 (0.7%), and BIRC3 in 1 (0.3%) patients. After a median follow-up of 9.5 years, 80 (27.1%) patients required treatment. In univariate analysis, molecular characteristics associated with a shorter TTFT were trisomy 12 (HR: 2.42; 95% CI 1.43-4.15; p=0.001), unmutated IGHV genes (HR: 4.51; 95% CI 2.83-7.05; p<0.0001) and mutations of XPO1 (HR: 8.88; 95% CI 3.77-20.95; p<0.0001), NOTCH1 (HR: 3.02; 95% CI 1.66-5.51; p<0.001) and SF3B1 (HR: 2.65; 95% CI 1.15-6.10; p=0.022). Interestingly, neither 17p deletion nor TP53 mutations associated with a shorter TTFT, in line with the notion that TP53 disruption interacts with treatment but not with a watch & wait strategy. By multivariate analysis, XPO1 mutations (HR: 4.24; 95% CI 1.72-10.44; p=0.002) maintained an independent association with a shorter TTFT (Table 1). At 10 years, XPO1 mutated patients had a probability of remaining free from treatment of 0% compared to 69.3% for wild type cases (p<0.0001) (Figure 1). Conclusions. Mutations of the XPO1 gene, encoding for exportin 1 which mediates the nuclear export of proteins and RNA, are an independent predictor of shorter TTFT and, if validated, might help clinicians in a better management of the watch & wait strategy for Binet A CLL patients. Moreover, since most of mutations, approximately 90%, affect the glutamic acid in position 571, polymerase chain reaction based methods may be used to identify XPO1 mutations in a simple and time effective manner. Disclosures Rossi: Abbvie: Honoraria, Other: Scientific advisory board; Janseen: Honoraria, Other: Scientific advisory board; Roche: Honoraria, Other: Scientific advisory board; Astra Zeneca: Honoraria, Other: Scientific advisory board; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding. Gaidano:AbbVie: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Astra-Zeneca: Consultancy, Honoraria; Janssen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Sunesys: Consultancy, Honoraria.

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Comparative Efficacy of First Line Therapies for Chronic Lymphocytic Leukemia: a Systematic Review and Meta-Analyses.

Blood ◽

10.1182/blood.v114.22.3432.3432 ◽

2009 ◽

Vol 114 (22) ◽

pp. 3432-3432 ◽

Cited By ~ 1

Author(s):

Ann Janssens ◽

Robin Foà ◽

Michael Keating ◽

Mario Ouwens ◽

Iain Tatt ◽

...

Keyword(s):

Systematic Review ◽

Chronic Lymphocytic Leukemia ◽

Board Member ◽

Advisory Board ◽

Lymphocytic Leukemia ◽

Mixed Treatment Comparison ◽

Inclusion Criteria ◽

Free Survival ◽

Treatment Comparison ◽

Meta Analyses

Abstract Abstract 3432 Poster Board III-320 There are no head-to-head randomized controlled trials (RCTs) assessing the efficacy of available treatments for naive patients with chronic lymphocytic leukemia (CLL). Bayesian mixed treatment comparison (MTC) meta-analyses provide a means of indirectly estimating the relative treatment effect of one intervention to another. Methods A systematic review identified RCTs that reported or summarized efficacy data for any of the treatments of interest in treatment-naive CLL patients. The primary endpoint was progression-free survival (PFS) and secondary endpoints included event-free survival (EFS), overall survival (OS), disease-free survival (DFS), duration of remission, overall response (OR), time to new CLL treatment or death, and rates of molecular complete and partial remission. Data were extracted using a standard electronic data form and study quality assessed using the Jadad checklist for RCTs. Extracted data were analyzed in a Bayesian MTC using a fixed-effects model. A Cox regression model was assumed for time to event outcomes, and the log hazards were summarized across RCTs and interpreted as medians based on the PFS curve for FCR presented in the CLL-8 study report. Results The systematic review identified 683 articles of which eight met pre-specified inclusion criteria on review of the title, abstract, or full-text. Although study design and reporting were often limited quality, with only one RCT reporting being blinded, the RCTs were sufficiently similar in design, patient inclusion criteria and characteristics, and outcome reporting to conduct a MTC (Table 1). Sufficient data were available to compare PFS, complete remission (CR) and OR although only small patient numbers were reported for some treatments and outcomes. The MTC suggested FCR to be the best therapy for treatment-naïve CLL when considering PFS and OR endpoints compared to all other treatments (Table 2). FCR significantly prolonged PFS compared to all other treatments with hazard ratios between 0.24 (0.17-0.34, chlorambucil) and 0.56 (0.43-0.72, FC). Median PFS was prolonged on FCR by 20 and 8 months when compared to chlorambucil and FC, respectively. The probability of CR was significantly higher for FCR compared to chlorambucil, fludarabine and FC, but data were insufficient to draw conclusions against alemtuzumab or bendamustine. FCR also significantly increased OR when compared to all other treatments. Conclusion This meta-analysis of available RCT data demonstrates that the addition of rituximab to FC prolongs PFS and significantly increases OR in comparison to all other treatments. FCR was also shown to increaseCR with respect to chlorambucil, fludarabine and FC. These findings are based on data from eight RCTs. Such analyses will be strengthened by the inclusion of additional RCT data that may become available in the future. Disclosures Janssens: Roche: Honoraria. Foà:Roche: Advisory board member, Speakers Bureau; Bayer: Advisory board member, Speakers Bureau; GlaxoSmithKline: Advisory board member, Speakers Bureau; Mundipharma: Advisory board member, Speakers Bureau; Celgene: Advisory board member, Speakers Bureau. Keating:Genzyme: Honoraria, Speakers Bureau; Genetech: Honoraria, Speakers Bureau. Ouwens:MAPI: Employment. Tatt:Roche: Employment. Carr:Roche: Employment.

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Single-agent ibrutinib in treatment-naïve and relapsed/refractory chronic lymphocytic leukemia: a 5-year experience

Blood ◽

10.1182/blood-2017-10-810044 ◽

2018 ◽

Vol 131 (17) ◽

pp. 1910-1919 ◽

Cited By ~ 171

Author(s):

Susan O’Brien ◽

Richard R. Furman ◽

Steven Coutre ◽

Ian W. Flinn ◽

Jan A. Burger ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Single Agent ◽

Complete Response ◽

Lymphocytic Leukemia ◽

Key Points ◽

Treatment Naïve ◽

Grade 3 ◽

Over Time ◽

Safety Signals

Key Points Our 5-year experience shows sustained single-agent efficacy of ibrutinib in CLL patients, with complete response rates increasing over time. Long-term ibrutinib was well tolerated with no new safety signals; rates of grade ≥3 cytopenias decreased with continued therapy.

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Clonal Evolution in Chronic Lymphocytic Leukemia is Scant in Relapsed But Accelerated in Refractory Cases

SSRN Electronic Journal ◽

10.2139/ssrn.3417948 ◽

2019 ◽

Author(s):

Marc Zapatka ◽

Eugen Tausch ◽

Selcen Öztürk ◽

Martina Seiffert ◽

Thorsten Zenz ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Clonal Evolution ◽

Lymphocytic Leukemia

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Immunological and genetic kinetics from diagnosis to clinical progression in chronic lymphocytic leukemia

Biomarker Research ◽

10.1186/s40364-021-00290-z ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Isabel Jiménez ◽

Bárbara Tazón-Vega ◽

Pau Abrisqueta ◽

Juan C. Nieto ◽

Sabela Bobillo ◽

...

Keyword(s):

T Cells ◽

Chronic Lymphocytic Leukemia ◽

Ex Vivo ◽

Clonal Evolution ◽

Lymphocytic Leukemia ◽

Clinical Progression ◽

Molecular Changes ◽

Main Driver ◽

Altered Gene

Abstract Background Mechanisms driving the progression of chronic lymphocytic leukemia (CLL) from its early stages are not fully understood. The acquisition of molecular changes at the time of progression has been observed in a small fraction of patients, suggesting that CLL progression is not mainly driven by dynamic clonal evolution. In order to shed light on mechanisms that lead to CLL progression, we investigated longitudinal changes in both the genetic and immunological scenarios. Methods We performed genetic and immunological longitudinal analysis using paired primary samples from untreated CLL patients that underwent clinical progression (sampling at diagnosis and progression) and from patients with stable disease (sampling at diagnosis and at long-term asymptomatic follow-up). Results Molecular analysis showed limited and non-recurrent molecular changes at progression, indicating that clonal evolution is not the main driver of clinical progression. Our analysis of the immune kinetics found an increasingly dysfunctional CD8+ T cell compartment in progressing patients that was not observed in those patients that remained asymptomatic. Specifically, terminally exhausted effector CD8+ T cells (T-betdim/−EomeshiPD1hi) accumulated, while the the co-expression of inhibitory receptors (PD1, CD244 and CD160) increased, along with an altered gene expression profile in T cells only in those patients that progressed. In addition, malignant cells from patients at clinical progression showed enhanced capacity to induce exhaustion-related markers in CD8+ T cells ex vivo mainly through a mechanism dependent on soluble factors including IL-10. Conclusions Altogether, we demonstrate that the interaction with the immune microenvironment plays a key role in clinical progression in CLL, thereby providing a rationale for the use of early immunotherapeutic intervention.

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Phase I to II Multicenter Study of Oblimersen Sodium, a Bcl-2 Antisense Oligonucleotide, in Patients With Advanced Chronic Lymphocytic Leukemia

Journal of Clinical Oncology ◽

10.1200/jco.2005.02.4364 ◽

2005 ◽

Vol 23 (30) ◽

pp. 7697-7702 ◽

Cited By ~ 142

Author(s):

Susan M. O'Brien ◽

Charles C. Cunningham ◽

Anatoliy K. Golenkov ◽

Anna G. Turkina ◽

Steven C. Novick ◽

...

Keyword(s):

Chronic Lymphocytic Leukemia ◽

Phase I ◽

Phase Ii ◽

Intravenous Infusion ◽

Single Agent ◽

Plasma Concentrations ◽

Parent Drug ◽

Lymphocytic Leukemia ◽

Complete Disappearance ◽

Continuous Intravenous Infusion

Purpose To determine the maximum-tolerated dose (MTD), efficacy, safety, and pharmacokinetics of oblimersen sodium in patients with advanced chronic lymphocytic leukemia (CLL). Patients and Methods Eligible patients had relapsed or refractory CLL after treatment with fludarabine. Oblimersen was administered at doses ranging from 3 to 7 mg/kg/d as a 5-day continuous intravenous infusion in cycle 1 and as a 7-day continuous intravenous infusion in subsequent cycles every 3 weeks in stable or responding patients. Results Forty patients were enrolled and treated (14 patients in phase I and 26 patients in phase II). Dose-limiting reactions in phase I included hypotension and fever, and the MTD for phase II dosing was established at 3 mg/kg/d. Two (8%) of 26 assessable patients achieved a partial response. Other evidence of antitumor activity included ≥ 50% reduction in splenomegaly (seven of 17 patients; 41%), complete disappearance of hepatomegaly (two of seven patients; 29%), ≥ 50% reduction of lymphadenopathy (seven of 22 patients; 32%), and ≥ 50% reduction in circulating lymphocyte counts (11 of 22 patients; 50%). Adverse events included transient hypotension, fever, fatigue, night sweats, diarrhea, nausea, vomiting, hypokalemia, and cough. Plasma concentrations of oblimersen (parent drug) and its major metabolites were variable. Renal clearance represented only a small portion of total parent drug clearance. Conclusion Dosing with oblimersen sodium in patients with CLL is limited by development of a cytokine release syndrome that is characterized by fever, hypotension, and back pain. Oblimersen sodium has modest single-agent activity in heavily pretreated patients with advanced CLL, and further evaluation of its activity in combination with cytotoxic drugs is warranted.

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