scholarly journals Efficacy of Phosphatidylinositol 3-Kinase (PI3K) Inhibitors in Patients with Relapsed and Refractory Chronic Lymphocytic Leukemia/ Small Lymphocytic Lymphoma

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5480-5480
Author(s):  
Anita Sultan ◽  
Bradley J. Grant ◽  
Donald P. Quick ◽  
Chandler Graf ◽  
Sriman Swarup ◽  
...  

Introduction: Chronic lymphocytic leukemia/ small lymphocytic lymphoma (CLL/ SLL) is the most common adult lymphoproliferative disorder in western countries and the B-cell receptor signaling pathway has been shown to be involved in the pathogenesis of CLL/ SLL. Phosphatidylinositol 3-kinase (PI3K) is a kinase protein in downstream signaling for multiple pathways in B cells, promoting B-cell survival, proliferation and metabolism. Two prominent PI3K inhibitors, idelalisib (PI3Kδ-selective inhibitor) and duvelisib (PI3Kδ/γ-combinatorial inhibitor), are currently being studied in the treatment of relapsed and refractory CLL/ SLL. The purpose of our study is to explore and consolidate the efficacy of PI3K inhibitors in patients with relapsed and refractory CLL/SLL. Methods: We systematically conducted a comprehensive literature search using MEDLINE, EMBASE databases and meeting abstracts from inception through June 2019. Phase 3 RCTs utilizing PI3K inhibitors in patients with relapsed and refractory CLL/SLL were incorporated in the analysis. A generic inverse variance method was used to calculate the estimated pooled hazard ratio (HR) for progression-free survival (PFS) with 95% confidence interval (CI). Heterogeneity was assessed with Cochran's Q -statistic. Random effects model was applied. Results: Four phase 3 RCTs with a total of 1,216 patients with relapsed and refractory CLL/SLL were eligible for analysis. Studies compared ofatumumab vs idelalisib+ofatumumab, rituximab vs idelalisib+rituximab, bendamustine+ rituximab vs idelalisib+bendamustine+rituximab and ofatumumab vs duvelisib. The randomization ratio was 2:1 in the study by Jones et al. and 1:1 in other studies. The I2 statistic for heterogeneity was 82%, suggesting moderate heterogeneity among RCTs. The overall pooled HR for PFS was statistically significant at 0.30 (95% CI: 0.20- 0.47; P < 0.0001). The PFS benefit was observed across all ages and regardless of del 17p or TP53 status; age <65 (HR, 0.35; 95% CI: 0.27- 0.46; P < 0.0001), age ≥65 (HR, 0.32; 95% CI: 0.19- 0.54; P < 0.0001), either del 17p or TP53 cohort (HR, 0.33; 95% CI: 0.21- 0.52; P < 0.0001), and neither del 17p nor TP53 cohort (HR, 0.32; 95% CI: 0.19- 0.54; P < 0.0001). In the subset of patients with CLL treated with idelalisib, the pooled HR for PFS was statistically significant at 0.26 (95% CI: 0.18-0.37; P < 0.0001) and the PFS benefit was observed across all ages, and regardless of del17p or TP53 status and IGHV mutation status; age <65 (HR, 0.32; 95% CI: 0.24- 0.43; P < 0.0001), age ≥65 (HR, 0.26; 95% CI: 0.14- 0.47; P < 0.0001), either del17p or TP53 cohort (HR, 0.29; 95% CI: 0.15- 0.57; P = 0.0003), neither del17p nor TP53 cohort (HR, 0.26; 95% CI: 0.20- 0.35; P < 0.0001), IGHV mutated cohort (HR, 0.29; 95% CI: 0.17- 0.51; P < 0.0001), and IGHV unmutated cohort (HR, 0.25; 95% CI: 0.15- 0.40; P < 0.0001). Conclusions: Our study showed that PI3K inhibitors, idelalisib (PI3Kδ-selective inhibitor) and duvelisib (PI3Kδ/γ-combinatorial inhibitor), significantly improved PFS in patients with relapsed and refractory CLL/ SLL regardless of age and poor prognostic features such as del17p or TP53 and IGHV unmutated status, compared to control arm. The efficacy of these drugs must be balanced against the possible side effects. Disclosures No relevant conflicts of interest to declare.

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 5877-5877
Author(s):  
Bradley J. Grant ◽  
Anita Sultan ◽  
Nicholas D'Cunha ◽  
Chandler Graf ◽  
Sriman Swarup ◽  
...  

Introduction: Chronic lymphocytic leukemia is the most prevalent adult leukemia in western countries. Phosphatidylinositol 3-kinase (PI3K) is a kinase protein involved in downstream signaling for the B-cell receptor signaling pathway and has been shown to involve in the pathogenesis of chronic lymphocytic leukemia and small lymphocytic lymphoma (CLL/ SLL) by promoting B-cell survival, proliferation and metabolism. Two prominent PI3K inhibitors, idelalisib (PI3Kδ-selective inhibitor) and duvelisib (PI3Kδ/γ-combinatorial inhibitor), have recently shown to improve survival in patients with relapsed and refractory CLL/ SLL. We undertook a systematic review and meta-analysis of phase 3 randomized controlled trials to determine the risk of hematological toxicities associated with PI3K inhibitors. Methods: We systematically conducted a comprehensive literature search using MEDLINE, EMBASE databases and meeting abstracts from inception through June 2019. Phase 3 RCTs utilizing PI3K inhibitors in patients with relapsed and refractory CLL/SLL that mention hematological toxicities as adverse effects were incorporated in the analysis. Mantel-Haenszel method was used to calculate the estimated pooled risk ratio (RR) with 95% confidence interval (CI). Heterogeneity was assessed with Cochran's Q- statistic. Random effects model was applied. Results: Four phase 3 RCTs with a total of 1,216 patients with relapsed and refractory CLL/SLL were included. Studies compared ofatumumab vs idelalisib+ofatumumab, rituximab vs idelalisib+rituximab, bendamustine+ rituximab vs idelalisib+bendamustine+rituximab and ofatumumab vs duvelisib. The randomization ratio was 2:1 in Jones et al. study and 1:1 in other studies. The I2 statistic for heterogeneity was 49, suggesting some heterogeneity among RCTs. The RR of all-grade side effects were as follows: anemia, 1.39 (95% CI: 0.89 - 2.17; p = 0.15); neutropenia, 1.33 (95% CI: 1.06 - 1.67; p = 0.02); and thrombocytopenia, 1.23 (95% CI: 0.69 - 2.18; p = 0.48). The RR of high-grade adverse effects were as follows: anemia, 1.29 (95% CI: 0.62 - 2.67, p = 0.50); neutropenia, 1.51 (95% CI: 1.22 - 1.88; p = 0.0001); and thrombocytopenia, 1.21 (95% CI: 0.66 - 2.22; p = 0.53). The incidence of febrile neutropenia was 76 (11.69%) in study group vs 22 (3.92%) in control group with RR of 2.62 (95% CI: 1.27 -5.41, P = 0.009). Conclusions: PI3K inhibitors, idelalisib (PI3Kδ-selective inhibitor) and duvelisib (PI3Kδ/γ-combinatorial inhibitor), increased the risk of all grades of neutropenia and febrile neutropenia, with RR of 2.62 for febrile neutropenia, in patients with relapsed and refractory CLL/SLL. Vigilant monitoring is warranted, and proper supportive care and dose modifications should be followed. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 798-798
Author(s):  
Sriman Swarup ◽  
Donald P. Quick ◽  
Anita Sultan ◽  
Myint Aung Win ◽  
Ei Moe Phyu ◽  
...  

Introduction: Phosphatidylinositol 3-kinase (PI3K) is a kinase protein involved in downstream signaling for multiple pathways in B cells and is important for B cell survival, proliferation and metabolism. Hence, PI3K inhibitors have become an attractive therapeutic option for treatment of B cell malignancies. Two prominent PI3K inhibitors, (PI3Kδ-selective inhibitor) and duvelisib (PI3Kδ/γ-combinatorial inhibitor), are currently being studied in relapsed and refractory chronic lymphocytic leukemia or small lymphocytic lymphoma (CLL/SLL) and have shown to improve survival in recent trials with notable toxicities. We analyzed phase 3 trials to assess the incidence of serious adverse events, pneumonitis, infection and sepsis associated with PI3K inhibitors in this susceptible population. Methods: We systematically conducted a comprehensive literature search using MEDLINE, EMBASE databases and meeting abstracts from inception through June 2019. Phase 3 RCTs utilizing PI3K inhibitors in patients with relapsed and refractory CLL/SLL that mention serious adverse events, pneumonitis, infection and sepsis as adverse effects were incorporated in the analysis. Mantel-Haenszel (MH) method was used to calculate the estimated pooled risk ratio (RR), and risk difference (RD) with 95% confidence interval (CI). Heterogeneity was assessed with Cochran's Q- statistic. Random effects model was applied. Results: Four phase 3 RCTs with a total of 1,216 patients with relapsed and refractory CLL/SLL were included in analysis. Studies compared ofatumumab vs idelalisib+ofatumumab, rituximab vs idelalisib+rituximab, bendamustine+ rituximab vs idelalisib+bendamustine+rituximab and ofatumumab vs duvelisib. The randomization ratio was 2:1 in Jones et al. study and 1:1 in other studies. The I2 statistic for heterogeneity was 49, suggesting some heterogeneity among RCTs. The incidence of serious adverse events was 479 (73.69%) in study group vs 252 (44.92%) in control group (RR, 1.58; 95% CI: 1.37 - 1.83; P &lt; 0.0001 and RD, 0.26; 95% CI: 0.13 - 0.40; P = 0.0002). Pneumonitis was noted in 20 (3.07%) vs 1 (0.18%) in control group with RR of 6.53 (95% CI: 1.74 -24.53; P = 0.005) and RD of 0.02 (95% CI: 0.01 - 0.04; P = 0.0004). The incidence of any-grade pneumonia was 107 (16.46%) in study group vs 54 (9.63%) in control group (RR, 1.61; 95% CI: 1.00 - 2.58; P = 0.05). High-grade pneumonia was reported in 81 (12.46%) in idelalisib arm versus 35 (6.24%) in control group with RR of 1.84 (95% CI: 0.82 - 4.13; P = 0.14). Pneumocystis jiroveci pneumonia (PJP) rate was 2.24% higher in study group compared to control arm (RR, 3.87; 95% CI: 1.22 - 12.29; P = 0.02). Any-grade upper respiratory tract infection (URTI) was 14% in study group versus 7.84% in control arm (RR, 1.65; 95% CI: 1.17 - 2.34; P = 0.005). Sepsis rate was 2.88% higher in idelalisib group compared to control arm and the pooled RR was statistically significant at 2.68 (95% CI: 1.19 - 6.04, P = 0.02). Treatment-related deaths were 64 (11.85%) in study arm vs 28 (6.17%) in control arm according to analysis of 3 trials. The pooled RR was also statistically significant at 1.87 (95% CI: 1.21 -2.88; P = 0.005). Conclusions: Our meta-analysis showed that the incidence of serious adverse events, pneumonitis, PJP pneumonia, any-grade URTI and sepsis was significantly higher in PI3K inhibitors group with RR of 1.58 for serious adverse events, RR of 6.53 for pneumonitis, RR of 3.87 for PJP pneumonia and RR of 2.68 for sepsis respectively. Moreover, patients on PI3K inhibitors experienced 5.68% higher incidence of treatment-related deaths with RR of 1.87, compared to control arm. Since treatment-related serious toxicities and deaths are higher amongst patients treated with these agents, extra caution should be observed and recommended with their use. Disclosures No relevant conflicts of interest to declare.


Haematologica ◽  
2022 ◽  
Author(s):  
Vera Kristin Schmid ◽  
Ahmad Khadour ◽  
Nabil Ahmed ◽  
Carolin Brandl ◽  
Lars Nitschke ◽  
...  

Chronic lymphocytic leukemia (CLL) is a frequent lymphoproliferative disorder of B cells. Although inhibitors targeting signal proteins involved in B cell antigen receptor (BCR) signaling constitute an important part of the current therapeutic protocols for CLL patients, the exact role of BCR signaling, as compared to genetic aberration, in the development and progression of CLL is controversial. To investigate whether BCR expression per se is pivotal for the development and maintenance of CLL B cells, we used the TCL1 mouse model. By ablating the BCR in CLL cells from TCL1 transgenic mice, we show that CLL cells cannot survive without BCR signaling and are lost within eight weeks in diseased mice. Furthermore, we tested whether mutations augmenting B cell signaling influence the course of CLL development and its severity. The Phosphatidylinositol-3-kinase (PI3K) signaling pathway is an integral part of the BCR signaling machinery and its activity is indispensable for B cell survival. It is negatively regulated by the lipid phosphatase PTEN, whose loss mimics PI3K pathway activation. Herein, we show that PTEN has a key regulatory function in the development of CLL, as deletion of the Pten gene resulted in greatly accelerated onset of the disease. By contrast, deletion of the gene TP53, which encodes the tumor suppressor p53 and is highly mutated in CLL, did not accelerate disease development, confirming that development of CLL was specifically triggered by augmented PI3K activity through loss of PTEN and suggesting that CLL driver consequences most likely affect BCR signaling. Moreover, we could show that in human CLL patient samples, 64% and 81% of CLL patients with a mutated and unmutated IgH VH, respectively, show downregulated PTEN protein expression in CLL B cells if compared to healthy donor B cells. Importantly, we found that B cells derived from CLL patients had higher expression levels of the miRNA-21 and miRNA-29, which suppresses PTEN translation, compared to healthy donors. The high levels of miRNA-29 might be induced by increased PAX5 expression of the B-CLL cells. We hypothesize that downregulation of PTEN by increased expression levels of miR-21, PAX5 and miR-29 could be a novel mechanism of CLL tumorigenesis that is not established yet. Together, our study demonstrates the pivotal role for BCR signaling in CLL development and deepens our understanding of the molecular mechanisms underlying the genesis of CLL and for the development of new treatment strategies.


Hematology ◽  
2020 ◽  
Vol 2020 (1) ◽  
pp. 346-356
Author(s):  
Ashley Hanlon ◽  
Danielle M. Brander

Abstract Despite the proven effective approach to targeting the phosphatidylinositol-3-kinase (PI3K) pathway in B-cell malignancies, the approved PI3K inhibitors idelalisib and duvelisib have been less commonly selected for patients with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), given the availability of other more tolerable agents. However, patients with CLL/SLL can experience a disease course that is multiply relapsed, refractory, or intolerant to treatment, and PI3K inhibitors can achieve meaningful responses. This article reviews the common early- and late-onset (considered immune-mediated) toxicities with PI3K inhibitors, including infections, hepatotoxicity, diarrhea and/or colitis, and pneumonitis. Data on pretreatment considerations, toxicity management, and drug rechallenge are presented. In addition, next-generation PI3K inhibitors and novel treatment approaches with PI3K inhibitors, including combinations, time-limited treatments, and intermittent dosing, are highlighted.


Blood ◽  
2010 ◽  
Vol 116 (12) ◽  
pp. 2078-2088 ◽  
Author(s):  
Sarah E. M. Herman ◽  
Amber L. Gordon ◽  
Amy J. Wagner ◽  
Nyla A. Heerema ◽  
Weiqiang Zhao ◽  
...  

Abstract Targeted therapy with imatinib in chronic myeloid leukemia (CML) prompted a new treatment paradigm. Unlike CML, chronic lymphocytic leukemia (CLL) lacks an aberrant fusion protein kinase but instead displays increased phosphatidylinositol 3-kinase (PI3K) activity. To date, PI3K inhibitor development has been limited because of the requirement of this pathway for many essential cellular functions. Identification of the hematopoietic-selective isoform PI3K-δ unlocks a new therapeutic potential for B-cell malignancies. Herein, we demonstrate that PI3K has increased enzymatic activity and that PI3K-δ is expressed in CLL cells. A PI3K-δ selective inhibitor CAL-101 promoted apoptosis in primary CLL cells ex vivo in a dose- and time-dependent fashion that was independent of common prognostic markers. CAL-101–mediated cytotoxicity was caspase dependent and was not diminished by coculture on stromal cells. In addition, CAL-101 abrogated protection from spontaneous apoptosis induced by B cell–activating factors CD40L, TNF-α, and fibronectin. In contrast to malignant cells, CAL-101 does not promote apoptosis in normal T cells or natural killer cells, nor does it diminish antibody-dependent cellular cytotoxicity. However, CAL-101 did decrease activated T-cell production of various inflammatory and antiapoptotic cytokines. Collectively, these studies provide rationale for the clinical development of CAL-101 as a first-in-class targeted therapy for CLL and related B-cell lymphoproliferative disorders.


Haematologica ◽  
2022 ◽  
Author(s):  
Carol Moreno ◽  
Richard Greil ◽  
Fatih Demirkan ◽  
Alessandra Tedeschi ◽  
Bertrand Anz ◽  
...  

iLLUMINATE is a randomized, open-label phase 3 study of ibrutinib plus obinutuzumab (n=113) versus chlorambucil plus obinutuzumab (n=116) as first-line therapy for patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma. Eligible patients were aged ≥65 years, or


2017 ◽  
Vol 39 (2) ◽  
pp. 141-144
Author(s):  
S V Andreieva ◽  
K V Korets ◽  
O E Ruzhinska ◽  
I M Skorokhod ◽  
O G Alkhimova

Aim: The genetic mechanisms of resistance to chemotherapy in B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (B-CLL/SLL) are not clear. We aimed to determine the peculiarities of abnormal karyotype formation in bone marrow (BM) cells and peripheral blood (PB) blast transformed B-cells in relapse of B-CLL/SLL. Materials and Methods: Cytogenetic GTG banding technique and molecular cytogenetic in interphase cells (i-FISH) studies of BM cells and PB blast transformed B-lymphocytes were performed in 14 patients (10 males and 4 females) with B-CLL/SLL. Results: The results of karyotyping BM and PB cells revealed the heterogeneity of cytogenetic abnormalities in combined single nosological group of B-CLL/SLL. In PB B-cells, chromosome abnormalities related to a poor prognosis group were registered 2.5 times more often than in BM cells. Additional near tetraploid clones that occurred in 57.1% cases were the peculiar feature of BM cell karyotypes. Chromosomal rearrangements characteristic of the group of adverse cytogenetic prognosis were revealed in all cases from which in 2 cases by karyotyping BM cells, in 6 cases in PB B-cells and in 8 cases by the i-FISH method in BM cells, i.e. their detection frequency was 3 times higher in PB B-cells and 4 times higher when analyzing by i-FISH in BM cells. Conclusions: Mismatch in abnormal karyotypes in BM and PB B-cells by the presence of quantitative and structural chromosomal rearrangements may be indicative of simultaneous and independent processes of abnormal clone formation in the lymph nodes and BM hematopoietic cells. Accumulation the information about previously unidentified chromosomal rearrangements in relapse of the disease may help to understand the ways of resistance formation to chemotherapy.


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