PI3k Inhibitors in NHL and CLL: An Unfulfilled Promise

Correlation of SNHG7 and BGL3 expression in patients with de novo acute myeloid leukemia; novel insights into lncRNA effect in PI3K signaling context in AML pathogenesis

Background

Acute myeloid leukemia (AML) has been identified as a top priority for discovering a reliable biomarker for treatment improvement and patient outcome prediction due to the heterogeneous nature of AML and the obstacle to find an appropriate treatment strategy for this malignancy. Considering the involvement of long noncoding RNA (lncRNA) SNHG7 and BGL3 found in various cancers, the exact expression pattern of these lncRNAs and their clinical implications in acute myeloid leukemia (AML) continue to be elusive. In order to demonstrate a possible mechanism underlying AML pathogenesis, our goal was to examine BGL3 and SNHG7 lncRNA expressions in PI3K pathway.

Methods

This case-control cross-sectional study were conducted on RNA extracted from blood samples of 30 patients diagnosed with AML (Ayatollah-Khansari hospital, Arak, Iran) and 30 (age and gender matched) healthy controls. The expression levels of SNHG7 and BGL3 lncRNAs and their target genes Akt and PTEN, were measured using qRT-PCR. Subsequently, by means of statistical analysis, we determined the plausible correlation between the expressions of the aforementioned genes and lncRNA respectively.

Results

In AML samples, a considerable increase in the expression levels of SNHG7 lncRNA and Akr gene was accompanied by a marked reduction in the expression levels of BGL3 lncRNA and PTEN gene. Nevertheless, No significant relationship between the expression level of the indicated genes/lncRNAs and age and sex was found. The remarkable correlation between the expression of genes/lncRNAs and the blast percentage in patients was the notable point in the result of this study.

Conclusions

As the most straightforward interpretation of our results, we propose that perhaps the association between SNHG7 and BGL3 built through the interaction between Akt and PTEN may play a crucial role in the AML pathogenesis and any element of this axis could be a potential novel target for further profound treatment strategies. Nonetheless, in the context of Hematological Malignancies, particularly AML, more detailed studies are needed in this area to elucidate the precise role played by this interesting testis-specific pathway.

Personalised therapy in follicular lymphoma - is the dial turning?

Follicular lymphoma is the most common indolent lymphoma accounting for approximately 20%-25% of all new non-Hodgkin lymphoma diagnoses in western countries. Whilst outcomes are mostly favorable, the spectrum of clinical phenotypes includes high-risk groups with significantly inferior outcomes. This review discusses recent updates in risk stratification and treatment approaches from upfront treatment for limited and advanced stage follicular lymphoma to the growing options for relapsed, refractory disease with perspectives on how to approach this from a personalized lens. Notable gaps remain on how one can precisely and prospectively select optimal treatment for patients based on varying risks, with an anticipation that an increased understanding of the biology of these different phenotypes and increasing refinement of imaging- and biomarker-based tools will, in time, allow these gaps to be closed.

Matching-adjusted indirect comparisons of zanubrutinib (MAGNOLIA, BGB-3111-AU-003) versus ibrutinib (PCYC-1121) and rituximab (CHRONOS-3) in relapsed/refractory marginal zone lymphoma

In the absence of head-to-head randomized trials, unanchored matching-adjusted indirect comparisons were conducted to estimate the relative efficacy of zanubrutinib versus ibrutinib and zanubrutinib versus rituximab in relapsed or refractory marginal zone lymphoma (MZL). Logistic propensity score models were used to estimate weights for the patient-level data from two phase II single-arm trials, MAGNOLIA and BGB-3111-AU-003, such that their characteristics matched the ibrutinib and rituximab aggregate-level data from PCYC-1121 and CHRONOS-3, respectively. The base case model for each comparison incorporated four key prognostic factors: prior lines of therapy, MZL subtype, response to prior therapy, and age. A sensitivity analysis incorporating additional prognostic factors was also conducted for the ibrutinib comparison. The impact of each covariate was explored via a leave-one-out analysis. Compared with ibrutinib and rituximab, zanubrutinib demonstrated significant benefits in terms of both overall response and progression-free survival in patients with previously treated MZL.

CHRONOS-4: phase 3 study of copanlisib plus rituximab-based immunochemotherapy in relapsed indolent B-cell lymphoma

ABSTRACT

Copanlisib, a pan-class I phosphatidylinositol 3-kinase inhibitor with predominant activity against the α and δ isoforms, previously demonstrated durable responses as monotherapy and improved progression-free survival (PFS) in combination with rituximab in patients with relapsed indolent non-Hodgkin lymphoma (iNHL). CHRONOS-4 was a phase 3, randomized, double-blind, placebo-controlled study to investigate the efficacy and safety of copanlisib in combination with standard immunochemotherapy in patients with relapsed iNHL. Patients (n = 524) were randomized (1:1) to copanlisib (60 mg IV) plus immunochemotherapy (rituximab and bendamustine [R-B] or placebo plus R-B). Copanlisib/placebo were administered with R-B (days 1, 8, and 15 of each 28-day cycle) for ≤6 cycles and as monotherapy from cycle 7 up to 12 months. The primary study end point was PFS. Median exposure was 8.5 months (0.2-12.9) for copanlisib plus R-B and 11.4 months (0.1-12.6) for placebo plus R-B. Median PFS was 32.9 months (95% confidence interval [CI], 24.4-38.6) for copanlisib plus R-B and 33.3 months (95% CI, 27.8-42.8) for placebo plus R-B (hazard ratio, 1.13; 95% CI, 0.88-1.44; P = .83). No differences between treatment arms were observed in overall survival (data not yet mature), objective response rate, and duration of response for the overall population or individual histology types. Overall, copanlisib plus R-B was associated with higher rates of serious treatment-emergent adverse events (TEAEs), grade 4 and 5 TEAEs, and treatment discontinuation. A number of serious TEAEs were infections. Overall, copanlisib plus R-B did not provide clinical benefit vs placebo plus R-B and was associated with worse tolerability in patients with relapsed iNHL. This trial was registered at www.ClinicalTrials.gov as #NCT02626455.

MLIP and Its Potential Influence on Key Oncogenic Pathways

Muscle-enriched A-type lamin-interacting protein (MLIP) is an emerging protein involved in cellular homeostasis and stress adaptation. Eukaryotic cells regulate various cellular processes, including metabolism, DNA repair, and cell cycle progression, to maintain cellular homeostasis. Disruptions in this homeostasis can lead to diseases such as cancer, characterized by uncontrolled cell growth and division. This review aims to explore for the first time the unique role MLIP may play in cancer development and progression, given its interactions with the PI3K/Akt/mTOR pathway, p53, MAPK9, and FOXO transcription factors, all critical regulators of cellular homeostasis and tumor suppression. We discuss the current understanding of MLIP's involvement in pro-survival pathways and its potential implications in cancer cells' metabolic remodeling and dysregulated homeostasis. Additionally, we examine the potential of MLIP as a novel therapeutic target for cancer treatment. This review aims to shed light on MLIP's potential impact on cancer biology and contribute to developing innovative therapeutic strategies.

Are we closer to a standard of care for Richter's syndrome? Novel treatments on the horizon

INTRODUCTION

The therapeutic landscape for chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) has significantly evolved over the past decade with dramatically improved outcomes with the introduction of targeted therapies. This unfortunately has not been the case for Richter transformation (RT), the histologic transformation to a more aggressive lymphoma, most typically diffuse large B-cell lymphoma (DLBCL). As such, RT continues to be one of the most challenging complications of CLL/SLL. Historically, RT has a poor response to treatment, with a minority reaching complete remission (CR) and overall survival (OS) being less than a year.

AREAS COVERED

The focus of this review is to discuss the effectiveness of commonly used regimens, and review existing data for emerging regimens being examined in ongoing clinical trials to improve prognosis and outcomes in patients with RT. Despite extensive efforts to optimize therapies for RT, there is still no generalized consensus on either first-line treatment regimens or regimens in the relapsed/refractory setting. RT continues to carry a high mortality rate without durable response to current therapeutic agents.

EXPERT OPINION

Ongoing and future research may identify novel treatment approaches that will eventually improve outcomes for patients with RT. The optimal care for RT patients is a clinical trial, when feasible.

Leniolisib: a novel treatment for activated phosphoinositide-3 kinase delta syndrome

IC50 = 11 nM (PI3Kδ); 244 nM (PI3Kα); 424 nM (PI3Kβ), 2,230 nM (PI3Kγ).

PI3Kδ Pathway Dysregulation and Unique Features of Its Inhibition by Leniolisib in Activated PI3Kδ Syndrome and Beyond

The phosphoinositide 3-kinase (PI3K) pathway regulates diverse cellular processes, with finely tuned PI3Kδ activity being crucial for immune cell development and function. Genetic hyperactivation of PI3Kδ causes the inborn error of immunity activated phosphoinositide 3-kinase δ syndrome (APDS). Several PI3Kδ inhibitors have been investigated as treatment options for APDS, but only leniolisib has shown both efficacy and tolerability. In contrast, severe immune-mediated adverse events such as colitis, neutropenia, and hepatotoxicity have been observed with other PI3Kδ inhibitors, particularly those indicated for hematological malignancies. We propose that leniolisib is distinguished from other PI3Kδ inhibitors due to its structure, specific inhibitory properties selectively targeting the δ isoform without overinhibition of the δ or γ isoforms, and the precise match between APDS mechanism of disease and drug mechanism of action.

Idelalisib (PI3Kδ inhibitor) therapy for patients with relapsed/refractory chronic lymphocytic leukemia: A Swedish nation-wide real-world report on consecutively identified patients

OBJECTIVES

We examined the efficacy and toxicity of the PI3Kδ inhibitor idelalisib in combination with rituximab salvage therapy in consecutively identified Swedish patients with chronic lymphocytic leukemia (CLL).

METHODS AND RESULTS

Thirty-seven patients with relapsed/refractory disease were included. The median number of prior lines of therapy was 3 (range 1-11); the median age was 69 years (range 50-89); 22% had Cumulative Illness Rating Scale (CIRS) >6 and 51% had del(17p)/TP53 mutation. The overall response rate was 65% (all but one was partial response [PR]). The median duration of therapy was 9.8 months (range 0.9-44.8). The median progression-free survival was 16.4 months (95% CI: 10.4-26.3) and median overall survival had not been reached (75% remained alive at 24 months of follow-up). The most common reason for cessation of therapy was colitis (n = 8, of which seven patients experienced grade ≥3 colitis). The most common serious adverse event was grade ≥3 infection, which occurred in 24 patients (65%).

CONCLUSIONS

Our real-world results suggest that idelalisib is an effective and relatively safe treatment for patients with advanced-stage CLL when no other therapies exist. Alternative dosing regimens and new PI3K inhibitors should be explored, particularly in patients who are double-refractory to inhibitors of BTK and Bcl-2.

Rationally designed chimeric PI3K-BET bromodomain inhibitors elicit curative responses in MYC-driven lymphoma

Targeted inhibitors of bromodomain and extraterminal (BET)-bromodomains and phosphatidylinositol-3-kinase (PI3K) signaling demonstrate potent but self-limited antilymphoma activity as single agents in the context of cellular Myelocytomatosis (cMYC) oncogene-dysregulation. However, combined PI3K and BET inhibition imparts synergistic anticancer activity with the potential for more sustained disease responses due to the mutual antagonism of compensatory epigenetic and signaling networks. Here, we describe the mechanistic and therapeutic validation of rationally designed dual PI3K/BET bromodomain inhibitors, built by linkage of established PI3K and BET inhibitor pharmacophores. The lead candidate demonstrates high selectivity, nanomolar range cellular potency, and compelling in vivo efficacy, including curative responses in the aggressive Eµ-Myc lymphoma model. These studies further support the therapeutic strategy of combined PI3K and BET inhibition and provide a potential step-change in approach to orthogonal MYC antagonism using optimized chimeric small-molecule technology.

Isoform-selective targeting of PI3K: time to consider new opportunities?

Phosphoinositide-3-kinases (PI3Ks) are central to several cellular signaling pathways in human physiology and are potential pharmacological targets for many pathologies including cancer, thrombosis, and pulmonary diseases. Tremendous efforts to develop isoform-selective inhibitors have culminated in the approval of several drugs, validating PI3K as a tractable and therapeutically relevant target. Although successful therapeutic validation has focused on isoform-selective class I orthosteric inhibitors, recent clinical findings have indicated challenges regarding poor drug tolerance owing to sustained on-target inhibition. Hence, additional approaches are warranted to increase the clinical benefits of specific clinical treatment options, which may involve the employment of so far underexploited targeting modalities or the development of inhibitors for currently underexplored PI3K class II isoforms. We review recent key discoveries in the development of isoform-selective inhibitors, focusing particularly on PI3K class II isoforms, and highlight the emerging importance of developing a broader arsenal of pharmacological tools.