New Treatment Options for Newly-Diagnosed and Relapsed Chronic Lymphocytic Leukemia

Bruton's tyrosine kinase (BTK) inhibitors for the treatment of primary central nervous system lymphoma (PCNSL): current progress and latest advances

The incidence of primary central nervous system lymphoma (PCNSL) has steadily increased, particularly in elderly patients. Although highly responsive to first-line chemotherapy and radiotherapy, approximately 50% of patients relapse or become refractory within 1 year. Prognosis following relapse is dismal and no standard salvage therapy exists. Bruton's tyrosine kinase (BTK), a key regulator of the B-cell receptor (BCR) pathway, has emerged as a promising therapeutic target. The first BTK inhibitor ibrutinib has been evaluated in the relapsed/refractory PCNSL setting, with overall response rates of 51.9%-89.0% and median progression-free survival of 4.6-4.8 months. However, ibrutinib inhibits several kinases in addition to BTK, leading to off-target effects. Second-generation BTK inhibitors have since been developed, which afford greater selectivity for BTK and fewer off-target effects. We review current practices in the diagnosis and evaluation of PCNSL, as well as clinical trials of BTK inhibitors in PCNSL and future developments in PCNSL treatment.

MNDA, a PYHIN factor involved in transcriptional regulation and apoptosis control in leukocytes

Inflammation control is critical during the innate immune response. Such response is triggered by the detection of molecules originating from pathogens or damaged host cells by pattern-recognition receptors (PRRs). PRRs subsequently initiate intra-cellular signalling through different pathways, resulting in i) the production of inflammatory cytokines, including type I interferon (IFN), and ii) the initiation of a cascade of events that promote both immediate host responses as well as adaptive immune responses. All human PYRIN and HIN-200 domains (PYHIN) protein family members were initially proposed to be PRRs, although this view has been challenged by reports that revealed their impact on other cellular mechanisms. Of relevance here, the human PYHIN factor myeloid nuclear differentiation antigen (MNDA) has recently been shown to directly control the transcription of genes encoding factors that regulate programmed cell death and inflammation. While MNDA is mainly found in the nucleus of leukocytes of both myeloid (neutrophils and monocytes) and lymphoid (B-cell) origin, its subcellular localization has been shown to be modulated in response to genotoxic agents that induce apoptosis and by bacterial constituents, mediators of inflammation. Prior studies have noted the importance of MNDA as a marker for certain forms of lymphoma, and as a clinical prognostic factor for hematopoietic diseases characterized by defective regulation of apoptosis. Abnormal expression of MNDA has also been associated with altered levels of cytokines and other inflammatory mediators. Refining our comprehension of the regulatory mechanisms governing the expression of MNDA and other PYHIN proteins, as well as enhancing our definition of their molecular functions, could significantly influence the management and treatment strategies of numerous human diseases. Here, we review the current state of knowledge regarding PYHIN proteins and their role in innate and adaptive immune responses. Emphasis will be placed on the regulation, function, and relevance of MNDA expression in the control of gene transcription and RNA stability during cell death and inflammation.

Inhibitors of phosphoinositide 3-kinase (PI3K) and phosphoinositide 3-kinase-related protein kinase family (PIKK)

Phosphoinositide 3-kinases (PI3K) and phosphoinositide 3-kinase-related protein kinases (PIKK) are two structurally related families of kinases that play vital roles in cell growth and DNA damage repair. Dysfunction of PIKK members and aberrant stimulation of the PI3K/AKT/mTOR signalling pathway are linked to a plethora of diseases including cancer. In recent decades, numerous inhibitors related to the PI3K/AKT/mTOR signalling have made great strides in cancer treatment, like copanlisib and sirolimus. Notably, most of the PIKK inhibitors (such as VX-970 and M3814) related to DNA damage response have also shown good efficacy in clinical trials. However, these drugs still require a suitable combination therapy to overcome drug resistance or improve antitumor activity. Based on the aforementioned facts, we summarised the efficacy of PIKK, PI3K, and AKT inhibitors in the therapy of human malignancies and the resistance mechanisms of targeted therapy, in order to provide deeper insights into cancer treatment.

Real-life diagnostic and therapeutic approach to CLL: a 2022 update from an expert panel in Tuscany

A panel of chronic lymphocytic leukemia (CLL) experts from Tuscany propose a real-life diagnostic and therapeutic approach CLL that considers the role of genomic and somatic prognostic factors in risk stratification and treatment decisions. Safety and efficacy of new agents has been demonstrated now not only in clinical trials but also in many real-world series. The BTK inhibitors, ibrutinib and acalabrutinib, and BH3 mimetic venetoclax are now indicated as first-line therapy and chemoimmunotherapy can be spared to the majority of CLL patients, thus preventing unnecessary hematological and non-hematological toxicity and second primary tumors. For treatment, FISH for 17 p and P53 mutational status are essential. IGHV mutation can be done at diagnosis or before treatment. Echography is the gold standard radiological investigation in CLL, at both diagnosis and response evaluation. Chemotherapy is virtually abandoned. Age, genetic risk, and patient comorbidities have to be carefully evaluated for treatment decision. With the availability of different drugs, there is a need for a uniform and shared approach in daily therapeutic choice. The proposed approach is based on current evidence and guidelines as well as results from clinical trials and daily clinical experience.

Bruton's Tyrosine Kinase Inhibitors (BTKIs): Review of Preclinical Studies and Evaluation of Clinical Trials

In the last few decades, there has been a growing interest in Bruton's tyrosine kinase (BTK) and the compounds that target it. BTK is a downstream mediator of the B-cell receptor (BCR) signaling pathway and affects B-cell proliferation and differentiation. Evidence demonstrating the expression of BTK on the majority of hematological cells has led to the hypothesis that BTK inhibitors (BTKIs) such as ibrutinib can be an effective treatment for leukemias and lymphomas. However, a growing body of experimental and clinical data has demonstrated the significance of BTK, not just in B-cell malignancies, but also in solid tumors, such as breast, ovarian, colorectal, and prostate cancers. In addition, enhanced BTK activity is correlated with autoimmune disease. This gave rise to the hypothesis that BTK inhibitors can be beneficial in the therapy of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), multiple sclerosis (MS), Sjögren's syndrome (SS), allergies, and asthma. In this review article, we summarize the most recent findings regarding this kinase as well as the most advanced BTK inhibitors that have been developed to date and their clinical applications mainly in cancer and chronic inflammatory disease patients.

Immunotherapy combinations for chronic lymphocytic leukemia: advantages and disadvantages

In the last few years, BTK inhibitors, PI3K inhibitors, and venetoclax have been approved for clinical use against chronic lymphocytic leukemia (CLL), both as single agents, and in combination. This article summarizes recent achievements in the treatment of patients with CLL, and pays special attention to novel targeted drugs and monoclonal antibodies (Mabs). A literature search was conducted of the PubMed and Google Scholar databases. Rituximab and obinutuzumab have been combined with chemotherapy, and more recently, with BTK inhibitors, PI3K inhibitors, and venetoclax. These agents have demonstrated high activity in treatment naïve (TN) and relapsed or refractory (RR) CLL. Immunochemotherapy regimens are currently considered in TN younger patients with IGHV-mutated disease and should not be given in patients without IGHV mutation. BTK inhibitors are more commonly used as monotherapy in TN and RR patients. PI3K inhibitors can be combined with CD20 Mabs, but their use in CLL is limited due to safety concerns. Venetoclax is typically combined with anti-CD20 Mabs in CLL. Generally, the optimal sequencing of therapies remains to be established, and the selection of upfront therapy needs to be tailored to the individual patient.