Safety and tolerability of idelalisib, lenalidomide, and rituximab in relapsed and refractory lymphoma: the Alliance for Clinical Trials in Oncology A051201 and A051202 phase 1 trials

Lenalidomide, rituximab (R2), and ixazomib for frontline treatment of high risk follicular and indolent non-Hodgkin lymphoma

Lenalidomide and rituximab (R2) is an effective frontline treatment for patients with indolent B-cell non-Hodgkin lymphoma (iNHL). We investigated the safety and efficacy of addition of the proteasome inhibitor ixazomib to R2 for treatment of iNHL through a phase I/II clinical trial for high-risk patients. Twenty patients were enrolled, 18 were treated. The target dose of ixazomib 4 mg weekly was achieved during dose escalation. The most common treatment-related adverse events (AEs) were low grade gastrointestinal, rash, neuropathy, and myalgia/arthralgia. There were 33% grade 2 and 17% grade 3 infections. With median follow-up of 5.2 years, four patients discontinued treatment due to lymphoma progression. Best overall response rate (ORR) was 61.2% [55.6% CR, 5.6% PR): 22.2% had stable disease and 16.7% had disease progression. Kaplan-Meier estimates of progression free and overall survival (OS) were 73% and 87% at 36 months, respectively. R2 can safely be combined with ixazomib for treatment-naïve iNHL patients.

Combating relapsed and refractory Mantle cell lymphoma with novel therapeutic armamentarium: Recent advances and clinical prospects

Mantle cell lymphoma (MCL) is a rare, aggressive subtype of non-Hodgkin's lymphoma (NHL), accounting for 5% of all cases. Due to its virulence factor, it is an incurable disease and keeps relapsing despite an intensive treatment regimen. Advancements in research and drug discovery have shifted the treatment strategy from conventional chemotherapy to targeted agents and immunotherapies. The establishment of the role of Bruton tyrosine kinase led to the development of ibrutinib, a first-generation BTK inhibitor, and its successors. A conditioning regimen based immunotherapeutic agent like ibritumumob, has also demonstrated a viable response with a favorable toxicity profile. Brexucabtagene Autoleucel, the only approved CAR T-cell therapy, has proven advantageous for relapsed/refractory MCL in both children and adults. This article reviews certain therapies that could help update the current approach and summarizes a few miscellaneous agents, which, seldom studied in trials, could alleviate the regression observed in traditional therapies. DATA AVAILABILITY: The datasets generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Metabolic and toxicological considerations for phosphoinositide 3-kinase delta inhibitors in the treatment of chronic lymphocytic leukemia

INTRODUCTION

Phosphoinositide 3-kinase delta (PI3Kδ) inhibitors are a class of novel agents that are mainly used to treat B-cell malignancies. They function by inhibiting one or more enzymes which are part of the PI3K/AKT/mTOR pathway. Idelalisib is a first-in-class PI3Kδ inhibitor effective in patients with B-cell lymphoid malignancies.

AREAS COVERED

This article reviews the chemical structure, mechanism of action, and metabolic and toxicological properties of PI3Kδ inhibitors and discusses their clinical applications in monotherapy and in combination with other agents for the treatment of chronic lymphocytic leukemia (CLL). A search was conducted of PubMed, Web of Science, and Google Scholar for articles in English.

RESULTS/CONCLUSION

PI3Kδ inhibitors hold potential for the treatment of B-cell malignancies, including CLL. However, their use is also associated with severe toxicities, including pneumonia, cytopenias, hepatitis, and rash. Newer drugs are in development to reduce toxicity with novel schedules and/or combinations.

EXPERT OPINION

The development of novel PI3Kδ inhibitors might help to reduce toxicity and improve efficacy in patients with CLL and other B-cell lymphoid malignancies.

Recent advances in treatment of nodal and gastrointestinal follicular lymphoma

Follicular lymphoma (FL) is the most common low-grade lymphoma, and although nodal FL is highly responsive to treatment, the majority of patients relapse repeatedly, and the disease has been incurable with a poor prognosis. However, primary FL of the gastrointestinal tract has been increasingly detected in Japan, especially due to recent advances in small bowel endoscopy and increased opportunities for endoscopic examinations and endoscopic diagnosis. However, many cases are detected at an early stage, and the prognosis is good in many cases. In contrast, in Europe and the United States, gastrointestinal FL has long been considered to be present in 12%-24% of Stage-IV patients, and the number of advanced gastrointestinal cases is expected to increase. This editorial provides an overview of the recent therapeutic advances in nodal FL, including antibody-targeted therapy, bispecific antibody therapy, epigenetic modulation, and chimeric antigen receptor T-cell therapy, and reviews the latest therapeutic manuscripts published in the past year. Based on an understanding of the therapeutic advances in nodal FL, we also discuss future possibilities for gastroenterologists to treat gastrointestinal FL, especially in advanced cases.

Hepatotoxicity of Small Molecule Protein Kinase Inhibitors for Cancer

Small molecule protein kinase inhibitors (PKIs) have become an effective strategy for cancer patients. However, hepatotoxicity is a major safety concern of these drugs, since the majority are reported to increase transaminases, and few of them (Idelalisib, Lapatinib, Pazopanib, Pexidartinib, Ponatinib, Regorafenib, Sunitinib) have a boxed label warning. The exact rate of PKI-induced hepatoxicity is not well defined due to the fact that the majority of data arise from pre-registration or registration trials on fairly selected patients, and the post-marketing data are often based only on the most severe described cases, whereas most real practice studies do not include drug-related hepatotoxicity as an end point. Although these side effects are usually reversible by dose adjustment or therapy suspension, or by switching to an alternative PKI, and fatality is uncommon, all patients undergoing PKIs should be carefully pre-evaluated and monitored. The management of this complication requires an individually tailored reappraisal of the risk/benefit ratio, especially in patients who are responding to therapy. This review reports the currently available data on the risk and management of hepatotoxicity of all the approved PKIs.

Follicular lymphoma: The long and winding road leading to your cure?

Follicular lymphoma, the most common indolent lymphoma, though highly responsive to therapy is coupled with multiple relapses for the majority of patients. Advances in biologic understanding of molecular events in lymphoma cells and the tumor microenvironment, along with novel cellular and targeted therapies, suggest this may soon change. Here we first review the development of the molecular concepts and classification of follicular lymphoma, along with therapeutic development of treatments based on chemotherapy plus monoclonal antibodies targeting CD20. We then focus on developments over the last decade in further defining follicular lymphoma pathophysiology, leading to targeted therapeutics, as well as novel immunotherapeutic strategies effective against B cell lymphomas including follicular, particularly patients with advanced stage disease. Additional alterations beyond the hallmark t(14;18) translocation are necessary for development of follicular lymphoma. Epigenetic mutations are almost universally identified in follicular lymphoma, most commonly involving histone-lysine N-methyltransferase 2D (KMT2D, the histone acetyltransferases, cAMP response element-binding protein binding protein (CREBBP) and E1A binding protein P300 (EP300) and the histone methyltransferase enhancer of zeste homologue 2 (EZH2). Mutations are also commonly identified in other proliferation/survival pathways such as B-cell receptor, RAS, mTOR and JAK-STAT pathways, as well as immune escape mutations. The host immune response plays a key role as well, based on studies correlating various immune cell subsets and gene expression signatures with outcomes. Over the last decade, many therapeutic options beyond the commonly used bendamustine-rituximab induction regimen have become available or are being investigated. We focus on these newer agents in the relapsed setting. New antibody-based agents include the naked CD19 directed antibody tafasitamab, the CD79b directed antibody drug conjugate (ADC) polatuzumab vedotin and the CD47 directed antibody magrolimab that targets macrophages rather than FL cells directly. Immune modulation by lenalidomide has moved to earlier lines of therapy and in combinations. Several small molecule inhibitors of proliferation signal pathways involving PI3kinase and BTK have activity against FL. Apoptotic pathway modulators also have activity. With increasing recognition of the high rate of epigenetic mutations in FL, HDAC inhibition has a role. More importantly, the EZH2 inhibitor tazemetostat is FDA approved for FL after 2 prior lines of therapy. The most exciting data currently involve immune attack against follicular lymphoma by chimeric antigen receptor T-cells (CART) or bispecific antibody constructs. Given these multiple potentially non-crossreactive mechanisms, studies of rationally designed combination strategies hold the promise of improving outcomes and possibly cure of follicular lymphoma.

Integrin Signaling Shaping BTK-Inhibitor Resistance

Integrins are adhesion molecules that function as anchors in retaining tumor cells in supportive tissues and facilitating metastasis. Beta1 integrins are known to contribute to cell adhesion-mediated drug resistance in cancer. Very late antigen-4 (VLA-4), a CD49d/CD29 heterodimer, is a beta1 integrin implicated in therapy resistance in both solid tumors and haematological malignancies such as chronic lymphocytic leukemia (CLL). A complex inside-out signaling mechanism activates VLA-4, which might include several therapeutic targets for CLL. Treatment regimens for this disease have recently shifted towards novel agents targeting BCR signaling. Bruton’s tyrosine kinase (BTK) is a component of B cell receptor signaling and BTK inhibitors such as ibrutinib are highly successful; however, their limitations include indefinite drug administration, the development of therapy resistance, and toxicities. VLA-4 might be activated independently of BTK, resulting in an ongoing interaction of CD49d-expressing leukemic cells with their surrounding tissue, which may reduce the success of therapy with BTK inhibitors and increases the need for alternative therapies. In this context, we discuss the inside-out signaling cascade culminating in VLA-4 activation, consider the advantages and disadvantages of BTK inhibitors in CLL and elucidate the mechanisms behind cell adhesion-mediated drug resistance.

Targeted Agents in the Treatment of Indolent B-Cell Non-Hodgkin Lymphomas

Targeted therapies continue to change the landscape of lymphoma treatment, resulting in improved therapy options and patient outcomes. Numerous agents are now approved for use in the indolent lymphomas and many others under development demonstrate significant promise. In this article, we review the landscape of targeted agents that apply to the indolent lymphomas, predominantly follicular lymphoma, lymphoplasmacytic lymphoma/Waldenstrom macroglobulinaemia and marginal zone lymphoma. The review covers small molecule inhibitors, immunomodulators and targeted immunotherapies, as well as presenting emerging and promising combination therapies.

Phase Ib study of combinations of avadomide (CC-122), CC-223, CC-292, and rituximab in patients with relapsed/refractory diffuse large B-cell lymphoma

There is a need for additional treatment options for patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) who do not benefit from available therapies. We examined combinations of the cereblon E3 ligase modulator (CELMoD) agent avadomide (CC-122), the selective, ATP-competitive mammalian target of rapamycin kinase inhibitor CC-223, and the potent, selective, covalent Bruton tyrosine kinase inhibitor CC-292 in patients with relapsed/refractory (R/R) DLBCL. In the multicenter, phase Ib CC-122-DLBCL-001 study (NCT02031419), the dose-escalation portion explored combinations of CC-122, CC-223, and CC-292 administered as doublets or triplets with rituximab in patients with chemorefractory DLBCL. Primary endpoints were safety, tolerability, and dose-limiting toxicities; additional endpoints included pharmacokinetics, pharmacodynamics, biomarkers, and preliminary efficacy. As of December 1, 2017, 106 patients were enrolled across four cohorts. The median age was 65 years (range 24-84 years), and patients had a median of 3 (range 1-10) prior to regimens. A total of 101 patients (95.3%) discontinued, most commonly due to disease progression (49.1%). The most common any-grade adverse events (AEs) across treatment arms were gastrointestinal and hematologic; the most common grade 3/4 AEs were hematologic. CC-122 was well tolerated, with no unexpected safety concerns. Preliminary efficacy was observed in three of four treatment arms. CC-122 plus rituximab was considered suitable for dose expansion, whereas CC-223 and CC-292 combinations were associated with enhanced toxicity and/or insufficient improvement in responses. CC-122 plus rituximab was well tolerated, with preliminary antitumor activity in patients with R/R DLBCL. This innovative study demonstrates the feasibility of assessing the tolerability and preliminary efficacy of novel combinations utilizing a multi-arm dose-finding design.

Recent Research Progress of Chiral Small Molecular Antitumor-Targeted Drugs Approved by the FDA From 2011 to 2019

Chiral drugs usually contain chiral centers, which are present as single enantiomers or racemates. Compared with achiral drugs, they have significant advantages in safety and efficacy with high stereoselectivity. Of these drugs, chirality not only exerts influence on the solubility and pharmacokinetic characteristics but also has specific mechanistic characteristics on their targets. We noted that small molecules with unique chiral properties have emerged as novel components of antitumor drugs approved by the FDA in decade. Since approved, these drugs have been continuously explored for new indications, new mechanisms, and novel combinations. In this mini review, recent research progress of twenty-two FDA-approved chiral small molecular-targeted antitumor drugs from 2011 to 2019 is summarized with highlighting the potential and advantages of their applications. We believe that these updated achievements may provide theoretical foundation and stimulate research interests for optimizing drug efficacy, expanding clinical application, overcoming drug resistance, and advancing safety in future clinical administrations of these chiral targeted drugs.

PI3K inhibitors are finally coming of age

Overactive phosphoinositide 3-kinase (PI3K) in cancer and immune dysregulation has spurred extensive efforts to develop therapeutic PI3K inhibitors. Although progress has been hampered by issues such as poor drug tolerance and drug resistance, several PI3K inhibitors have now received regulatory approval - the PI3Kα isoform-selective inhibitor alpelisib for the treatment of breast cancer and inhibitors mainly aimed at the leukocyte-enriched PI3Kδ in B cell malignancies. In addition to targeting cancer cell-intrinsic PI3K activity, emerging evidence highlights the potential of PI3K inhibitors in cancer immunotherapy. This Review summarizes key discoveries that aid the clinical translation of PI3Kα and PI3Kδ inhibitors, highlighting lessons learnt and future opportunities.

An Overview of Lenalidomide in Combination with Rituximab for the Treatment of Adult Patients with Follicular Lymphoma: The Evidence to Date

Follicular lymphoma (FL) is an indolent (low-grade) malignancy of B cells and is among the most common hematological cancers affecting adults. Its clinical presentation, natural course, and severity are highly variable. Management of FL depends on the clinical setting; most patients require multiple lines of treatment. Chemoimmunotherapy is the standard of care for FL patients needing treatment; however, alternative treatments are limited for refractory patients or those unfit for chemoimmunotherapy. Multiple alternatives to chemoimmunotherapy for FL are being developed, with some showing significant promise. Lenalidomide combination with rituximab (LR) is among the most successful and extensively studied novel approaches. LR has been compared head-to-head in clinical trials with rituximab monotherapy and chemoimmunotherapy in the frontline and to lenalidomide or rituximab monotherapy in the relapsed or refractory setting for the treatment of FL. Initial reports of these nine trials have been published in the last decade, and their long-term data will be available in the coming years. LR offered superior efficacy to either lenalidomide or rituximab monotherapy alone. The RELEVANCE trial compared the efficacy of LR with chemoimmunotherapy among 1030 FL patients and demonstrated similar efficacy with a different side effect profile. Myelosuppression, rash, and fatigue were among the significant adverse events. Most patients treated with LR received thromboprophylaxis. This paper aims to summarize and comment on the published evidence regarding LR treatment for FL through a literature review. The clinical trials will be presented in detail, and methodological differences complicating their comparisons will be discussed.

Recent Advances in the Management of Patients with Relapsed/Refractory Follicular Lymphoma

Advanced follicular lymphoma (FL) often relapses after front-line chemoimmunotherapy, and many patients will eventually require subsequent therapy. In 2021, two new therapies were granted approval by the Food and Drug Administration (FDA), including the PI3Kδ inhibitor umbralisib and the chimeric antigen receptor–T-cell therapy (CAR-T) axicabtagene ciloleucel. Herein, we present the latest advances in the management of FL, discussing the recently approved therapies in the relapsed and refractory (R/R) setting and various new therapeutic modalities that have the potential to change the treatment landscape and natural history of R/R FL.

Targeting B-cell receptor and PI3K signaling in diffuse large B-cell lymphoma

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous diagnostic category comprising distinct molecular subtypes characterized by diverse genetic aberrations that dictate patient outcome. As roughly one-third of DLBCL patients are not cured by current standard chemo-immunotherapy a better understanding of the molecular pathogenesis is warranted to improve outcome. B-cell receptor (BCR) signaling is crucial for the development, growth and survival of both normal and a substantial fraction of malignant B-cells. Various analyses revealed genetic alterations of central components of the BCR or its downstream signaling effectors in some subtypes of DLBCL. Thus, BCR signaling and the downstream NF-κB and PI3K cascades have been proposed as potential targets for the treatment of DLBCL patients. As one of the main effectors of BCR activation, PI3K mediated signals play a crucial role in the pathogenesis and survival of DLBCL. In this review, we summarize our current understanding of BCR signaling with a special focus on the PI3K pathway in DLBCL and how to utilize this knowledge therapeutically.

Evolving therapeutic landscape in follicular lymphoma: a look at emerging and investigational therapies

Follicular Lymphoma (FL) is the most common subtype of indolent B cell non-Hodgkin lymphoma. The clinical course can be very heterogeneous with some patients being safely observed over many years without ever requiring treatment to other patients having more rapidly progressive disease requiring multiple lines of treatment for disease control. Front-line treatment of advanced FL has historically consisted of chemoimmunotherapy but has extended to immunomodulatory agents such as lenalidomide. In the relapsed setting, several exciting therapies that target the underlying biology and immune microenvironment have emerged, most notable among them include targeted therapies such as phosphoinositide-3 kinase and Enhancer of Zeste 2 Polycomb Repressive Complex 2 inhibitors and cellular therapies including chimeric antigen receptor T cells and bispecific T cell engagers. There are several combination therapies currently in clinical trials that appear promising. These therapies will likely reshape the treatment approach for patients with relapsed and refractory FL in the coming years. In this article, we provide a comprehensive review of the emerging and investigational therapies in FL and discuss how these agents will impact the therapeutic landscape in FL.

Copanlisib synergizes with conventional and targeted agents including venetoclax in B- and T-cell lymphoma models

Copanlisib is a pan-class I phosphoinositide 3-kinase (PI3K) inhibitor with preferred activity toward PI3Kα and PI3Kδ. Despite the clear overall clinical benefit, the number of patients achieving complete remissions with the single agent is relatively low, a problem shared by the vast majority of targeted agents. Here, we searched for novel copanlisib-based combinations. Copanlisib was tested as a single agent, in combination with an additional 17 drugs in 26 cell lines derived from mantle cell lymphoma (MCL), marginal zone lymphoma (MZL), and T-cell lymphomas. In vivo experiments, transcriptome analyses, and immunoblotting experiments were also performed. Copanlisib as a single agent showed in vitro dose-dependent antitumor activity in the vast majority of the models. Combination screening identified several compounds that synergized with copanlisib. The strongest combination was with the B-cell lymphoma 2 (BCL2) inhibitor venetoclax. The benefit of the combination over single agents was also validated in an MZL xenograft model and in MCL primary cells, and was due to increased induction of apoptosis, an effect likely sustained by the reduction of the antiapoptotic proteins myeloid cell leukemia 1 (MCL1) and BCL-XL, observed in MCL and MZL cell lines, respectively. These data supported the rationale for the design of the Swiss Group for Clinical Cancer Research (SAKK) 66/18 phase 1 study currently exploring the combination of copanlisib and venetoclax in relapsed/refractory lymphomas.

Chemotherapy-Free Management of Follicular and Marginal Zone Lymphoma

Many patients with follicular (FL) or marginal zone lymphoma (MZL) are not eligible to receive immunochemotherapy due to advanced age or comorbidities. Recent innovations in the treatment of these indolent lymphomas provide options for multiple lines of chemotherapy-free management. More research is needed to determine which older patients are best served by a chemotherapy-free approach in the context of geriatric vulnerabilities. In the first line, regardless of disease burden, rituximab monotherapy can provide high rates of disease control with minimal toxicity, while judicious use of brief maintenance extends the duration of response. Radioimmunotherapy using ibritumomab tiuxetan is an effective and safe post-rituximab consolidation for older patients who have <25% bone marrow involvement. The combination of rituximab and lenalidomide, although “chemotherapy-free”, does not improve tolerability over immunochemotherapy. However, studies support lower doses and shorter duration of lenalidomide exposure as a means to improve safety without materially compromising efficacy for older individuals. Extranodal MZL can often be effectively controlled with low-dose radiation therapy, and splenic MZL has excellent outcomes with rituximab monotherapy. For many patients with relapsed FL/MZL, simple retreatment with anti-CD20 antibodies will prove sufficient. Other currently available options for relapsed/refractory disease include ibritumomab tiuxetan, lenalidomide with rituximab, umbralisib as a potentially less toxic PI3K inhibitor, ibrutinib (for MZL), and tazemetostat (for FL, especially with EZH2 mutation). Emerging data with novel forms of immunotherapy (antibody-drug conjugates like polatuzumab vedotin or loncastuximab tesirine; T-cell-engaging bispecific antibodies like mosunetuzumab or epcoritamab; and chimeric antigen receptor CAR T-cells like axicabtagene ciloleucel) suggest that immune-directed approaches can produce very high and potentially durable responses in FL/MZL with limited toxicities, further obviating the need for chemotherapy.

PI3K Inhibitors in Cancer: Clinical Implications and Adverse Effects

The phospatidylinositol-3 kinase (PI3K) pathway is a crucial intracellular signaling pathway which is mutated or amplified in a wide variety of cancers including breast, gastric, ovarian, colorectal, prostate, glioblastoma and endometrial cancers. PI3K signaling plays an important role in cancer cell survival, angiogenesis and metastasis, making it a promising therapeutic target. There are several ongoing and completed clinical trials involving PI3K inhibitors (pan, isoform-specific and dual PI3K/mTOR) with the goal to find efficient PI3K inhibitors that could overcome resistance to current therapies. This review focuses on the current landscape of various PI3K inhibitors either as monotherapy or in combination therapies and the treatment outcomes involved in various phases of clinical trials in different cancer types. There is a discussion of the drug-related toxicities, challenges associated with these PI3K inhibitors and the adverse events leading to treatment failure. In addition, novel PI3K drugs that have potential to be translated in the clinic are highlighted.

Cardiovascular toxicity of PI3Kα inhibitors

The phosphoinositide 3-kinases (PI3Ks) are a family of intracellular lipid kinases that phosphorylate the 3'-hydroxyl group of inositol membrane lipids, resulting in the production of phosphatidylinositol 3,4,5-trisphosphate from phosphatidylinositol 4,5-bisphosphate. This results in downstream effects, including cell growth, proliferation, and migration. The heart expresses three PI3K class I enzyme isoforms (α, β, and γ), and these enzymes play a role in cardiac cellular survival, myocardial hypertrophy, myocardial contractility, excitation, and mechanotransduction. The PI3K pathway is associated with various disease processes but is particularly important to human cancers since many gain-of-function mutations in this pathway occur in various cancers. Despite the development, testing, and regulatory approval of PI3K inhibitors in recent years, there are still significant challenges when creating and utilizing these drugs, including concerns of adverse effects on the heart. There is a growing body of evidence from preclinical studies revealing that PI3Ks play a crucial cardioprotective role, and thus inhibition of this pathway could lead to cardiac dysfunction, electrical remodeling, vascular damage, and ultimately, cardiovascular disease. This review will focus on PI3Kα, including the mechanisms underlying the adverse cardiovascular effects resulting from PI3Kα inhibition and the potential clinical implications of treating patients with these drugs, such as increased arrhythmia burden, biventricular cardiac dysfunction, and impaired recovery from cardiotoxicity. Recommendations for future directions for preclinical and clinical work are made, highlighting the possible role of PI3Kα inhibition in the progression of cancer-related cachexia and female sex and pre-existing comorbidities as independent risk factors for cardiac abnormalities after cancer treatment.

Targeted Treatment of Follicular Lymphoma

Follicular lymphoma (FL) is the most common indolent B-cell lymphoma. Advanced stage disease is considered incurable and is characterized by a prolonged relapsing/remitting course. A significant minority have less favorable outcomes, particularly those with transformed or early progressive disease. Recent advances in our understanding of the unique genetic and immune biology of FL have led to increasingly potent and precise novel targeted agents, suggesting that a chemotherapy-future may one day be attainable. The current pipeline of new therapeutics is unprecedented. Particularly exciting is that many agents have non-overlapping modes of action, offering potential new combinatorial options and synergies. This review provides up-to-date clinical and mechanistic data on these new therapeutics. Ongoing dedicated attention to basic, translational and clinical research will provide further clarity as to when and how to best use these agents, to improve efficacy without eliciting unnecessary toxicity.

Lenalidomide in follicular lymphoma

Lenalidomide is an immunomodulatory drug approved in the United States for use with rituximab in patients with relapsed/refractory follicular lymphoma. We reviewed data from trials addressing the safety and efficacy of lenalidomide alone and in combination with rituximab as a first-line therapy and as a treatment of patients with relapsed/refractory follicular lymphoma. Lenalidomide-rituximab has been demonstrated to be an effective chemotherapy-free therapy that improves upon single-agent rituximab and may become an alternative to chemoimmunotherapy.

Copanlisib in the Treatment of Relapsed Follicular Lymphoma: Utility and Experience from the Clinic

The phosphatidylinositol-3-kinase (PI3K) pathway is ubiquitous to multiple cellular processes and is intricately implicated in lymphomagenesis. The development of PI3K inhibitors has broadened treatment options for relapsed and/or refractory follicular lymphoma (FL) and currently three PI3K inhibitors have been approved in the third-line setting for FL, including idelalisib (oral), duvelisib (oral), and copanlisib (intravenous), with other agents under investigation. In this review, we discuss the clinical advance of copanlisib through preclinical to Phase III trials, its unique cellular targets and side effect profile that have poised it as a safer and equally efficacious option when compared to the older-generation oral PI3Kis, and its utility to the clinician as part of the therapeutic armamentarium for relapsed and/or refractory FL.

ADCs, BiTEs, CARs, and Small Molecules: A New Era of Targeted Therapy in Non-Hodgkin Lymphoma

Novel immunotherapies and small molecular inhibitors are transforming our approach to previously treated and newly diagnosed patients across the spectrum of non-Hodgkin lymphomas (NHLs). Anti-CD19 CAR T cells are now indicated for the treatment of relapsed/refractory aggressive B-cell lymphomas after at least two previous lines of therapy in which durable remissions are achieved in approximately 40% of previously incurable patients. Second-line chemoimmunotherapy remains the standard of care at first relapse, but poor outcomes with conventional treatment in this setting creates an appealing rationale for earlier use of CAR T cells, which is currently under investigation, along with even earlier use in selected high-risk patients in the frontline setting. Other emerging immunotherapies include antibody-drug conjugates (ADCs), such as polatuzumab vedotin for multiple-relapsed diffuse large B-cell lymphoma (DLBCL) in combination with bendamustine-rituximab. Multiple bispecific antibodies that bring malignant B cells in contact with effector T cells appear promising in early clinical trials and will likely emerge as off-the-shelf immunotherapy options. Chemotherapy-free small molecule-based regimens are increasingly available for mantle cell (MCLs) and follicular lymphomas (FLs). Bruton tyrosine kinase inhibitors (BTKi) now represent standard second-line therapy for MCL and are being investigated in combination and as initial therapy. Lenalidomide-rituximab is an active regimen in both FL and MCL and may be used in either relapsed/refractory or previously untreated disease. Three PI3K inhibitors are approved for multiple-relapsed FL and can induce durable remissions in patients with chemotherapy- and rituximab-refractory disease. Additional emerging targeted therapies include BCL2 inhibition in MCL and EZH2 inhibition in FL.

Managing toxicities of phosphatidylinositol-3-kinase (PI3K) inhibitors

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.

The role of PI3K inhibitors in the treatment of malignant lymphomas

Deregulated phosphatidylinositide 3-kinase (PI3K) signaling plays a crucial role in the biology of different lymphoma entities leading to the proliferation and survival of the malignant cells. Due to novel treatment options and modern supportive care, the outcome of patients with lymphomas has significantly improved in the past years. However, patients with relapsed or refractory disease still have a limited prognosis. PI3K inhibitors represent a modern and effective therapeutic option for patients with different types of lymphoma. However, the efficacy of PI3K inhibitors varies among lymphoma entities. Additionally, severe toxicity including infectious and autoimmune complications leading to therapy-related deaths has been observed. Next-generation PI3K inhibitors show promising efficacy and manageable toxicity profiles. Future research might identify effective combinatorial therapy approaches for PI3K inhibitors to further improve response rates. This review discusses the most recent developments in the field of PI3K inhibition in different subtypes of lymphoma.

Toxicity patterns of novel PI3K combinations in patients with non-Hodgkin lymphoma

Phosphoinositide-3-kinase (PI3K) inhibitors have efficacy in lymphoid malignancies; however, inflammatory and infectious toxicities can compromise the treatment course. An improved understanding of these toxicities will guide clinical use and further development. We evaluated the occurrence of treatment-related adverse events (AEs) in a retrospective review of 79 patients treated in standard fashion with PI3K inhibitor monotherapy or with anti-CD20 monoclonal antibodies or as part of a novel combination regimen. Patients treated with a novel combination were at a higher risk of developing a severe AE compared to those treated with standard therapy (HR 1.89, 95% CI 1.02, 3.49; p = .04). Additionally, previously untreated patients were at higher risk of developing a severe AE compared to previously treated patients (HR 3.19, 95% CI 1.48, 6.84; p = .003). These results caution against the use of untested PI3K inhibitor combinations in routine practice and suggest that early phase clinical trials should utilize conservative treatment schemas.

SHC014748M, a novel selective inhi-bitor of PI3Kδ, demonstrates promising preclinical antitumor activity in B cell lymphomas and chronic lymphocytic leukemia

•

SHC014748M was proved to be more selective for PI3Kδ inhibition relative to other class i PI3K enzymes.

•

SHC014748M showed in vitro activity in most of 23 B lymphoma cell lines and primary CLL cells and also inhibited phosphorylation of AKT, targets downstream of PI3Kδ.

•

In vivo study revealed that SHC014748M significantly reduced lymphoma cell growth in the treatment group compared with control mice.

•

SHC014748M seemed to be a novel promising compound in the treatment of B cell lymphomas and CLL.

PI3Kδ (phosphatidylinositol 3-kinase-δ), one of the class I PI3Ks, is found expressed primarily in leukocytes and plays an essential role in B-cell development and function. This provides a rationale for the development of small molecule inhibitors that selectively target p110δ for patients with indolent non-Hodgkin lymphomas. Here in this paper, we comprehensively evaluated the in vitro and in vivo antitumor activity of SHC014748M, an oral selective inhibitor of PI3Kδ under Phase I clinical evaluation. Biochemical and cell-based assays were used to measure compound potency and selectivity in lymphoma cell lines as well as primary chronic lymphocytic leukemia (CLL) cells. Scid mice were subcutaneously inoculated with the SU-DHL-6 cell line. SHC014748M was more selective for PI3Kδ inhibition relative to other class I PI3K enzymes and showed in vitro activity in most of 23 B lymphoma cell lines and primary CLL cells. SHC014748M also inhibited phosphorylation of AKT, targets downstream of PI3Kδ, in both lymphoma cells and primary CLL cells. In vivo study revealed that SHC014748M significantly reduced lymphoma cell growth in the treatment group compared with control mice. CCL4, CCL17, CCL22 and CXCL13 in patient serum decreased sharply after SHC014748M treatment. According to the results, SHC014748M appeared to be a novel promising compound in the treatment of B cell lymphomas and CLL.

Infections in patients with lymphoproliferative diseases treated with targeted agents: SEIFEM multicentric retrospective study

We describe the opportunistic infections occurring in 362 patients with lymphoproliferative disorders treated with ibrutinib and idelalisib in clinical practice. Overall, 108 of 362 patients (29·8%) developed infections, for a total of 152 events. Clinically defined infections (CDI) were 49·3% (75/152) and microbiologically defined infections (MDI) were 50·7% (77/152). Among 250 patients treated with ibrutinib, 28·8% (72/250) experienced one or more infections, for a total of 104 episodes. MDI were 49% (51/104). Bacterial infections were 66·7% (34/51), viral 19·6% (10/51) and invasive fungal diseases (IFD) 13·7% (7/51). Among the 112 patients treated with idelalisib, 32·1% (36/112) experienced one or more infections, for a total of 48 episodes. MDI were 54·2% (26/48). Bacterial infections were 34·6% (9/26), viral 61·5% (16/26) and IFD 3·8% (1/26). With ibrutinib, the rate of bacterial infections was significantly higher compared to idelalisib (66·7% vs. 34·6%; P = 0·007), while viral infections were most frequent in idelalisib (61·5% vs. 19·6%; P < 0·001). Although a higher rate of IFD was observed in patients treated with ibrutinib, the difference was not statistically significant (13·7% vs. 3·8% respectively; P = 0·18). Bacteria are the most frequent infections with ibrutinib, while viruses are most frequently involved with idelalisib.

The safety of available chemo-free treatments for mantle cell lymphoma

INTRODUCTION

Conventional treatment for mantle cell lymphoma (MCL) patients includes regimens combining rituximab with other cytotoxic drugs, followed or not by consolidation with autologous stem cell transplantation and rituximab maintenance. However, older, unfit, and relapsed/refractory patients are often ineligible for intense treatment. Currently, available new targeted treatment options seem to offer hope in this group of patients.

AREAS COVERED

This article reviews the safety profiles of new therapeutic chemotherapy-free options for MCL patients. Publications in English from 2010 through June 2020 were surveyed on the MEDLINE database for articles. Proceedings of the American Society of Hematology during the last 5 years were also included.

EXPERT OPINION

MCL is a clinically heterogenous disease predominantly affecting elderly patients. Its variable clinical course requires personalization and individualization of treatment to achieve optimal survival and acceptable safety profiles, especially in poor prognosis patients. Results of clinical trials performed in the past decade indicated that novel drugs used as a single agent or as part of a conventional chemotherapeutic treatment offer promise in minimalizing the relapse rate for MCL and may allow more effective and safer treatment options by reducing the risk of adverse events, especially cytopenias and infections.

Safety considerations with targeted therapy drugs for B-cell non-Hodgkin lymphoma

INTRODUCTION

B-cell non-Hodgkin lymphomas (B-NHLs) are the most frequent hematologic malignant cancers. Molecular targeted therapy is an important aspect of B-NHL treatment alongside cytotoxic chemotherapy, radiotherapy, and immunotherapy.

AREAS COVERED

Molecular targeted therapies have changed the landscape of treatment strategies for B-NHLs since the approval of rituximab, an anti-CD20 monoclonal antibody, by the US Food and Drug Administration in 1997. Currently, several targeted therapies have been approved or are in the later-phase of clinical trials including naked antibodies, antibody-drug conjugates, and small molecules, such as Bruton's tyrosine kinase (BTK) inhibitors, phosphatidylinositol 3-kinase (PI3 K) inhibitors, enhancer of zeste homolog 2 (EZH2) inhibitors, and B-cell lymphoma 2 (Bcl-2) inhibitors. These drugs have various toxicities because of their unique mechanisms of action. In this review, the available toxicity data of the targeted therapies for B-NHLs have been summarized.

EXPERT OPINION

Recent clinical developments of targeted therapies for B-NHLs have provided several useful effective therapeutic options for patients. However, there are unique toxicities that need to be resolved. It is necessary to find out the toxicity mechanism; optimal treatment strategy for these toxicities; and novel targeted therapies that might potentially overcome the toxicities of previously approved targeted therapies.

Exploring a Future for PI3K Inhibitors in Chronic Lymphocytic Leukemia

PURPOSE OF REVIEW

Treatment for chronic lymphocytic leukemia has changed substantially in the past decade with an increasing shift towards use of targeted therapies, in particular agents targeting the B cell receptor pathway. Inhibition of PI3K, downstream of the B cell receptor pathway, represents an active therapeutic strategy in CLL. Here, we explore the relevance of PI3K inhibition in CLL, examine efficacy and toxicity of approved PI3K inhibitors in CLL, examine barriers to use of PI3K inhibitors, and explore strategies to optimize use of PI3K inhibitors in CLL.

RECENT FINDINGS

Current generation PI3K inhibitors are active agents in CLL but their use may be limited by immune-mediated toxicities. Clinical trials of next generation PI3K inhibitors are ongoing and early data suggests these agents are highly active with potentially differentiated toxicity profiles. Furthermore, alternative dosing schedules may reduce toxicities of these agents. Inhibition of PI3K remains an important strategy in management of CLL and novel approaches to limit toxicities of PI3K inhibitors represent an important area of clinical research in CLL.

Efficacy and safety of idelalisib for the treatment of indolent B-cell malignancies

INTRODUCTION

The outcome of patients with lymphoid malignancies has markedly improved in recent years due to the implementation of new therapeutic options. Chronic lymphocytic leukemia (CLL) and indolent B-cell non-Hodgkin lymphomas (NHL) are characterized by the activation of the phosphatidylinositol 3-kinase (PI3 K) pathway via B-cell receptor signaling. The PI3 K delta (PI3 Kδ) p110δ isoform inhibitor, idelalisib, showed high anti-tumor activity in this group of tumors. It was the first agent from a new class of isoform-specific inhibitors to receive regulatory approvals for the treatment of refractory/relapsed CLL, as well as small lymphocytic lymphoma and follicular lymphoma.

AREAS COVERED

In this paper, the authors provide a comprehensive overview of the activity and safety profile of idelalisib and other, newly developed PI3 K inhibitors in patients with indolent B-cell malignancies.

EXPERT OPINION

Idelalisib is a very potent anti-lymphoma agent in CLL and other NHL. However, there are some limitations of its broad clinical use according to some important side effects observed during treatment. Consequently, the development of new PI3 K inhibitors, which will be highly active and possess better safety profiles are warranted.

PI3Kα in cardioprotection: Cytoskeleton, late Na+ current, and mechanism of arrhythmias

PI 3-kinase α (PI3Kα) is a lipid kinase that converts phosphatidylinositol-4,5-bisphosphate (PIP2) to phosphatidylinositol-3,4,5-triphosphate (PIP3). PI3Kα regulates a variety of cellular processes such as nutrient sensing, cell cycle, migration, and others. Heightened activity of PI3Kα in many types of cancer made it a prime oncology drug target, but also raises concerns of possible adverse effects on the heart. Indeed, recent advances in preclinical models demonstrate an important role of PI3Kα in the control of cytoskeletal integrity, Na⁺ channel activity, cardioprotection, and prevention of arrhythmias.

PI3K Inhibitors and Their Role as Novel Agents for Targeted Therapy in Lymphoma

OPINION STATEMENT

Phosphatidylinositol 3-kinase (PI3K) inhibitors represent a novel class of agents targeting the key cellular regulatory PI3K/AKT/mTOR pathway involved in crucial functions such as cellular proliferation, cell cycle regulation, protein synthesis, and cell motility. This review starts with an overview of the PI3K pathway and the rationale for its targeting in lymphoma and potential on-target side effects of PI3K inhibition. With three agents now FDA approved for the treatment of relapsed and refractory (R/R) indolent non-Hodgkin lymphoma (iNHL), idelalisib, copanlisib, and duvelisib, we aim to review the pivotal trials leading to their approval as well as their clinical applications according to lymphoma subtypes. Important treatment-related adverse events are also reviewed and a perspective on the clinical role of these agents is provided, as well as some practical guidance on how to prevent, monitor, and manage potential adverse events in the clinic. PI3K inhibitors have an established role in the management of R/R iNHL, but their use and development are hampered by adverse events, particularly when used in combination with other anti-lymphoma therapies. Finally, this review highlights areas in need of more research in order to optimally use these agents in the care of patients with lymphoma.

Advances in targeted therapy for malignant lymphoma

The incidence of lymphoma has gradually increased over previous decades, and it ranks among the ten most prevalent cancers worldwide. With the development of targeted therapeutic strategies, though a subset of lymphoma patients has become curable, the treatment of refractory and relapsed diseases remains challenging. Many efforts have been made to explore new targets and to develop corresponding therapies. In addition to novel antibodies targeting surface antigens and small molecular inhibitors targeting oncogenic signaling pathways and tumor suppressors, immune checkpoint inhibitors and chimeric antigen receptor T-cells have been rapidly developed to target the tumor microenvironment. Although these targeted agents have shown great success in treating lymphoma patients, adverse events should be noted. The selection of the most suitable candidates, optimal dosage, and effective combinations warrant further investigation. In this review, we systematically outlined the advances in targeted therapy for malignant lymphoma, providing a clinical rationale for mechanism-based lymphoma treatment in the era of precision medicine.

First-in-Human Study of Utomilumab, a 4-1BB/CD137 Agonist, in Combination with Rituximab in Patients with Follicular and Other CD20+ Non-Hodgkin Lymphomas

PURPOSE

In this phase I study (NCT01307267), we evaluated safety, pharmacokinetics, clinical activity, and pharmacodynamics of treatment with utomilumab plus rituximab in patients with relapsed/refractory follicular lymphoma (FL) and other CD20⁺ non-Hodgkin lymphomas (NHL).

PATIENTS AND METHODS

Primary objectives were to assess treatment safety and tolerability for estimating the MTD, using a modified time-to-event continual reassessment method, and selecting the recommended phase II dose (RP2D).

RESULTS

Sixty-seven patients received utomilumab (0.03-10.0 mg/kg every 4 weeks) and rituximab (375 mg/m² weekly) in the dose-escalation groups or utomilumab (1.2 mg/kg every 4 weeks) plus rituximab in the dose-expansion cohort. No patient experienced dose-limiting toxicity. The MTD for utomilumab in combination with rituximab was not reached and estimated to be ≥10 mg/kg every 4 weeks. The majority of the utomilumab treatment-related adverse events (AE) were grade 1 to 2; the most common AE was fatigue (16.4%). The pharmacokinetics of utomilumab in combination with rituximab was linear in the 0.03 to 10 mg/kg dose range. A low incidence (1.5%) of treatment-induced antidrug antibodies against utomilumab was observed. The objective response rate was 21.2% (95% CI, 12.1%-33.0%) in all patients with NHL, including four complete and 10 partial responses. Analysis of paired biopsies from a relapsed/refractory FL patient with complete response showed increased T-cell infiltration and cytotoxic activity in tumors. Biomarker correlations with outcomes suggested that clinical benefit may be contingent on patient immune function.

CONCLUSIONS

Utomilumab in combination with rituximab demonstrated clinical activity and a favorable safety profile in patients with CD20⁺ NHLs.

Therapeutic potential of PI3K signaling in distinct entities of B-cell lymphoma

Introduction: Aberrant phosphatidylinositide 3-kinase (PI3K) signaling drives survival and proliferation of malignant B-cells of different lymphoma entities. Thus, inhibition of PI3K isoforms represents a novel and promising therapeutic approach for the treatment of patients with B-cell lymphomas.Areas covered: Here the authors provide an overview about the PI3K signaling pathway as well as available preclinical and clinical results of different PI3K inhibitors in both indolent and aggressive lymphoma entities.Expert opinion: PI3K inhibitors have shown to be efficacious in different entities of B-cell lymphoma, at this stage particularly in relapsed/refractory settings. However, responses of PI3K inhibitors widely vary among different lymphomas. Additionally, especially infectious and immune-mediated toxicities limit their use at this stage. Thus, the decision to use PI3K inhibitors needs to be balanced between the potential efficacy and associated toxicities as well as the availability of other therapeutic options. Future research might eventually lead to the stratification of patients according to the specific oncogenic addictions of the underlying lymphoma. Additionally, PI3K inhibitors will need to be combined with other therapeutic agents for more specific and effective treatment regimens.

The Role of PI3K Inhibition in Lymphoid Malignancies

PURPOSE OF REVIEW

The outcome of patients with lymphoid malignancies has markedly improved in recent years which is likely due to a combination of advances in supportive care, and therapeutic options. In this article, we will provide an overview over the role PI3-kinase signalling, one of the most important dysregulated pathways in cancer, and its successful inhibition in lymphoma.

RECENT FINDINGS

PI3-kinase inhibitors have shown remarkable activity in an increasing subset of patients with non-Hodgkin lymphomas. The first drug to be approved was idelalisib for patients with relapsed/refractory follicular lymphoma and CLL/SLL as monotherapy, or in combination with rituximab, respectively. After an initial setback related to increased toxicity including deaths observed in several upfront studies, there has been a resurgence in interest in this pathway following the promising efficacy of second-generation PI3K inhibitors including in patients with T cell lymphomas. PI3K inhibition continues to be an invaluable tool in the therapy of patients with lymphoid malignancies if managed cautiously. Preclinical models are helpful in predicting possible side effects and identifying new lymphoma subtypes that may be susceptible to this class of agents. The future will likely involve rationally designed combinatorial approaches to deepen the response rate and prevent the emergence of resistance.

Clinical Pharmacokinetic and Pharmacodynamic Considerations in Treating Non-Hodgkin Lymphoma

Non-Hodgkin lymphoma (NHL) includes a variety of closely related malignancies that originate from lymphoid precursors. The majority of NHLs are of B-cell lineage, for which traditional therapy involves chemotherapy in combination with the anti-CD20 monoclonal antibody rituximab. Ongoing research into the pathogenesis of NHL subtypes has given rise to the use of novel agents that target specific molecular pathways. While the incidence of NHL extends over a range of ages from pediatric to elderly settings, the majority of diagnoses occur over age 60 years. Increasing the use of concomitant medication coupled with declining organ function among this group of patients creates pharmacokinetic (PK) challenges in administering a number of agents involved in the treatment of NHL. In addition, since many of the new agents are administered orally, there are a number of added PK factors that must be taken into consideration with their prescribing and administration. This article will review the available literature on the PK and pharmacodynamic properties of agents commonly used in the treatment of NHL, and intends to provide information that can assist with properly using these drugs in this setting.

How I manage patients with follicular lymphoma

Recent advances in the treatment of follicular lymphoma (FL) have provided insight into molecular and biological influences on pathogenesis and prognosis. Additionally, numerous available treatment strategies for both newly diagnosed and relapsed disease require thoughtful consideration of patient selection to avoid the burden of overtreatment and toxicities. This review provides a broad overview on our approach to managing patients with low grade FL.

Evolution of CLL treatment - from chemoimmunotherapy to targeted and individualized therapy

During the past 5 years, a number of highly active novel agents, including kinase inhibitors targeting BTK or PI3Kδ, an antagonist of the antiapoptotic protein BCL-2, and new anti-CD20 monoclonal antibodies, have been added to the therapeutic armamentarium for patients with chronic lymphocytic leukaemia (CLL). In these exciting times, care is needed to optimally integrate these novel agents into the traditional treatment algorithm without overlooking or compromising the benefits of established treatments, especially chemoimmunotherapy. A more personalized approach to CLL therapy that takes into account individual risk factors, patient characteristics, and their treatment preferences is now possible. Herein, we discuss the biological basis for the novel therapeutic agents and outline not only the major advantages of these agents over traditional therapies but also their adverse effects and the rationale for continued use of older versus newer types of therapy for selected patients with CLL. We conclude by providing recommendations for an individualized therapy approach for different populations of patients with CLL.

Cancer drug development: The missing links

IMPACT STATEMENT

The success rate for cancer drugs which enter into phase 1 clinical trials is utterly less. Why the vast majority of drugs fail is not understood but suggests that pre-clinical studies are not adequate for human diseases. In 1975, as per the Tufts Center for the Study of Drug Development, pharmaceutical industries expended 100 million dollars for research and development of the average FDA approved drug. By 2005, this figure had more than quadrupled, to $1.3 billion. In order to recover their high and risky investment cost, pharmaceutical companies charge more for their products. However, there exists no correlation between drug development cost and actual sale of the drug. This high drug development cost could be due to the reason that all patients might not respond to the drug. Hence, a given drug has to be tested in large number of patients to show drug benefits and obtain significant results.

Prolonged survival in the absence of disease-recurrence in advanced-stage follicular lymphoma following chemo-immunotherapy: 13-year update of the prospective, multicenter randomized GITMO-IIL trial

A prospective trial conducted in the period 2000-2005 showed no survival advantage for high-dose chemotherapy with rituximab and autograft (R-HDS) versus conventional chemotherapy with rituximab (CHOP-R) as first-line therapy in 134 high-risk follicular lymphoma patients aged <60 years. The study has been updated at the 13-year median follow up. As of February 2017, 88 (66%) patients were alive, with overall survival of 66.4% at 13 years, without a significant difference between R-HDS (64.5%) and CHOP-R (68.5%). To date, 46 patients have died, mainly because of disease progression (47.8% of all deaths), secondary malignancies (3 solid tumor, 9 myelodysplasia/acute leukemia; 26.1% of all deaths), and other toxicities (21.7% of all deaths). Complete remission was documented in 98 (73.1%) patients and associated with overall survival, with 13-year estimates of 77.0% and 36.8% for complete remission versus no-complete remission, respectively. Molecular remission was documented in 39 (65%) out of 60 evaluable patients and associated with improved survival. In multivariate analysis, complete remission achievement had the strongest effect on survival (P<0.001), along with younger age (P=0.002) and female sex (P=0.013). Overall, 50 patients (37.3%) survived with no disease recurrence (18 CHOP-R, 32 R-HDS). This follow up is the longest reported on follicular lymphoma treated upfront with rituximab-chemotherapy and demonstrates an unprecedented improvement in survival compared to the pre-rituximab era, regardless of the use of intensified or conventional treatment. Complete remission was the most important factor for prolonged survival and a high proportion of patients had prolonged survival in their first remission, raising the issue of curability in follicular lymphoma. (Registered at clinicaltrials.gov identifier: 00435955)

Infections associated with immunotherapeutic and molecular targeted agents in hematology and oncology. A position paper by the European Conference on Infections in Leukemia (ECIL)

A multitude of new agents for the treatment of hematologic malignancies has been introduced over the past decade. Hematologists, infectious disease specialists, stem cell transplant experts, pulmonologists and radiologists have met within the framework of the European Conference on Infections in Leukemia (ECIL) to provide a critical state-of-the-art on infectious complications associated with immunotherapeutic and molecular targeted agents used in clinical routine. For brentuximab vedotin, blinatumomab, CTLA4- and PD-1/PD-L1-inhibitors as well as for ibrutinib, idelalisib, HDAC inhibitors, mTOR inhibitors, ruxolitinib, and venetoclax, a detailed review of data available until August 2018 has been conducted, and specific recommendations for prophylaxis, diagnostic and differential diagnostic procedures as well as for clinical management have been developed.

Targeting PI3K in cancer: mechanisms and advances in clinical trials

Phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling is one of the most important intracellular pathways, which can be considered as a master regulator for cancer. Enormous efforts have been dedicated to the development of drugs targeting PI3K signaling, many of which are currently employed in clinical trials evaluation, and it is becoming increasingly clear that PI3K inhibitors are effective in inhibiting tumor progression. PI3K inhibitors are subdivided into dual PI3K/mTOR inhibitors, pan-PI3K inhibitors and isoform-specific inhibitors. In this review, we performed a critical review to summarize the role of the PI3K pathway in tumor development, recent PI3K inhibitors development based on clinical trials, and the mechanisms of resistance to PI3K inhibition.

Lenalidomide for the treatment of mantle cell lymphoma

INTRODUCTION

Although a variety of therapeutic schemes for Mantle Cell Lymphoma (MCL) have been attempted, the clinical outcome of patients continues to be unsatisfactory especially among patients with a very high-risk profile and in the relapsed/refractory setting. For this reason, recent clinical trials have explored novel approaches, either by the use of biological agents in chemotherapy-free schedules or by integrating them with chemoimmunotherapy regimens. Areas covered: The efficacy of lenalidomide monotherapy and combination therapy established in clinical studies mainly involving relapsed/refractory MCL is reviewed. The mechanism of action of lenalidomide is also discussed. Furthermore, the current position of lenalidomide in the MCL treatment algorithm is debated. Expert opinion: Lenalidomide demonstrated high efficacy and tolerability in several clinical trials as well as in retrospective real-world reports, even in patients who relapsed or were resistant to bortezomib and ibrutinib. In 2013, lenalidomide was approved by the Food and Drug Administration (FDA) for relapsed/refractory MCL after two prior therapies including at least one prior treatment with bortezomib. However, the potential synergistic anti-neoplastic effects of lenalidomide in combination with other biological agents, i.e. ibrutinib and venetoclax, especially in the management of p53-mutated cases, still remain an open issue.

New Treatment Options in Advanced Stage Follicular Lymphoma

Follicular lymphoma is one of the most common non-Hodgkin's lymphomas with an expected survival of more than 20 years for the majority of patients. This impressive outcome has been achieved with the introduction of immunochemotherapy, as first line treatment with remissions lasting over 8 years, followed by other treatment options at first or subsequent relapse. However, certain groups of patients still have a poor prognosis. In recent years the efficacy of chemotherapy regimens has been augmented by new compounds selectively targeting the cell surface, intracellular pathways, and/or the microenvironment. Some of these are beginning to change the therapeutic landscape. This review summarizes prognostic factors in follicular lymphoma in order to identify patients with greatest medical need for these new treatment options and reviews recent data from prospective clinical studies testing new agents in first-line and relapsed follicular lymphoma. Finally, we assess the current role of immunochemotherapy and discuss the requirements for future clinical trials.

Novel immunotherapy approaches to follicular lymphoma

Follicular lymphoma (FL) remains a lymphoma subtype that is remarkably sensitive to immunotherapy-based treatment strategies. Anti-CD20 antibody therapy administered as a single agent and in combination as a first-line treatment and at relapse continues to be the most broadly used therapy for this disease. Autologous and allogeneic stem cell transplantation provide meaningful durable remissions for patients with FL. However, identifying the most suitable patients and the optimal timing for these approaches has become increasingly challenging with the advent of novel therapies. Lenalidomide and phosphatidylinositol 3-kinase inhibitors are emerging as agents that can be applied in the relapsed setting. Other immunotherapy approaches, including checkpoint inhibitors and chimeric antigen receptor T cells, appear promising but remain experimental. Utilization of all forms of immunotherapy requires careful consideration of the unique toxicities associated with these agents and the means to mitigate them by selection of appropriate patients, optimal timing, and the use of supportive care.