Tumor Lysis Syndrome in Chronic Lymphocytic Leukemia with Novel Targeted Agents

Current Approaches and Novel Agents in the Treatment of Chronic Lymphocytic Leukemia

The treatment of CLL has evolved from traditional chemoimmunotherapy (CIT) to an increasing number of targeted and biologic approaches. Randomized trials have demonstrated superiority of covalent bruton tyrosine kinase inhibitors (cBTKis) over CIT, and second-generation compounds such as acalabrutinib and zanubrutinib appear to have a more favorable efficacy/safety profile than ibrutinib. The noncovalent BTKi, pirtobrutinib, has shown impressive activity after failure of the cBTKis and is quite tolerable. The Bcl-2 inhibitor venetoclax plus a CD20, generally obinutuzumab, provides a high level of efficacy as initial treatment or after failure on a cBTKi, with many patients achieving a state of undetectable minimal residual disease. Promising novel approaches include BTK degraders, bispecific antibodies, and chimeric antigen receptor T-cell (CAR-T)-cell therapy. What is clear is that CIT is archaic, and current and future targeted approaches will continue to improve the outcome for patients with chronic lymphocytic leukemia.

Assessing the risk of tumor lysis syndrome associated with the use of antineoplastic agents: a real-world pharmacovigilance study based on the FDA Adverse Event Reporting System database

Background

The use of antineoplastic agents is one of the important triggers of tumor lysis syndrome (TLS), but there is still a lack of comprehensive understanding of antineoplastic agents that may trigger TLS and the TLS risk differences between different antineoplastic agents.

Objectives

This study aims to investigate the TLS risk of different antineoplastic agents and provide reference information for clinical practice.

Design

Real-world adverse events data in the FDA Adverse Event Reporting System (FAERS) database were used as the basis for the disproportionality analysis.

Methods

We reviewed the TLS reports in the FAERS database from 2004 to 2022 to summarize an antineoplastic agent list that was reported to trigger TLS, based on which we conducted disproportionality analysis to assess the TLS risk of each antineoplastic agent.

Results

In all, 164 antineoplastic agents were reported to trigger TLS. On the whole, rituximab was the most reported antineoplastic agent in TLS reports, followed by cyclophosphamide, venetoclax, doxorubicin, and etoposide, while tagraxofusp was the antineoplastic agent with the highest adverse drug reaction (ADR) signal strength in signal detection, followed by floxuridine, pentostatin, tebentafusp, and venetoclax. Integrating ADR signal detection results, 129 of 164 antineoplastic agents showed at least one positive ADR signal, and six antineoplastic agents (bevacizumab, carboplatin, cisplatin, fluorouracil, lenvatinib, and paclitaxel) have the highest total number of positive signals. Further classifying the 164 antineoplastic agents into 46 chemical subgroups to conduct ADR signal detection, nitrogen mustard analogs were the most reported antineoplastic agent subclasses, followed by clusters of differentiation 20 inhibitors, and pyrimidine analogs, while clusters of differentiation 22 inhibitors were the antineoplastic agent subclass with the highest ADR signal strength, followed by podophyllotoxin derivatives and actinomycines.

Conclusion

Our study showed the TLS risk characteristics of 164 antineoplastic agents by detecting and integrating ADR signals, which may help to optimize clinical practice.

Unexpected Rasburicase-Induced Hemolysis in a Patient With Normal Glucose-6-Phosphate Dehydrogenase Activity

Tumor lysis syndrome (TLS) presents significant challenges in oncology, primarily due to metabolic complications such as hyperuricemia, which can lead to acute kidney injury. Rasburicase, a recombinant urate oxidase, is frequently employed to manage hyperuricemia in TLS patients. However, its use is an absolute contraindication in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the risk of hemolysis. In this case, the patient developed hemolytic anemia post-rasburicase administration even though she had normal G6PD activity, which was confirmed on two separate occasions, including during an acute episode and 3 months later. This case is unique as it documents hemolytic anemia induced by rasburicase in a patient without G6PD deficiency, challenging current understandings of the drug's safety profile. It suggests the need for caution and thorough screening before rasburicase use, even in patients considered low risk for G6PD deficiency. The report highlights the importance of close monitoring for adverse effects and the potential for alternative mechanisms of rasburicase-induced hemolysis.

Low incidence of tumor lysis syndrome in elderly patients with chronic lymphocytic leukemia treated with venetoclax under real-world conditions: results from the prospective observational VeRVe study

Venetoclax is active in both frontline and relapsed/refractory settings for the treatment of chronic lymphocytic leukemia (CLL). Although the prevalence and severity of tumor lysis syndrome (TLS) are well characterized in clinical trials, laboratory and clinical TLS remain relatively unexplored in real-world clinical practice.In this prospective, real-world observational study, we aimed to determine the incidence and outcomes of TLS in patients with CLL receiving venetoclax outside a clinical trial. The study (VeRVe) was conducted in centers in Austria, Germany, and Switzerland.Two hundred and thirty-nine patients were treated according to local label with at least one dose of venetoclax. Patient demographics, baseline characteristics, and blood chemistry at baseline were documented, and descriptive statistical analyses were conducted.Seventy eight patients (33%) were treated with venetoclax monotherapy, 101 (42%) with venetoclax in combination with rituximab and 60 (25%) with venetoclax in combination with obinutuzumab. In all cases, the TLS risk mitigation strategy adhered to the ramp-up protocol. Median age was 73 years and 66% of patients were male. The majority of patients (75%) had relapsed/refractory CLL, 63/192 (32.8%) patients tested had a del(17p) and 93/134 (69.4%) patients tested had unmutated immunoglobulin heavy chain variable region gene (IGHV). Clinical TLS occurred in 5 patients (2.1%) and laboratory TLS occurred in 15 patients (6.3%). Ten patients received specific treatment, of which 6 were hospitalized. There were no deaths due to a TLS event and venetoclax was well-tolerated. Of the 5 clinical TLS events reported, none were fatal or resulted in renal failure (NCT03342144, registered on Nov 10, 2017).

The Safety of Novel Therapies in Chronic Lymphocytic Leukemia in the Era of Intermittent Fasting: A Pharmacology-Based Review

Intermittent fasting (IF) has recently gained popularity due to its emerging benefits in reducing weight and improving metabolic health. Concurrently, novel agents (NAs) like venetoclax and Bruton tyrosine kinase inhibitors (BTKIs) have revolutionized the treatment of chronic lymphocytic leukemia (CLL). Unfortunately, it is unclear whether the associated risks of tumor lysis syndrome (TLS) and gastrointestinal bleeding (GIB) are increased in IF practitioners receiving NAs. This review explored the literature available on the permissibility of IF in CLL patients undergoing treatment with first-line NAs (FLNAs). Literature was scoped to identify IF patterns and the available data on TLS and GIB risks associated with food and fluid intake in CLL patients receiving FLNAs. Although current evidence is insufficient to recommend IF in this population, it may be possible for patients on venetoclax to conservatively practice fluid-liberal IF, provided that adequate hydration and the consistent administration of food are achieved. In contrast, considering the significant risk of TLS and the pharmacokinetics of venetoclax, patients should be discouraged from practicing fluid-restricted IF, especially during the ramp-up phase. Moreover, patients on BTKIs ought to refrain from IF due to the possible risk of GIB until further data are available. Further research is needed to provide conclusive recommendations.

Tumor Lysis Syndrome with CD20 Monoclonal Antibodies for Chronic Lymphocytic Leukemia: Signals from the FDA Adverse Event Reporting System

BACKGROUND AND OBJECTIVE

Although tumor lysis syndrome was reported with obinutuzumab and rituximab, the association with CD20 monoclonal antibodies for chronic lymphocytic leukemia is unclear.

METHODS

A disproportionality analysis was conducted to investigate the link between CD20 monoclonal antibodies and tumor lysis syndrome by accounting for known confounders and comparing with other anticancer drugs, using data from the US Food and Drug Administration Adverse Event Reporting System. Reporting odds ratios and the information component were calculated as disproportionality measures. A stepwise sensitivity analysis was conducted to test the robustness of disproportionality signals. Bradford Hill criteria were adopted to globally assess the potential causal relationship.

RESULTS

From 2004 to 2022, 197, 368, 41, and 14 tumor lysis syndrome reports were detected for obinutuzumab, rituximab, ofatumumab, and alemtuzumab (CD52 monoclonal antibody), respectively. Disproportionality signals were found for the above four monoclonal antibodies when compared with other anticancer drugs. Sensitivity analyses confirmed robust disproportionality signals for obinutuzumab, rituximab, and ofatumumab. The median onset time was 4.5, 1.5, and 2.5 days for rituximab, obinutuzumab, and ofatumumab, respectively. A potential causal relationship was fulfilled by assessing Bradford Hill criteria.

CONCLUSIONS

This pharmacovigilance study on the FDA Adverse Event Reporting System detected a plausible association between CD20 monoclonal antibodies (but not CD52) and tumor lysis syndrome by assessing the adapted Bradford Hill criteria. Urgent clarification of drug- and patient-related risk factors is needed through large comparative population-based studies.

Rasburicase in treating tumor lysis syndrome: An umbrella review

Tumor lysis syndrome (TLS) remains a debilitating cause of hospitalization and death in patients with cancer and is a significant challenge for healthcare providers despite advancements in its management. This umbrella review analyzed the results of meta-analyses on the use of rasburicase in the treatment of patients with cancer. A literature search was performed of five databases (PubMed, Google Scholar, Cochrane Library, Scopus, Global Index Medicus, and ScienceDirect) for articles with full texts available online. A measurement tool to assess systematic reviews 2 (AMSTAR 2) was used to assess the quality of the included studies, and Review Manager software was used to conduct all statistical analyses. The systematic search identified eight relevant meta-analyses, with primary analyses including outcome data that analyzed mortality, renal failure, and comparisons with allopurinol. The pooled data showed that rasburicase effectively reduced TLS development and serum uric acid levels in children and adults with malignancies. Most outcomes did not differ significantly compared with those of allopurinol. Future trials should focus on the cost-effectiveness of rasburicase compared to that of allopurinol while including high-, intermediate-, and low-risk patients. Rasburicase is safe and effective for managing patients with TLS. However, recent large-scale meta-analyses have reported conflicting results. Most meta-analyses were graded as low to critically low as per AMSTAR 2. The analysis revealed that the benefit of rasburicase did not differ significantly from that of allopurinol, which has higher cost-effectiveness and fewer side effects.

Real-world analysis of tumor lysis syndrome in patients started on venetoclax combination for acute myeloid leukemia

INTRODUCTION

Venetoclax is utilized with low-dose cytarabine or a hypomethylating agent for the treatment of acute myeloid leukemia. Clinical trials report a risk of tumor lysis syndrome and the package insert recommends a venetoclax dose ramp-up at the initiation. The purpose of this study was to evaluate the risk of tumor lysis syndrome in a large population of patients with acute myeloid leukemia outside of a clinical trial and evaluate the incidence of hospital-acquired complications during inpatient ramp-up.

METHODS

We performed a retrospective study of adult patients with acute myeloid leukemia receiving venetoclax with a hypomethylating agent or low-dose cytarabine. The primary outcome was the incidence of tumor lysis syndrome. Secondary outcomes included risk factors for tumor lysis syndrome, length of admission, and incidence of hospital-acquired complications.

RESULTS

One hundred thirteen patients were included. Although all patients were given some form of prophylaxis, the incidence of tumor lysis syndrome was 8.8%. All were laboratory tumor lysis syndrome; one with hyperuricemia, nine with hypocalcemia, and ten with hyperphosphatemia. Six patients received sevelamer. Tumor lysis syndrome was resolved in all cases. No clinical tumor lysis syndrome occurred. Hepatic dysfunction, tumor lysis syndrome high-risk stratification, higher baseline white blood cell count, and lactate dehydrogenase levels were more common in the tumor lysis syndrome group. Hospital-acquired complications reached 13% in those directly admitted for dose ramp-up.

CONCLUSIONS

Tumor lysis syndrome was uncommon and manifested as minor lab abnormalities. White blood cell count continues to be an indicator of risk for tumor lysis syndrome. Those who present with an elevated white blood cell or are otherwise at high risk for tumor lysis syndrome should be admitted for ramp-up. Otherwise, initiation and monitoring of venetoclax are feasible in the outpatient setting.

A real-world pharmacovigilance study of FDA Adverse Event Reporting System (FAERS) events for venetoclax

BACKGROUND

Venetoclax (VEN) is the first selective small molecule Bcl-2 inhibitor approved by FDA and used in adult chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL) and some acute myeloid leukemia (AML). However, the long-term safety of VEN in large sample population was unknown. This study evaluated the adverse events (AEs) of VEN from FDA Adverse Event Reporting System (FAERS) since its approval in 2016 by data mining.

METHODS

The disproportionality analyses, including four algorithms of reporting odd ratio (ROR), proportional reporting ratio (PRR), bayesian configuration promotion neural network (BCPNN), and multi item gamma poisson shrinker (MGPS), were employed to quantify the signals of VEN-associated AEs.

RESULTS

From the FAERS database, a total of 8,379,682 reports were collected during the study period. After removing the duplication, the number of reports with VEN as the primary suspect (PS) was 19,107. The 19,107 cases of AEs involved 27 organ systems, 256 significant PTs which conforming to the four algorithms. Unexpected serious AEs, such as pleural effusion, splenic infarction, atrial fibrillation, skin squamous cell carcinoma, etc., have signals. The median time of occurrence of AEs related to VEN was 31 days (inter quartile range [IQR] 7-131 days), and half of the reported AEs occurred within 1 month after administration.

CONCLUSION

Our research has found new significant AEs signals of VEN, which improved its safety information in real-world after marketing approval, and contributed to its risk control of use in clinic.

Unusual complications in the management of chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a common, indolent disease that typically presents with a proliferation of mature, immunologically dysfunctional CD5+ B-cells which preferentially occupy the bone marrow, peripheral blood and lymphoid organs. Immune dysfunction leads to an increase in autoimmune diseases which occur in approximately 10% of patients with CLL. Autoimmune cytopenias are the most common, but other organs may be affected as well. The treatment of these conditions typically depends on the extent of CLL and severity of symptoms, but generally consists of CLL-directed therapies, immunosuppression or both. CLL may also infiltrate extranodal sites in the body. Symptomatic extranodal CLL or extranodal disease which threatens normal organ function is an indication for initiation of CLL-directed therapy. The following review summarizes autoimmune and extranodal complications that can occur in patients with CLL and our suggested approach to their treatment.

Tyrosine kinase inhibitors and tumor lysis syndrome in hematologic malignancies: A systemic review

BACKGROUND

Effective treatments for hematologic malignancies include therapies that target tyrosine kinase (TK) signaling pathways. Tumor lysis syndrome (TLS) is an oncologic emergency that can occur due to rapid turnover following the initiation of treatments for hematologic malignancy. The incidence of TLS is under-reported and it is unclear as to whether TK inhibitors (TKIs) are associated with TLS.

OBJECTIVE

To conduct a systematic review to determine the incidence of TLS with TKIs.

METHODS

A search was performed using EMBASE, MEDLINE, and Web of Science electronic databases, as well as a manual search of the American Society of Hematology and American Society of Clinical Oncology abstract databases. Keywords included: "tumor lysis syndrome," "tyrosine kinase inhibitors," "lymphoma," and "leukemia."

RESULTS

We identified a total of 57 publications that commented on the incidence of TLS with TKIs for hematologic malignancy. Thirty-nine of those publications reported TLS as an adverse event. TLS was described as an adverse event among essentially all the subclasses of TKIs that are used to manage hematologic malignancies.

CONCLUSION

The overall number of articles commenting on TLS as an adverse event is sparse and there needs to be more transparency regarding the incidence of TLS when employing newer targeted therapies. Physicians should consider the risk of TLS on an individual basis and the added risk of TLS when using TKIs to treat hematologic malignancy.

Successful treatment of relapsed chronic lymphocytic leukemia with venetoclax in a patient with severe chronic kidney disease

Venetoclax is a promising new drug for relapsed or refractory chronic lymphocytic leukemia (CLL). However, venetoclax use had not been reported in severe chronic kidney disease (CKD) patients. We report the first case of relapsed CLL in a severe CKD patient that was successfully treated with venetoclax.

Cancer Immunotherapies: What the Perioperative Physician Needs to Know

Purpose of Review

For patients with cancer, treatment may include combination therapy, including surgery and immunotherapy. Here, we review perioperative considerations for the patient prescribed immunotherapeutic agents.

Recent Findings

The perioperative period is a poignant moment in the journey of a patient with cancer, potentially deemed most influential compared to other moments in the care continuum. Several immunotherapeutic medications have been employed near the time of surgery to potentially increase effectiveness. Of the various drug classes, including immune checkpoint inhibitors, cytokines, toll-like receptor agonists, and oncolytic viruses, among others, several notable immune-related adverse effects were noted. They range from minor effects to more serious ones, such as renal failure, myocarditis, and tumor growth.

Summary

Surgery and immunotherapy are often employed in combination for primary treatment and prevention of cancer recurrence. Careful review and consideration of the pharmacokinetics, pharmacodynamics, and toxicities of immunotherapy benefit the perioperative physician and their patients.

A Rare Side Effect of Ibrutinib: Tumor Lysis Syndrome

Chronic lymphocytic leukemia (CLL) is a progressive disease with an indolent course, and tumor lysis syndrome (TLS) is rarely seen in CLL. Ibrutinib is a novel bruton kinase (BTK) inhibitor increasingly used in CLL treatment. Ibrutinib has significant side effects such as atrial fibrillation, bleeding, diarrhea, and infections. However, TLS is reported rarely with ibrutinib treatment. This report focuses on a 69-year-old female patient diagnosed with relapsed CLL who developed grade 4 TLS after ibrutinib monotherapy. The patient developed TLS on the third day of ibrutinib treatment necessitating discontinuation of the treatment and initiation of hemodialysis and supportive care. Ibrutinib treatment was re-initiated at a daily dose of 140 mg therapy after an interval of seven days, and then any additional side effect was not seen. Tumor lysis syndrome secondary to ibrutinib has been reported in an increasing number of cases. There is currently no information on managing adverse effects of TLS attributed to ibrutinib. Consequently, ibrutinib treatment of this patient was not terminated, and restarted after a short interval. It must not be forgotten that TLS secondary to ibrutinib treatment may be rarely seen, and can be life-threatening. Treatment with ibrutinib should be initiated in consideration of this side effect, and the development of complication of TLS may not necessitate discontinuation of ibrutinib treatment.

B-Cell Malignancies: The Use of Small Molecule Agents for Treatment and Management

Hematologic B-cell malignancies, which have varying behavior patterns, disease processes, and treatment responses, include non-Hodgkin lymphoma, leukemias, and myeloma. Although monoclonal antibodies and other agents have led to dramatic advances in the treatment of B-cell malignancies, the development of small molecules have enhanced the ability to treat and manage these malignancies and their adverse events (AEs). Oncology nurses need to be educated on the unique side effects for each class of these agents so that they can administer interventions to prevent and manage AEs in patients.

An Unusual Case of Prolymphocytic Leukemia Transformation in a Patient With Chronic Lymphocytic Leukemia

B-cell prolymphocytic leukemia (B-PLL) is a rare leukemia characterized by rapidly increasing leukocytosis with splenomegaly and lymphadenopathy. Treatment strategies are largely based on studies of chronic lymphocytic leukemia (CLL). Antibodies against the cell surface protein CD20 are considered to be first-line therapy. A 76-year-old male with known CLL presented 2 weeks after starting chemoimmunotherapy for newly refractory CLL after failing ibrutinib therapy. White blood cell count was elevated at 226.7 × 10³/µL. Fluorescent in situ hybridization analysis of a bone marrow specimen showed new development of complex cytogenetics. Flow cytometry revealed B cells appearing slightly dimmer on CD45 and brighter on CD20 compared with typical B-CLL suggestive of less mature lymphocyte forms. The patient was diagnosed with B-PLL and started on obinutuzumab and venetoclax with rapid normalization of white blood cells. This case recapitulates the challenges in diagnosing and treating B-PLL. Ibrutinib resistance is a growing area of study with several proposed mechanisms of acquired resistance. The pathogenesis of B-PLL is not completely understood, although mutations in MYC are presumed to play a role.

Non-overt disseminated intravascular coagulopathy associated with the first obinutuzumab administration in patients with chronic lymphocytic leukemia

Infusion-related reactions are among the worst complications of obinutuzumab (G) administration and occur predominantly during the first infusion. We reported another adverse event related to the first G infusion, a subclinical coagulopathy. We retrospectively analyzed a cohort of 13 pts with chronic lymphocytic leukemia treated with a frontline G-chlorambucil regimen. Six pts developed non-overt disseminated intravascular coagulopathy (DIC) (46%) after the first administration of G. The coagulopathy was subclinical and self-limited in all pts, not requiring any intervention apart from the suspension of anticoagulant therapy in one pt. We observed a drop in the platelet count, an elevation of D-dimer levels, and an elongation of activated partial thromboplastin time. We found a significant difference in the platelet count between the pts with DIC and those withouts; in fact, all the six pts with non-overt DIC had a platelet count greater than 100 × 10⁹ /L, while in the other group only one (p = 0.019). A trend towards a lower lymphocyte count and a higher CD20 expression was found in the pts with DIC. No other correlation between the DIC complication and the clinical or laboratory characteristics of the patients was found. The pathogenesis of the G-related non-overt DIC could be related to the consumption of the platelets after the lysis of lymphocytes, probably triggered by the damage associated molecular patterns. Despite its limitations, this study describes a new adverse event and identifies a specific subgroup of patients whose clinical management at the time of the infusion of G may need to be refined.

Prevention and Treatment of Tumor Lysis Syndrome in the Era of Onco-Nephrology Progress

Background: Tumor lysis syndrome (TLS) is an oncologic emergency due to a rapid break down of malignant cells usually induced by cytotoxic therapy, with hyperuricemia, hyperkalemia, hyperphosphatemia, hypocalcemia, and serious clinical consequences such as acute renal injury, cardiac arrhythmia, hypotension, and death. Rapidly expanding knowledge of cancer immune evasion mechanisms and host-tumor interactions has significantly changed our therapeutic strategies in hemato-oncology what resulted in the expanding spectrum of neoplasms with a risk of TLS. Summary: Since clinical TLS is a life-threatening condition, identifying patients with risk factors for TLS development and implementation of adequate preventive measures remains the most critical component of its medical management. In general, these consist of vigilant laboratory and clinical monitoring, vigorous IV hydration, urate-lowering therapy, avoidance of exogenous potassium, use of phosphate binders, and – in high-risk cases – considering cytoreduction before the start of the aggressive agent or a gradual escalation of its dose. Key Messages: In patients with a high risk of TLS, cytotoxic chemotherapy should be given in the facility with ready access to dialysis and a treatment plan discussed with the nephrology team. In the case of hyperkalemia, severe hyperphosphatemia or acidosis, and fluid overload unresponsive to diuretic therapy, the early renal replacement therapy (RRT) should be considered. One must remember that in TLS, the threshold for RRT initiation may be lower than in other clinical situations since the process of cell breakdown is ongoing, and rapid increases in serum electrolytes cannot be predicted.

Critical Care Management of Toxicities Associated With Targeted Agents and Immunotherapies for Cancer

OBJECTIVES

To describe the most common serious adverse effects and organ toxicities associated with emerging therapies for cancer that may necessitate admission to the ICU.

DATA SOURCES AND STUDY SELECTION

PubMed and Medline search of relevant articles in English on the management of adverse effects of immunotherapy for cancer.

DATA EXTRACTION AND DATA SYNTHESIS

Targeted therapies including tyrosine kinase inhibitors, monoclonal antibodies, checkpoint inhibitors, and immune effector cell therapy have improved the outcome and quality of life of patients with cancer. However, severe and life-threatening side effects can occur. These toxicities include infusion or hypersensitivity reactions, cytokine release syndrome, pulmonary, cardiac, renal, hepatic, and neurologic toxicities, hemophagocytic lymphohistiocytosis, opportunistic infections, and endocrinopathies. Cytokine release syndrome is the most common serious toxicity after administration of monoclonal antibodies and immune effector cell therapies. Most of the adverse events from immunotherapy results from an exaggerated T-cell response directed against normal tissue, resulting in the generation of high levels of proinflammatory cytokines. Toxicities from targeted therapies are usually secondary to "on target toxicities." Management is largely supportive and may include discontinuation of the specific agent, corticosteroids, and other immune suppressing agents for severe (grade 3 or 4) immune-related adverse events like neurotoxicity and pneumonitis.

CONCLUSIONS

The complexity of toxicities associated with modern targeted and immunotherapeutic agents for cancer require a multidisciplinary approach among ICU staff, oncologists, and organ specialists and adoption of standardized treatment protocols to ensure the best possible patient outcomes.

Acute Kidney Injury in Oncology Patients

With rapid progress in cancer diagnosis and treatment in the last two decades, outcomes in oncological patients have improved significantly. However, the incidence of acute kidney injury (AKI) in this population has also increased significantly. AKI complicates many aspects of patients' care and adversely affects their prognoses; thus, accurately diagnosing the risk factors for AKI ensures appropriate management. AKI may be caused by pre-renal, intrinsic renal, and post-renal reasons, as well as for combined reasons. This review summarizes the potential etiologies of AKI according to the three classifications. For each underlying cause of AKI, the cancer itself and/or cancer treatment may contribute to a patient developing AKI. Therefore, we present disease- and treatment-related factors for each cause category, with special focus on immune checkpoint inhibitors, which are being used increasingly more often. It is important for nephrology services to be knowledgeable to provide the best level of care.

Nephrotoxicity in cancer treatment: An overview

Anticancer drug nephrotoxicity is an important and increasing adverse drug event that limits the efficacy of cancer treatment. The kidney is an important elimination pathway for many antineoplastic drugs and their metabolites, which occurs by glomerular filtration and tubular secretion. Chemotherapeutic agents, both conventional cytotoxic agents and molecularly targeted agents, can affect any segment of the nephron including its microvasculature, leading to many clinical manifestations such as proteinuria, hypertension, electrolyte disturbances, glomerulopathy, acute and chronic interstitial nephritis, acute kidney injury and at times chronic kidney disease. The clinician should be alert to recognize several factors that may maximize renal dysfunction and contribute to the increased incidence of nephrotoxicity associated with these drugs, such as intravascular volume depletion, the associated use of nonchemotherapeutic nephrotoxic drugs (analgesics, antibiotics, proton pump inhibitors, and bone-targeted therapies), radiographic ionic contrast media or radiation therapy, urinary tract obstruction, and intrinsic renal disease. Identification of patients at higher risk for nephrotoxicity may allow the prevention or at least reduction in the development and severity of this adverse effect. Therefore, the aim of this brief review is to provide currently available evidences on oncologic drug-related nephrotoxicity.

Hyperuricemia might be an early manifestation of undiagnosed adult leukemia in a population-based cohort study

Background/objective

No published population-based study investigates the association between hyperuricemia and undiagnosed adult leukemia in Taiwan. The aim of the study was to investigate whether hyperuricemia might be an early manifestation of undiagnosed adult leukemia in Taiwan.

Methods

A population-based cohort study was conducted to analyze the database of the Taiwan National Health Insurance Program. There were 47708 subjects aged 20 to 84 years with newly diagnosed hyperuricemia as the hyperuricemia group from 2000 to 2013, and 190832 randomly selected subjects without hyperuricemia as the non-hyperuricemia group. The hyperuricemia group and the non-hyperuricemia group were followed for one year to estimate the incidence of new diagnosis of leukemia.

Results

The overall incidence of leukemia was 1.32-fold higher in the hyperuricemia group than the non-hyperuricemia group (0.74 versus 0.55 per 10000 person-months, 95% confidence interval 1.28-1.37). The incidence rate ratio of leukemia was statistically higher in the first 3 months of hyperuricemia diagnosis (incidence rate ratio 4.05).

Conclusion

Adults with hyperuricemia have a higher incidence of being diagnosed with leukemia than those without hyperuricemia. Hyperuricemia might be an early manifestation of undiagnosed adult leukemia. Clinicians should check the complete blood count with differential to detect the possibility of leukemia when adults present with hyperuricemia.

Management of Adverse Events From the Combination of Rituximab and Lenalidomide in the Treatment of Patients With Follicular and Low-Grade Non-Hodgkin Lymphoma

Frontline treatment for patients with indolent non-Hodgkin lymphoma often includes immunochemotherapy. Although the disease of most patients responds to initial treatment, relapse is common. Recent results from the phase 3 Augment trial showed that combining rituximab with the immunomodulatory drug lenalidomide (R²) significantly improved efficacy over rituximab monotherapy in patients with recurrent non-Hodgkin lymphoma. As a result of these data, R² was approved in the US (Food and Drug Administration) and Japan (Pharmaceuticals and Medical Devices Agency) for previously treated adult patients with follicular and marginal zone lymphoma; and by the European Medicine Agency and the Swiss Agency for Therapeutic Products (Swissmedic) for previously treated adult patients with follicular lymphoma. R² has also been studied as initial treatment, where results have been comparable, but not superior, to chemoimmunotherapy. The resulting expanded use of R² reinforces the need for a detailed review of its safety profile and management, as presented here. Tolerability of R² has been consistent among trials, with most adverse events (AEs) being predictable and manageable. Hematologic AEs, particularly grade 3/4 neutropenia; low-grade cutaneous reactions, such as rash; and gastrointestinal AEs represent the most common AEs associated with R². The general R² safety profile and optimal strategies for AE management are discussed.

Novel Therapies in Chronic Lymphocytic Leukemia: A Rapidly Changing Landscape

OPINION STATEMENT

Treatment landscape of chronic lymphocytic leukemia (CLL) has changed since 2014 after the introduction of inhibitors of B-cell receptor signaling pathway (ibrutinib, acalabrutinib, idelalisib and duvelisib) and the inhibitor of the anti-apoptotic protein BCL-2 (venetoclax). In 2019, novel agents were upgraded from being a "great treatment option" to the "preferred choice" for all lines of treatment after number of randomized clinical trials proved their superiority compared to conventional chemoimmunotherapy (CIT) regimens. A growing number of next-generation molecules are in clinical trials with a promise of improved efficacy and less toxicity. This includes agents with expected better safety profile (zanubrutinib, umbralisib, etc.) or more importantly with a potential to overcome the resistance mechanism to early generation agents (ARQ-531, LOXO-305, or vecabrutinib). Early intervention has once again become an active topic of research and, if proven to provide an overall survival benefit, will eliminate the "watch and wait" strategy for asymptomatic CLL patients. Until then, treatment should only be offered to patients who meet the standard treatment indication in standard practice. With our upgraded therapeutic toolbox, there are and will be many unanswered questions. CLL field will need to define the optimal treatment sequence and most effective combinations with a goal of having a time-limited and chemotherapy-free regimen that provides longest remissions and potentially cure. Cellular immunotherapy with chimeric antigen receptor T-cell (CAR-T) may become available for high-risk CLL along with allogeneic stem cell transplant (allo-SCT). Financial toxicity of novel agents especially when used in combination will need to be an important aspect of research in coming years to avoid unnecessary overtreatment of patients. As current prognostic models (CLL-IPI, etc.) were developed and validated in the CIT era, there is ongoing effort to develop new models using clinical and molecular characteristics to accurately define high-risk CLL in the era of novel agents. We all need to keep in mind that access to the novel agents is currently limited to certain developed countries and every effort should be made to make sure patients around the world also benefit from these outstanding drugs.

Tumor lysis syndrome in childhood malignancies

BACKGROUND

Tumor lysis syndrome (TLS) is the most common life-threatening oncological emergency encountered by physicians treating children with lymphoproliferative malignancies. Healthcare providers should be aware of the condition in order to prevent occurrence and prompt timely management to avoid severe consequences.

OBJECTIVE

To provide an update on the current understanding, evaluation, and management of tumor lysis syndrome in childhood malignancies.

METHODS

A PubMed search was performed in Clinical Queries using the keywords 'tumor lysis syndrome' and 'malignancies' with Category limited to clinical trials and reviews for ages from birth to 18 years.

RESULTS

There were 22 clinical trials and 37 reviews under the search criteria. TLS is characterized by acute electrolyte and metabolic disturbances resulting from massive and abrupt release of cellular contents into the circulation due to breakdown of tumor cells. If left untreated, it can lead to multiorgan compromise and eventually death. Apart from close monitoring and medical therapies, early recognition of risk factors for development of TLS is also necessary for successful management.

CONCLUSIONS

Prophylactic measures to patients at risk of TLS include aggressive fluid management and judicious use of diuretics and hypouricemic agents. Both allopurinol and urate oxidase are effective in reducing serum uric acid. Allopurinol should be used as prophylaxis in low-risk cases while urate oxidase should be used as treatment in intermediate to high-risk cases. There is no evidence on better drug of choice among different urate oxidases. The routine use of diuretics and urine alkalinization are not recommended. Correction of electrolytes and use of renal replacement therapy may also be required during treatment of TLS.

Role of Non-Coding RNAs in the Development of Targeted Therapy and Immunotherapy Approaches for Chronic Lymphocytic Leukemia

In the past decade, novel targeted therapy approaches, such as BTK inhibitors and Bcl2 blockers, and innovative treatments that regulate the immune response against cancer cells, such as monoclonal antibodies, CAR-T cell therapy, and immunomodulatory molecules, have been established to provide support for the treatment of patients. However, drug resistance development and relapse are still major challenges in CLL treatment. Several studies revealed that non-coding RNAs have a main role in the development and progression of CLL. Specifically, microRNAs (miRs) and tRNA-derived small-RNAs (tsRNAs) were shown to be outstanding biomarkers that can be used to diagnose and monitor the disease and to possibly anticipate drug resistance and relapse, thus supporting physicians in the selection of treatment regimens tailored to the patient needs. In this review, we will summarize the most recent discoveries in the field of targeted therapy and immunotherapy for CLL and discuss the role of ncRNAs in the development of novel drugs and combination regimens for CLL patients.

Revolution of Chronic Lymphocytic Leukemia Therapy: the Chemo-Free Treatment Paradigm

Purpose of Review

Over the last years, targeted anticancer therapy with small molecule inhibitors and antibodies has much replaced chemoimmunotherapy, which has been the gold standard of care for patients with chronic lymphocytic leukemia (CLL). Here we give an overview of novel targeted agents used in therapy of chronic lymphocytic leukemia, as well as efforts to overcome resistance development, focusing on approved drugs since they gained high relevance in clinical practice.

Recent Findings

Novel agents moved to the forefront as a treatment strategy of CLL due to their outstanding efficacy, almost irrespectively of the underlying genetic features. Inhibition of Bruton’s tyrosine kinase (BTK), a key molecule in the B cell receptor pathway, achieved dramatic efficacy even in poor-risk and chemo-refractory patients. Further success was accomplished with venetoclax, which specifically inhibits anti-apoptotic BCL2 and induces apoptosis of CLL cells.

Summary

Inhibition of BTK or BCL2 is very effective and induces prolongation of progression-free and overall survival. Approved combination treatments such as venetoclax or ibrutinib with obinutuzumab show high responses rates and long remission durations. However, evolution and selection of subclones with continuous treatment leads to resistance towards these novel drugs and disease relapse. Hence, comparison of sequential treatment with combinations and discontinuation of therapy are important aspects which need to be investigated.

Emergencies in haematology: tumour lysis syndrome

Tumour lysis syndrome (TLS) is a significant complication of haematologic malignancies and their management. The syndrome consists of laboratory abnormalities either alone (laboratory TLS) or with clinical sequelae including renal failure, seizures, and arrhythmias (clinical TLS). Clinical TLS is a predictor for worse overall morbidity and mortality in cancer patients, but can be prevented. Thus, accurate prognostication is critical to appropriate management of patients at risk for TLS, and incorporates both disease factors (tumour type and burden) and patient factors (baseline renal insufficiency or hyperuricaemia). Strategies to prevent TLS include hydration and allopurinol in low- and intermediate-risk patients and rasburicase in high-risk patients.

Tumor lysis syndrome in gynecologic cancers: An uncommon but important diagnosis to recognize

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TLS treated with rasburicase is rare and associated with approximately 5% of gynecologic cancers.

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TLS is most frequently associated with new diagnosis of high-grade gynecologic malignancies.

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The most common presenting symptoms of TLS include acute kidney injury and electrolyte derangement.

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Early recognition and treatment of TLS can rapidly improve uric acid and electrolyte derangements.

Objectives

To describe the incidence, treatment and outcomes associated with tumor lysis syndrome (TLS) in women with gynecologic cancer (GOC).

Methods

A retrospective multi-institutional review of TLS associated with GOC. Women presenting with an elevated serum uric acid managed with intravenous (IV) rasburicase were included. Descriptive statistics of patient demographics, clinical findings, and outcome data was completed.

Results

From two large academic institutions N = 18 patients were found to meet inclusion criteria from 2008 to 2018, reflecting an approximate 5% incidence of clinically treated TLS associated with GOC in our cohort. Median age was 60 years, a majority were Caucasian (n = 11, 61.1%), median BMI was 36.2. TLS was associated with a high-grade GOC in n = 17 (94.4%) cases. TLS was commonly diagnosed with a new GOC (n = 12, 70.6%) and following receipt of chemotherapy in n = 9 (50.0%) cases. Six (66.7%) patients were treated with paclitaxel or combination, five (55.5%) with a platinum or combination, and two (22.2%) with a CD47 inhibitor. Chief complaints included electrolyte and renal abnormalities (n = 11, 73.3%). Peak serum uric acid, potassium, creatinine and phosphorus levels were 14.1 mg/dL, 5.7 mEq/L, 5.1 mg/dL, and 6.8 mg/dL, respectively. Nine patients received hospice during their admission with 3 (20%) deaths occurring as inpatients. There were 12 deaths with median OS of 16 d (range: 2–87 d).

Conclusions

Though rare, TLS can be associated with GOC. Early recognition of presenting symptoms, laboratory findings and expedited treatment may help with electrolyte recovery; however, TLS associated with GOC may herald a rapidly deteriorating state with significant associated mortality.

Obinutuzumab pretreatment abrogates tumor lysis risk while maintaining undetectable MRD for venetoclax + obinutuzumab in CLL

Early data on venetoclax-containing regimens for the treatment of chronic lymphocytic leukemia (CLL) show promising results with deep remissions, but are hampered by potential risk for tumor lysis syndrome (TLS). Whether optimal duration of venetoclax treatment can be guided by minimal residual disease (MRD) is currently unknown. To study whether TLS risk can be mitigated in an unfit population by introducing preinduction, and whether MRD-guided duration of venetoclax treatment is a feasible and efficacious approach, we performed the Dutch-Belgian Cooperative Trial Group for Hemato-oncology (HOVON) 139/GIVE trial. The study treatment consists of 4 treatment phases: preinduction (2 cycles obinutuzumab), induction I (6 cycles obinutuzumab and venetoclax), induction II (6 cycles venetoclax), and a randomization phase (group A: maintenance with 12 additional cycles of venetoclax irrespective of MRD; group B: MRD guided venetoclax maintenance with a maximum of 12 cycles). Here we report on a planned interim safety analysis as well as preliminary efficacy and MRD data of the first 30 patients enrolled. Downgrading of TLS risk after preinduction occurred in 25 patients: 3 from high to medium, 3 from high to low, and 19 from medium to low risk. No patient remained high risk. From these 30 patients, peripheral blood MRD data were obtained for 28 patients at the end of induction II (6 months after the last obinutuzumab dose), of whom 26 had undetectable MRD levels, and for 18 patients who reached the 3-month after-randomization point, of whom 16 had undetectable MRD levels. Obinutuzumab preinduction is tolerated well in these unfit patients and results in abrogating high TLS risk in all patients. Preliminary data indicate that efficacy is maintained with a high proportion of patients with undetectable MRD levels after combination treatment.

Current understanding of tumor lysis syndrome

Tumor lysis syndrome (TLS) is an oncologic emergency from the intracellular release of material in lysing malignant cells. The earlier it is treated, the less likely it is to be harmful to an individual and spread through the body. Common complications of TLS include arrhythmias, which are caused by hypocalcemia or hyperkalemia, renal failures due to hyperuricemia or hyperphosphatemia, and seizures. Furthermore, the risk to develop TLS varies widely based on several factors including factors that are related to disease, the patient, and the treatment of the patient. Laboratory data can be used to gauge the severity of TLS based on patient serum levels for specific markers. On the contrary, evidence of TLS via radiological imaging and electrocardiogram findings has been a limited way to evaluate TLS, indicating the need for further research in this area. Common trends of treatment have also been seen in the past several years, evident by case studies seen in the following literature review.

Treatment Outcomes of Novel Targeted Agents in Relapse/Refractory Chronic Lymphocytic Leukemia: A Systematic Review and Network Meta-Analysis

Most chronic lymphocytic leukemia patients experience a relapse or become refractory to treatment with conventional chemotherapeutic agents. The network meta-analysis assesses the relative efficacy of novel targeted agents for the treatment of a relapse or refractory chronic lymphocytic leukemia. A systematic literature search included seven phase III randomized controlled trials, including a total of 2512 patients treated with nine regimens. Data were extracted and evidence synthesized using network meta-analysis. All novel targeted therapies were significantly more effective than ofatumumab and demonstrated promising prolongation of progression free survival (PFS), with a hazard ratio (HR) ranging from 0.10 to 0.52. Two novel targeted agent regimens, venetoclax plus rituximab and ibrutinib monotherapy, resulted in greater overall survival (HR, 0.335 and 0.361, respectively). Venetoclax plus rituximab and ibrutinib monotherapy were most favorable based on (1) HR for PFS compared with ofatumumab (Ibrutinib: HR, 0.10; 95% CI, 0.07-0.14; Venetoclax plus rituximab: HR, 0.10; 95% CI, 0.05-0.21) and SUCRA value (probability of being best) (Ibrutinib SUCRA, 0.92; Venetoclax rituximab SUCRA, 0.90) (2) HR for overall survival compared with ofatumumab (Ibrutinib: HR, 0.361; 95% CI, 0.208-0.627; Venetoclax rituximab: HR, 0.335; 95% CI, 0.112-0.997) and SUCRA value (Ibrutinib SUCRA, 0.84; Venetoclax rituximab SUCRA, 0.85) Both treatments reduced the risk of progression or death by 90% versus conventional ofatumumab. Both ibrutinib monotherapy and venetoclax rituximab have a high probability of being the most effective treatments for a relapse or refractory chronic lymphocytic leukemia with respect to long-term progression-free survival and overall survival.

Venetoclax plus R- or G-CHOP in non-Hodgkin lymphoma: results from the CAVALLI phase 1b trial

Novel strategies, such as chemosensitization with targeted agents, that build on the success of standard immunochemotherapy show promise for the treatment of non-Hodgkin lymphoma (NHL). Here, we report a phase 1b study investigating dose escalation of the BCL2 inhibitor, venetoclax, in combination with rituximab or obinutuzumab and cyclophosphamide, doxorubicin, vincristine, and prednisone (R-/G-CHOP) chemotherapy in B-cell NHL. Objectives included safety assessment and determination of a recommended phase 2 dose (RP2D). Fifty-six patients were enrolled, most with follicular lymphoma (43%) or diffuse large B-cell lymphoma (DLBCL; 32%). Dose-limiting toxicities were reported in 3/14 patients at the first venetoclax dose (200 mg/d), after which dosing was changed from daily to 10 days per cycle and escalated to 800 mg. A further reduction to 5 days per cycle occurred at the 800-mg dose level in the G-CHOP arm. Cytopenias were predominant among grade 3/4 events and reported at a higher rate than expected, particularly in the G-CHOP arm; however, safety was manageable. Overall response rates were 87.5% (R-CHOP and G-CHOP combinations); complete response (CR) rates were 79.2% and 78.1%, respectively. Most double-expressor (BCL2⁺ and MYC⁺) DLBCL patients (87.5%; n = 7/8) achieved CR. Although the maximum tolerated dose was not reached, the RP2D for venetoclax with R-CHOP was established at 800 mg days 4 to 10 of cycle 1 and days 1 to 10 of cycles 2 to 8; higher doses were not explored, and this dosing schedule demonstrated an acceptable safety profile. This regimen is subsequently being evaluated in first-line DLBCL in the phase 2 portion of the study. This trial was registered at www.clinicaltrials.gov as #NCT02055820.

Management of unfit elderly patients with chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a disease characterized by an increasing incidence with age reaching 35/100,000 in patients over 85 years. Elderly CLL patients carry several challenges, which have to be considered particularly in advanced stages including a higher risk of infections and individual differences in comorbidities and geriatric syndromes. Although no specific tool for geriatric evaluation in CLL has been developed so far, several of them (e.g. CIRS or Charlson-Score) have been tested in CLL patients. Several treatment options exist for frontline and relapse therapy in unfit CLL patients. Less intensive chemoimmunotherapy with engineered CD20 antibodies (e.g. obinutuzumab) is one of the treatment options, if TP53 mutation or deletion has been ruled out by genetic testing. Single agent treatment with the Btk-inhibitor ibrutinib is not only approved in relapsed CLL; but also for frontline therapy. The kinase inhibitor idelalisib (plus rituximab) and the bcl2 inhibitor venetoclax are other novel compounds, which showed great efficacy in relapsed CLL even in unfit patients. Treatment decisions in unfit patients have to take patient-related as well as disease-related risk factors into consideration.

Renal involvement in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most commonly diagnosed adult leukemia in the USA and Western Europe. Kidney disease can present in patients with CLL as a manifestation of the disease process such as acute kidney injury with infiltration or with a paraneoplastic glomerular disease or as a manifestation of extra renal obstruction and tumor lysis syndrome. In the current era of novel targeted therapies, kidney disease can also present as a complication of treatment. Tumor lysis syndrome associated with novel agents such as the B-cell lymphoma 2 inhibitor venetoclax and the monoclonal antibody obinutuzumab are important nephrotoxicities associated with these agents. Here we review the various forms of kidney diseases associated with CLL and its therapies.

Balancing efficacy and toxicity of targeted agents currently used for the treatment of patients with chronic lymphocytic leukemia

INTRODUCTION

In recent years, innovative mechanism-based drugs have enriched the therapeutic armamentarium for patients with chronic lymphocytic leukemia (CLL) and are widely used in the clinical practice. These small molecules targeting the B-cell receptor signaling pathway and the BCL-2 anti-apoptotic protein offer new chemo-free options to both unfit patients and high-risk patients who show a poor response to chemoimmunotherapy. Nonetheless, treatment with ibrutinib, idelalisib and venetoclax is associated with unique side effects. Awareness, prevention and the appropriate management of these specific toxicities are of crucial importance for a successful treatment. Areas covered: The purpose of this review is to discuss the most relevant studies on small molecules in CLL, with particular attention to the emerging toxicity profile of these agents and to the factors that should be considered to address the most appropriate treatment approach for each patient. Expert opinion: The increased knowledge on the biology of CLL has translated into the development of targeted agents that are highly effective and produce deep responses. Toxicities potentially associated with these agents should be known for an optimal management of CLL patients.

Evolving Treatment Strategies for Elderly Leukemia Patients with IDH Mutations

Acute myeloid leukemia (AML) is a debilitating and life-threatening condition, especially for elderly patients who account for over 50% of diagnoses. For over four decades, standard induction therapy with intensive cytotoxic chemotherapy for AML had remained unchanged. However, for most patients, standard therapy continues to have its shortcomings, especially for elderly patients who may not be able to tolerate the complications from intensive cytotoxic chemotherapy. New research into the development of targeted and alternative therapies has led to a new era in AML therapy. For the nearly 20% of diagnoses harboring a mutation in isocitrate dehydrogenase 1 or 2 (IDH1/2), potential treatment options have undergone a paradigm shift away from intensive cytotoxic chemotherapy and towards targeted therapy alone or in combination with lower intensity chemotherapy. The first FDA approved IDH2 inhibitor was enasidenib in 2017. In addition, IDH1 inhibitors are in ongoing clinical studies, and the oral BCL-2 inhibitor venetoclax shows preliminary efficacy in this subset of patients. These new tools aim to improve outcomes and change the treatment paradigm for elderly patients with IDH mutant AML. However, the challenge of how to best incorporate these agents into standard practice remains.

Approved CAR T cell therapies: ice bucket challenges on glaring safety risks and long-term impacts

Two autologous chimeric antigen receptor (CAR) T cell therapies (Kymriah™ and Yescarta™) were recently approved by the FDA. Kymriah™ is for the treatment of pediatric patients and young adults with refractory or relapse (R/R) B cell precursor acute lymphoblastic leukemia and Yescarta™ is for the treatment of adult patients with R/R large B cell lymphoma. In common, both are CD19-specific CAR T cell therapies lysing CD19-positive targets. Their dramatic efficacy in the short term has been highlighted by many media reports. By contrast, their glaring safety gaps behind the miracles remain much less addressed. Here, we focus on addressing the crucial challenges in relation to the gaps.

Venetoclax: Targeting BCL2 in Hematological Cancers

Over the last years, targeted anti-cancer therapy with small-molecule inhibitors and antibodies moved to the forefront as a strategy to treat hematological cancers. These novel agents showed outstanding effects in treatment of patients, often irrespective of their underlying genetic features. However, evolution and selection of subclones with continuous treatment leads to disease relapse and resistance toward these novel drugs. Venetoclax (ABT-199) is a novel, orally bioavailable small-molecule inhibitor for selective targeting of B-cell lymphoma 2 (BCL2). Venetoclax is in clinical development and shows high efficacy and safety in particular in the treatment of chronic lymphocytic leukemia (CLL), but preliminarily also in acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL). The most important and impressive outcomes of venetoclax treatment include a rapid induction of apoptosis and drastic reduction of the tumor bulk within a few hours after administration. Venetoclax was approved by the FDA and EMA in 2016 for patients with previously treated CLL with del(17p13) and patients failing B cell receptor signaling inhibitors (EMA only), on the basis of a single-arm phase II trial demonstrating a tremendous response rate of 79% with complete remission in 20% of cases and an estimated 1-year progression-free survival of 72%. This review focuses on the mode of action, the preclinical models, and outcomes from various clinical trials with venetoclax in different hematologic cancers as well as future development.