Ibrutinib-associated Arthralgias/Myalgias in Patients With Chronic Lymphocytic Leukemia: Incidence and Impact on Clinical Outcomes

How We Manage Patients with Indolent B-Cell Malignancies on Bruton's Tyrosine Kinase Inhibitors: Practical Considerations for Nurses and Pharmacists

The most common forms of B-cell malignancy, non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL), have seen a drastic shift in the treatment landscape over the last two decades with the introduction of targeted agents. Among them are Bruton's tyrosine kinase (BTK) inhibitors, which have demonstrated excellent efficacy in indolent B-cell NHLs and CLL. Although BTK inhibitors are generally thought to be more tolerable than chemoimmunotherapy, they are associated with a unique safety profile including varying rates of rash, diarrhea, musculoskeletal events, cardiovascular events, and bleeding. Ibrutinib was the first BTK inhibitor to gain a Health Canada indication, followed by second-generation BTK inhibitors acalabrutinib and zanubrutinib, which have better safety profiles compared to ibrutinib, likely due to their improved selectivity for BTK. As BTK inhibitors are oral agents given continuously until disease progression, long-term adverse event (AE) monitoring and management as well as polypharmacy considerations are important for maintaining patient quality of life. This paper intends to serve as a reference for Canadian nurses and pharmacists on dosing, co-administration, and AE management strategies when caring for patients with indolent B-cell NHL or CLL being treated with BTK inhibitors.

Managing Waldenström's macroglobulinemia with BTK inhibitors

Bruton's tyrosine kinase (BTK) inhibition is one of the treatment standards for patients with relapsed/refractory Waldenström's macroglobulinemia (WM) and for patients with WM who are unsuitable for immunochemotherapy (ICT). It offers deep and durable responses with a manageable safety profile that is generally favorable compared with ICT regimens. However, the limitations of the first approved BTK inhibitor (BTKi), ibrutinib, include reduced efficacy in patients lacking the characteristic WM mutation (MYD88^L265P) and toxicities related to off-target activity. The risk of atrial fibrillation (AF) and other cardiovascular side effects are a notable feature of ibrutinib therapy. Several next-generation covalent BTKis with greater selectivity for BTK are at various stages of development. In November 2021, zanubrutinib became the first of these agents to be approved by the European Medicines Agency for the treatment of WM. Head-to-head trial data indicate that it has comparable efficacy to ibrutinib for patients with WM overall, although it may be more effective in patients with CXCR4 mutations or wild-type MYD88. In the clinical trial setting, its greater selectivity translates into a reduced risk of cardiovascular side effects, including AF. Acalabrutinib, which is pre-approval in WM, appears to offer similar advantages over ibrutinib in terms of its safety profile. Beyond the next-generation covalent BTKis, non-covalent BTKis are an emerging class with the potential to provide a therapeutic option for patients who relapse on covalent BTKis. In the future, BTKis may be increasingly utilized within combination regimens. Several ongoing trials in WM are investigating the potential for BTKi use in combination with established and novel targeted agents.

Case Report: Syndrome of Remitting Seronegative Symmetrical Synovitis with Pitting Edema-A Rare but Treatable Condition in Palliative Medicine

The syndrome of remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is a rare diagnosis that is often missed due to lack of both definitive diagnostic criteria and awareness of the disease. This case report describes a patient with chronic lymphocytic leukemia whose diagnosis of RS3PE was possibly delayed due to concomitant treatment-related arthralgias. The pathophysiology, presentation, and treatment of RS3PE are discussed. Greater awareness of malignancy-related RS3PE is crucial from a palliative care perspective as typical opioid pain management will prove ineffective and delay appropriate treatment.

Systematic Literature Review of Real-World Effectiveness Results Data for First-Line Ibrutinib in Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma

BACKGROUND AND OBJECTIVE

Ibrutinib, an oral Bruton's tyrosine kinase inhibitor, has demonstrated efficacy as a first-line treatment for chronic lymphocytic leukemia in multiple, phase III, randomized clinical trials. This systematic literature review assessed the clinical effectiveness of ibrutinib in the first-line treatment of chronic lymphocytic leukemia in real-world clinical settings.

METHODS

MEDLINE, EMBASE, and relevant conference websites were searched for articles published in the USA from 1 January, 2014 to 30 June, 2020. Overall survival, progression-free survival, overall response rate, and time to next treatment were summarized.

RESULTS

This analysis included a total of 12 publications representing data from 112 to 2033 patients from community and academic centers, and the multicenter informCLL registry. Patients were predominantly male (60-99%) with a median age range from 62 to 77 years, and included those with high-risk genomic features (del[17p]: 21-33%; del[11q]: 33%; and unmutated immunoglobulin heavy chain variable gene: 59%). Real-world effectiveness with ibrutinib complemented the efficacy demonstrated in randomized clinical trials. Across various studies, the 12-month overall survival rates ranged from 95% to 96%; 18-month overall survival rates were similarly high (91%). Twelve-month progression-free survival rates ranged from 89% to 93%, and the overall response rate ranged from 71% to 90% across four studies. In the studies that reported time to next treatment, 91% and 87% of patients treated with first-line ibrutinib did not initiate new treatment at 12 months and 24 months, respectively.

CONCLUSIONS

This systematic literature review confirms the benefit of ibrutinib as a first-line treatment in patients with chronic lymphocytic leukemia in real-world clinical settings and is consistent with results from randomized clinical trials, including in patients with high-risk genomic features.

The Role of Bruton's Kinase Inhibitors in Chronic Lymphocytic Leukemia: Current Status and Future Directions

The use of Bruton's tyrosine kinase (BTK) inhibitors has changed the management and clinical history of patients with chronic lymphocytic leukemia (CLL). BTK is a critical molecule that interconnects B-cell antigen receptor (BCR) signaling. BTKis are classified into two categories: irreversible (covalent) inhibitors and reversible (non-covalent) inhibitors. Ibrutinib was the first irreversible BTK inhibitor approved by the U.S. Food and Drug Administration in 2013 as a breakthrough therapy in CLL patients. Subsequently, several studies have evaluated the efficacy and safety of new agents with reduced toxicity when compared with ibrutinib. Two other irreversible, second-generation BTK inhibitors, acalabrutinib and zanubrutinib, were developed to reduce ibrutinib-mediated adverse effects. Additionally, new reversible BTK inhibitors are currently under development in early-phase studies to improve their activity and to diminish adverse effects. This review summarizes the pharmacology, clinical efficacy, safety, dosing, and drug-drug interactions associated with the treatment of CLL with BTK inhibitors and examines their further implications.

Clinical Trials of the BTK Inhibitors Ibrutinib and Acalabrutinib in Human Diseases Beyond B Cell Malignancies

The BTK inhibitors ibrutinib and acalabrutinib are FDA-approved drugs for the treatment of B cell malignances. Both drugs have demonstrated clinical efficacy and safety profiles superior to chemoimmunotherapy regimens in patients with chronic lymphocytic leukemia. Mounting preclinical and clinical evidence indicates that both ibrutinib and acalabrutinib are versatile and have direct effects on many immune cell subsets as well as other cell types beyond B cells. The versatility and immunomodulatory effects of both drugs have been exploited to expand their therapeutic potential in a wide variety of human diseases. Over 470 clinical trials are currently registered at ClinicalTrials.gov to test the efficacy of ibrutinib or acalabrutinib not only in almost every type of B cell malignancies, but also in hematological malignancies of myeloid cells and T cells, solid tumors, chronic graft versus host disease (cGHVD), autoimmune diseases, allergy and COVID-19 (http:www.clinicaltrials.gov). In this review, we present brief discussions of the clinical trials and relevant key preclinical evidence of ibrutinib and acalabrutinib as monotherapies or as part of combination therapies for the treatment of human diseases beyond B cell malignancies. Adding to the proven efficacy of ibrutinib for cGVHD, preliminary results of clinical trials have shown promising efficacy of ibrutinib or acalabrutinib for certain T cell malignancies, allergies and severe COVID-19. However, both BTK inhibitors have no or limited efficacy for refractory or recurrent solid tumors. These clinical data together with additional pending results from ongoing trials will provide valuable information to guide the design and improvement of future trials, including optimization of combination regimens and dosing sequences as well as better patient stratification and more efficient delivery strategies. Such information will further advance the precise implementation of BTK inhibitors into the clinical toolbox for the treatment of different human diseases.

Monitoring and Managing BTK Inhibitor Treatment-Related Adverse Events in Clinical Practice

Bruton tyrosine kinase (BTK) inhibitors represent an important therapeutic advancement for B cell malignancies. Ibrutinib, the first-in-class BTK inhibitor, is approved by the US FDA to treat patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL), and mantle cell lymphoma (MCL; after ≥1 prior therapy); and by the European Medicines Agency (EMA) for adult patients with relapsed/refractory (R/R) MCL and patients with CLL. Ibrutinib treatment can be limited by adverse events (AEs) including atrial fibrillation, arthralgias, rash, diarrhea, and bleeding events, leading to drug discontinuation in 4%-26% of patients. Acalabrutinib, a second-generation BTK inhibitor, is approved by the FDA to treat adult patients with CLL/SLL or MCL (relapsed after 1 prior therapy); and by the EMA to treat adult patients with CLL or R/R MCL. The most common AE associated with acalabrutinib is headache of limited duration, which occurs in 22%-51% of patients, and is mainly grade 1-2 in severity, with only 1% of patients experiencing grade ≥3 headache. Furthermore, acalabrutinib is associated with a low incidence of atrial fibrillation. Zanubrutinib, a selective next-generation covalent BTK inhibitor, is approved by the FDA to treat adult patients with MCL who have received ≥1 prior therapy, and is under investigation for the treatment of patients with CLL. In the phase 3 SEQUOIA trial in patients with CLL, the most common grade ≥3 AEs were neutropenia/neutrophil count decreased and infections. This review provides an overview of BTK inhibitor-related AEs in patients with CLL, and strategies for their management.

Multifaceted Immunomodulatory Effects of the BTK Inhibitors Ibrutinib and Acalabrutinib on Different Immune Cell Subsets - Beyond B Lymphocytes

The clinical success of the two BTK inhibitors, ibrutinib and acalabrutinib, represents a major breakthrough in the treatment of chronic lymphocytic leukemia (CLL) and has also revolutionized the treatment options for other B cell malignancies. Increasing evidence indicates that in addition to their direct effects on B lymphocytes, both BTK inhibitors also directly impact the homeostasis, phenotype and function of many other cell subsets of the immune system, which contribute to their high efficacy as well as adverse effects observed in CLL patients. In this review, we attempt to provide an overview on the overlapping and differential effects of ibrutinib and acalabrutinib on specific receptor signaling pathways in different immune cell subsets other than B cells, including T cells, NK cells, monocytes, macrophages, granulocytes, myeloid-derived suppressor cells, dendritic cells, osteoclasts, mast cells and platelets. The shared and distinct effects of ibrutinib versus acalabrutinib are mediated through BTK-dependent and BTK-independent mechanisms, respectively. Such immunomodulatory effects of the two drugs have fueled myriad explorations of their repurposing opportunities for the treatment of a wide variety of other human diseases involving immune dysregulation.

Treating CLL with Bruton Tyrosine Kinase Inhibitors: The Role of the Outpatient Oncology Nurse

OBJECTIVES

To summarize the role of Bruton tyrosine kinase (BTK) inhibitors in the management of chronic lymphocytic leukemia with a focus on the nursing role in relation to patients with chronic lymphocytic leukemia being treated with BTK inhibitors.

DATA SOURCES

These include published articles (PubMed) and national and international guideline documents.

CONCLUSION

BTK inhibitors have revolutionized the therapy of chronic lymphocytic leukemia and have become the most frequently used therapy today. Despite the many advantages of BTK inhibitors, adverse events remain a leading cause of treatment discontinuation, particularly for the first-in-class BTK inhibitor. Second-generation BTK inhibitors appear to have a better tolerability profile but still require adverse event management given their prolonged duration of therapy. Awareness and management of side effects by the oncology care team is essential for ensuring both compliance and safety with ongoing treatment.

IMPLICATIONS FOR NURSING PRACTICE

Chronic lymphocytic leukemia is a chronic illness with a long-life expectancy. For the patients who require therapy, BTK inhibitor therapy is a frequently applied treatment with impressive efficacy. BTK inhibitors are continued indefinitely until disease progression or significant toxicity; therefore, the overall principles of careful assessment for side effects, diligent management for these, and individualized patient support provided by oncology nurses is vital in this patient population.

Acute gout flare of bilateral first metatarsophalangeal joints due to ibrutinib use in chronic lymphocytic leukemia

INTRODUCTION

Bruton tyrosine kinase inhibitors represent important tools in the therapeutic armamentarium against chronic lymphocytic leukemia (CLL) and other B-lymphoproliferative disorders.

CASE REPORT

We describe herein a unique 65-year-old patient who presented with bilateral foot pain four months after starting treatment with ibrutinib for CLL. Of note, the patient had previously been diagnosed with gout, and was taking allopurinol prophylactically at the time of the event. Compliance with allopurinol was in excess of 99%. Yet, he was diagnosed with acute gout flare of bilateral first metatarsophalangeal (MTP) joints.Management & Outcome: Ibrutinib dose was reduced by one third, and the patient's gout flare up was treated with ibuprofen as needed. After symptoms abated, ibrutinib was continued at 2/3rds of the dose, with an excellent CLL control. The patient tolerated this dose without any further adverse effects.Discussion/Conclusions: We have reported a unique side effect of acute bilateral first MTP joint gout flare likely triggered by ibrutinib use for CLL while the patient was taking a xanthine oxidase inhibitor. The mechanism by which ibrutinib caused this phenomenon remains to be elucidated.

A case of inflammatory myopathy in graft vs host disease - A potential role for ibrutinib

Myositis is a known complication of chronic graft-vs-host disease (cGVHD) following allogeneic haematopoietic stem cell transplantation, but can be difficult to diagnose and manage. We present the case of a 57 year old man with cGVHD in whom the full manifestations of myositis were suppressed for some time, likely due to partial treatment of his condition with immunosuppression including ibrutinib. Though initial muscle biopsy showed necrotising myopathy without significant inflammation, on cessation of ibrutinib he developed increasing weakness and creatine kinase levels, with repeat muscle biopsy showing histological changes more in keeping with dermatomyositis. The close temporal correlation of his clinical course with commencement and cessation of ibrutinib suggests a potential role for ibrutinib in treating inflammatory myopathy in cGVHD.

Ibrutinib does not prevent kidney fibrosis following acute and chronic injury

Recent studies suggested that ibrutinib, a Bruton tyrosine kinase (BTK) inhibitor, developed for the treatment of chronic lymphocytic leukemia, may prevent NLRP3 inflammasome activation in macrophages, IL-1β secretion and subsequent development of inflammation and organ fibrosis. The role of NLRP3 has been underlined in the various causes of acute kidney injury (AKI), a pathology characterized by high morbimortality and risk of transition toward chronic kidney disease (CKD). We therefore hypothesized that the BTK-inhibitor ibrutinib could be a candidate drug for AKI treatment. Here, we observed in both an AKI model (glycerol-induced rhabdomyolysis) and a model of rapidly progressive kidney fibrosis (unilateral ureteral obstruction), that ibrutinib did not prevent inflammatory cell recruitment in the kidney and fibrosis. Moreover, ibrutinib pre-exposure led to high mortality rate owing to severer rhabdomyolysis and AKI. In vitro, ibrutinib potentiated or had no effect on the secretion of IL-1β by monocytes exposed to uromodulin or myoglobin, two danger-associated molecule patterns proteins involved in the AKI to CKD transition. According to these results, ibrutinib should not be considered a candidate drug for patients developing AKI.

Zanubrutinib (BGB-3111), a Second-Generation Selective Covalent Inhibitor of Bruton's Tyrosine Kinase and Its Utility in Treating Chronic Lymphocytic Leukemia

The understanding of the B cell receptor (BCR) pathway and its contribution to chronic lymphocytic leukemia (CLL) pathogenesis have led to the development of targeted BCR inhibitors which have transformed the treatment paradigm of CLL. Ibrutinib is a first-in-class oral Bruton’s tyrosine kinase (BTK) inhibitor which has demonstrated improvements in both progression free (PFS) and overall survival (OS) in both the treatment naïve and relapsed/refractory setting as compared to traditional chemoimmunotherapy. Despite its clinical efficacy, many patients discontinue treatment due to adverse events, which are thought to be mediated through off-target kinase inhibition. Zanubrutinib is a second-generation non-covalent BTK inhibitor with higher potency, allowing for inhibition of BTK with fewer off target effects. Early phase clinical trials have demonstrated excellent efficacy and a well-tolerated safety profile. Long-term follow-up is needed, but zanubrutinib holds promise to be an effective therapy for CLL with a manageable side effect profile and will be an exciting addition to our treatment paradigm.

Managing toxicities of Bruton tyrosine kinase inhibitors

Inhibition of Bruton's tyrosine kinase (BTK) has revolutionized the treatment landscape for patients with chronic lymphocytic leukemia (CLL). By targeting this critical kinase in proximal B-cell receptor signaling, BTK inhibitors (BTKis) impair cell proliferation, migration, and activation of NF-κB. Clinically, because indefinite inhibition is a mainstay of therapy, there is an extended period of exposure in which adverse effects can develop. Given the impressive efficacy and activity of BTKis in the treatment of patients with CLL, appropriate management of treatment-emergent adverse events (AEs) is of paramount importance. Here we review the BTKi landscape and present the available toxicity and safety data for each agent. The long-term toxicity profile of ibrutinib, a first-in-class inhibitor, is well characterized and includes a clinically significant incidence of cardiac arrhythmias, bleeding, infection, diarrhea, arthralgias, and hypertension. Acalabrutinib, the initial second-generation BTKi to earn approval from the US Food and Drug Administration, demonstrates improved kinase selectivity for BTK, with commonly observed adverse reactions including infection, headache, and diarrhea. Mediated by both on-target inhibition of BTK and variable off-target inhibition of other kinases including interleukin-2-inducible T-cell kinase (ITK), tyrosine-protein kinase (TEC), and endothelial growth factor receptor (EGFR), the toxicity profile of BTKis is closely linked to their pattern of kinase binding. Other emerging BTKis include second-generation agents with variable degrees of kinase selectivity and third-generation agents that exhibit reversible noncovalent binding to BTK. We also highlight critical considerations for the prevention and monitoring of AEs and offer practical management strategies for treatment-emergent toxicities.

Chemotherapy-free frontline therapy for CLL: is it worth it?

The treatment of chronic lymphocytic leukemia (CLL) embodies one of the great success stories in translational research, with the development of therapies aimed at disrupting crucial pathways that allow for the survival and proliferation of the malignant clone. The arrival of targeted agents into our armamentarium, along with the advent of novel monoclonal antibodies that can achieve deeper remissions, has steered the field to a new treatment paradigm. Given the panoply of therapeutic options available, the question arises whether chemotherapy still has a role in the management of CLL. The novel targeted agents, which include the Bruton's tyrosine kinase inhibitors, ibrutinib and acalabrutinib, along with the B-cell lymphoma-2 inhibitor, venetoclax, are highly effective in achieving a response with improved remission duration and survival, particularly in high-risk patients. Despite this major progress, the new agents bring a unique set of toxicities unlike those associated with cytotoxic chemotherapy. There is a paucity of head-to-head comparisons among all of the novel agents, because their approval was based on randomization against traditional chemoimmunotherapeutic regimens. Parallel to the increase in the number of available targeted agents, there has been a significant improvement in quality of life and life expectancy of the patients with a CLL diagnosis over the last decade. Our review will examine whether "chemotherapy-free" frontline treatment approaches are worth the associated risks. Our goal is to help identify optimal treatment strategies tailored to the individual by reviewing available data on monotherapy vs combination strategies, depth of response, treatment duration, and potential toxicities.