Long-term follow-up of the RESONATE phase 3 trial of ibrutinib vs ofatumumab

Efficacy and safety of ibrutinib in relapsed/refractory CLL and SLL in Japan: a post-marketing surveillance

Ibrutinib is approved in Japan for the treatment of chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) based on the results of global and domestic clinical studies. Following approval, we conducted an all-case post-marketing surveillance in Japanese patients with relapsed/refractory CLL/SLL newly initiated on ibrutinib treatment between May 2016−September 2017. Of the 323 patients enrolled, the safety and efficacy analysis sets comprised 289 and 205 patients, respectively. The overall response rate with ibrutinib treatment was 64.4%, and the estimated 52-week progression-free survival (PFS) and overall survival (OS) rates were 71.7 and 79.1%, respectively. No significant difference in the PFS rate was observed among patients with and without del(17p) (P = 0.160); however, PFS was significantly longer in patients who received 1 prior line of therapy versus >1 prior lines of therapy (P = 0.007). Adverse events occurred in 74.0% of patients, and typically occurred early (≤12 weeks) after ibrutinib initiation, followed by a decline in incidence thereafter. The overall rates of infection, bleeding, and arrhythmia were 22.5, 12.8, and 4.8%, respectively. Grade ≥3 bleeding events and atrial fibrillation occurred in 2.4% of patients each. The efficacy and safety profile of ibrutinib treatment in routine clinical practice was consistent with clinical trials and previously reported domestic data.

UMIN-CTR Clinical Trials Register ID: UMIN000021963.

SOHO State of the Art Updates and Next Questions: What is Fitness in the Era of Targeted Agents?

The importance of coexisting conditions in chronic lymphocytic leukemia (CLL) outcome has been increasingly recognized over the past years. The role of comorbidities to predict patients' vulnerability toward immunochemotherapy has been well establish, especially since some of the tools commonly used to evaluate patients' fitness were employed to determine treatment eligibility in randomized trials. Nevertheless, is it still unclear how much fitness weights on treatment outcome with targeted agents and which assessment should be preferred. There are key differences in the toxicity profile between novel agents that are getting much more evident in retrospective, real-life experiences, rather than clinical trials. Therefore, an individual patient's comorbid medical conditions may be a deciding factor in therapy selection. Here, we analyze main evidence in literature on the predicting value of comorbidity assessment on outcome and management of CLL patients receiving novel agents.

Cardiovascular adverse events in patients with chronic lymphocytic leukemia receiving acalabrutinib monotherapy: pooled analysis of 762 patients

Cardiovascular (CV) toxicities of the Bruton tyrosine kinase (BTK) inhibitor ibrutinib may limit use of this effective therapy in patients with chronic lymphocytic leukemia (CLL). Acalabrutinib is a second-generation BTK inhibitor with greater BTK selectivity. This analysis characterizes pooled CV adverse events (AE) data in patients with CLL who received acalabrutinib monotherapy in clinical trials (clinicaltrials gov. Identifier: NCT02029443, NCT02475681, NCT02970318 and NCT02337829). Acalabrutinib was given orally at total daily doses of 100-400 mg, later switched to 100 mg twice daily, and continued until disease progression or toxicity. Data from 762 patients (median age: 67 years [range, 32-89]; median follow-up: 25.9 months [range, 0-58.5]) were analyzed. Cardiac AE of any grade were reported in 129 patients (17%; grade ≥3, n=37 [5%]) and led to treatment discontinuation in seven patients (1%). The most common any-grade cardiac AE were atrial fibrillation/flutter (5%), palpitations (3%), and tachycardia (2%). Overall, 91% of patients with cardiac AE had CV risk factors before acalabrutinib treatment. Among 38 patients with atrial fibrillation/flutter events, seven (18%) had prior history of arrhythmia or atrial fibrillation/flutter. Hypertension AE were reported in 67 patients (9%), 43 (64%) of whom had a preexisting history of hypertension; no patients discontinued treatment due to hypertension. No sudden cardiac deaths were reported. Overall, these data demonstrate a low incidence of new-onset cardiac AE with acalabrutinib in patients with CLL. Findings from the head-to-head, randomized trial of ibrutinib and acalabrutinib in patients with highrisk CLL (clinicaltrials gov. Identifier: NCT02477696) prospectively assess differences in CV toxicity between the two agents.

Immunoglobulin replacement therapy in chronic lymphocytic leukaemia patients with hypogammaglobulinaemia and infection

OBJECTIVES

To analyse total national utilisation of immunoglobulin (Ig) replacement therapy (IgRT) for Chronic Lymphocytic Leukaemia patients with acquired hypogammaglobulinaemia and severe and/or recurrent bacterial infections.

METHODS

In 2007, the National Blood Authority first published Criteria for the clinical use of intravenous immunoglobulin in Australia. The Australian Red Cross Lifeblood assessed, approved, and recorded all supply with patient demographics, distribution data, intravenous Ig (IVIg) volumes and treatment episodes. IVIg was the sole product used in Australia from 2008-2013 inclusive.

RESULTS

From 2008 to 2013 across Australia, 2734 individual CLL patients received 48,870 treatment episodes using a total 1,324,926 g of IVIg therapy. Six IVIg products were available, with domestically manufactured Intragam^® P accounting for 89.7% of supply. The average age for first dose was 74 years. Males received 60.6% of the total treatment episodes representing 20% more than females. The average pre-treatment IgG level was 4.03 ± 2.03 g/L (range 0.30-10.50 g/L). A sustained average annual increased IVIg utilisation of 5.5% was observed. There was significant regional variation consistent with differences in prescriber preferences across states and territories.

CONCLUSION

This study provides a globally unique insight into IgRT supply and demand in CLL patients by analysis of total national use in Australia over a 6-year period.

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

OPINION STATEMENT

The better understanding of the biology of chronic lymphocytic leukemia (CLL) gained over the past decade has led to the development and introduction of several targeted drugs, with an demonstrable improvement in the prognosis for this currently incurable condition. Currently, Bruton's tyrosine kinase (BTK) inhibitors, phosphoinositide 3-kinase (PI3K) inhibitors, venetoclax, and CD20 monoclonal antibodies are the key elements in the treatment of both previously untreated and relapsed/refractory CLL patients. Ibrutinib was the first BTK inhibitor approved for clinical use, and showed excellent efficacy and an acceptable safety profile. Following this, the better-tolerated second-generation irreversible BTK inhibitors acalabrutinib and zanubrutinib have been introduced for the treatment of lymphoid malignancies, and acalabrutinib was approved for CLL. When used as single drugs, BTK inhibitors are given continuously until unacceptable toxicity or disease progression; however, when combined with venetoclax and/or CD20 antibodies, they induce deeper response and can be given for a limited time. Recently, promising new reversible BTK inhibitors pirtobrutinib and nemtabrutinib were discovered, and these seem to be more active and better tolerated than their irreversible predecessors. However, they are in an early phase of development and are not currently approved for CLL. The phosphatidylinositol 3-kinase (PI3K) inhibitors idelalisib and duvelisib are highly effective in patients with relapsed CLL, including high-risk disease. The major limitations for their use are adverse events, mostly of autoimmune origin (hepatitis, enteritis/colitis, and pneumonitis). Otherwise, cellular therapies like allogeneic hematopoietic stem cell transplantation and chimeric antigen receptor (CAR) T cells and bispecific monoclonal antibodies offer promise for patients who have failed BTK inhibitors and venetoclax treatment. In the coming years, it is likely that novel targeted therapies will replace immunochemotherapy regimens in most patients.

Recent advances of nanodrug delivery system in the treatment of hematologic malignancies

Although the survival rate of hematological malignancies (HM) has increased in recent years, the unnecessary adverse effect to the body is usually generated by the traditional chemotherapy for HM due to the lack of specificity to tumor tissue. Nanodrug delivery systems have exhibited unique advantages in targetability, stability and reducing toxicity, attracting wide concern, which is expected to be the prevalent alternative for the treatment of HM. In this review, we systemically introduced the current therapeutic strategies and the categories of HM. Subsequently, five key factors including circulation, targeting, penetration, internalization and release involving in tailoring nanoparticles were demonstrated, followed by the introduction of the development of nanodrug delivery-traditional synthetic nanomaterilas, biomimetic cell membrane coating nanomaterials, cell-based nanomaterials as well as immunotherapy combined with nanodrug. Afterwards, the recent advances of nanodrug delivery system for the treatment of HM were introduced. Moreover, the challenge and prospect of nanodrug delivery system in treating HM were discussed. The promising drug delivery system will provide new therapeutic avenues for the treatment of HM.

Elucidation of Focal Adhesion Kinase as a Modulator of Migration and Invasion and as a Potential Therapeutic Target in Chronic Lymphocytic Leukemia

The retention and re-migration of Chronic Lymphocytic Leukemia cells into cytoprotective and proliferative lymphoid niches is thought to contribute to the development of resistance, leading to subsequent disease relapse. The aim of this study was to elucidate the molecular processes that govern CLL cell migration to elicit a more complete inhibition of tumor cell migration. We compared the phenotypic and transcriptional changes induced in CLL cells using two distinct models designed to recapitulate the peripheral circulation, CLL cell migration across an endothelial barrier, and the lymph node interaction between CLL cells and activated T cells. Initially, CLL cells were co-cultured with CD40L-expressing fibroblasts and exhibited an activated B-cell phenotype, and their transcriptional signatures demonstrated the upregulation of pro-survival and anti-apoptotic genes and overrepresentation of the NF-κB signaling pathway. Using our dynamic circulating model, we were able to study the transcriptomics and miRNomics associated with CLL migration. More than 3000 genes were altered when CLL cells underwent transendothelial migration, with an overrepresentation of adhesion and cell migration gene sets. From this analysis, an upregulation of the FAK signaling pathway was observed. Importantly, PTK2 (FAK) gene expression was significantly upregulated in migrating CLL cells (PTK2 Fold-change = 4.9). Here we demonstrate that TLR9 agonism increased levels of p-FAK (p ≤ 0.05), which could be prevented by pharmacological inhibition of FAK with defactinib (p ≤ 0.01). Furthermore, a reduction in CLL cell migration and invasion was observed when FAK was inhibited (p ≤ 0.0001), supporting a role for FAK in both CLL migration and tissue invasion. When taken together, our data highlights the potential for combining FAK inhibition with current targeted therapies as a more effective treatment regime for CLL.

Druggable Molecular Pathways in Chronic Lymphocytic Leukemia

Chronic lymphocytic leukemia (CLL), the most common type of leukemia in adults, is characterized by a high degree of clinical heterogeneity that is influenced by the disease’s molecular complexity. The genes most frequently affected in CLL cluster into specific biological pathways, including B-cell receptor (BCR) signaling, apoptosis, NF-κB, and NOTCH1 signaling. BCR signaling and the apoptosis pathway have been exploited to design targeted medicines for CLL therapy. Consistently, molecules that selectively inhibit specific BCR components, namely Bruton tyrosine kinase (BTK) and phosphoinositide 3-kinase (PI3K) as well as inhibitors of BCL2, have revolutionized the therapeutic management of CLL patients. Several BTK inhibitors and PI3K inhibitors with different modes of action are currently used or are in development in advanced stage clinical trials. Moreover, the restoration of apoptosis by the BCL2 inhibitor venetoclax offers meaningful clinical activity with a fixed-duration scheme. Inhibitors of the BCR and of BCL2 are able to overcome the chemorefractoriness associated with high-risk genetic features, including TP53 disruption. Other signaling cascades involved in CLL pathogenesis, in particular NOTCH signaling and NF-kB signaling, already provide biomarkers for a precision medicine approach to CLL and may represent potential druggable targets for the future. The aim of the present review is to discuss the druggable pathways of CLL and to provide the biological background of the high efficacy of targeted biological drugs in CLL.

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.

Management of Relapsed/Refractory Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma in the Era of Targeted Therapies

PURPOSE OF REVIEW

The treatment landscape for relapsed chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) has changed substantially over the past decade and continues to evolve. Despite the emergence of targeted therapies that are well tolerated and prolong survival, the disease remains incurable and relapse is common particularly in individuals with high-risk features. Herein, we review the key literature about the current options for relapsed disease and explore the emerging role of cellular therapies.

RECENT FINDINGS

Clinical trials have established the role of Bruton tyrosine kinase inhibitors, selective BCL-2 inhibition, and anti-CD20 monoclonal antibodies as treatment options for CLL/SLL. The role of chimeric antigen receptor T cells has shown promise in individuals with CLL/SLL in early phase clinical trials. Novel therapeutic approaches with targeted therapies have redefined the management of CLL/SLL in both the front-line and relapsed/refractory settings. Optimal management in terms of sequencing or combining therapies, especially in individuals with high-risk features, remains a challenge. The emerging role of cellular therapies has the potential to build upon and further improve the current treatment paradigm.

Up to 6.5 years (median 4 years) of follow-up of first-line ibrutinib in patients with chronic lymphocytic leukemia/small lymphocytic lymphoma and high-risk genomic features: integrated analysis of two phase 3 studies

Genomic abnormalities, including del(17p)/TP53 mutation, del(11q), unmutated IGHV, and mutations in BIRC3, NOTCH1, SF3B1, and XPO1 predict poor outcomes with chemoimmunotherapy in chronic lymphocytic leukemia. To better understand the impact of these high-risk genomic features on outcomes with first-line ibrutinib-based therapy, we performed pooled analysis of two phase 3 studies with 498 patients randomized to receive ibrutinib- or chlorambucil-based therapy with median follow-up of 49.1 months. Ibrutinib-based therapy improved overall response rates (ORRs), complete response rates, and progression-free survival (PFS) versus chlorambucil-based therapy across all subgroups. In ibrutinib-randomized patients with versus without specified genomic features, ORR and PFS were comparable across subgroups. PFS hazard ratio (95% CI) for del(17p)/TP53 mutated/BIRC3 mutated: 1.05 (0.54-2.04); del(17p)/TP53 mutation, del(11q), and/or unmutated IGHV: 1.11 (0.69-1.77); unmutated IGHV: 1.79 (0.99-3.24); and NOTCH1 mutated 1.05 (0.65-1.69). This integrated analysis demonstrated efficacy of first-line ibrutinib-based treatment irrespective of cytogenetic and mutational risk features.Registered at ClinicalTrials.gov (NCT01722487 and NCT02264574).

Bruton Tyrosine Kinase Inhibitors in B-Cell Malignancies: Their Use and Differential Features

Starting with the first-in-class agent ibrutinib, the development of Bruton tyrosine kinase (BTK) inhibitors has led to dramatic improvements in the management of B-cell malignancies. Subsequently, more-highly selective second-generation BTK inhibitors (including acalabrutinib, zanubrutinib, tirabrutinib and orelabrutinib) have been developed, primarily with an aim to reduce off-target toxicities. More recently, third-generation agents including the non-covalent BTK inhibitors pirtobrutinib and nemtabrutinib have entered later-stage clinical development. BTK inhibitors have shown strong activity in a range of B-cell malignancies, including chronic lymphocytic leukaemia/small lymphocytic lymphoma, mantle cell lymphoma, Waldenström's macroglobulinaemia and marginal zone lymphoma. The agents have acceptable tolerability, with adverse events generally being manageable with dosage modification. This review article summarises the evidence supporting the role of BTK inhibitors in the management of B-cell malignancies, including highlighting some differential features between agents.

Treatment Approaches to Chronic Lymphocytic Leukemia With High-Risk Molecular Features

The clinical course of chronic lymphocytic leukemia (CLL) is highly variable. Over the past decades, several cytogenetic, immunogenetic and molecular features have emerged that identify patients suffering from CLL with high-risk molecular features. These biomarkers can clearly aid prognostication, but may also be capable of predicting the efficacy of various treatment strategies in subgroups of patients. In this narrative review, we discuss treatment approaches to CLL with high-risk molecular features. Specifically, we review and provide a comprehensive overview of clinical trials evaluating the efficacy of chemotherapy, chemoimmunotherapy and novel agent-based treatments in CLL patients with TP53 aberrations, deletion of the long arm of chromosome 11, complex karyotype, unmutated IGHV, B cell receptor stereotypy, and mutations in NOTCH1 or BIRC3. Furthermore, we discuss future pharmaceutical and immunotherapeutic perspectives for CLL with high-risk molecular features, focusing on agents currently under investigation in clinical trials.

Do age, fitness, and concomitant medications influence management and outcomes of patients with CLL treated with ibrutinib?

Functional reserve of organs and systems is known to be relevant in predicting immunochemotherapy tolerance. Age and comorbidities, assessed by the cumulative illness rating scale (CIRS), have been used to address chemotherapy intensity. In the ibrutinib era, it is still unclear whether age, CIRS, and Eastern Cooperative Oncology Group performance status (ECOG-PS) retain their predictive role on treatment vulnerability. In this series of 712 patients with chronic lymphocytic leukemia (CLL) treated with ibrutinib outside clinical trials, baseline ECOG-PS and neutropenia resulted as the most accurate predictors of treatment feasibility and outcomes. Age did not independently influence survival and ibrutinib tolerance, indicating that not age per se, but age-related conditions, may affect drug management. We confirmed the role of CIRS > 6 as a predictor of a poorer progression- and event-free survival (PFS, EFS). The presence of a severe comorbidity was significantly associated with permanent dose reductions (PDRs), not translating into worse outcomes. As expected, del(17p) and/or TP53mut and previous therapies affected PFS, EFS, and overall survival. No study so far has analyzed the influence of concomitant medications and CYP3A inhibitors with ibrutinib. In our series, these factors had no impact, although CYP3A4 inhibitors use correlated with Cox regression analysis, with an increased risk of PDR. Despite the limitation of its retrospective nature, this large study confirmed the role of ECOG-PS as the most accurate predictor of ibrutinib feasibility and outcomes, and importantly, neutropenia emerged as a relevant tool influencing patients' vulnerability. Although CIRS > 6 retained a significant impact on PFS and EFS, its value should be confirmed by prospective studies.

Bruton's Tyrosine Kinase Inhibitors Impair FcγRIIA-Driven Platelet Responses to Bacteria in Chronic Lymphocytic Leukemia

Bacterial infections are a major cause of morbidity and mortality in chronic lymphocytic leukemia (CLL), and infection risk increases in patients treated with the Bruton’s tyrosine kinase (Btk) inhibitor, ibrutinib. Btk and related kinases (like Tec) are expressed in non-leukemic hematopoietic cells and can be targeted by ibrutinib. In platelets, ibrutinib therapy is associated with bleeding complications mostly due to off-target effects. But the ability of platelets to respond to bacteria in CLL, and the potential impact of ibrutinib on platelet innate immune functions remain unknown. FcγRIIA is a tyrosine kinase-dependent receptor critical for platelet activation in response to IgG-coated pathogens. Crosslinking of this receptor with monoclonal antibodies causes downstream activation of Btk and Tec in platelets, however, this has not been investigated in response to bacteria. We asked whether ibrutinib impacts on FcγRIIA-mediated activation of platelets derived from CLL patients and healthy donors after exposure to Staphylococcus aureus Newman and Escherichia coli RS218. Platelet aggregation, α-granule secretion and integrin αIIbβ3-dependent scavenging of bacteria were detected in CLL platelets but impaired in platelets from ibrutinib-treated patients and in healthy donor-derived platelets exposed to ibrutinib in vitro. While levels of surface FcγRIIA remained unaffected, CLL platelets had reduced expression of integrin αIIbβ3 and GPVI compared to controls regardless of therapy. In respect of intracellular signaling, bacteria induced Btk and Tec phosphorylation in both CLL and control platelets that was inhibited by ibrutinib. To address if Btk is essential for platelet activation in response to bacteria, platelets derived from X-linked agammaglobulinemia patients (lacking functional Btk) were exposed to S. aureus Newman and E. coli RS218, and FcγRIIA-dependent aggregation was observed. Our data suggest that ibrutinib impairment of FcγRIIA-mediated platelet activation by bacteria results from a combination of Btk and Tec inhibition, although off-target effects on additional kinases cannot be discarded. This is potentially relevant to control infection-risk in CLL patients and, thus, future studies should carefully evaluate the effects of CLL therapies, including Btk inhibitors with higher specificity for Btk, on platelet-mediated immune functions.

Clonal Evolution of High-Risk Chronic Lymphocytic Leukemia: A Contemporary Perspective

Clonal evolution represents the natural process through which cancer cells continuously search for phenotypic advantages that enable them to develop and expand within microenvironmental constraints. In chronic lymphocytic leukemia (CLL), clonal evolution underpins leukemic progression and therapeutic resistance, with differences in clonal evolutionary dynamics accounting for its characteristically diverse clinical course. The past few years have witnessed profound changes in our understanding of CLL clonal evolution, facilitated by a maturing definition of high-risk CLL and an increasing sophistication of next-generation sequencing technology. In this review, we offer a modern perspective on clonal evolution of high-risk CLL, highlighting recent discoveries, paradigm shifts and unresolved questions. We appraise recent advances in our understanding of the molecular basis of CLL clonal evolution, focusing on the genetic and non-genetic sources of intratumoral heterogeneity, as well as tumor-immune dynamics. We review the technological innovations, particularly in single-cell technology, which have fostered these advances and represent essential tools for future discoveries. In addition, we discuss clonal evolution within several contexts of particular relevance to contemporary clinical practice, including the settings of therapeutic resistance to CLL targeted therapy and immunotherapy, as well as Richter transformation of CLL to high-grade lymphoma.

Zanubrutinib for treatment-naïve and relapsed/refractory chronic lymphocytic leukaemia: long-term follow-up of the phase I/II AU-003 study

The phase I/II AU-003 study in patients with treatment-naïve (TN) or relapsed/refractory (R/R) chronic lymphocytic leukaemia/small lymphocytic lymphoma demonstrated that zanubrutinib therapy results in clinically meaningful and durable responses with acceptable safety and tolerability. We report updated safety and efficacy data for 123 patients with a median follow-up of 47·2 months. Patients received zanubrutinib 160 mg twice daily (81 patients), 320 mg once daily (40), or 160 mg once daily (two). Discontinuations due to adverse events or disease progression were uncommon. The overall response rate (ORR) was 95·9% (TN, 100%; R/R, 95%) with 18·7% achieving complete response (CR). Ongoing response at 3 years was reported in 85·7%. The ORR in patients with del(17p)/tumour protein p53 mutation was 87·5% (CR 16·7%). The 2- and 3-year progression-free survival estimates were 90% (TN, 90%; R/R, 91%) and 83% (TN, 81%; R/R, 83%) respectively. The most reported Grade ≥3 adverse events were neutropenia (15·4%), pneumonia (9·8%), hypertension (8·9%) and anaemia (6·5%). The annual incidence of atrial fibrillation, major haemorrhage, Grade ≥3 neutropenia and Grade ≥3 infection decreased over time. With a median follow-up of ~4 years, responses remain clinically meaningful and durable and long-term tolerability to zanubrutinib therapy continues.

Longitudinal Single-Cell Dynamics of Chromatin Accessibility and Mitochondrial Mutations in Chronic Lymphocytic Leukemia Mirror Disease History

While cancers evolve during disease progression and in response to therapy, temporal dynamics remain difficult to study in humans due to the lack of consistent barcodes marking individual clones in vivo. We employ mitochondrial single-cell assay for transposase-accessible chromatin with sequencing to profile 163,279 cells from 9 patients with chronic lymphocytic leukemia (CLL) collected across disease course and utilize mitochondrial DNA (mtDNA) mutations as natural genetic markers of cancer clones. We observe stable propagation of mtDNA mutations over years in the absence of strong selective pressure, indicating clonal persistence, but dramatic changes following tight bottlenecks, including disease transformation and relapse posttherapy, paralleled by acquisition of copy-number variants and changes in chromatin accessibility and gene expression. Furthermore, we link CLL subclones to distinct chromatin states, providing insight into nongenetic sources of relapse. mtDNA mutations thus mirror disease history and provide naturally occurring genetic barcodes to enable patient-specific study of cancer subclonal dynamics.

SIGNIFICANCE

Single-cell multi-omic profiling of CLL reveals the utility of somatic mtDNA mutations as in vivo barcodes, which mark subclones that can evolve over time along with changes in accessible chromatin and gene expression profiles to capture dynamics of disease evolution. See related commentary by Hilton and Scott, p. 2965. This article is highlighted in the In This Issue feature, p. 2945.

Expert-independent classification of mature B-cell neoplasms using standardized flow cytometry: a multicentric study

Reproducible expert-independent flow-cytometric criteria for the differential diagnoses between mature B-cell neoplasms are lacking. We developed an algorithm-driven classification for these lymphomas by flow cytometry and compared it to the WHO gold standard diagnosis. Overall, 662 samples from 662 patients representing nine disease categories were analyzed at 9 laboratories using the previously published EuroFlow 5-tube-8-color B-cell chronic lymphoproliferative disease antibody panel. Expression levels of all 26 markers from the panel were plotted by B-cell entity to construct a univariate, fully standardized diagnostic reference library. For multivariate data analysis we subsequently utilized Canonical Correlation Analysis of 176 training cases to project the multi-dimensional space of all 26 immunophenotypic parameters into 36 two-dimensional plots for each possible pair-wise differential diagnosis. Diagnostic boundaries were fitted according to the distribution of the immunophenotypes of a given differential diagnosis. A diagnostic algorithm based on these projections was developed and subsequently validated using 486 independent cases. Negative predictive values exceeding 92.1% were observed for all disease categories except for follicular lymphoma. Particularly high positive predictive values were returned in chronic lymphocytic leukemia (99.1%), hairy cell leukemia (97.2%), follicular lymphoma (97.2%) and mantle cell lymphoma (95.4%). Burkitt and CD10+ diffuse large B-cell lymphomas were difficult to distinguish by the algorithm. A similar ambiguity was observed between marginal zone, lymphoplasmacytic, and CD10- diffuse large B-cell lymphomas. The specificity of the approach exceeded 98% for all entities. The univariate immunophenotypic library and the multivariate expert-independent diagnostic algorithm might contribute to increased reproducibility of future diagnostics in mature B-cell neoplasms.

Ibrutinib protects T cells in patients with CLL from proliferation-induced senescence

Background

The development of Bruton’s tyrosine kinase inhibitors (BTKi) for the treatment of chronic lymphocytic leukaemia (CLL) has provided a highly effective and relatively non-toxic alternative to conventional chemotherapy. Some studies have shown that BTKi can also lead to improvements in T cell immunity in patients despite in vitro analyses suggesting an immunosuppressive effect of BTKi on T cell function.

Methods

In this study, we examined both the in vitro effect and long-term in vivo effect of two clinically available BTKi, ibrutinib and zanubrutinib. Additional in vitro assessments were undertaken for a third BTKi, acalabrutinib. Immune subset phenotyping, cytokine secretion, T cell degranulation and proliferation assays were performed on peripheral blood mononuclear cells isolated from untreated CLL patients, and CLL patients on long-term (> 12 months) BTKi treatment.

Results

Similar to prior studies we observed that long-term BTKi treatment normalises lymphocyte subset frequency and reduces PD-1 expression on T cells. We also observed that T cells from patients taken prior to BTKi therapy showed an abnormal hyper-proliferation pattern typical of senescent T cells, which was normalised by long-term BTKi treatment. Furthermore, BTKi therapy resulted in reduced expression of the T cell exhaustion markers PD-1, TIM3 and LAG3 in late generations of T cells undergoing proliferation.

Conclusions

Collectively, these findings indicate that there are critical differences between the in vitro effects of BTKi on T cell function and the effects derived from long-term BTKi exposure in vivo. Overall long-term exposure to BTKi, and particularly ibrutinib, resulted in improved T cell fitness in part due to suppressing the abnormal hyper-proliferation of CLL T cells and the associated development of T cell senescence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03136-2.

Janus kinases restrain chronic lymphocytic leukemia cells in patients on ibrutinib: Results of a phase II trial

Preclinical observations that killing of chronic lymphocytic leukemia (CLL) cells was dexamethasone (DEX) were enhanced by concomitant inhibition of Bruton's tyrosine kinase and janus kinases (JAKs) motivated a phase II trial to determine if clinical responses to ibrutinib could be deepened by DEX and the JAK inhibitor ruxolitinib. Patients on ibrutinib at 420 mg daily for 2 months or with abnormal serum β2M levels after 6 months or with persistent lymphadenopathy or splenomegaly after 12 months were randomized to receive DEX 40 mg on days 1-4 of a 4-week cycle for six cycles alone (three patients) or with ruxolitinib 15 mg BID on days 1-21 of each cycle (five patients). Ruxolitinib dosing was based on a previous phase I trial. Steroid withdrawal symptoms and significantly decreased serum IgG levels occurred in all patients regardless of their exposure to ruxolitinib. A fatal invasive fungal infection was seen in a patient taking DEX without ruxolitinib. Complete responses anticipated with addition of ruxolitinib were not seen. Gene expression studies suggested ruxolitinib had turned off interferon signaling in CLL cells and turned on genes associated with the activation of NFκB by TNF-α. Ruxolitinib increased blood levels of TNF-α by cycle 3 and decreased the inhibitory cytokine IL-10. These results suggest ruxolitinib releases activating signals for CLL cells that persist in patients on ibrutinib. This inhibitory JAK signaling may contribute to the therapeutic activity of ibrutinib. Thus JAK inhibitors provide no added value with ibrutinib for disease control and should be used with caution in CLL patients. Combining glucocorticoids with ibrutinib may increase the risk of serious infects.

Safety Profile of Ibrutinib: An Analysis of the WHO Pharmacovigilance Database

As ibrutinib has become a standard of care in B-cell malignancies in monotherapy or in combination with other agents, definition of its safety profile appears essential. The aim of this study was to further characterize the safety profile of ibrutinib through the identification of potential safety signals in a large-scale pharmacovigilance database. All serious individual case safety reports (ICSRs) in patients aged ≥18 years involving ibrutinib suspected in the occurrence of serious adverse drug reactions or drug interacting from November 13th, 2013 to December 31st, 2020 were extracted from VigiBase, the World Health Organization global safety database. Disproportionality reporting was assessed using the information component (IC) and the proportional reporting ratio (PRR), with all other anticancer drugs used as the reference group. To mitigate the confounding of age, two subgroups were considered: patients aged<75 years and ≥75 years. A signal of disproportionate reporting (SDR) was defined if both IC and PRR were significant. A total of 16,196 ICSRs were included. The median age of patients was 72.9 years, 42.6% of ICSRs concerned patients aged ≥75 years, and 64.2% male patients. More than half (56.2%) of ICSRs resulted in hospitalization or prolonged hospitalization. Among 713 SDRs, 36 potential safety signals emerged in ibrutinib-treated patients, mainly ischemic heart diseases, pericarditis, uveitis, retinal disorders and fractures. All potential safety signals having arisen in this analysis may support patient care and monitoring of ongoing clinical trials. However, owing to the mandatory limitations of this study, our results need further confirmation using population-based studies.

Acalabrutinib Versus Ibrutinib in Previously Treated Chronic Lymphocytic Leukemia: Results of the First Randomized Phase III Trial

PURPOSE

Among Bruton's tyrosine kinase inhibitors, acalabrutinib has greater selectivity than ibrutinib, which we hypothesized would improve continuous therapy tolerability. We conducted an open-label, randomized, noninferiority, phase III trial comparing acalabrutinib and ibrutinib in patients with chronic lymphocytic leukemia (CLL).

METHODS

Patients with previously treated CLL with centrally confirmed del(17)(p13.1) or del(11)(q22.3) were randomly assigned to oral acalabrutinib 100 mg twice daily or ibrutinib 420 mg once daily until progression or unacceptable toxicity. The primary end point was independent review committee-assessed noninferiority of progression-free survival (PFS).

RESULTS

Overall, 533 patients (acalabrutinib, n = 268; ibrutinib, n = 265) were randomly assigned. At the data cutoff, 124 (46.3%) acalabrutinib patients and 109 (41.1%) ibrutinib patients remained on treatment. After a median follow-up of 40.9 months, acalabrutinib was determined to be noninferior to ibrutinib with a median PFS of 38.4 months in both arms (95% CI acalabrutinib, 33.0 to 38.6 and ibrutinib, 33.0 to 41.6; hazard ratio: 1.00; 95% CI, 0.79 to 1.27). All-grade atrial fibrillation/atrial flutter incidence was significantly lower with acalabrutinib versus ibrutinib (9.4% v 16.0%; P = .02); among other selected secondary end points, grade 3 or higher infections (30.8% v 30.0%) and Richter transformations (3.8% v 4.9%) were comparable between groups and median overall survival was not reached in either arm (hazard ratio, 0.82; 95% CI, 0.59 to 1.15), with 63 (23.5%) deaths with acalabrutinib and 73 (27.5%) with ibrutinib. Treatment discontinuations because of adverse events occurred in 14.7% of acalabrutinib-treated patients and 21.3% of ibrutinib-treated patients.

CONCLUSION

In this first direct comparison of less versus more selective Bruton's tyrosine kinase inhibitors in CLL, acalabrutinib demonstrated noninferior PFS with fewer cardiovascular adverse events.

The road to chemotherapy-free treatment in chronic lymphocytic leukaemia

PURPOSE OF REVIEW

The treatment landscape of chronic lymphocytic leukaemia (CLL) has tremendously evolved in the last decades, from chemo to chemoimmunotherapy (CIT) and, eventually, to pathway inhibitors that target critical pathways for leukaemic cells survival. Also, treatment goals are moving towards achieving undetectable minimal residual disease with little toxicity.

RECENT FINDINGS

We performed a thorough review of the history of treatment approvals by both the Food and Drug Administration (FDA) and the European Medicines Agency (EMA). This review especially focuses on therapies that are currently approved by both agencies. The indications and particular characteristics of each drug are examined.

SUMMARY

Currently available treatment approaches for CLL offer the opportunity to individualize therapy for every single patient with CLL. Inhibitors of B-cell receptor (BCR) signalling pathways and antiapoptotic proteins are nowadays the treatment of choice for most CLL patients, but CIT can be an option for younger and fit patients with low-risk disease [mutated IGHV, no del(11q) or del(17p)/TP53 mutations].

BTK Inhibitors Combined With Chemoimmunotherapy in CLL - The Best of Both Worlds?

Chemoimmunotherapy (CIT) remains a standard-of-care in many regions for first line (1L) therapy of CLL. In fit patients, fludarabine, cyclophosphamide, and rituximab (FCR) has the advantage of achieving undetectable measurable residual disease (MRD) with time-limited treatment and prolonged treatment-free remissions with a plateau on the PFS curve, but have several limitations, most notably the inferior PFS and survival outcomes for patients with unmutated IGHV compared to ibrutinib + rituximab seen in the E1912 study and a risk for long-term toxicities such as therapy-related myeloid neoplasms. Given the nonoverlapping toxicity profile with CIT and its efficacy in patients with high risk genomics, ibrutinib is a potentially useful agent to combine with CIT, with the aim of achieving deep and durable remissions, with time-limited treatment. Three recent phase 2 studies have combined ibrutinib with chemoimmunotherapy, utilizing different approaches in terms of patient selection, sequencing and duration of therapy and choice of monoclonal antibody. These studies all demonstrated favorable toxicity profiles and higher rates of undetectable MRD than with any other previously utilized 1L regimen. This review will focus on this novel treatment approach in CLL.

Ibrutinib in Advanced Chronic Lymphocytic Leukemia/Small Lymphocytic Lymphoma: Lower Risk of Hepatitis B Virus Reactivation

INTRODUCTION

Therapy of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) with drugs such as ibrutinib and rituximab is often associated with immune suppression, opportunistic infections, and reactivation of virus infections such as hepatitis B virus (HBV). This risk is especially important in geographical regions like Asia where many potential therapy recipients have HBV infection. Also, whether safety and efficacy of ibrutinib in Asians and Europeans with advanced CLL/SLL are similar is unknown. We determined the safety and efficacy of ibrutinib compared with rituximab in advanced CLL/SLL including persons with HBV infection. We compared outcomes with data published from trials in persons of European descent.

METHODS

This is a post hoc analysis of a multicenter, phase-3 trial (NCT01973387). Subjects with advanced CLL/SLL were randomized 2:1 to receive ibrutinib, 420 mg/day, or rituximab, 500 mg/mE + 2, for 6 cycles. Subjects with resolved HBV infection were included. Endpoints were progression-free survival (PFS), overall response rate (ORR), survival, and adverse events including resolved HBV reactivation.

RESULTS

131 subjects received ibrutinib (N = 87) or rituximab (N = 44) including 53 with resolved HBV infection. Median follow-up was 31 months (95% confidence interval: 28, 32 months). ORR was 61% (50, 71%) versus 7% (2, 18%; p < 0.001). Median PFS was not reached in the ibrutinib cohort but must be >40 months versus 8 months (7, 9 months; p < 0.0001) in the rituximab cohort. Median survival was not reached but must be >40 months versus 27 months (17 months, NE; p = 0.0006). In multivariable analyses, receiving ibrutinib increased PFS (hazard rate [HR] for failure = 0.12 [0.06, 0.23]; p < 0.001) and decreased risk of death (HR = 0.31 [0.15, 0.63]; p < 0.001). Median duration of exposure to ibrutinib was significantly longer than exposure to rituximab (28 vs. 5 months). The safety profile of ibrutinib was consistent with that observed in previous studies with no new safety signal. No subject receiving ibrutinib had HBV reactivation versus 2 receiving rituximab, despite much greater use of drugs to prevent HBV reactivation in the rituximab cohort. Outcomes were like those reported in persons of European descent, except ORR which, was unreliably correlated with PFS in Asians.

CONCLUSION

Ibrutinib is safe and effective in persons with advanced CLL/SLL and better than rituximab in all therapy outcomes including risk of HBV reactivation. Outcomes with ibrutinib in Chinese were like those reported in persons of predominately European descent.

Targeting the p53 Pathway in CLL: State of the Art and Future Perspectives

The p53 pathway is a desirable therapeutic target, owing to its critical role in the maintenance of genome integrity. This is exemplified in chronic lymphocytic leukemia (CLL), one of the most common adult hematologic malignancies, in which functional loss of p53 arising from genomic aberrations are frequently associated with clonal evolution, disease progression, and therapeutic resistance, even in the contemporary era of CLL targeted therapy and immunotherapy. Targeting the 'undruggable' p53 pathway therefore arguably represents the holy grail of cancer research. In recent years, several strategies have been proposed to exploit p53 pathway defects for cancer treatment. Such strategies include upregulating wild-type p53, restoring tumor suppressive function in mutant p53, inducing synthetic lethality by targeting collateral genome maintenance pathways, and harnessing the immunogenicity of p53 pathway aberrations. In this review, we will examine the biological and clinical implications of p53 pathway defects, as well as our progress towards development of therapeutic approaches targeting the p53 pathway, specifically within the context of CLL. We will appraise the opportunities and pitfalls associated with these therapeutic strategies, and evaluate their place amongst the array of new biological therapies for CLL.

Efficacy of venetoclax plus rituximab for relapsed CLL: 5-year follow-up of continuous or limited- duration therapy

We report long-term follow-up of the phase 1b study of venetoclax and rituximab (VenR) in patients with relapsed chronic lymphocytic leukemia (CLL), including outcomes with continuous or limited-duration therapy. Patients received venetoclax daily (200-600 mg) and rituximab over 6 months and then received venetoclax monotherapy. Patients achieving complete response (CR), CR with incomplete marrow recovery (CRi), or undetectable minimal residual disease (uMRD) assessed by flow cytometry (<10-4 cutoff) were allowed, but not required, to discontinue therapy, while remaining in the study and could be retreated with VenR upon progression. Median follow-up for all patients (N = 49) was 5.3 years. Five-year rates (95% CI) for overall survival, progression-free survival, and duration of response were 86% (72-94), 56% (40-70), and 58% (40-73), respectively. Of the 33 deep responders (CR/CRi or uMRD), 14 remained on venetoclax monotherapy (continuous therapy), and 19 stopped venetoclax therapy (limited-duration therapy) after a median of 1.4 years. Five-year estimates of ongoing response were similar between continuous (71%; 95% CI, 39-88) or limited-duration therapy (79% [49-93]). Six of 19 patients in the latter group had subsequent disease progression, all >2 years off venetoclax (range, 2.1-6.4). Four patients were retreated with VenR, with partial responses observed in the 3 evaluable to date. VenR induced deep responses that were highly durable with either continuous or limited-duration therapy. Retreatment with VenR induced responses in patients with CLL progression after discontinuing therapy. Continuous exposure to venetoclax in deep responders does not appear to provide incremental benefit.

How I treat and prevent venous thrombotic complications in patients with lymphoma

Venous thromboembolism (VTE) is a common complication occurring in 5-10% of patients with lymphoma. As the complexity of lymphoma management has increased with novel therapies, so too has the treatment of VTE. Therapeutic options for the treatment of cancer-associated VTE have expanded from only warfarin and low-molecular-weight heparins (LMWHs) to include the direct oral anticoagulants (DOACs) apixaban, edoxaban and rivaroxaban. There have been no head-to-head trials comparing different DOACs in this setting and randomized trials comparing a DOAC with LMWH dalteparin differ in trial design and results. Drug-drug interactions, drug-specific side effects and patient selection are important considerations when prescribing anticoagulant therapy. In all patients, the relative risks of thrombosis and bleeding, the availability of the anticoagulant, and the life expectancy of the patient are vital elements in selecting the most appropriate anticoagulant (which can vary over time) for the individual patient. We describe the intricacies and challenges of treating thrombotic complications in patients with lymphoma with an emphasis on evidence and guideline-based care.

Is There a Role for Cellular Therapy in Chronic Lymphocytic Leukemia?

ABSTRACT

Despite multiple advances in the treatment landscape of chronic lymphocytic leukemia (CLL) during recent years, cellular therapies, such as allogeneic hematopoietic cell transplantation and chimeric antigen-engineered T cells, represent valuable therapeutic options for patients with multiply relapsed or poor-risk disease. This brief overview will summarize current results of cellular therapies in CLL including Richter transformation, suggest an indication algorithm and strategies for performing cellular therapies in these conditions, and discuss the impact of COVID-19 (coronavirus disease 2019) on allogeneic hematopoietic cell transplantation and chimeric antigen-engineered T cells in CLL.

Tafasitamab combined with idelalisib or venetoclax in patients with CLL previously treated with a BTK inhibitor

Patients with relapsed/refractory chronic lymphocytic leukemia (R/R CLL) whose treatment failed with a Bruton's tyrosine kinase inhibitor have poor outcomes. We investigated tafasitamab plus idelalisib (cohort A) or venetoclax (cohort B) in this patient population in a phase II study (NCT02639910). In total, 24 patients were enrolled (cohort A: n = 11, median time on study, 7.4 months; cohort B: n = 13, median time on study, 15.6 months). The most common treatment-emergent adverse event (TEAE) in cohort A was anemia (63.6%) and in cohort B was infusion-related reaction (53.8%). The most common severe TEAE was neutropenia (cohort A: 45.5%; cohort B: 46.2%). The best overall response rate was 90.9% (cohort A) and 76.9% (cohort B). Undetectable minimal residual disease in peripheral blood was achieved in 2/8 patients (cohort A) and 6/7 patients (cohort B). Overall, these results suggest that anti-CD19 antibody-based combinations may be important in the treatment of patients with CLL.

A phase Ib, open label, dose escalation trial of the anti-CD37 monoclonal antibody, BI 836826, in combination with ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia

BI 836826 is a chimeric immunoglobulin G1 antibody targeting CD37, a transmembrane protein expressed on normal and malignant B cells. This open-label, phase Ib, dose-escalation study was conducted to determine the recommended phase II dose (RP2D) of BI 836826 + ibrutinib in patients with relapsed/refractory chronic lymphocytic leukemia (CLL). Eligible patients received 420 mg/day of ibrutinib with escalating doses of BI 836826. BI 836826 was administered in 4-week cycles. After Cycle 12, patients achieving complete response (CR), CR with incomplete marrow recovery, or minimal residual disease-negative partial response could continue to receive BI 836826 + ibrutinib every 4 weeks for ≤ 12 additional cycles. Patients received either 100 mg (n = 3) or 200 mg (n = 3) BI 836826 + ibrutinib. In the 100 mg BI 836826 cohort, one patient received two cycles and two patients received 22 cycles of BI 836826. In the 200 mg BI 836826 cohort, patients received 12, 16 and 20 cycles of BI 836826, respectively. All patients discontinued BI 836826 and continued ibrutinib outside the trial. No dose-limiting toxicities were reported in the maximum tolerated dose (MTD) evaluation period. As the trial was discontinued before the MTD was reached, the RP2D was not determined. Grade 3/4 adverse events (AEs) were predominantly hematological. Pseudomonal bacteremia was the only drug-related AE of special interest. BI 836826 + ibrutinib did not exceed the MTD at doses up to 200 mg in patients with CLL. However, RP2D and MTD were not formally established, as the sponsor discontinued the trial.

Real-world treatment sequencing and healthcare costs among CLL/SLL patients treated with venetoclax

OBJECTIVE

This study aimed to describe treatment sequencing and healthcare costs among chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL) patients treated with venetoclax in a US managed care population.

METHODS

CLL/SLL patients initiating venetoclax between 04/11/2016 and 06/30/2019 were selected from Optum's de-identified Clinformatics Data Mart Database. Costs per-patient-per-month were described during the first 60 days of venetoclax-based treatment (initiation phase) and subsequent post-initiation phase. Based on venetoclax prescribing information, clinical event-related costs were identified through claims for tumor lysis syndrome (TLS) diagnosis, monitoring, prophylaxis, immunoglobulin treatment, neutropenia, thrombocytopenia, infection, renal impairment, hypertension, or cardiac arrhythmia. Statistical testing was not conducted due to small sample size.

RESULTS

Twenty-five, 30, and 66 patients initiated venetoclax as their first observed regimen (1L), second observed regimen (2L), and third or later observed regimen (3L+), respectively. Most 2L (56.7%) and 3L+ (74.2%) venetoclax recipients previously received ibrutinib. Mean monthly all-cause costs during the initiation phase were $26,429 (1L cohort), $19,580 (2L cohort), and $23,918 (3L + cohort). Among the 2L cohort, mean monthly all-cause [clinical event-related] (including TLS) costs during initiation and post-initiation phases of venetoclax treatment were $15,506 [$6368] (initiation phase) and $14,318 [$5273] (post-initiation phase; median duration: 3.7 months) for patients receiving 1L ibrutinib, and $24,908 [$12,198] (initiation phase) and $16,905 [$7066] (post-initiation phase; median duration: 3.0 months) for patients not receiving 1L ibrutinib.

CONCLUSIONS

In this descriptive study, highest mean costs were observed during venetoclax initiation phase. Venetoclax patients previously receiving ibrutinib had lower mean total all-cause and clinical event-related (including TLS) costs during their venetoclax line of therapy than those previously receiving non-ibrutinib therapy.

Acalabrutinib in management of chronic lymphocytic leukemia: An Indian perspective

The treatment landscape of chronic lymphocytic leukemia (CLL) has witnessed immense changes in the past decade. Several newer target therapies and their combinations with anti-CD 20 therapies have got approval for management of CLL in the treatment-naïve and relapsed/refractory setting. Also, the availability of newer diagnostic techniques has helped differentiate the disease into high- and low-risk CLL which acts not just as a prognostic marker but also helps decide the best drug management that can be administered to the patients. Targeted therapy has largely overtaken chemoimmunotherapy in the management of CLL, except for a small subset of the population (young and fit with IGHV mutation). However, with targeted therapy, there is also an issue of previously uncommon treatment-emergent adverse events, the duration of therapy, and financial toxicity. The aim of this review article is to gather results from all landmark CLL trials and discuss the feasibility of incorporating Acalabrutinib in the CLL landscape from an Indian perspective.

A fixed-duration, measurable residual disease-guided approach in CLL: follow-up data from the phase 2 ICLL-07 FILO trial

Trials assessing first-line, fixed-duration approaches in chronic lymphocytic leukemia (CLL) are yielding promising activity, but few long-term data are available. We report follow-up data from a phase 2 trial (ICLL07 FILO) in previously untreated, medically fit patients (N = 135). Patients underwent obinutuzumab-ibrutinib induction for 9 months; then, following evaluation (N = 130 evaluable), those in complete remission and with bone marrow measurable residual disease (BM MRD) <0.01% (n = 10) received ibrutinib for 6 additional months; those in partial remission and/or with BM MRD ≥0.01%, the majority (n = 120), also received 4 cycles of immunochemotherapy (fludarabine/cyclophosphamide-obinutuzumab). Beyond end of treatment, responses were assessed every 3 month and peripheral blood MRD every 6 months. At median follow-up 36.7 months from treatment start, progression-free and overall survival rates (95% confidence interval) at 3 years were 95.7% (92.0% to 99.5%) and 98% (95.1% to 100%), respectively. Peripheral blood MRD <0.01% rates were 97%, 96%, 90%, 84%, and 89% at months 16, 22, 28, 34, and 40, respectively. No new treatment-related or serious adverse event occurred beyond end of treatment. Thus, in previously untreated, medically fit patients with CLL, a fixed-duration (15 months), MRD-guided approach achieved high survival rates, a persistent MRD benefit beyond the end of treatment, and low long-term toxicity. This trial was registered at www.clinicaltrials.gov as #NCT02666898.

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.

Integrating New Therapies for Chronic Lymphocytic Leukemia

ABSTRACT

Over the last 2 decades, treatment of chronic lymphocytic leukemia (CLL) therapy has drastically changed, resulting in greatly improved survival and treatment tolerance with current targeted therapies. First, the transition from chemotherapy (alkylating agents, nucleoside analogs) to chemoimmunotherapy with the addition of anti-CD20 antibodies resulted in deeper and more complete remissions, with an improvement in progression-free and overall survival. Over the last few years, chemoimmunotherapy has gradually been replaced by new targeted agents, based on further improvement in survival, especially in patients with high-risk CLL, and fewer adverse effects, that is, a lack of myelosuppression and lack of DNA damage and associated risk of secondary acute myeloid leukemia/myelodysplastic syndrome. The most active targeted treatments for CLL patients are the kinase inhibitors, which inhibit signaling of surface receptors, especially the B-cell antigen receptor, and the BCL-2 antagonist venetoclax. Among the kinase inhibitors, Bruton tyrosine kinase inhibitors are highly effective and generally well-tolerated and induce durable responses in the vast majority of patients. PI3 kinase inhibitors are alternatives for patients with intolerance to Bruton tyrosine kinase inhibitors. This review discusses the rationale for the transition from chemotherapy-based treatment to the novel agents, the activity, adverse effects, sequencing, and combinations of the novel agents and provides an outlook into future CLL therapy for the next decade.

The Biology of Chronic Lymphocytic Leukemia: Diagnostic and Prognostic Implications

ABSTRACT

The high degree of clinical heterogeneity of chronic lymphocytic leukemia (CLL) is influenced by the disease molecular complexity. Genetic studies have allowed to better understand CLL biology and to identify molecular biomarkers of clinical relevance. TP53 disruption represents the strongest prognosticator of chemorefractoriness and indicates the use of Bruton tyrosine kinase inhibitors (BTKis) and BCL2 inhibitors. Unmutated IGHV (immunoglobulin heavy variable) genes also predict refractoriness to chemoimmunotherapy; importantly, when treated with B-cell receptor inhibitors or BCL2 inhibitors, IGHV unmutated patients display an outcome similar to that of IGHV mutated CLL. Before choosing treatment, a comprehensive assessment of TP53 and IGHV status is recommended by all guidelines for CLL clinical management. In case of fixed-duration therapeutic strategies, monitoring of minimal residual disease may provide a tool to decide treatment duration. The current precision medicine management of CLL patients might be further improved by the adoption of novel biomarkers that are emerging as clinically meaningful for this disease.

Prognostic Impact and Risk Factors of Infections in Patients with Chronic Lymphocytic Leukemia Treated with Ibrutinib

Ibrutinib represents extraordinary progress in the treatment of chronic lymphocytic leukemia (CLL). However, treatment-related adverse events limit the benefit of this agent. This observational, multicenter study focused on the incidence, risk factors, and prognostic impact of infections in 494 patients with CLL treated with an ibrutinib-based treatment. Ibrutinib was given to 89 (18%) previously untreated patients (combined with rituximab, 24) and 405 (82%) relapsed/refractory patients. Pneumonia (PN), grade ≥3 non-opportunistic infections (NOI), and opportunistic infections (OI) were recorded in 32% of patients with an overall incidence rate per 100 person-year of 15.3% (PN, 10%; NOI, 3.3%; OI, 2%). Infections were the reason for the permanent discontinuation of ibrutinib in 9% of patients. Patients who experienced pneumonia or a severe infection showed a significantly inferior survival than those who were infection-free (p < 0.0001). A scoring system based on the three factors associated with a significant and independent impact on infections-PN or severe infection in the year before starting ibrutinib, chronic obstructive pulmonary disease, ≥2 prior treatments-identified patients with a two- to threefold increase in the rate of infections. In conclusion, the results of this study highlight the adverse impact of infectious events on the outcomes of CLL patients treated with ibrutinib.

Challenges with Approved Targeted Therapies against Recurrent Mutations in CLL: A Place for New Actionable Targets

Chronic lymphocytic leukemia (CLL) is characterized by a high degree of genetic variability and interpatient heterogeneity. In the last decade, novel alterations have been described. Some of them impact on the prognosis and evolution of patients. The approval of BTK inhibitors, PI3K inhibitors and Bcl-2 inhibitors has drastically changed the treatment of patients with CLL. The effect of these new targeted therapies has been widely analyzed in TP53-mutated cases, but few data exist about the response of patients carrying other recurrent mutations. In this review, we describe the biological pathways recurrently altered in CLL that might have an impact on the response to these new therapies together with the possibility to use new actionable targets to optimize treatment responses.

Immune Therapy for Chronic Lymphocytic Leukemia: Allogeneic Transplant, Chimeric Antigen Receptor T-cell Therapy, and Beyond

Despite significant improvement in clinical outcomes of chronic lymphocytic leukemia (CLL), patients who experience failure of Bruton tyrosine kinase inhibitors or venetoclax benefit from immune therapy approaches. Allogeneic transplant is a potentially curative treatment of CLL but is associated with risk of morbidity and mortality. Although still experimental, chimeric antigen receptor T-cell therapy provides durable remissions in patients with deep molecular responses. This review summarizes the relevant literature and discusses an approach to treatment sequencing and timing of referral for immune therapy. Novel immunotherapy approaches are being investigated and potentially can be utilized in sequence or combination with targeted agents.

Current Treatment Options in CLL

After impressive developments in recent years with the rise of new targeted agents, chemoimmunotherapy (CIT) only plays a minor role in the treatment of patients with chronic lymphocytic leukemia (CLL). Inhibitors of the Bruton tyrosine kinase (BTK), such as ibrutinib or more recently acalabrutinib, are highly effective, even in poor-risk or chemo-refractory patients. Venetoclax, an inhibitor of the anti-apoptotic BCL2 protein and, to a lesser extent, phosphoinositide-3 kinase (PI3K) delta inhibitors, add to the armamentarium of targeted agents for the treatment of CLL. Furthermore, anti-CD20 monoclonal antibodies are used very successfully either alone or in combination with BTK, BCL2 or PI3K inhibitors. Despite these advances, there is still an ongoing pursuit for new therapeutic approaches in the treatment of CLL. An even bigger challenge poses the determination of the optimal combination and sequence of those drugs. Here, we give an overview of current treatment options in CLL, weighing the advantages and disadvantages of each approach in the light of different clinical settings.

Durable ibrutinib responses in relapsed/refractory marginal zone lymphoma: long-term follow-up and biomarker analysis

Advanced marginal zone lymphoma (MZL) is an incurable B-cell malignancy dependent on B-cell receptor signaling. The phase 2 PCYC-1121 study demonstrated the safety and efficacy of single-agent ibrutinib 560 mg/d in 63 patients with relapsed/refractory MZL treated with prior rituximab (RTX) or rituximab-based chemoimmunotherapy (RTX-CIT). We report the final analysis of PCYC-1121 with median follow-up of 33.1 months (range: 1.4-44.6). Overall response rate (ORR) was 58%; median duration of response (DOR) was 27.6 months (95% confidence interval [CI]: 12.1 to not estimable [NE]); median progression-free survival (PFS) was 15.7 months (95% CI: 12.2-30.4); and median overall survival (OS) was not reached (95% CI: NE to NE). Patients with prior RTX treatment had better outcomes (ORR: 81%; median DOR: not reached [95% CI: 12.2 to NE]; median PFS: 30.4 months [95% CI: 22.1 to NE]; median OS: not reached [95% CI: 30.3 to NE]) vs those with prior RTX-CIT treatment (ORR: 51%; DOR: 12.4 months [95% CI: 2.8 to NE]; PFS: 13.8 months [95% CI: 8.3-22.5]; OS: not reached [95% CI: NE to NE]). ORRs were 63%, 47%, and 62% for extranodal, nodal, and splenic subtypes, respectively. With up to 45 months of ibrutinib treatment, the safety profile remained consistent with prior reports. The most common grade ≥3 event was anemia (16%). Exploratory biomarker analysis showed NF-κB pathway gene mutations correlated with outcomes. Final analysis of PCYC-1121 demonstrated long-term safety and efficacy of ibrutinib in patients with relapsed/refractory MZL, regardless of prior treatment or MZL subtype. This trial was registered at www.clinicaltrials.gov as #NCT01980628.

Novel mouse model resistant to irreversible BTK inhibitors: a tool identifying new therapeutic targets and side effects

Pharmacological inhibitors of Bruton tyrosine kinase (BTK) have revolutionized treatment of B-lymphocyte malignancies and show great promise for dampening autoimmunity. The predominant BTK inhibitors tether irreversibly by covalently binding to cysteine 481 in the BTK catalytic domain. Substitution of cysteine 481 for serine (C481S) is the most common mechanism for acquired drug resistance. We generated a novel C481S knock-in mouse model and, using a battery of tests, no overt B-lymphocyte phenotype was found. B lymphocytes from C481S animals were resistant to irreversible, but sensitive to reversible, BTK inhibitors. In contrast, irreversible inhibitors equally impaired T-lymphocyte activation in mice, mimicking the effect of treatment in patients. This demonstrates that T-lymphocyte blockage is independent of BTK. We suggest that the C481S knock-in mouse can serve as a useful tool for the study of BTK-independent effects of irreversible inhibitors, allowing for the identification of novel therapeutic targets and pinpointing potential side effects.