Novel Therapies in Chronic Lymphocytic Leukemia: A Rapidly Changing Landscape

Utilizing risk factors to guide treatment decisions in chronic lymphocytic leukemia

INTRODUCTION

In the era of chemo-immunotherapy, high-risk factors unequivocally predicted inferior outcomes for patients with CLL. The widespread adoption of BTK inhibitors has challenged the practical implications of such testing, as many patients have improved outcomes despite the presence of high-risk features. The impact of adverse prognostic factors, such as unmutated IGHV, on survival has been ameliorated by continuous treatment with BTK inhibitors, but not by finite-duration therapy with venetoclax-based combinations. Furthermore, TP53 abnormalities continue to be associated with worse outcomes in the era of novel agents. New treatment modalities, such as pirtobrutinib, lisocabtagene maraleucel, and ongoing studies combining BTK inhibitors with venetoclax, raise new questions on the significance of prognostic factors of survival for patients with CLL.

AREAS COVERED

Herein, we summarized the available literature on patients with CLL harboring high-risk biomarkers, with a focus on data from key clinical trials.

EXPERT OPINION

Testing for prognostic biomarkers will remain relevant to identify patients who may have increased benefit from novel therapeutic strategies, such as combination therapies and novel agents. Patients with high-risk disease should be encouraged to participate in clinical trials.

Real-World Health Care Resource Use and Costs Among Patients With Chronic Lymphocytic Leukemia Treated With Venetoclax-Based and Bruton Tyrosine Kinase Inhibitor-Based Regimens in the Second-Line Setting

PURPOSE

Real-world evidence comparing health care resource use (HRU) and costs between novel targeted therapies among patients with chronic lymphocytic leukemia (CLL) is lacking. We compared all-cause and CLL-specific HRU and costs between patients initiated on B-cell lymphoma 2 inhibitor (venetoclax)- or Bruton tyrosine kinase inhibitor (BTKi)-based regimens in the second-line (2L) setting.

METHODS

This is a retrospective observational study using Optum Clinformatics Data Mart of adult patients with CLL/small lymphocytic lymphoma who received 2L venetoclax- or BTKi-based regimens (January 2018-December 2021) for the first time and had ≥one CLL diagnostic claim after 2L initiation and ≥two claims for venetoclax or BTKi. Baseline characteristics were balanced using stabilized inverse probability of treatment weights. Mean monthly cost difference (MMCD) between cohorts for all-cause and CLL-specific per patient per month (PPPM) costs was estimated. Rates of PPPM-HRU were compared between cohorts using rate ratios (RRs).

RESULTS

Of 280 patients, median age 75.5 years, 64.6% and 35.4% received BTKi- versus venetoclax-based regimens, respectively. Most BTKi-treated patients received monotherapy (88.4%), whereas 62.3% of venetoclax-treated patients received combination therapy with anti-CD20 agents. The median duration of 2L therapy was 11.6 and 11.0 months for BTKi versus venetoclax cohorts, respectively. All-cause total costs were lower for venetoclax versus BTKi (MMCD [SE], $-2,497.64 [$1,006.77] in US dollars (USD); P = .01), driven by lower medication costs offsetting medical costs; trends were similar for CLL-specific estimates. Outpatient HRU was higher for venetoclax versus BTKi (RR all-cause: 1.22 versus CLL-specific: 1.64).

CONCLUSION

Venetoclax was associated with total monthly cost savings versus BTKis, illustrating the economic value of time-limited venetoclax-based regimens in the 2L setting.

Real-world comparative effectiveness of venetoclax-obinutuzumab versus Bruton tyrosine kinase inhibitors for frontline chronic lymphocytic leukaemia

Real-world evidence comparing clinical outcomes between venetoclax and Bruton tyrosine kinase inhibitors (BTKis) in patients with frontline (1 L) chronic lymphocytic leukaemia (CLL) is lacking. We compared treatment effectiveness of 1 L venetoclax plus obinutuzumab (VenO) versus BTKi-based regimens. This retrospective observational study using Optum Clinformatics Data Mart® included adult patients with CLL (≥2 outpatient or ≥1 inpatient claim) who received VenO or BTKi-based regimens in 1 L (1/2019-9/2022). Baseline characteristics were balanced using stabilised inverse probability weighting. Outcomes included duration of therapy (DoT), persistence, time to next treatment or death (TTNT-D), and time off-treatment. Among 1506 eligible patients (VenO: 203; BTKi: 1303), the median follow-up duration was 12.6 (VenO) and 16.2 months (BTKi). Median DoT for VenO was 12.3 months; persistence remained higher in VenO versus BTKi through expected 1 L fixed treatment duration. Median TTNT-D was not reached for VenO; however, more VenO- versus BTKi-treated patients had not switched therapies/experienced death through Month 12 (87.1% vs. 75.3%). Among patients that discontinued, median time to discontinuation was 11.7 vs. 5.9 months for VenO versus BTKi and median time off-treatment was 11.3 vs. 4.3 months. In this real-world study, VenO was associated with better effectiveness outcomes than BTKi-based regimens in 1 L CLL.

Real-world comparison of health care costs of venetoclax-obinutuzumab vs Bruton's tyrosine kinase inhibitor use among US Medicare beneficiaries with chronic lymphocytic leukemia in the frontline setting

BACKGROUND

Bruton's tyrosine kinase inhibitors (BTKis) and the BCL-2 inhibitor venetoclax in combination with obinutuzumab (VEN-O) are both recommended as frontline therapy in chronic lymphocytic leukemia (CLL). However, VEN-O is a 12-month fixed-duration therapy generating durable remissions whereas BTKis are continuous treat-to-progression treatments.

OBJECTIVE

To examine costs before and after the fixed-duration treatment period for VEN-O relative to that observed for BTKis in a national sample of older US adults with CLL in the frontline setting.

METHODS

This retrospective analysis used Medicare Parts A, B, and D claims from 2016 to 2021. Fee-for-service Medicare beneficiaries aged 66 years or older initiating frontline CLL treatment with VEN-O or a BTKi treatment between June 1, 2019, and June 30, 2020 (index date = first prescription fill date), were included in the sample. Mean cost measures were captured for both groups over 2 fixed time periods calculated from the index date: Month 0 to 12 (proxy for VEN-O on-treatment period) and Month 13 to 18 (proxy for VEN-O off-treatment period). A difference-in-difference approach was used. Multivariate generalized linear models estimated changes in adjusted mean monthly costs during Month 0 to 12 vs Month 13 to 18, for the VEN-O group relative to the BTKi group.

RESULTS

The final sample contained 193 beneficiaries treated with VEN-O and 1,577 beneficiaries treated with BTKis. Risk-adjusted all-cause monthly total costs were similar for VEN-O patients ($13,887) and BTKi patients ($14,492) between Month 0 and 12. Moreover, during Month 13 to 18, the mean monthly all-cause total costs declined by 67% for VEN-O ($13,887 to $4,462) but only by 10% for BTKi ($14,492 to $13,051). Hence, the relative reduction in costs across the 2 periods was significantly larger for VEN-O (-$9,425) vs BTKi (-$1,441) patients (ie, difference in difference = -$7,984; P < 0.001). Similar patterns were observed for CLL-related costs, with the substantially larger reductions in CLL-related total monthly costs (-$9,880 VEN-O vs -$1,753 BTKi; P < 0.001) for the VEN-O group primarily driven by the larger reduction in CLL-related monthly prescription costs (-$9,437 VEN-O vs -$2,020 BTKi; P < 0.001).

CONCLUSIONS

This real-world study of older adults with CLL found a large reduction in monthly Medicare costs in the 6 months after completion of the fixed-duration treatment period of VEN-O, largely driven by the reduction in CLL-related prescription drug costs. A similar decline in costs was not observed among those treated with BTKis. Our study highlights the substantial economic benefits of fixed-duration VEN-O relative to treat-to-progression therapies like BTKis in the first-line CLL setting.

CNS Aspergillosis and Cryptococcosis with Cytomegalovirus Pneumonia in a Patient with Chronic Lymphocytic Leukemia Treated with Acalabrutinib

Bruton's tyrosine kinase inhibitors (BTKis) are the preferred treatment for chronic lymphocytic leukemia (CLL). Despite their therapeutic benefits, these targeted agents have been associated with an increased risk of invasive infections. We describe a 68-year-old male who developed multiple bacterial, fungal and viral infections while on treatment with acalabrutinib. To our knowledge, this is the first reported case of concomitant CNS infections with Cryptococcus neoformans and Aspergillus fumigatus, along with cytomegalovirus (CMV) and herpes simplex virus type 1 (HSV-1) pneumonia while on acalabrutinib. This case adds to the scarce literature of fungal and bacterial infections associated with acalabrutinib, raising the suspicion that infection risk is a medication class effect for BTKis.

Lymphoid blood cancers, incidence and survival 2005-2023: A report from the UK's Haematological Malignancy Research Network

BACKGROUND

Population-based information on cancer incidence and outcome are required to inform clinical practice and research; but contemporary data are lacking for many lymphoid cancer subtypes.

METHODS

Set within a socio-demographically representative UK population of ∼4 million, data are from an established UK patient cohort (N = 22,414 diagnoses). Information on incidence (crude and age-standardised) and survival (overall and net) is presented for > 40 subtypes.

RESULTS

The median diagnostic age was 69.9 years (interquartile range 59.1-78.3), but unlike many other cancers, lymphoid malignancies can be diagnosed at any age; different subtypes dominating at different ages. Males were more likely to be diagnosed than females (age-standardised sex rate ratio: 1.55 (95% Confidence Interval: 1.50,1.59)), and most subtypes had a male predominance, some more than three-fold (e.g. Burkitt lymphoma 3.26 (2.42, 4.40)). Five-year net survival estimates varied hugely, ranging from 97.4% (95% CI: 56.5, 99.9) in patients with hairy cell leukaemia to 31.6% (95% CI: 2.5, 69.8) in those with T-cell prolymphocytic leukaemia. No significant sex difference in survival were observed for the majority of diagnoses; one exception being classical Hodgkin lymphoma, where males had a higher mortality (Excess Mortality Ratio: 1.44 (95% CI: 1.11, 1.87)). An improvement in survival over time was observed for some, but not all, of the major diagnostic groups.

CONCLUSIONS

Marked incidence and survival variations by subtype, sex and age confirm the heterogeneity of lymphoid neoplasms and highlight the importance of accurately characterising disease entities. Despite recent improvements, routine cancer registration of lymphoid neoplasms remains challenging and new issues continue to emerge; including the lack of an international consensus on classification and the recording of progressions and transformations. Furthermore, the increasing need for additional molecular and genomic information required for accurate classification is likely to impact negatively on the quality of cancer registration data, especially in low income countries.

Real-world adherence and discontinuation among Medicare beneficiaries initiating venetoclax vs. BTKis in relapsed/refractory chronic lymphocytic leukemia

The treatment landscape for chronic lymphocytic leukemia (CLL) has been transformed by the availability of Bruton's tyrosine kinase inhibitors (BTKis) and the B-cell lymphoma 2 (BCL-2) inhibitor venetoclax. Despite clinical trial data supporting these novel oral agents, evidence evaluating real-world adherence is limited. This study used 2015-2019 Medicare claims data for elderly patients with relapsed/refractory CLL to assess differences in real-world adherence and discontinuation in the 12 months after treatment initiation. In the final sample of 711 venetoclax patients and 1,566 BTKi patients, we found that those initiating venetoclax tended to be younger (mean age 75.6 [SD 6.0] vs 77.6 [SD 6.9] years, p < .001) but had poorer clinical characteristics. After risk-adjustment, the venetoclax group had higher adherence (61.9% vs. 45.4%, p < .0001) and lower discontinuation when compared to the BTKi group (28.5% vs. 47.4%, p < .001). These favorable real-world findings underscore the importance of developing well-tolerated novel combinations for older adults.

Ibrutinib discontinuation and associated factors in a real-world national sample of elderly Medicare beneficiaries with chronic lymphocytic leukemia

Prior studies evaluating ibrutinib discontinuation are limited to clinical trials and selected medical centers and hence may not reflect real-world practice. This study used Medicare claims (2013-2019) to examine ibrutinib discontinuation and associated factors among elderly patients with chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL). Over a median follow-up of 2.1 years, two-thirds (65.2%) of the 11,870 new ibrutinib initiators were discontinued, with half (45.1%) of patients discontinuing within 12 months of initiation. Factors such as advanced age, lack of Part D low-income subsidy, evidence of prior CLL/SLL treatment, and cardiovascular comorbidities (e.g. atrial fibrillation) were associated with higher risk of discontinuation. Over a median of 1.2 years from discontinuation, 40% of discontinuers initiated another CLL/SLL treatment after ibrutinib discontinuation; 25% of patients restarted ibrutinib treatment at some point over follow-up. Our findings point to a large unmet need with the widely used BTKi ibrutinib and underscore the importance of ongoing development of efficacious and well-tolerated CLL/SLL therapies.

Treatment pattern of chronic lymphocytic leukemia/small lymphocytic lymphoma in Korea: a multicenter retrospective study (KCSG LY20-06)

BACKGROUND/AIMS

Little attention is paid to chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in Korea due to the rarity of the disease. With its rising incidence, we aimed to evaluate recent changes in treatment patterns and survival outcomes of patients with CLL/SLL.

METHODS

A total of 141 patients diagnosed with CLL/SLL between January 2010 and March 2020 who received systemic therapy were analyzed in this multicenter retrospective study.

RESULTS

The median patient age was 66 years at diagnosis, and 68.1% were male. The median interval from diagnosis to initial treatment was 0.9 months (range: 0-77.6 months), and the most common treatment indication was progressive marrow failure (50.4%). Regarding first-line therapy, 46.8% received fludarabine, cyclophosphamide, plus rituximab (FCR), followed by chlorambucil (19.9%), and obinutuzumab plus chlorambucil (GC) (12.1%). The median progression-free survival (PFS) was 49.3 months (95% confidence interval [CI], 32.7-61.4), and median overall survival was not reached (95% CI, 98.4 mo- not reached). Multivariable analysis revealed younger age (≤ 65 yr) (hazard ratio [HR], 0.46; p < 0.001) and first-line therapy with FCR (HR, 0.64; p = 0.019) were independently associated with improved PFS. TP53 aberrations were observed in 7.0% (4/57) of evaluable patients. Following reimbursement, GC became the most common therapy among patients over 65 years and second in the overall population after 2017.

CONCLUSION

Age and reimbursement mainly influenced treatment strategies. Greater effort to apply risk stratifications into practice and clinical trials for novel agents could help improve treatment outcomes in Korean patients.

A Mobile App to Support Self-Management in Patients with Multiple Myeloma or Chronic Lymphocytic Leukemia: Pilot Randomized Controlled Trial

BACKGROUND

Patients with blood cancer experience serious physical and emotional symptoms throughout their cancer journey.

OBJECTIVE

Building on previous work, we aimed to develop an app designed to help patients with multiple myeloma and chronic lymphocytic leukemia self-manage symptoms and test it for acceptability and preliminary efficacy.

METHODS

We developed our Blood Cancer Coach app with input from clinicians and patients. Our 2-armed randomized controlled pilot trial recruited participants from Duke Health and nationally in partnerships with the Association of Oncology Social Work, Leukemia and Lymphoma Society, and other patient groups. Participants were randomized to the attention control (Springboard Beyond Cancer website) arm or the Blood Cancer Coach app intervention arm. The fully automated Blood Cancer Coach app included symptom and distress tracking with tailored feedback, medication reminders and adherence tracking, multiple myeloma and chronic lymphocytic leukemia education resources, and mindfulness activities. Patient-reported data were collected at baseline, 4 weeks, and 8 weeks for both arms through the Blood Cancer Coach app. Outcomes of interest were global health (Patient Reported Outcomes Measurement Information System Global Health), posttraumatic stress (Posttraumatic Stress Disorder Checklist for DSM-5), and cancer symptoms (Edmonton Symptom Assessment System Revised). Among participants in the intervention arm, satisfaction surveys and usage data were used to evaluate acceptability.

RESULTS

Among 180 patients who downloaded the app, 49% (89) of them consented to participate and 40% (72) of them completed baseline surveys. Of those who completed baseline surveys, 53% (38) of them completed week 4 surveys (16 intervention and 22 control) and 39% (28) of them completed week 8 surveys (13 intervention and 15 control). Most participants found the app at least moderately effective at helping manage symptoms (87%), feeling more comfortable seeking help (87%), increasing awareness of resources (73%), and reported being satisfied with the app overall (73%). Participants completed an average of 248.5 app tasks over the 8-week study period. The most used functions within the app were medication log, distress tracking, guided meditations, and symptom tracking. There were no significant differences between the control and intervention arms at week 4 or 8 on any outcomes. We also saw no significant improvement over time within the intervention arm.

CONCLUSIONS

The results of our feasibility pilot were promising in which most participants found the app to be helpful in managing their symptoms, reported satisfaction with the app, and that it was helpful in several important areas. We did not, however, find significantly reduced symptoms or improved global mental and physical health over 2 months. Recruitment and retention were challenging for this app-based study, an experience echoed by others. Limitations included a predominantly White and college educated sample. Future studies would do well to include self-efficacy outcomes, target those with more symptoms, and emphasize diversity in recruitment and retention.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05928156; https://clinicaltrials.gov/study/NCT05928156.

CircRNA: a rising star in leukemia

Non-coding RNA are a class of RNA that lack the potential to encode proteins. CircRNAs, generated by a post-splicing mechanism, are a newly discovered type of non-coding RNA with multi-functional covalent loop structures. CircRNAs may play an important role in the occurrence and progression of tumors. Research has shown that circRNAs are aberrantly expressed in various types of human cancers, including leukemia. In this review, we summarize the expression and function of circRNAs and their impact on different types of leukemia. We also illustrate the function of circRNAs on immune modulation and chemoresistance in leukemia and their impact on its diagnosis and prognosis. Herein, we provide an understanding of recent advances in research that highlight the importance of circRNAs in proliferation, apoptosis, migration, and autophagy in different types of leukemia. Furthermore, circRNAs make an indispensable difference in the modulation of the immunity and chemoresistance of leukemia. Increasing evidence suggests that circRNAs may play a vital role in the diagnostic and prognostic markers of leukemia because of their prominent properties. More detailed preclinical studies on circRNAs are needed to explore effective ways in which they can serve as biomarkers for the diagnosis and prognosis of leukemia in vivo.

Discovery of a high potent PIM kinase inhibitor for acute myeloid leukemia based on N-pyridinyl amide scaffold by optimizing the fragments toward to Lys67 and Asp128/Glu171

Despite the recent development of PIM inhibitors based on N-(pyridin-3-yl)acetamide scaffold for acute myeloid leukemia (AML), the structural-activity relationship (SAR) associated with the effects of positional isomerization of N toward to Lys67 and freedom of solvent fragment toward to Asp128/Glu171 still remains an open question. In this work, a structurally novel compound based on N-pyridinyl amide was designed by fragment hybridization and then our SAR exploration revealed that the positional isomerization would lead to a decrease in activity, while increase of the freedom of solvent fragment by breaking the intramolecular hydrogen bond unprecedentedly leads to an increase in activity. These studies finally resulted in the screening out of a potent PIM inhibitor FD1024 (compound 24) which exerts strong antiproliferative activity against the tested AML cell lines and achieves profound antitumor efficacy in mice at well-tolerated dose schedules.

Low Serum Cholesterol Level Is a Significant Prognostic Factor That Improves CLL-IPI in Chronic Lymphocytic Leukaemia

Hypocholesterolaemia is associated with elevated cancer risk and mortality, yet the relation between chronic lymphocytic leukaemia (CLL) and serum lipid profile remains unclear. Our study aims to evaluate the prognostic value of cholesterol levels in CLL and develop a prognostic nomogram that incorporates lipid metabolism. We enrolled 761 newly diagnosed CLL patients and separated them into either derivation (n = 507) or validation (n = 254) cohorts. The prognostic nomogram was constructed through multivariate Cox regression analyses, with performance evaluated using C-index, the area under the curve, calibration, and decision curve analyses. Decreased total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) at diagnosis were significantly associated with worse time to first treatment (TTFT) and cancer-specific survival (CSS), and simultaneously, low HDL-C with low LDL-C was identified as an independent prognostic indicator for both TTFT and CSS. CLL patients achieving complete or partial remission post-chemotherapy had significantly increased TC, HDL-C, and LDL-C levels compared with the baseline, and post-therapeutic HDL-C and LDL-C elevation correlated with favourable survival. The prognostic nomogram augmenting the CLL international prognostic index with low cholesterol levels yielded higher predictive accuracy and discrimination capacity for both 3-year and 5-year CSS. In conclusion, cholesterol profiles can be used as a cheap and readily accessible tool for predicting prognosis in CLL practice.

Canadian evidence-based guideline for frontline treatment of chronic lymphocytic leukemia: 2022 update

Chronic lymphocytic leukemia (cll) is the most common adult leukemia in North America. In 2018, the first unified national guideline in Canada was developed for the front-line treatment of cll that helped guide treatment across the country. As an update in 2022, a group of clinical experts from across Canada came together to provide input and guidance that included new and innovative treatments and approaches that will continue to provide health care professionals with clear guidance on the first-line management of cll. Recommendations were provided in consensus based on available evidence for the first-line treatment of cll.

Approved and emerging Bruton's tyrosine kinase inhibitors for the treatment of chronic lymphocytic leukemia

INTRODUCTION

The Bruton's tyrosine kinase (BTK) pathway has proven to be an effective and transformative therapeutic target in the treatment of chronic lymphocytic leukemia (CLL), fueling the growth of BTK inhibitors (BTKis) and landmark approval of first-generation BTKi, ibrutinib. However, ibrutinib's side effect profile left an unmet need for BTKis with improved tolerability thus spurring the subsequent development of second-generation acalabrutinib and zanubrutinib. The treatment landscape continues to evolve with studies using BTKi combination therapies, notably with venetoclax, with and without an anti-CD20 monoclonal antibody as well as third generation BTKis aimed to overcome BTKi resistance.

AREAS COVERED

This article details the current literature highlighting the efficacy, toxicities, and potential therapeutic combinations of approved and preclinical BTKis.

EXPERT OPINION

BTKis have signaled the start of a new treatment paradigm in CLL and improved clinical outcomes especially for patients with high-risk disease. However, drug resistance, low CR rates, and indefinite treatment necessitate the development of novel BTKis and fixed duration combination therapy. The results from recently completed and ongoing clinical trials are eagerly awaited with the potential promise of reduced treatment durations and financial burden while achieving durable remissions.

Efficacy and safety of phosphatidylinositol 3-kinase inhibitors in patients with chronic lymphocytic leukemia: a meta-analysis and systematic review

BACKGROUND

Phosphatidylinositol 3-kinase (PI3K) inhibitors demonstrate promising effects in the treatment of relapsed/refractory chronic lymphocytic leukemia (CLL). Emerging evidence of the therapeutic effects of the PI3K inhibitors in various aspects remains controversial.

RESEARCH DESIGN AND METHODS

This meta-analysis was to evaluate the efficacy and safety of PI3K inhibitors based on a synthesis of the data generated by randomized controlled trials (RCTs) of patients with CLL, by searching PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov registry.

RESULTS

Five RCTs with 1593 patients were included. The PI3K inhibitors significantly improved progression-free survival (PFS), the chance of overall response, and partial response than the control arm. Regarding adverse events (AEs), the PI3K inhibitors increased the risk of pyrexia, chills, diarrhea, decreased appetite, vomiting, rash, pneumonia, and upper respiratory tract infection.

CONCLUSIONS

Available evidence showed significant improvements over conventional therapy in PFS of the PI3K inhibitors in patients with CLL, with relatively manageable AEs.

Managing the Risk of Infection in Chronic Lymphocytic Leukemia in the Era of New Therapies

PURPOSE OF REVIEW

Patients diagnosed with CLL have an increased susceptibility to infections. Over the years, there has been a shift of the treatment arsenal to an increasing use of chemotherapy-free regimens, particularly small molecule inhibitors. These therapies have proven to be effective and have a favorable toxicity profile. Infections continue to represent a significant complication in the era of novel therapies.

RECENT FINDINGS

Recent studies continue to bring new insights into the effects of modern therapies on the immune system. Evidence supporting infection prevention strategies is scarce. We will review the available recommendations to prevent infections in patients with CLL treated with novel therapies. New CLL therapies are broadly adopted in routine practice, requiring optimization of their side effects. Timely prevention, recognition, and treatment of infections should remain an important aspect of the standard management of a patient with CLL.

Development of a Patient-Centered Preference Tool for Patients With Hematologic Malignancies: Protocol for a Mixed Methods Study

BACKGROUND

The approval of novel therapies for patients diagnosed with hematologic malignancies have improved survival outcomes but increased the challenge of aligning chemotherapy choices with patient preferences. We previously developed paper versions of a discrete choice experiment (DCE) and a best-worst scaling (BWS) instrument to quantify the treatment outcome preferences of patients with hematologic malignancies to inform shared decision making.

OBJECTIVE

We aim to develop an electronic health care tool (EHT) to guide clinical decision making that uses either a BWS or DCE instrument to capture patient preferences. The primary objective of this study is to use both qualitative and quantitative methods to evaluate the perceived usability, cognitive workload (CWL), and performance of electronic prototypes that include the DCE and BWS instrument.

METHODS

This mixed methods study includes iterative co-design methods that will involve healthy volunteers, patient-caregiver pairs, and health care workers to evaluate the perceived usability, CWL, and performance of tasks within distinct prototypes. Think-aloud sessions and semistructured interviews will be conducted to collect qualitative data to develop an affinity diagram for thematic analysis. Validated assessments (Post-Study System Usability Questionnaire [PSSUQ] and the National Aeronautical and Space Administration's Task Load Index [NASA-TLX]) will be used to evaluate the usability and CWL required to complete tasks within the prototypes. Performance assessments of the DCE and BWS will include the evaluation of tasks using the Single Easy Questionnaire (SEQ), time to complete using the prototype, and the number of errors. Additional qualitative assessments will be conducted to gather participants' feedback on visualizations used in the Personalized Treatment Preferences Dashboard that provides a representation of user results after completing the choice tasks within the prototype.

RESULTS

Ethical approval was obtained in June 2021 from the Institutional Review Board of the University of North Carolina at Chapel Hill. The DCE and BWS instruments were developed and incorporated into the PRIME (Preference Reporting to Improve Management and Experience) prototype in early 2021 and prototypes were completed by June 2021. Heuristic evaluations were conducted in phase 1 and completed by July 2021. Recruitment of healthy volunteers began in August 2021 and concluded in September 2021. In December 2021, our findings from phase 2 were accepted for publication. Phase 3 recruitment began in January 2022 and is expected to conclude in September 2022. The data analysis from phase 3 is expected to be completed by November 2022.

CONCLUSIONS

Our findings will help differentiate the usability, CWL, and performance of the DCE and BWS within the prototypes. These findings will contribute to the optimization of the prototypes, leading to the development of an EHT that helps facilitate shared decision making. This evaluation will inform the development of EHTs to be used clinically with patients and health care workers.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/39586.

Trends in Disease Burden of Chronic Lymphocytic Leukemia at the Global, Regional, and National Levels From 1990 to 2019, and Projections Until 2030: A Population-Based Epidemiologic Study

Background

The prognosis of chronic lymphocytic leukemia (CLL) has been improved dramatically, but there are limited studies focusing on CLL disease burden on a global scale. We aimed to evaluate the accurate assessment of the disease burden of CLL that may provide more detailed epidemiological information for rational policies.

Methods

The main source of the data was the Global Burden of Disease (GBD) study 2019. Incident cases, death cases, disability-adjusted life years (DALYs), and their corresponding age-standardized rates (ASRs) from 1990 to 2019 were used to describe the burden of CLL. Data about attributable risk factors were also extracted and analyzed. Bayesian age-period-cohort (BAPC) models were used to assess and project the incidence and mortality rates till 2030.

Results

Globally, the incidence of CLL had been increasing. Deaths and DALYs decreased slightly. The burden of death and DALY is affected by socio-demographic index (SDI). The incidence rate, death rate, and DALY rate of CLL increased significantly with age. Male-to-female ratios of incidence rates varied in different SDI quintiles. Smoking, high body mass index, and occupational exposure to benzene or formaldehyde were the potential risk factors related to CLL. Global ASIRs might tend to increase until 2030, while ASDR would decrease until 2030.

Conclusion

The disease burden of CLL decreased in higher SDI countries but increased in lower ones. Strategies for early detection of asymptomatic CLL, development of novel drugs, and measures against attributable factors should be implemented to combat CLL burden.

The Two-Step Allogeneic Stem Cell Transplant Approach Results in Rapid Engraftment and Excellent Outcomes in Patients with Lymphoid Malignancies

The two-step graft engineering approach has been the main platform for allogeneic hematopoietic cell transplantation (allo-HCT) at Thomas Jefferson University since 2005. We have previously described separating donor lymphocytes infusion followed by cyclophosphamide for bidirectional tolerization from CD34-selected hematopoietic grafts in haploidentical and matched related donors. We analyzed 60 patients with high-risk lymphoid malignancies who underwent a two-step allo-HCT from 2008-2020. The majority of patients received haploidentical (82%) and (20%) patients received matched related stem cell grafts. Patients underwent transplant for DLBCL (n = 17, 28%), CLL (n = 10, 17%), follicular lymphoma (n=8, 13%), and Hodgkin lymphoma (n = 7, 12%). Eight patients (13%) had prior high dose chemotherapy. Thirty patients (50%) had HCT-CI ≥ 3; 20 patients (33%) had CIBMTR RDRI high or very high-risk disease. The median age for the group was 56 years (range 24-75). Neutrophils engrafted at a median of 11 days (range from 9 to 16 days) and platelets engrafted at a median of 16 days (range from 13 to 37 days). With a median follow up of six years, the 3-year probability of overall survival and disease-free survival were 62.9% (95% confidence interval is 49.3% to 73.8%) and 60.2% (95% confidence interval is 46.4% to 71.6%) respectively. The cumulative incidence of relapse at 3 years was 11.9% (confidence interval 0.052-0.216). The cumulative incidence of non-relapse mortality at 3 years was 30.1% (confidence interval 0.191-0.420). The cumulative incidence of grade 2-4 acute GVHD at one year was 45% (95% confidence interval 0.322 to 0.570). The cumulative incidence of grade 3-4 acute GVHD at one year was 5% (95% confidence interval 0.013 to 0.126). The cumulative incidence of cGVHD at 3 years was 15.2% (95% confidence interval 0.075 to 0.254). In conclusion, the two-step approach achieved excellent outcomes in high-risk lymphoid malignancies with rapid neutrophil and platelet recovery.

The role of Bruton's tyrosine kinase in the immune system and disease

Bruton's tyrosine kinase (BTK) is a TEC kinase with a multifaceted role in B-cell biology and function, highlighted by its position as a critical component of the B-cell receptor signalling pathway. Due to its role as a therapeutic target in several haematological malignancies including chronic lymphocytic leukaemia, BTK has been gaining tremendous momentum in recent years. Within the immune system, BTK plays a part in numerous pathways and cells beyond B cells (i.e. T cells, macrophages). Not surprisingly, BTK has been elucidated to be a driving factor not only in lymphoproliferative disorders but also in autoimmune diseases and response to infection. To extort this role, BTK inhibitors such as ibrutinib have been developed to target BTK in other diseases. However, due to rising levels of resistance, the urgency to develop new inhibitors with alternative modes of targeting BTK is high. To meet this demand, an expanding list of BTK inhibitors is currently being trialled. In this review, we synopsize recent discoveries regarding BTK and its role within different immune cells and pathways. Additionally, we discuss the broad significance and relevance of BTK for various diseases ranging from haematology and rheumatology to the COVID-19 pandemic. Overall, BTK signalling and its targetable nature have emerged as immensely important for a wide range of clinical applications. The development of novel, more specific and less toxic BTK inhibitors could be revolutionary for a significant number of diseases with yet unmet treatment needs.

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.

A novel class of oxazepine-based anti-cancer agents induces cell death in primary human CLL cells and efficiently reduces tumor growth in Eμ-TCL1 mice through the JNK/STAT4/p66Shc axis

Survival and expansion of malignant B cells in chronic lymphocytic leukemia (CLL) are highly dependent both on intrinsic defects in the apoptotic machinery and on the interactions with cells and soluble factors in the lymphoid microenvironment. The adaptor protein p66Shc is a negative regulator of antigen receptor signaling, chemotaxis and apoptosis whose loss in CLL B cells contributes to their extended survival and poor prognosis. Hence, the identification of compounds that restore p66Shc expression and function in malignant B cells may pave the way to a new therapeutic approach for CLL. Here we show that a novel oxazepine-based compound (OBC-1) restores p66Shc expression in primary human CLL cells by promoting JNK-dependent STAT4 activation without affecting normal B cells. Moreover, we demonstrate that the potent pro-apoptotic activity of OBC-1 in human leukemic cells directly correlates with p66Shc expression levels and is abrogated when p66Shc is genetically deleted. Preclinical testing of OBC-1 and the novel analogue OBC-2 in Eμ-TCL1 tumor-bearing mice resulted in a significantly longer overall survival and a reduction of the tumor burden in the spleen and peritoneum. Interestingly, OBCs promote leukemic cell mobilization from the spleen to the blood, which correlates with upregulation of sphingosine-1-phosphate receptor expression. In summary, our work identifies OBCs as a promising class of compounds that, by boosting p66Shc expression through the activation of the JNK/STAT4 pathway, display dual therapeutic effects for CLL intervention, namely the ability to mobilize cells from secondary lymphoid organs and a potent pro-apoptotic activity against circulating leukemic cells.

Treatment strategies for a rapidly evolving landscape in chronic lymphocytic leukemia management

With the advent of targeted therapies for chronic lymphocytic leukemia (CLL), treatment choice has expanded and patients are living longer. Careful consideration is needed regarding treatment duration and sequence, how best to meet patients' needs, balancing toxicities while improving long-term survival and maximizing depth of response. This review addresses these considerations and discusses current targeted treatment dilemmas. Targeted therapies have dramatically transformed the CLL treatment landscape. Two treatment paradigms have emerged using B-cell lymphoma 2 inhibitors (BCL2i) and Bruton's tyrosine kinase (BTK): (i) fixed duration and (ii) continuous treatment. The BCL2i venetoclax can attain deep remissions with a fixed-duration approach, resulting in high rates of undetectable minimal residual disease (uMRD) in treatment-naïve and relapsed/refractory (R/R) patients with CLL. BTKis such as ibrutinib and acalabrutinib achieve high objective response rates and long-term disease control, although they rarely attain complete response or uMRD status as monotherapy. Numerous studies are evaluating the clinical utility of BTKi and BCL2i as combination therapies, where deep remissions have been found to occur. MRD status may also be a useful marker for deciding when to stop continuous therapy, and randomized trials on MRD-guided treatment strategies are currently ongoing. The current treatment choice between continuous or fixed-duration therapy should be based on comorbidities, risks, preferences, and treatment goals, whilst areas of emerging clinical interest include the potential utility of BTKi-BCL2i combination therapies, as well as an MRD-guided treatment strategies in the future.

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.

Cell therapy of chronic lymphocytic leukaemia: Transplants and chimeric antigen receptor (CAR)-T cells

There is substantial progress in the therapy of chronic lymphocytic leukaemia (CLL), much of it the result of new drug development. As such the definition of high-risk CLL is changing. Nevertheless, few persons with CLL are cured with current therapy. Two types of cell therapies of CLL are currently being evaluated or re-evaluated in the context of these advances: haematopoietic cell transplants and chimeric antigen receptor (CAR)-T-cells. We discuss the potential role of these cell therapies in the context of the evolving therapy topography of CLL including how these therapies work and who, if anyone, is an appropriate candidate for cell therapy.

Will New Drugs Replace Transplants for Chronic Lymphocytic Leukaemia?

Transplants have been used to treat chronic lymphocytic leukemia (CLL) for more than 35 years. Use has been restricted to <1 percent of highly selected persons typically failing concurrent conventional therapies. As therapies of CLL have evolved, so have indications for transplantation and transplant techniques. The data that we review indicate that transplants can result in long-term leukemia-free survival in some persons but are associated with substantial transplant-related morbidity and mortality. We discuss the mechanisms underlying the anti-leukemia effects of transplants including drugs, ionizing radiations, immune-mediated mechanisms and/or a combination. We discuss prognostic and predicative covariates for transplant outcomes. Importantly, we consider whether there is presently a role of transplants in CLL and who, if anyone, is an appropriate candidate in the context of new drugs.

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.

Genomics of Resistance to Targeted Therapies

Targeting BCR and BCL-2 signaling is a widely used therapeutic strategy for chronic lymphocytic leukemia. C481S mutation decreases the covalent binding affinity of ibrutinib to BTK, resulting in reversible rather than irreversible inhibition. In addition to BTK, mutations in PLCG2 have been demonstrated to mediate acquired ibrutinib resistance. Venetoclax, a highly selective BCL2 inhibitor, has high affinity to the BH3-binding grove of BCL2. Mutation in BCL2 (Gly101Val) decreases the affinity of BCL2 for venetoclax and confers acquired resistance in cell lines and primary patient cells. This review discusses the common mechanisms of resistance to targeted therapies in chronic lymphocytic leukemia.

Current and future treatment strategies in chronic lymphocytic leukemia

Treatment decisions for patients with chronic lymphocytic leukemia (CLL) are dependent on symptoms and classification into high-, medium-, or low-risk categories. The prognosis for CLL hinges, in part, on the presence or absence of less-favorable genetic aberrations, including del(17p), del(11q), TP53 dysfunction, and IGHV mutations, as these markers are associated with worse treatment response. Promising results from multiple clinical trials show emerging therapies targeting Burton tyrosine kinase, B-cell leukemia/lymphoma 2, and phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit delta result in better outcomes and prolonged progression-free survival for patients both with and without certain high-risk aberrations. Favorable outcomes using these novel oral targeted therapies, either alone or in combination with other treatments such as anti-CD20 antibodies, has led to their use almost entirely supplanting chemoimmunotherapy in the treatment of CLL. In this narrative review, we summarize the current clinical evidence for the use of targeted mono- and combination therapies for CLL, discuss new and next-generation treatment approaches currently in development, and provide insight into areas of unmet need for the treatment of patients with CLL.

Research advances in chimeric antigen receptor-modified T-cell therapy (Review)

Chimeric antigen receptor (CAR)-modified T-cells are T-cells that have been genetically engineered to express CAR molecules to target specific surface antigens on tumor cells. CAR T-cell therapy, a novel cancer immunotherapy, has been attracting increasing attention, since it exhibited notable efficacy in the treatment of hematological tumors in clinical trials. However, for this type of therapy, challenges must be overcome in the treatment of solid tumors. Furthermore, certain side effects associated with CAR T-cell therapy, including cytokine release syndrome, immune effector cell-related neurotoxicity syndrome, tumor lysis syndrome and on-target off-tumor toxicity, must be taken into consideration. The present study provides a systematic review of the principle, clinical application, current challenges, possible solutions and future perspectives for CAR T-cell therapy.

Venetoclax as a therapeutic option for the treatment of chronic lymphocytic leukemia: the evidence so far

INTRODUCTION

Venetoclax, an oral, BCL-2 inhibitor, is approved by the FDA for treatment of CLL in all lines of therapy. Data from landmark studies, including the CLL14 and MURANO trials, demonstrated marked improvement in clinical outcomes compared to chemoimmunotherapy when venetoclax was used in combination with CD20 monoclonal antibodies for fixed treatment duration.

AREAS COVERED

This article reviews the mechanism of action of venetoclax and discusses how curtailing the BCL signaling pathway undermines CLL pathophysiology. The authors also give their clinical experience with the drug, with emphasis on assessing and managing the risk of venetoclax-associated tumor lysis syndrome (TLS).

EXPERT OPINION

Venetoclax has positioned itself as one of the primary treatment options for CLL, given the consistent efficacy and deep remissions it has elicited across multiple settings of the disease with a time-limited schedule. Accurate TLS risk evaluation and stringent adherence to the dose-escalation protocols will help optimize patient outcomes. Finally, we expect that current and future studies will (1) ascertain the ideal treatment duration using the minimal residual disease state as a guide and (2) help us understand the optimal role of venetoclax in combination or in sequence with other novel targeted therapies in the treatment of CLL.

Venetoclax induces deep hematologic remissions in t(11;14) relapsed/refractory AL amyloidosis

Venetoclax is efficacious in relapsed/refractory t(11;14) multiple myeloma, thus warranting investigation in light-chain amyloidosis (AL). This retrospective cohort includes 43 patients with previously treated AL, from 14 centers in the US and Europe. Thirty-one patients harbored t(11;14), 11 did not, and one t(11;14) status was unknown. Patients received a venetoclax-containing regimen for at least one 21- or 28-day cycle; the median prior treatments was three. The hematologic response rate for all patients was 68%; 63% achieved VGPR/CR. t(11;14) patients had higher hematologic response (81% vs. 40%) and higher VGPR/CR rate (78% vs. 30%, odds ratio: 0.12, 95% CI 0.02–0.62) than non-t(11;14) patients. For the unsegregated cohort, median progression-free survival (PFS) was 31.0 months and median OS was not reached (NR). For t(11;14), median PFS was NR and for non-t(11;14) median PFS was 6.7 months (HR: 0.14, 95% CI 0.04–0.53). Multivariate analysis incorporating age, sex, prior lines of therapy, and disease stage suggested a risk reduction for progression or death in t(11;14) patients. Median OS was NR for either subgroup. The organ response rate was 38%; most responders harbored t(11;14). Grade 3 or higher adverse events occurred in 19% with 7% due to infections. These promising results require confirmation in a randomized clinical trial.

Concurrent BK polyomavirus, adenovirus and cytomegalovirus infections in a patient treated for chronic lymphocytic leukaemia

A 58-year-old woman with chronic lymphocytic leukaemia (CLL) presented with 2 weeks of fever and haematuria following chemo-immunotherapy. CT scan showed thickening of her left urethra and bladder, suggesting pyleo-ureteritis with cystitis. The patient was initially treated for suspected bacterial urinary tract infection although repeated blood and urine cultures remained negative. She then received multiple transfusions for chemotherapy-induced pancytopenia while her urinary symptoms did not improve. Due to her immunocompromised status, she was tested for viral infection, which revealed, BK polyomavirus, adenovirus and cytomegalovirus in serum and urine. Cidofovir was initially administered to treat these infections while ganciclovir was used with filgrastim due to neutropenia. The patient subsequently improved. This case represents a diagnostic and therapeutic challenge due to the multiple concurrent viral infections causing haematuria as well as the combined post-chemo-immunotherapy and antiviral myelotoxicity in a CLL patient.

HDAC6 Inhibition Alleviates CLL-Induced T-Cell Dysfunction and Enhances Immune Checkpoint Blockade Efficacy in the Eμ-TCL1 Model

Development of chronic lymphocytic leukemia (CLL) is associated with severe immune dysfunction. T-cell exhaustion, immune checkpoint upregulation, and increase of regulatory T cells contribute to an immunosuppressive tumor microenvironment. As a result, CLL patients are severely susceptible to infectious complications that increase morbidity and mortality. CLL B-cell survival is highly dependent upon interaction with the supportive tumor microenvironment. It has been postulated that the reversal of T-cell dysfunction in CLL may be beneficial to reduce tumor burden. Previous studies have also highlighted roles for histone deacetylase 6 (HDAC6) in regulation of immune cell phenotype and function. Here, we report for the first time that HDAC6 inhibition exerts beneficial immunomodulatory effects on CLL B cells and alleviates CLL-induced immunosuppression of CLL T cells. In the Eμ-TCL1 adoptive transfer murine model, genetic silencing or inhibition of HDAC6 reduced surface expression of programmed death-ligand 1 (PD-L1) on CLL B cells and lowered interleukin-10 (IL-10) levels. This occurred concurrently with a bolstered T-cell phenotype, demonstrated by alteration of coinhibitory molecules and activation status. Analysis of mice with similar tumor burden indicated that the majority of T-cell changes elicited by silencing or inhibition of HDAC6 in vivo are likely secondary to decrease of tumor burden and immunomodulation of CLL B cells. The data reported here suggest that CLL B cell phenotype may be altered by HDAC6-mediated hyperacetylation of the chaperone heat shock protein 90 (HSP90) and subsequent inhibition of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway. Based on the beneficial immunomodulatory activity of HDAC6 inhibition, we rationalized that HDAC6 inhibitors could enhance immune checkpoint blockade in CLL. Conclusively, combination treatment with ACY738 augmented the antitumor efficacy of anti-PD-1 and anti-PD-L1 monoclonal antibodies in the Eμ-TCL1 adoptive transfer murine model. These combinatorial antitumor effects coincided with an increased cytotoxic CD8⁺ T-cell phenotype. Taken together, these data highlight a role for HDAC inhibitors in combination with immunotherapy and provides the rationale to investigate HDAC6 inhibition together with immune checkpoint blockade for treatment of CLL patients.

Efficacy of bendamustine and rituximab in unfit patients with previously untreated chronic lymphocytic leukemia. Indirect comparison with ibrutinib in a real-world setting. A GIMEMA-ERIC and US study

Limited information is available on the efficacy of front‐line bendamustine and rituximab (BR) in chronic lymphocytic leukemia (CLL) with reduced renal function or coexisting conditions. We therefore analyzed a cohort of real‐world patients and performed a matched adjusted indirect comparison with a cohort of patients treated with ibrutinib. One hundred and fifty‐seven patients with creatinine clearance (CrCl) <70 mL/min and/or CIRS score >6 were treated with BR. The median age was 72 years; 69% of patients had ≥2 comorbidities and the median CrCl was 59.8 mL/min. 17.6% of patients carried TP53 disruption. The median progression‐free survival (PFS) was 45 months; TP53 disruption was associated with a shorter PFS (P = 0.05). The overall survival (OS) at 12, 24, and 36 months was 96.2%, 90.1%, and 79.5%, respectively. TP53 disruption was associated with an increased risk of death (P = 0.01). Data on 162 patients ≥65 years treated with ibrutinib were analyzed and compared with 165 patients ≥65 years treated with BR. Factors predicting for a longer PFS at multivariable analysis in the total patient population treated with BR and ibrutinib were age (HR 1.06, 95% CI 1.02‐1.10, P < 0.01) and treatment with ibrutinib (HR 0.55, 95% CI 0.33‐0.93, P = 0.03). In a post hoc analysis of patients in advanced stage, a significant PFS advantage was observed in patient who had received ibrutinib (P = 0.03), who showed a trend for OS advantage (P = 0.08). We arrived at the following conclusions: (a) BR is a relatively effective first‐line regimen in a real‐world population of unfit patients without TP53 disruption, (b) ibrutinib provided longer disease control than BR in patients with advanced disease stage.

Recent progress of prognostic biomarkers and risk scoring systems in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia with high heterogeneity in the western world. Thus, investigators identified a number of prognostic biomarkers and scoring systems to guide treatment decisions and validated them in the context of immunochemotherapy. A better understanding of prognostic biomarkers, including serum markers, flow cytometry outcomes, IGHV mutation status, microRNAs, chromosome aberrations and gene mutations, have contributed to prognosis in CLL. Del17p/ TP53 mutation, NOTCH1 mutation, CD49d, IGHV mutation status, complex karyotypes and microRNAs were reported to be of predictive values to guide clinical decisions. Based on the biomarkers above, classic prognostic models, such as the Rai and Binet staging systems, MDACC nomogram, GCLLSG model and CLL-IPI, were developed to improve risk stratification and tailor treatment intensity. Considering the presence of novel agents, many investigators validated the conventional prognostic biomarkers in the setting of novel agents and only TP53 mutation status/del 17p and CD49d expression were reported to be of prognostic value. Whether other prognostic indicators and models can be used in the context of novel agents, further studies are required.

Resistance-Associated Mutations in Chronic Lymphocytic Leukemia Patients Treated With Novel Agents

Inhibitors of B-cell receptor signaling, ibrutinib and idelalisib, and BCL-2 antagonist, venetoclax, have become the mainstay of treatment for chronic lymphocytic leukemia (CLL). Despite significant efficacy in most CLL patients, some patients develop resistance to these agents and progress on these drugs. We provide a state-of-the-art overview of the acquired resistance to novel agents. In 80% of patients with ibrutinib failure, acquired mutations in BTK and PLCG2 genes were detected. No distinct unifying resistance-associated mutations or deregulated signaling pathways have been reported in idelalisib failure. Acquired mutations in the BCL2 gene were detected in patients who had failed on venetoclax. In most cases, patients who have progressed on ibrutinib and venetoclax experience resistance-associated mutations, often present at low allelic frequencies. Resistance-associated mutations tend to occur between the second and fourth years of treatment and may already be detected several months before clinical relapse. We also discuss the development of next-generation agents for CLL patients who have acquired resistant mutations to current inhibitors.