A multicenter study of venetoclax-based treatment for patients with Richter transformation of chronic lymphocytic leukemia

ABSTRACT

Patients with chronic lymphocytic leukemia (CLL) who develop Richter transformation (RT) have a poor prognosis when treated with chemoimmunotherapy regimens used for de novo diffuse large B-cell lymphoma. Venetoclax, a BCL2 inhibitor, has single-agent efficacy in patients with RT and is potentially synergistic with chemoimmunotherapy. In this multicenter, retrospective study, we evaluated 62 patients with RT who received venetoclax-based treatment outside of a clinical trial, in combination with a Bruton tyrosine kinase inhibitor (BTKi; n=28), rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP) (n=13), or intensive chemoimmunotherapy other than R-CHOP (n=21). The best overall and complete response rates were 36%/25%, 54%/46%, and 52%/38%, respectively. The median progression-free and overall survival estimates for the same treatment groups were 4.9/14.3 months, 14.9 months/not reached, and 3.3/9 months, respectively. CLL with del(17p) was associated with a lower complete response rate in the total cohort (odds ratio [OR] 0.15; 95% confidence interval [CI] 0.04-0.6; p=0.01) and venetoclax-naïve subgroup (OR 0.13; 95%CI 0.02-0.66; p=0.01). TP53 mutated CLL was associated with a lower complete response rate (OR 0.15; 95%CI 0.03-0.74; p=0.02) and shorter progression-free survival (hazard ratio 3.1; 95%CI 1.21-7.95; p=0.02) only in venetoclax-naïve subgroup. No other clinical or baseline characteristics, including prior venetoclax treatment for CLL, showed statistically significant association with outcomes. Grade 3-4 neutropenia and thrombocytopenia events were most frequent with intensive chemoimmunotherapy + venetoclax; grade 3-4 infection rates were similar across treatment groups. In this difficult-to-treat RT patient population, venetoclax-based combination regimens achieved high response rates, with durable remission and survival observed in a subset of patients.

Prediction of outcomes for high-count monoclonal B lymphocytosis using an epigenetic and immunogenetic signature

ABSTRACT

Monoclonal B-cell lymphocytosis (MBL) progresses to chronic lymphocytic leukemia (CLL) requiring therapy at 1% to 5% per year. Improved prediction of progression would greatly benefit individuals with MBL. Patients with CLL separate into 3 distinct epigenetic subtypes (epitypes) with high prognostic significance, and recently the intermediate epitype has been shown to be enriched for high-risk immunoglobulin lambda variable (IGLV) 3-21 rearrangements, impacting outcomes for these patients. Here, we employed this combined strategy to generate the epigenetic and light chain immunoglobulin (ELCLV3-21) signature to classify 219 individuals with MBL. The ELCLV3-21 high-risk signature distinguished MBL individuals with a high probability of progression (39.9% and 71.1% at 5 and 10 years, respectively). ELCLV3-21 improved the accuracy of predicting time to therapy for individuals with MBL compared with other established prognostic indicators, including the CLL international prognostic index (c-statistic, 0.767 vs 0.668, respectively). Comparing ELCLV3-21 risk groups in MBL vs a cohort of 226 patients with CLL revealed ELCLV3-21 high-risk individuals with MBL had significantly shorter time to therapy (P = .003) and reduced overall survival (P = .03) compared with ELCLV3-21 low-risk individuals with CLL. These results highlight the power of the ELCLV3-21 approach to identify individuals with a higher likelihood of adverse clinical outcome and may provide a more accurate approach to classify individuals with small B-cell clones.

Artificial Intelligence Electrocardiography to Predict Atrial Fibrillation in Patients With Chronic Lymphocytic Leukemia

Background

The use of an artificial intelligence electrocardiography (AI-ECG) algorithm has demonstrated its reliability in predicting the risk of atrial fibrillation (AF) within the general population.

Objectives

This study aimed to determine the effectiveness of the AI-ECG score in identifying patients with chronic lymphocytic leukemia (CLL) who are at high risk of developing AF.

Methods

We estimated the probability of AF based on AI-ECG among patients with CLL extracted from the Mayo Clinic CLL database. Additionally, we computed the Mayo Clinic CLL AF risk score and determined its ability to predict AF.

Results

Among 754 newly diagnosed patients with CLL, 71.4% were male (median age = 69 years). The median baseline AI-ECG score was 0.02 (range = 0-0.93), with a value ≥0.1 indicating high risk. Over a median follow-up of 5.8 years, the estimated 10-year cumulative risk of AF was 26.1%. Patients with an AI-ECG score of ≥0.1 had a significantly higher risk of AF (HR: 3.9; 95% CI: 2.6-5.7; P < 0.001). This heightened risk remained significant (HR: 2.5; 95% CI: 1.6-3.9; P < 0.001) even after adjusting for the Mayo CLL AF risk score, heart failure, chronic kidney disease, and CLL therapy. In a second cohort of CLL patients treated with a Bruton tyrosine kinase inhibitor (n = 220), a pretreatment AI-ECG score ≥0.1 showed a nonsignificant increase in the risk of AF (HR: 1.7; 95% CI: 0.8-3.6; P = 0.19).

Conclusions

An AI-ECG algorithm, in conjunction with the Mayo CLL AF risk score, can predict the risk of AF in patients with newly diagnosed CLL. Additional studies are needed to determine the role of AI-ECG in predicting AF risk in CLL patients treated with a Bruton tyrosine kinase inhibitor.

Rechallenge With High-Dose Methotrexate After Treatment With Glucarpidase in Adult Patients With Lymphoma

PURPOSE

Limited evidence exists regarding methotrexate (MTX) resumption after patients with lymphoma receive glucarpidase for toxic MTX levels and acute kidney injury (AKI).

METHODS

This retrospective review included adults with lymphoma treated with glucarpidase after MTX at Mayo Clinic between January 31, 2020, and October 10, 2022. Descriptive statistics summarize patient characteristics and clinical outcomes.

RESULTS

Of 11 patients treated with glucarpidase after MTX, seven (64%) were rechallenged with MTX. Indications for MTX rechallenge included confirmed CNS disease (n = 6, 86%) and intravascular lymphoma (n = 1, 14%). Compared with the nonrechallenged subgroup, before receiving MTX that required glucarpidase rescue, the rechallenged patients had lower median pretreatment serum creatinine (Scr; 0.7 v 1.2 mg/dL), and none had AKI with previous MTX doses, n = 0 (0%) versus n = 2 (50%). During the MTX dose requiring glucarpidase rescue, the rechallenged group had lower median peak Scr (1.26 v 3.32 mg/dL) and lower incidence of AKI stage III (n = 1 [14%] v n = 3 [75%]), and none of the rechallenged patients required renal replacement therapy (RRT; n = 0 [0%] v n = 1 [25%]). At the first rechallenge after glucarpidase administration, the median MTX dose reduction was 56% (range, 46%-75%), and the lowest used dose when prescribed according to each treatment protocol schedule was 1.5 g/m2. Two (29%) patients experienced AKI (n = 1 stage I, n = 1 stage II) after MTX rechallenge. Zero patients required RRT, and zero required another glucarpidase administration. Six (86%) patients completed all recommended MTX doses.

CONCLUSION

In selected adults with lymphoma who required glucarpidase for toxic MTX levels after administration of high-dose MTX, resumption of MTX therapy at lower doses is safe. Patients selected for MTX resumption had experienced less severe AKI during the previous cycle compared with those not selected for MTX resumption.

Efficacy of immune checkpoint inhibitors for the treatment of advanced melanoma in patients with concomitant chronic lymphocytic leukemia

BACKGROUND

Immune checkpoint inhibitors (ICIs) have revolutionized the management of advanced melanoma (AM). However, data on ICI effectiveness have largely been restricted to clinical trials, thereby excluding patients with co-existing malignancies. Chronic lymphocytic leukemia (CLL) is the most prevalent adult leukemia and is associated with increased risk of melanoma. CLL alters systemic immunity and can induce T-cell exhaustion, which may limit the efficacy of ICIs in patients with CLL. We, therefore, sought to examine the efficacy of ICI in patients with these co-occurring diagnoses.

PATIENTS AND METHODS

In this international multicenter study, a retrospective review of clinical databases identified patients with concomitant diagnoses of CLL and AM treated with ICI (US-MD Anderson Cancer Center, N = 24; US-Mayo Clinic, N = 15; AUS, N = 19). Objective response rates (ORRs), assessed by RECIST v1.1, and survival outcomes [overall survival (OS) and progression-free survival (PFS)] among patients with CLL and AM were assessed. Clinical factors associated with improved ORR and survival were explored. Additionally, ORR and survival outcomes were compared between the Australian CLL/AM cohort and a control cohort of 148 Australian patients with AM alone.

RESULTS

Between 1997 and 2020, 58 patients with concomitant CLL and AM were treated with ICI. ORRs were comparable between AUS-CLL/AM and AM control cohorts (53% versus 48%, P = 0.81). PFS and OS from ICI initiation were also comparable between cohorts. Among CLL/AM patients, a majority were untreated for their CLL (64%) at the time of ICI. Patients with prior history of chemoimmunotherapy treatment for CLL (19%) had significantly reduced ORRs, PFS, and OS.

CONCLUSIONS

Our case series of patients with concomitant CLL and melanoma demonstrate frequent, durable clinical responses to ICI. However, those with prior chemoimmunotherapy treatment for CLL had significantly worse outcomes. We found that CLL disease course is largely unchanged by treatment with ICI.

Differential prognosis of single and multiple TP53 abnormalities in high-count MBL and untreated CLL

TP53 aberrations, including mutations and deletion of 17p13, are important adverse prognostic markers in chronic lymphocytic leukemia (CLL) but are less studied in high count monoclonal B-cell lymphocytosis (HCMBL), an asymptomatic pre-malignant stage of CLL. Here we estimated the prevalence and impact of TP53 aberrations in 1,230 newly diagnosed treatment-naïve individuals (849 CLL, 381 HCMBL). We defined TP53 state as: wild-type (no TP53 mutations and normal 17p), single-hit (del(17p) or one TP53 mutation), or multi-hit (TP53 mutation and del(17p), TP53 mutation and loss of heterozygosity, or multiple TP53 mutations). Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for time to first treatment and overall survival by TP53 state. We found 64 (7.5%) CLL patients and 17 (4.5%) HCMBL individuals had TP53 mutations with variant allele fraction >10%. Del(17p) was present in 58 (6.8%) of CLL and 11 (2.9%) of HCMBL cases. Most individuals had wild-type (N=1,128, 91.7%) TP53 state, followed by multi-hit (N=55, 4.5%) and then single-hit (N=47, 3.8%) TP53 state. The risk of shorter time to therapy and death increased with the number of TP53 abnormalities. Compared to wild-type patients, multi-hit patients had 3-fold and single-hit patients had 1.5-fold increased risk of requiring therapy. Multi-hit patients also had 2.9-fold increased risk of death compared to wild-type. These results remained stable after accounting for other known poor prognostic factors. Both TP53 mutations and del(17p) may provide important prognostic information for HCMBL and CLL that would be missed if only one were measured.

Clinical outcomes in patients with chronic lymphocytic leukemia with disease progression on ibrutinib

Patients with chronic lymphocytic leukemia (CLL) with disease progression on ibrutinib have worse outcomes compared to patients stopping ibrutinib due to toxicity. A better understanding of expected outcomes in these patients is necessary to establish a benchmark for evaluating novel agents currently available and in development. We evaluated outcomes of 144 patients with CLL treated at Mayo Clinic with 2018 iwCLL disease progression on ibrutinib. The median overall survival (OS) for the entire cohort was 25.5 months; it was 29.8 months and 8.3 months among patients with CLL progression (n = 104) and Richter transformation (n = 38), respectively. Longer OS was observed among patients with CLL progression who had received ibrutinib in the frontline compared to relapsed/refractory setting (not reached versus 28.5 months; p = 0.04), but was similar amongst patients treated with 1, 2, or ≥3 prior lines (18.5, 30.9, and 26.0 months, respectively, p = 0.24). Among patients with CLL disease progression on ibrutinib, OS was significantly longer when next-line treatment was chimeric antigen receptor T-cell therapy (median not reached) or venetoclax-based treatment (median 29.8 months) compared to other approved treatments, such as chemoimmunotherapy, phosphoinositide 3'-kinase inhibitors, and anti-CD20 monoclonal antibodies (9.1 months; p = 0.03). These findings suggest an unmet need for this growing patient population.

Combined ibrutinib and venetoclax for treatment of patients with ibrutinib-resistant or double-refractory chronic lymphocytic leukaemia

Patients with chronic lymphocytic leukaemia (CLL) disease progression on ibrutinib or after sequential ibrutinib and venetoclax-based treatments (double-refractory) have poor outcomes. In this retrospective study, we analysed outcomes with combined ibrutinib and venetoclax treatment in these groups of patients. The median treatment-free and overall survival for 22 patients with prior progression on ibrutinib (venetoclax-naïve) were 23.7 and 47.1 months respectively. In 11 patients with double-refractory CLL, the median treatment-free and overall survival were 11.2 and 27.0 months respectively. The combination of ibrutinib and venetoclax may help bridge the current gap in options for patients with disease refractory to the most commonly used novel agents.

Humoral and cellular immune responses to recombinant herpes zoster vaccine in patients with chronic lymphocytic leukemia and monoclonal B cell lymphocytosis

Monoclonal B-cell lymphocytosis (MBL) and chronic lymphocytic leukemia (CLL) are clonal B-cell disorders associated with an increased risk of infections and impaired vaccination responses. We investigated the immunogenicity of recombinant zoster vaccine (RZV) in these patients. Individuals with MBL/untreated CLL and Bruton tyrosine kinase inhibitor (BTKi)-treated CLL patients were given two doses of RZV separated by 2 months. Responses assessed at 3 and 12 months from the first dose of RZV by an anti-glycoprotein E ELISA antibody assay and by dual-color Interferon-γ and Interleukin-2FLUOROSPOT assays were compared to historic controls matched by age and sex. About 62 patients (37 MBL/untreated CLL and 25 BTKi-treated CLL) were enrolled with a median age of 68 years at vaccination. An antibody response at 3 months was seen in 45% of participants, which was significantly lower compared to historic controls (63%, p = .03). The antibody response did not significantly differ between MBL/untreated CLL and BTKi-treated CLL (51% vs. 36%, respectively, p = .23). The CD4+ T-cell response to vaccination was significantly lower in study participants compared to controls (54% vs. 96%, p < .001), mainly due to lower responses among BTKi-treated patients compared to untreated MBL/CLL (32% vs. 73%, p = .008). Overall, only 29% of participants achieved combined antibody and cellular responses to RZV. Among participants with response assessment at 12 months (n = 47), 24% had antibody titers below the response threshold. Hypogammaglobulinemia and BTKi therapy were associated with reduced T-cell responses in a univariate analysis. Strategies to improve vaccine response to RZV among MBL/CLL patients are needed.

Incorporating molecular biomarkers into the continuum of care in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a mature B-cell malignancy characterized by marked heterogeneity. Discoveries in disease biology over the past two decades have helped explain clinical variability and heralded the arrival of the targeted therapy era. In this article, we review improvements in risk stratification which have coincided with this progress, including individual biomarkers and their incorporation into prognostic models. Amidst an ever-expanding list of biomarkers, we seek to bring focus to the essential tests to improve patient care and counseling at particular times in the disease course, beginning with prognosis at diagnosis. The majority of patients do not require treatment at the time of diagnosis, making time-to-first-treatment a key initial prognostic concern. Prognostic and predictive biomarkers are then considered at subsequent major junctures, including at the time of treatment initiation, while on therapy, and at the time of relapse on novel agents.

Disease Flare During Temporary Interruption of Ibrutinib Therapy in Patients with Chronic Lymphocytic Leukemia

BACKGROUND

Approximately 25% of patients with chronic lymphocytic leukemia (CLL) experience a flare of disease following ibrutinib discontinuation. A critical question is whether this phenomenon may also occur when ibrutinib is temporarily held. This study aimed to determine the frequency and characteristics of disease flares in this setting and assess risk factors and clinical outcomes.

MATERIALS AND METHODS

We identified all patients with CLL seen at Mayo Clinic between October 2012 and March 2019 who received ibrutinib. Temporary interruptions in treatment and associated clinical findings were ascertained.

RESULTS

Among the 372 patients identified, 143 (38%) had at least one temporary interruption (median 1 hold, range 1-7 holds) in treatment. The median duration of interruption was 8 days (range 1-59 days) and the most common indication was periprocedural. Among the 143 patients with ≥1 hold, an associated disease flare was seen in 35 (25%) patients: mild (constitutional symptoms only) in 21 patients and severe (constitutional symptoms with exam/radiographic findings or laboratory changes) in 14 patients. Disease flare resolved with resuming ibrutinib in all patients. Predictive factors of disease flare included progressive disease at time of hold and ≥ 24 months of ibrutinib exposure. The occurrence of disease flare with an ibrutinib hold was associated with shorter event-free survival (hazard ratio 2.3; 95% confidence interval 1.3-4.1; p = .007) but not overall survival.

CONCLUSION

Temporary interruptions in ibrutinib treatment of patients with CLL are common, and one quarter of patients who held ibrutinib in this study experienced a disease flare. Resolution with resuming ibrutinib underscores the importance of awareness of this phenomenon for optimal management.

IMPLICATIONS FOR PRACTICE

Ibrutinib is a very effective treatment for chronic lymphocytic leukemia (CLL) but needs to be taken continuously. Side effects, such as increased bleeding risk with procedures, require temporary interruptions in this continuous treatment. Rapid CLL progression following ibrutinib discontinuation has been increasingly recognized. This study demonstrates that similar flares in disease signs or symptoms may occur during ibrutinib holds as well. Importantly, management with restarting ibrutinib led to quick clinical improvement. Awareness of this phenomenon among clinicians is critical to avoid associated patient morbidity and premature cessation of effective treatment with ibrutinib if the flare is misidentified as true progression of disease.

Rapid disease progression following discontinuation of ibrutinib in patients with chronic lymphocytic leukemia treated in routine clinical practice

We identified all patients with chronic lymphocytic leukemia at Mayo Clinic treated with ibrutinib outside the context of a clinical trial; timing and reasons for discontinuation were ascertained, as were symptoms, exam and radiographic findings, and laboratory changes following discontinuation. Of 202 patients who received ibrutinib, 52 discontinued therapy (estimated 1- and 2-year risk of discontinuation 18% and 28%, respectively). The most common reasons for discontinuation were toxicity (56%) and progression of disease (32%, including Richter's transformation in 15%). Rapid progression of disease within 4 weeks after discontinuation was observed in 9/36 (25%) patients with adequate records for review, mostly in those stopping ibrutinib for disease progression (n = 8) rather than toxicity (n = 1). This was evident by sudden worsening of disease-related symptoms (n = 9), exam/radiographic changes (n = 7), and laboratory changes (n = 8). An estimated one in every three patients discontinued ibrutinib by 2 years, with 25% developing rapid disease progression afterwards.

Autoimmune cytopenias in patients with chronic lymphocytic leukaemia treated with ibrutinib in routine clinical practice at an academic medical centre

The effects of ibrutinib on the natural history of autoimmune cytopenias (AIC) among chronic lymphocytic leukaemia (CLL) patients treated in routine clinical practice require further investigation. Using the Mayo Clinical CLL Database, 193 CLL patients treated with ibrutinib between November 2013 and January 2017 outside the context of a clinical trial were identified; complete review of their medical records was performed for details of past history of AIC and treatment-emergent AIC. We identified 29/193 (15%) patients with history of AIC prior to ibrutinib start. Of 12 patients requiring AIC therapy at ibrutinib start, 8 (67%) were able to discontinue or de-escalate AIC treatment, and no patient had worsening of their AIC after initiating ibrutinib. Eleven (6%) patients developed treatment-emergent AIC after a median of 59 (range, 6-319) days following the initiation of ibrutinib, 7 of whom (64%) were able to continue ibrutinib. Overall and event-free survival from time of ibrutinib start were not significantly different between patients with history of AIC and those with no history of AIC. Treatment-emergent AIC were seen exclusively in patients with unmutated IGHV and were associated with a shorter EFS. These results suggest a low rate of treatment-emergent AIC and improvement in patients with existing AIC.

Liver dysfunction in chronic lymphocytic leukemia: Prevalence, outcomes, and pathological findings

The prevalence of liver dysfunction and its association with outcomes in patients with previously untreated chronic lymphocytic leukemia (CLL) is unknown. Newly diagnosed (<12 months) previously untreated CLL patients seen at Mayo Clinic, Rochester, MN between 9/1993 and 4/2016 who had baseline assessment of at least one liver function test (LFT) were included in this analysis. The prevalence of liver dysfunction at baseline, proportion of patients who acquired LFT abnormalities, time to first therapy (TTFT) and overall survival (OS) were assessed. An abnormal LFT was present in 82/2336 (3.5%) patients at diagnosis and was associated with advanced Rai stage (Rai III-IV) (21% vs. 6%; P < .001), lower hemoglobin (13.1 g/dL vs. 13.9 g/dL; P < .001), and lower platelet count (187 × 109/L vs. 200 × 109/L; P = .03). Additionally, 236 patients with normal LFTs at diagnosis developed acquired liver dysfunction during follow-up. Patients with abnormal LFTs at diagnosis had a shorter OS compared to those with normal LFTs (HR 1.80 95% CI 1.13-2.87; P = .014, adjusted for age, sex, Rai stage, and treatment), although TTFT was not different. Of 52 patients who underwent a liver biopsy, CLL was present in liver tissue in 39/52 (73%) patients, with the portal tracts the most common region involved. Histopathology findings of liver involvement by CLL had limited correlation with choice of CLL therapy. In conclusion, approximately 1 of 25 newly diagnosed CLL patients has abnormal LFTs at diagnosis. Although the TTFT was not different among patients with abnormal LFTs, these patients have a shorter OS compared to those with normal LFTs.