Ibrutinib Therapy Research Articles

Deuterated water labeling in ibrutinib-treated patients with CLL: leukemia cell kinetics correlate with IGHV, ZAP-70, and residual disease

AbstractDeuterated (“heavy”) water labeling in CLL patients demonstrates that IGHV unmutated and ZAP-70+ patients have higher blood and tissue CLL death rates on ibrutinib therapy, resulting in lower measurable residual disease levels with long-term ibrutinib treatment. This trial was registered at www.clinicaltrials.gov as #NCT01752426.

Carfilzomib, lenalidomide, dexamethasone (KRD) in BTKi relapsed or refractory mantle cell lymphoma: A phase II study fromFondazione Italiana Linfomi.

Mantle cell lymphoma (MCL) is a rare lymphoproliferative neoplasm considered incurable, with a median survival of 3-5 years. In recent years, Bruton's tyrosine kinase inhibitors (BTKi) have been introduced, demonstrating high therapeutic activity. However, the prognosis for MCL patients failing ibrutinib therapy is particularly poor, with a survival expectation of a few months. In this phase II trial, we assessed the efficacy and safety of the carfilzomib-lenalidomide-dexamethasone (KRD) combination in MCL patients who were relapsed/refractory (R/R) or intolerant to BTKi and in need of treatment. The primary objective of the study was to evaluate the antitumor efficacy of the KRD combination in terms of 12-month overall survival (12-month OS). From September 2019 to December 2020, 16 patients were enrolled from 11 Italian centers. After a median follow-up of 2.37 months (95% CI 0.92-6.47), the 12-month OS was 13%. The rate of grade 3-4 adverse events (AEs) was 35%, and the overall response rate (ORR) was 19%. These results led to the premature termination of enrollment, as defined in the protocol stopping rules. The efficacy of the KRD combination in advanced-stage MCL patients who are R/R to BTKi is unsatisfactory and too toxic.

A Phase II Study Assessing Long-term Response to Ibrutinib Monotherapy in Recurrent or Refractory CNS Lymphoma.

Ibrutinib is a first-in-class inhibitor of Bruton tyrosine kinase. We previously reported the safety and short-term antitumor activity of ibrutinib in 20 patients with relapsed or refractory (r/r) primary central nervous system (CNS) lymphoma (PCNSL) or secondary CNS lymphoma (SCNSL). We enrolled 26 additional patients with r/r PCNSL/SCNSL into the dose-expansion cohort of the trial into a combined cohort of 46 patients (31 with PCNSL and 15 with SCNSL). Patients received ibrutinib at 560 or 840 mg daily in the dose-escalation cohort and ibrutinib at 840 mg daily in the expansion cohort. The median follow-up was 49.9 and 62.1 months for patients with PCNSL and SCNSL, respectively. We sequenced DNA from available tumor biopsies and cerebrospinal fluid collected before and during ibrutinib therapy. Tumor responses were observed in 23/31 (74%) patients with PCNSL and 9/15 (60%) patients with SCNSL, including 12 complete responses in PCNSL and 7 in SCNSL. The median progression-free survival (PFS) for PCNSL was 4.5 months [95% confidence interval (CI), 2.8-9.2] with 1-year PFS at 23.7% (95% CI, 12.4%-45.1%). The median duration of response in the 23 PCNSL responders was 5.5 months. The median PFS in SCNSL was 5.3 months (95% CI, 1.3-14.5) with a median duration of response of 8.7 months for the 9 responders. Exploratory biomarker analysis suggests that mutations in TBL1XR1 may be associated with a long-term response to ibrutinib in PCNSL (P = 0.0075). Clearance of ctDNA from cerebrospinal fluid was associated with complete and long-term ibrutinib responses. Our study confirms single-agent activity of ibrutinib in r/r CNS lymphoma and identifies molecular determinants of response based on long-term follow-up.

Cardiovascular Outcomes in patients treated with Ibrutinib and related therapies

Cardiovascular Outcomes in patients treated with Ibrutinib and related therapies

New pharmacodynamic parameters linked with ibrutinib responses in chronic lymphocytic leukemia: Prospective study in real-world patients and mathematical modeling.

One of the first clinical observations of ibrutinib activity in the treatment of chronic lymphocytic leukemia (CLL) is a rapid decline in lymph nodes size. This phenomenon is accompanied by an hyperlymphocytosis, either transient or prolonged, which is associated with distinct clinical responses and thus has an impact on long-term outcomes. Understanding which factors determine distinct disease courses upon ibrutinib treatment remains a scientific challenge. From 2016 to 2021, we conducted a longitudinal and observational study in 2 cohorts of patients with chronic lymphocytic leukemia (CLL) (cohort 1, n = 41; cohort 2, n = 81). These cohorts reflect the well-known clinical features of CLL patients, such as Male/Female sex ratio of 2/1, a median age of 70 years at diagnosis, and include patients in first-line therapy (27%) or relapsed/refractory patients (73%). Blood cell counts were followed for each patient during 2 years of ibrutinib treatment. In addition, immunophenotyping and whole-body magnetic resonance imaging (MRI) were assessed in patients from cohort 1. These data were integrated in a newly built mathematical model, inspired by previous mathematical works on CLL treatment and combining dynamical and statistical models, leading to the identification of biological mechanisms associated with the 2 types of clinical responses. This multidisciplinary approach allowed to identify baseline parameters that dictated lymphocytes kinetics upon ibrutinib treatment. Indeed, ibrutinib-induced lymphocytosis defined 2 CLL patient subgroups, transient hyperlymphocytosis (tHL) or prolonged hyperlymphocytosis (pHL), that can be discriminated, before the treatment, by absolute counts of CD4+ T lymphocytes (p = 0.026) and regulatory CD4 T cells (p = 0.007), programmed cell death protein 1 PD1 (p = 0.022) and CD69 (p = 0.03) expression on B leukemic cells, CD19/CD5high/CXCR4low level (p = 0.04), and lymph node cellularity. We also pinpointed that the group of patients identified by the transient hyperlymphocytosis has lower duration response and a poor clinical outcome. The mathematical approach led to the reproduction of patient-specific dynamics and the estimation of associated patient-specific biological parameters, and highlighted that the differences between the 2 groups were mainly due to the production of leukemic B cells in lymph node compartments, and to a lesser extent to T lymphocytes and leukemic B cell egress into bloodstream. Access to additional data, especially longitudinal MRI data, could strengthen the conclusions regarding leukemic B cell dynamics in lymph nodes and the relevance of 2 distinct groups of patients. Altogether, our multidisciplinary study provides a better understanding of ibrutinib response and highlights new pharmacodynamic parameters before and along ibrutinib treatment. Since our results highlight a reduced duration response and outcome in patients with transient hyperlymphocytosis, our approach provides support for managing ibrutinib therapy after 3 months of treatment. ClinicalTrials.gov NCT02824159.

Australians with chronic lymphocytic leukaemia continue to have high rates of second primary malignancies in the modern era.

Population-based studies have demonstrated a high risk of second cancers, especially of the skin, among patients with chronic lymphocytic leukaemia (CLL). We describe age-standardised incidence ratios (SIRs) of second primary malignancies (SPM) in Australian patients with relapsed/refractory CLL treated with at least two lines of therapy, including ibrutinib. From December 2014 to November 2017, 156 patients were identified from 13 sites enrolled in the Australasian Lymphoma and Related Diseases Registry, and 111 had follow-up data on rates of SPM. At 38.4 months from ibrutinib therapy commencement, 25% experienced any SPM. SIR for melanoma and all cancers (excluding nonmelanomatous skin cancers) were 15.8 (95% confidence interval (CI): 7.0-35.3) and 4.6 (95% CI: 3.1-6.9) respectively. These data highlight the importance of primary preventive interventions and surveillance, particularly as survival from CLL continues to improve.

Early reappearance of intraclonal proliferative subpopulations in ibrutinib-resistant chronic lymphocytic leukemia

The Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib represents an effective strategy for treatment of chronic lymphocytic leukemia (CLL), nevertheless about 30% of patients eventually undergo disease progression. Here we investigated by flow cytometry the long-term modulation of the CLL CXCR4dim/CD5bright proliferative fraction (PF), its correlation with therapeutic outcome and emergence of ibrutinib resistance. By longitudinal tracking, the PF, initially suppressed by ibrutinib, reappeared upon early disease progression, without association with lymphocyte count or serum beta-2-microglobulin. Somatic mutations of BTK/PLCG2, detected in 57% of progressing cases, were significantly enriched in PF with a 3-fold greater allele frequency than the non-PF fraction, suggesting a BTK/PLCG2-mutated reservoir resident within the proliferative compartments. PF increase was also present in BTK/PLCG2-unmutated cases at progression, indicating that PF evaluation could represent a marker of CLL progression under ibrutinib. Furthermore, we evidence different transcriptomic profiles of PF at progression in cases with or without BTK/PLCG2 mutations, suggestive of a reactivation of B-cell receptor signaling or the emergence of bypass signaling through MYC and/or Toll-Like-Receptor-9. Clinically, longitudinal monitoring of the CXCR4dim/CD5bright PF by flow cytometry may provide a simple tool helping to intercept CLL progression under ibrutinib therapy.

Ibrutinib and atrial fibrillation: An in-depth review of clinical implications and management strategies.

Ibrutinib, a targeted therapy for B-cell malignancies, has shown remarkable efficacy in treating various hematologic cancers. However, its clinical use has raised concerns regarding cardiovascular complications, notably atrial fibrillation (AF). This comprehensive review critically evaluates the association between ibrutinib and AF by examining incidence, risk factors, mechanistic links, and management strategies. Through an extensive analysis of original research articles, this review elucidates the complex interplay between ibrutinib's therapeutic benefits and cardiovascular risks. Moreover, it highlights the need for personalized treatment approaches, vigilant monitoring, and interdisciplinary collaboration to optimize patient outcomes and safety in the context of ibrutinib therapy. The review provides a valuable resource for healthcare professionals aiming to navigate the intricacies of ibrutinib's therapeutic landscape while prioritizing patient well-being.

Efficacy of catheter ablation in patients with persistent atrial fibrillation on chronic ibrutinib therapy

Abstract Background Ibrutinib represents a cornerstone in the management of B-Cells malignancies and chronic lymphatic leukaemia. This drug however was associated with a 5-fold increased risk of developing atrial fibrillation (AF). The consequences of AF in this category of frailty patients such as heart failure may lead to the need of Ibrutinib withdrawal, which is considered a disease modifying therapy. Purpose This study aims to evaluate the safety and efficacy of catheter ablation in managing AF in patients on chronic ibrutinib therapy. Methods this study evaluated 20 consecutive patients from two centres in Italy who developed persistent AF during chronic therapy with Ibrutinib for chronic lymphatic leukaemia or small lymphocytic lymphoma and underwent AF catheter ablation from 2016 to 2020. Antiarrhythmic drugs were withdrawn because of side effects and drug interaction. All receive pulmonary vein (PV) isolation + isolation of left atrial posterior wall (PW) and superior vena cava. A standardized protocol was performed to confirm persistent PVI and elicit any triggers originating from non-PV sites. Ablation of non-PV sites triggering runs of atrial tachyarrhythmias was left to operator's discretion. Exclusion criteria were age<18 years and history of AF before ibrutinib therapy. Patients were monitored for arrhythmia at quarterly office visits, ECGs, 7-day Holter monitoring and event recorders during the first year followed by biannual checkups during the remaining part of the follow-up period. Results 12 patients received PV+PW+SVC isolation plus ablation of non-PV trigger (Group 1) whereas 8 receive only PV+PW+SVC isolation (Group 2). 10 (83,3%) patients in group 1 remained arrhythmia-free without the need for additional antiarrhythmic drugs while only 3 (37,5%) in group 2 maintained sinus rhythms. Non pulmonary triggers were mostly found in left atrial appendage (5/12, 41,6%), coronary sinus (4/12, 33,3%) and crista terminalis (3/12 25%). More than one trigger was found in 4 (33.3) patients. After 22.3 ±3.6 months follow-up, patients with ablation of induced non-PV triggers had a significantly higher arrhythmia control than those whose triggers were not ablated (Chi – square p value: 0.035; Log rank p value: 0.014) (Fig.1). 5 patient that received left atrial appendage isolation underwent a left atrial appendage closure with Watchman device 3 months after atrial fibrillation ablation. Conclusion Catheter ablation in this category of patients seems to be a safe and effective tool for managing atrial fibrillation in patients with persistent AF on chronic ibrutinib therapy; an ablation strategy that includes as a first line therapy non pulmonary vein triggers appears to be an effective approach when compared to pulmonary vein plus posterior wall only. This approach will allow continuation of ibrutinib treatment, which markedly enhances the prognosis and diminishes the risk of adverse cardiovascular events in this patient population.Kaplan-Meier curve showing recurrence-fr

Effect of Combined Oral Contraceptive Pills on Established Biomarkers of Lipid Metabolism: Systematic Review and Meta-Analysis

Background and aims: Bruton tyrosine kinase inhibitors, such as ibrutinib, are medications that are actively used for Chronic Lymphocytic Leukemia (CLL) and several lymphomas. They work by inhibiting Bruton’s tyrosine kinase therefore affecting B cell proliferation. Ibrutinib itself is associated with multiple cardiotoxicities including atrial fibrillation, ventricular arrhythmias, heart failure, and bleeding. There are well-established studies that show the incidence of atrial fibrillation with ibrutinib therapy. However, only a few reports show an association between ibrutinib therapy and advanced heart block. Methods: A systematic review was carried out involving searching in research databases including PubMed using key search terms. This was followed by a meta-analysis that compared cholesterol, high density lipoprotein, low-density lipoprotein and triglycerides in a population taking combined oral contraceptive pills containing ethinyl oestradiol/levonorgestrel at 6 months vs the baseline measurement. Results: Six studies (9 intervention groups), totalling 274 participants were analysed. Hedge’s g for the cholesterol comparison was 0.133 (95% confidence intervals -0.058, 0.324; p=0.173; I2 =74.652), which was not significant. In contrast high density lipoprotein was significantly lower, Hedge’s g -0.546 (95% confidence intervals -0.834, -0.259; p<0.001; I2 =92.546) and lowdensity lipoprotein significantly higher, Hedge’s g 0.248 (95% confidence intervals 0.055, 0.442; p=0.012; I2 =83.116 as were the triglycerides, Hedge’s g 0.667 (95% confidence intervals 0.491, 0.842; p<0.001; I2 =64.627. Conclusion: After 6 months use the combined oral contraceptive pills containing ethinyl oestradiol/levonorgestrel led to a significantly increased concentration of low-density lipoprotein and triglycerides and a significantly lower concentration of high-density lipoprotein. More research is required to investigate whether these changes are associated with an increased risk of cardiovascular disease.

Advanced Cardiac Conduction Abnormalities in Patients on Ibrutinib Therapy

Background: Bruton tyrosine kinase inhibitors, such as ibrutinib, are medications that are actively used for Chronic Lymphocytic Leukemia (CLL) and several lymphomas. They work by inhibiting Bruton’s tyrosine kinase therefore affecting B cell proliferation. Ibrutinib itself is associated with multiple cardiotoxicities including atrial fibrillation, ventricular arrhythmias, heart failure, and bleeding. There are well-established studies that show the incidence of atrial fibrillation with ibrutinib therapy. However, only a few reports show an association between ibrutinib therapy and advanced heart block. Case presentation: We present two unique cases of patients who presented to the emergency room with syncope while being on ibrutinib therapy for CLL. At presentation, the patients were found to have conduction abnormalities seen on their EKG that included complete heart block in one patient and sick sinus syndrome in the other. Ultimately, each patient was treated with a pacemaker, ibrutinib therapy was discontinued, and they were started on alternative therapy for their CLL. Discussion: No clear mechanism has been established for how ibrutinib therapy causes these conduction abnormalities. This case series proposes a possible mechanism of advanced conduction abnormalities that is caused by ibrutinib therapy that is associated with the NOTCH gene. We propose that the downregulation of the NOTCH gene may prevent cardiac myocyte remodeling and therefore can cause conduction abnormalities as seen in our patients along with others that presented with advanced heart block with ibrutinib therapy.

A306 A CASE OF SCLEROSING CHOLANGITIS AS A COMPLICATION OF CAR-T THERAPY

Abstract Background Chimeric antigen receptor T-cell (CAR-T) therapy is a novel immunotherapy for treating hematological malignancies. CAR-T therapy starts with the collection of T-cells from patients. Then, receptors on the T-cell membrane are re-engineered to become chimeric antigen receptors that specifically target antigens on the surface of malignant cells. These engineered cells are grown ex vivo and infused back into the patient, leading to a targeted immune response against cancer. While CAR-T therapy has shown promising results in treating malignancies refractory to conventional treatment, there have also been reports of complications from unwanted off-target effects with CAR-T therapy. Aims We report a case of sclerosing cholangitis secondary to CAR-T therapy for the treatment of mantle cell lymphoma. Methods Case report. Results A 67-year-old male with refractory stage IVB mantle cell lymphoma underwent CAR-T therapy. His lymphoma was first diagnosed in 2011 and previous treatment included R-CHOP followed by autologous stem cell transplant. He had disease progression despite rituximab maintenance therapy and was switched to ibrutinib therapy with good response until 2023. In 2023, he was noted to have progression of his lymphoma. He subsequently underwent CAR-T therapy. His treatment was complicated by grade 2 cytokine release syndrome requiring two doses of tocilizumab. Other complications included immune effector cell-associated neurotoxicity syndrome leading to status epilepticus. He was intubated and required monitoring in the ICU however he was not in shock, nor did he require vasopressors. Post-CAR-T therapy he developed an increase of his liver enzymes in a cholestatic pattern. Magnetic resonance cholangiopancreatography (MRCP) showed irregular biliary dilation with beading suggestive of sclerosing cholangiopathy. He subsequently underwent multiple endoscopic retrograde cholangiopancreatography (ERCP) with stent insertions but there were no improvements in his liver enzymes and jaundice. A liver biopsy was performed which showed large bile duct obstruction with extensive cholestasis and some evidence of non-caseating granulomatous inflammation. Given the timing of new sclerosing cholangiopathy post-CAR-T therapy along with multiple other complications related to CAR-T therapy, it was thought this patient developed sclerosing cholangitis secondary to CAR-T therapy. Due to worsening clinical status along with progression of mantle cell lymphoma, he was transitioned to comfort care. Conclusions CAR-T therapy is a novel immunotherapy for the treatment of refractory hematological malignancies. However, complications from the off-target effects of CAR-T therapy can occur. This case highlighted a rare side effect associated with CAR-T therapy. In the future, more research will be needed to further characterize the risks associated with CAR-T therapy. Cholangiogram showing no visible filling defects or obstructive lesion. Funding Agencies None

Phase 2 study of ibrutinib plus venetoclax in Japanese patients with relapsed/refractory mantle cell lymphoma

BackgroundDespite high response rates to initial therapy, most patients with mantle cell lymphoma (MCL) experience relapsed or refractory (R/R) disease. Here, we report the efficacy, safety, and pharmacokinetics of the Phase 2, single-arm M20-075 study (NCT04477486) of ibrutinib and venetoclax combination therapy in Japanese patients with R/R MCL.MethodsPatients received 560 mg ibrutinib and 400 mg venetoclax (after a 5-week ramp-up from 20 mg) once daily for up to 104 weeks. Primary endpoint was complete response (CR) rate by independent review committee (IRC). Secondary endpoints included overall response rate (ORR), duration of response (DOR), undetectable minimal residual disease (uMRD) rate, progression-free survival (PFS), overall survival (OS), safety including dose-limiting toxicity (DLT) assessment in the first six patients, and pharmacokinetic parameters. Full analysis set (FAS) comprised all treated patients. Per protocol set (PPS) excluded treated patients with non-evaluable disease at baseline by IRC.ResultsThirteen patients were treated (FAS n = 13; PPS, n = 12). Median age was 71 years, patients had a median of two prior treatments. After a median follow-up of 9.6 months, IRC-assessed CR rate and ORR were both 83% (PPS). All six MRD-evaluable patients had uMRD. Median DOR, PFS, and OS were unreached. The most common Grade ≥ 3 treatment-emergent adverse event (TEAE) was neutropenia (23%); 1 patient discontinued due to squamous cell carcinoma of the lung. No DLTs, tumor lysis syndrome, or deaths related to TEAEs were observed.ConclusionIbrutinib plus venetoclax exhibited high response rates and a well-tolerated safety profile in Japanese patients with R/R MCL.

CD49d Expression Is Included in a Revised 4-Factor Model Predicting Outcome in Patients with Chronic Lymphocytic Leukemia Treated with Ibrutinib: A Multi-Center Real-World Experience

Introduction. Expression of the CD49d integrin chain has prognostic impact on ibrutinib (IB)-treated CLL patients (Tissino et al, J Exp Med, 2018; Tissino et al, Blood 2020). In addition, a 4-factor (4-f) score, based on TP53 aberration, β2-microglobulin (β2M), lactate dehydrogenase (LDH) and previous therapy lines was proposed to identify patients at a higher risk of treatment failure or death during IB therapy (Ahn et al, J Clin Oncol, 2020; Morabito et al, Am J Hematol, 2021). The clinical impact of TP53 disruption was recently refined by demonstrating that only the co-presence of TP53 deletion and mutations, and not the single aberrations, has prognostic value in the IB setting (Bomben et al, Leukemia 2022). The aim here is to integrate these observations in a comprehensive scoring for the management of IB-treated patients. Methods. This study is a retrospective/multicenter analysis of 410 CLL patients treated with IB in the current clinical practice (December/2013-March/2021). Outcome data were updated as of March/2023. Median follow-up from IB treatment was 29.5 months (95% CI 26.7-33.1 months); 57 patients were treatment naïve (0 previous lines), while 353 had ≥1 previous lines. CLL patients were characterized for CD49d expression and for the 4-f variables, TP53 disruption was evaluated by FISH and TP53 mutational status by NGS (low-VAF mutations included). OS or PFS were measured from the date of IB treatment to the date of death (OS), or progression/death (PFS) or last follow-up. Results. 1) The canonical 4-f was applied as previously described, identifying 111 low-, 163 intermediate (int)-, and 136 high-risk patients. Patients in the low-risk group had a longer OS than patients in the int-, and high-risk groups ( P=0.0115 and P=0.0011), while no difference was found comparing patients in the int- vs. high-risk groups (P=0.3036). 2) We generated a modified version of the 4-f score by considering: i) as TP53 disrupted only patients presenting a concomitant TP53 deletion and mutation (n=93); ii) since no difference in terms of OS was found comparing previously untreated patients (n=57) and patients treated with 1 previous line (n=157; P=0.78), these two groups were combined (n=214) and kept separated from patients who had received >1 previous lines of therapy (n=196). Accordingly, the 4-f-modified identified 218 low-, 109 int-, and 83 high-risk patients, the 3 groups presented different OS, the latter model outperforming the canonical 4-f score (C-indices 0.616 vs 0.639; P<0.0001). 3) CD49d-high CLL cases (i.e. CLL with CD49d expression ≥30% and/or with CD49d-bimodal expression; n=268) had shorter OS and PFS intervals ( P=0.0005 and 0.0194, respectively) than CD49d-low cases (n=142). By combining these observations, CD49d remained an independent prognostic factor for OS ( P=0.004) in a multivariable model, which included the 4-f-modified int-risk ( P=0.0585) and high-risk ( P=0.0011) groups. Driven by these findings, we re-analyzed the single parameters of the 4-f score along with CD49d expression. According to a new multivariable analysis (Fig. A), LDH was not included in the final model, which in turn included CD49d expression as independent OS predictor ( P=0.0011). 4) We then redesigned a novel 4-f model excluding LDH data in favor of CD49d expression data (4-factor-CD49d). Each of the four factors contributed one point and stratified patients (n=407/410) into three groups with a significantly different risk for OS probability, merged on a one-to-one risk group comparison basis: score 0-1, low-risk (n=185); score 2-3, int-risk (n=211); score 4, high-risk (n=11; Fig. B). The inclusion of CD49d into this novel 4-f model improved its prediction capability (C-index=0.663; P<0.0001 versus both the original 4-f and the 4-f-modified). Similar results were obtained when considering PFS as clinical readout. Conclusions. Evidence is provided that in the context of CLL patients treated with IB in a real-world setting, variables like B2M, the number of previous lines of therapy and assessment of TP53 disruption remain important tools for identifying patients at a higher risk of relapse/death. Here we emphasize the need of a comprehensive assessment of TP53 aberrations considering TP53 deletions and mutations simultaneously, and propose to add the assessment CD49d expression, integrating these four variables into a novel 4-f-CD49d scoring system. Further validation in independent cohorts is needed.

Nivolumab and Ibrutinib for Treatment of Patients with Refractory or Relapsed Central Nervous System Lymphoma

Background: Central Nervous System (CNS) lymphoma is a distinct entity of large B-cell lymphoma (LBCL) with a unique genomic profile with similarities to the activated B-cell (ABC) subtype, which may offer potential targets for therapy. These aberrancies commonly include MYD88 mutations, which enhances sensitivity to Bruton's tyrosine kinase (BTK) inhibitors, and translocation or copy number alterations of 9p24, which may associate with sensitivity with programmed death (PD)-targeted therapies. Expression of PD-L1 is common in CNS lymphoma and tumor infiltrating lymphocytes, and the majority of CNS lymphomas have a copy gain of 9p24.1. This suggests an attenuated immune response against CNS lymphoma. Ibrutinib in combination with nivolumab has shown safety and clinical activity in patients with relapsed non-Hodgkin lymphoma or chronic lymphocytic leukemia in a phase 1/2 trial, and therefore we hypothesized that this combination may be active in CNS lymphoma. Methods: We conducted an investigator-initiated, open label, single center, phase 2 clinical trial combining ibrutinib with nivolumab to treat patients with relapsed CNS lymphoma (NCT03770416). Adult patients were eligible if they had CNS lymphoma (primary or secondary) refractory to or relapsed after at least 1 prior CNS directed therapy, with adequate organ and bone marrow function, without prior ibrutinib or PD1 inhibitor therapy, and did not require persistent high dose steroids. The trial had two sequentially enrolled cohorts: Cohort A included ibrutinib 560mg oral daily for one cycle (28-days per cycle), followed by ibrutinib combined with nivolumab 240mg IV every 14 days. Cohort B included ibrutinib and nivolumab during the first cycle. Patients with a partial response or greater after 6 cycles of combined ibrutinib and nivolumab could continue therapy for up to 2 years or until progression of disease or unacceptable toxicity occurs. The primary objective was to determine the best overall response rate (ORR) of ibrutinib and nivolumab. Secondary objectives included the ORR of ibrutinib as a lead in prior to the combination, best complete response (CR) rate, landmark survival outcomes, and the safety of the combination. The trial planned to enroll 20 patients in both cohort A and B, but closed early due to slow accrual, due in part to the COVID19 pandemic. Results: The trial accrued 18 patients from February 2019 to June 2022, with all patients evaluable for response. The median age was 63 years (range 43-88), 33% were >70 years, and 78% were female. 89% had primary CNS lymphoma, 50% had non-GCB, 22% had GCB, and 28% were unable to be classified due to missing components of the Hans algorithm. The median number of prior lines of therapy was 2 (range, 1-4), 55% had refractory disease, 17% had prior stem cell transplant, and 11% had prior CAR T-cell therapy. 10 patients were enrolled to Cohort A (ibrutinib lead in), and 8 patients were enrolled to Cohort B (initial combination therapy). Adverse events included 50% with fatigue, 33% with nausea, and 28% with mucositis. For both cohorts, the best ORR was 77.8% (95% CI: 52~94%) and the best CR rate was 50% (95% CI: 26-74%). In cohort A, the ORR of ibrutinib as a lead in after 1 cycle was 90% (95% CI: 55.5-99.7%), and the CR rate was 60%. In GCB patients (n = 4), the ORR and CR rates were 25%. In non-GCB patients (n =9), the ORR and CR rates were 100% and 56%, respectively. With a median follow up time of 34.6 months, the median overall survival (OS) was 25.4 months (95% CI 12.5-NR), and the OS rate at 12 months was 70%. The median progression free survival (PFS) was 6.6 months (95% CI: 2.9 - NR), and the PFS rate at 18 months was 47%. 4 patients withdrew from protocol therapy in CR, including 2 who proceeded to stem cell transplant consolidation, and 2 who stopped due to fatigue. 3 patients withdrew from protocol therapy in PR, 2 due to mucositis and 1 due to arthralgias. 1 patient died of COVID19 infection with a CR after 4 cycles of therapy. Conclusion: Ibrutinib and Nivolumab resulted in significant clinical activity in patients with refractory/relapsed CNS lymphoma. Our trial is limited by small patient numbers but suggests the potential for targeted therapy combinations in future larger clinical studies.

Venetoclax after Progression on Ibrutinib: Results of a Russian Multicenter Study

Introduction Currently, venetoclax is the therapeutic choice for many patients with chronic lymphocytic leukemia progressed on ibrutinib. The optimal drug combinations with venetoclax, the goals and timing of therapy, as well as predictors of response are not yet clear. Only a few clinical trials have included patients with progression on ibrutinib (Kater AP, et.al., J Clin Oncol 2019). Approach to ibrutinib discontinuation and addition of antibodies to CD20 are still a matter of debates. Objectives The aim of this multicenter study was to retrospectively compare outcomes in patients who received venetoclax either alone or in combination with monoclonal antibodies to CD20, as well as outcome of patients who continued ibrutinib after switching to venetoclax. Methods The study included 122 patients with disease progression on ibrutinib according to iwCLL2018 criteria. The data were collected by 27 centers from 25 regions of Russia. Fifty four patients (44%) received venetoclax without monoclonal antibodies, 46 (38%) in combination with obinutuzumab, 22 (18%) with rituximab. Nineteen patients stopped ibrutinib before venetoclax with median interval between treatments of 10 days (range 0 - 91 days). All other patients received venetoclax concomitantly with ibrutinib for some time after progression. Patients who stopped ibrutinib less than 3 months from the date of onset of venetoclax were considered to have discontinued ibrutinib. Results The median age was 63 years (range 30-82), 76 patients were males (62%). Median progression free survival (PFS) for all patients was 26.5 months, overall survival (OS) was 35.2 months. Fifteen patients (12%) had Richter transformation before venetoclax. Overall survival of these patients was significantly worse when compared to other patients, with hazard ratio (HR) 3.46 95% CI 1,42 - 8,48 (p<0.0001). Twenty two patients stopped therapy before the event of death or progression. Reasons included toxicity (N=10), three consecutive confirmation of MRD-negative remission 3 months apart (N=11), and allogeneic stem cell transplantation (N=1). Patients who died or had progression within 3 months after the onset of venetoclax, as well as patients with Richter syndrome diagnosed before the onset of venetoclax were excluded from survival analysis. Table 1 presents patients' characteristics. On pre-treatment, poor outcome was significantly predicted by time to progression on ibrutinib <24 months (PFS: HR 0.53, 95% CI 0.27 - 1.06, p=0,04; OS: HR 0.45, 95% CI 0,22 - 0,93, p=0,01) and ECOG status > 2 (PFS: HR 0.37, 95% CI 0,1 - 1,35, p=0,007; OS: HR 0.32, 95% CI 0,08 - 1.27, p=0,002). There were no differences in baseline characteristics in patients who continued and discontinued ibrutinib, although in the former group more patients have developed Richter syndrome during treatment. Ibrutinib discontinuation was associated with better outcome (PFS: HR 3.72, 95% CI 1.95 - 7.09; OS: HR 3.93, 95% CI 1.96 - 7.88, Figure 1A, B). In total 15 deaths occurred before progression (COVID-19 - 11 patients, secondary cancers - 2, sudden death - 1, pneumonia - 1), and the majority (N = 13) in the group of patients who continued ibrutinib. The group of patients who received antibodies to CD20 was younger (63 versus 69 years, p=0.03), while other baseline parameters were similar. No significant differences were found in either PFS (HR 1.38, 95% CI 0.69 - 2.7) or OS (HR 1.36, 95% CI 0.67 - 2.8, Figure 1C, D). Subgroup analysis of patients who discontinued ibrutinib showed that patients who received venetoclax with monoclonal antibodies had better PFS compared to those on venetoclax alone (HR 6.32, 95% CI 1.43 - 27.8, p=0.045), while OS in the two subgroups did not differ. Conclusion Our data do not support the hypothesis that continuing ibrutinib therapy beyond 2 - 3 months in the context of progression on ibrutinib benefits patients. As evident from increase in PFS, it seems that patients who had discontinued ibrutinib may benefit from adding CD20 antibodies to venetoclax.

Efficacy and safety outcomes of single-agent ibrutinib therapy in chronic lymphocytic leukemia and relapsed/refractory mantle-cell lymphoma

Objectives: We aimed to evaluate patients using ibrutinib for the treatment of chronic lymphocytic leukemia (CLL) and relapsed/refractory mantle-cell lymphoma (MCL), focusing on high-risk subgroups, predictors of efficacy, response levels, and safety profile. Methods: This retrospective cohort study included adult patients diagnosed with CLL and relapsed/refractory MCL who were started on ibrutinib as a single-agent between May 2015 and December 2021 in Bursa Uludag University, Department of Hematology. Results: Of the 45 patients (23 CLL, 22 MCL) started on ibrutinib, the median age was 65 (range: 48-86) years, and 66.7% were male. Del(17p) was present in 47.8% of CLL patients; there was no remarkable difference between del(17p) status and the rates of achieving CR. The median follow-up with ibrutinib treatment in CLL patients was 13.3 (range: 0.3-77.8) months. In univariate analysis, progression-free survival (PFS) and overall survival (OS) were associated with the advanced Eastern Cooperative Oncology Group (ECOG) score (p = 0.003 and p = 0.004, respectively), and > 2 lines treatment regimens before ibrutinib (p = 0.016 and p = 0.050, respectively). In multivariate analysis, the ECOG performance status remained significant for OS. The median use of ibrutinib for MCL patients was 6 (range: 1-48) months, and the proportion of patients who achieved CR was 27.3%. In the univariate analysis of MCL patients, the ECOG performance status for PFS and OS was statistically significant (p = 0.045 and p = 0.016, respectively). Patients' most common non-hematological adverse events were pneumonia and urinary tract infection. Conclusions: Our investigation of patient outcomes treated outside clinical trials confirms ibrutinib's sufficient efficacy and safety profile in CLL and relapsed/refractory MCL.

Real World Experience of Ibrutinib in an Ethnically Diverse Canadian Community Hospital

Chronic Lymphocytic Leukemia (CLL) is an indolent lymphoproliferative disorder commonly managed in community centers. Ibrutinib revolutionized the management of patients with CLL (2). Ibrutinib was initially considered an easy to administer, well tolerated oral medication with excellent efficacy. It was the first clinically available Bruton's Tyrosine Kinase (BTK) inhibitor widely used to treat CLL (3). Recently there have been concerns about cardiovascular toxicities leading to the use of alternative BTK inhibitors (5). Where alternative BTK inhibitors are available these toxicity concerns have led to a decline in the use of ibrutinib to treat CLL. The population served is ethnically diverse consisting of 52% South East Asian with a significant population of African origin. We suspected that the concerns regarding Ibrutinib toxicity were not seen in our patient population prompting a retrospective review of our experience. Ibrutinib therapy A total of 106 CLL patients treated with Ibrutinib were identified from which data was extracted. The mean age was 63.4 years. Patients with CLL treated with Ibrutinib from 2014 to 2021 were identified using OPIS and Meditech and data was extracted manually. Table 1 60% of patient received their initial drug funding through compassionate access, 2% via private insurance and the remaining 38% through the provincial health system. The majority of patients who received funding through compassionate access were eventually transitioned to the provincial health system for drug funding. Toxicity and outcomes Table 2 81% of treated patients never required a dose adjustment of Ibrutinib. The majority of dose reductions were of a temporary nature. We were unable to obtain accurate response data in our retrospective review. 82 of the 106 patients continue on ibrutinib therapy. It is presumed that these patients continue to benefit from therapy without disease progression although response data details were poorly recorded in the medical record. Conclusions There is a lack of data of community real world experience with Ibrutinib particularly in the Canadian setting. Community centers generally are lacking in information technology required to do retrospective audits. Our data shows that ibrutinib therapy for CLL is a reasonable and effective option with good tolerability in a patient population with high cardiovascular risk. The data is limited by the retrospective data collection. The efficacy of therapy is likely comparable to that of the published literature. These data suggest that the tolerability of Ibrutinib therapy seems better than that of the published literature (1) with a low incidence of atrial fibrillation, dose adjustments and low drug discontinuation rate. Of note Richter's transformation was also uncommon in our patient population. This is particularly of interest as our study did capture patients in the early days of ibrutinib therapy when there were concerns that Richter's transformation was more common than seen today. Many of the patients who were treated with ibrutinib would not have received the drug today because of cardiovascular concerns (4). At that time, it was the only available oral targeted agent for the treatment of chronic lymphocytic leukemia. Other agents such as Venetoclax, Acalabrutinib, Zanubrutinib and novel combinations were unavailable at that time or were not funded. These lack of options likely contribute to the persistence of Ibrutinib therapy in our patients. These data suggest that ibrutinib can be used in a high cardiovascular risk population with good efficacy and tolerability. 1.Alloucjery, M., Tomowiak, C., Lombard, T., & et al. (2021). Safety Profile of Ibrutinib: An Analysis of the WHO Pharmacovigilance Database. Front Pharmacology, 12:769315. 2.Byrd, J. C., Brown, J. R., O'Brien, S., & et al. (2014). Ibrutinib versus ofatumumab in previously treated chronic lymphoid leukemia. NEJM, 371(3):213-223. 3.Byrd, J. C., Furman, R. R., & Coutre, S. S. (2013). Targeting BTK with ibrutinib in relapsed chronic lymphocytic leukemia. NEJM, 369(1):32-42. 4.Lovell, A. R., Jammal, N., & Bose, P. (2022). Selecting the optimal BTK inhibitor therapy in CLL: rationale and practical considerations. Therapueltic Advances in Hematology, 13:1177/20406207221116577. 5.Salem, J. E., Manouchehri, A., & Bretagne, M. (2019). Targeting BTK with ibrutinib in relapsed chronic lymphocytic leukemia. J Am Coll Cardiol, 74:1667-1678.

Reappearance of CXCR4 dim/CD5 bright Proliferative Fraction Associates with BTK Mutations and Anticipates Progression in Ibrutinib-Treated CLL

Reciprocal expression of CXCR4 and CD5 on the surface of chronic lymphocytic leukemia (CLL) cells can discriminate the proliferative fraction (CD5high/CXCR4dim, PF), recently egressed from the lymph node, from the resting fraction (CXCR4high/CD5dim, RF) of older, quiescent cells. BTK inhibitors affect the proliferative capacity of CLL cells and cause the redistribution from nodal compartments to the blood stream. Nevertheless, little is known about the impact of long-term treatment of the BTK-inhibitor ibrutinib (IBR) on the PF/RF phenotype. Here, we monitored the PF dynamics in two cohorts of IBR-treated CLL cases with long-term follow-up, and correlated with the emergence of IBR resistance. Longitudinal analysis of the PF under IBR in 31 CLL cases, enrolled in the IOSI-EMA-001 with sequential blood samplings (156 samples, median 6 samples/case) showed a depletion of the PF over time, from 17.7% at pre-treatment to 4.75, 0.4, 1.5, 0.6, 1.5% at later timepoints (0.5, 6, 12, 18, 24 months; p < 0.001, U test), along with loss of proliferative potential by Ki67 expression. We then retrospectively analyzed the PF in 100 IBR-treated CLL cases from the real world, referred for routine immunophenotyping (296 samples, median 3 samples/case). Median PF of pre-IBR samples was 12.0% (range 0.7-50), with a significant drop to 2.7% within one year of treatment and to 1.0% in the second year (p<0.001, U test). 77 cases discontinued IBR due to: toxicity (n=13), progression (n=51), other/death (n=13). Mutations of BTK/ PLCG2 were detected in 30 cases, 28 of which discontinued IBR due to progression and 2 for other/death. To correlate reappearance of the PF with cause of discontinuation, we focused on 64 cases collected within 12 months before/after IBR discontinuation due to toxicity (n=10), progression (n=47) or other/death (n=7), and compared with 22 samples still on treatment for the next 12 months after testing (Panel A). ROC analysis of the PF suggested a criterion of PF>3% as the most discriminating to predict IBR discontinuation due to progression, with a sensitivity of 86.7% and a specificity of 71.1%. This cut-off could separate patients with a longer time-to-progression (median 56 vs. 45 months, p=0.031). 26/47 progressing cases bore BTK/ PLCG2 mutations, with a PF higher than wild-type cases discontinuing for toxicity (8.4% vs. 2.2%; p<0.001) or still on treatment (1.8%, p<0.001). Notably, the 21 BTK/ PLCG2- wild-type progressing cases also showed higher PF compared to cases discontinuing for toxicity (6.9% vs. 2.2%; p<0.001) or still on treatment (1.8%; p<0.001). Notably, PF levels showed no significant correlation with white blood cell counts. Sequential dosages of plasmatic B2M in progressing cases (n=5) revealed steady levels below the 3.5 ug/mL threshold, despite the PF increase (median PF 18%). Cell sorting of the PF/RF fractions from 10 cases showing PF reappearance after prolonged IBR treatment (median 50.7 months) revealed a mean of 1.7 BTK mutations per sample (27 total, range 1-4), a median VAF higher in the PF (23.0%, 0.3-92.3) on average 2.8 times larger than in the RF (5.2%, 0.1-84.8; p=0.003, paired rank test). A similar skewing was present for PLCG2 mutations (median PF VAF: 2.0%, 0.1-6.2; RF VAF: 1.35%, 0.4-2.8; p=0.014). Finally, mRNA-seq was performed in 20 cases, on matching PF/RF fractions both at pre-IBR and progression (9 cases with BTK mutations). Differential expression signature of pre-IBR PF vs. RF, concordant with published gene sets, drove co-clustering of post-IBR PF/RF with their respective counterparts, indicating that PF at progression functionally resembles its pre-treatment counterpart. A strong enrichment of multiple proliferation-related signatures, present in pre-treatment samples, was significantly up-regulated also at progression, independently from BTK mutations (Panel B). In summary, here we report that CLL progression under IBR associates with reappearance of the CD5bright/CXCR4dim PF which precedes clinical progression, increase of serum B2M and WBC counts. Transcriptomic/genetic profiling of the post-IBR PF suggests presence of clonal selection dynamics and active bypass signaling pathways, bona fide taking place within the lymph node microenvironment, including BTK/ PLCG2 mutations. Clinically, longitudinal monitoring of the CXCR4/CD5 fractions by flow cytometry may provide a simple tool helping to intercept CLL progression under IBR therapy.

Time Limited Exposure to a ROR1 Targeting Bispecific T Cell Engager (NVG-111) Leads to Durable Responses in Subjects with Relapsed Refractory Chronic Lymphocytic Leukemia (CLL) and Mantle Cell Lymphoma (MCL)

Background: Receptor tyrosine kinase-like orphan receptor 1 (ROR1) is an oncofetal protein that is absent or expressed at low levels in normal adult tissues but overexpressed in a range of malignancies including CLL and MCL. NVG-111 is a humanized first in class, tandem scFv, ROR1xCD3 bispecific T cell engager. NVG-111 mediates potent killing of ROR1 + tumors by engaging a unique epitope on the Frizzled domain of ROR1 and redirecting T cell activity via the CD3 binder engineered for attenuated cytokine release. Methods: In this phase 1, first-in-human, dose-escalation study (ClinicalTrials.gov identifier: NCT04763083), NVG-111 was evaluated in relapsed/refractory CLL and MCL subjects with an ECOG PS of 0-2 who received ≥2 prior lines of treatment including a Bruton tyrosine kinase inhibitor (BTKi). Bayesian continual reassessment method with overdose control was implemented to guide escalation over a dose range of 0.3-45ug/day. Each subject received at least one dose of NVG-111, administered as a continuous intravenous infusion (cIV) over 21 days followed by 7 days off drug (=1 cycle). NVG-111 was administered in combination (N=8) with ibrutinib to subjects who had achieved a partial response to >1 year of ibrutinib therapy, or as monotherapy in subjects that progressed after covalent BTKi/B-cell lymphoma 2 inhibitor (BCL2i) (N=4). Primary objective was safety, with the secondary objectives being efficacy (overall response rates [ORR], minimal residual disease (MRD) measured by ERIC-compliant flow cytometry and duration of response [DoR]). Serum cytokine levels were determined using a human high sensitivity cytokine premixed magnetic Luminex assay and T cell function was longitudinally evaluated using cytometry by time of flight (CyTOF) analysis. Results: Between May 2021 and July 2023 12 subjects (10 males and 2 females, median age 60 years) completed a maximum of 6 cycles of treatment with NVG-111 (median=3 cycles [range 1-6 cycles]). Pharmacokinetic and pharmacodynamic data demonstrated systemic NVG-111 exposure and exposure-dependent NVG-111 targeting of ROR1 on circulating tumor cells. Adverse events (AEs) related to NVG-111 occurred in 10 subjects (83%), with the most common being nausea (58%), headaches (67%), and fatigue (33%), majority of which were grade 1 or 2. Grade 1(71%) or 2(29%) cytokine release syndrome (CRS) occurred in 58% of subjects during week 1 of cycle 1 except in one subject who had a second grade 1 CRS in cycle 2. Grade 3 dose limiting toxicities (DLTs) occurred in three subjects (25%) consisting of transient elevation of liver enzymes (ALT and AST) in one subject dosed at 3ug/day, immune effector cell-associated neurotoxicity syndrome-like symptoms (ICANS) in one subject dosed at 30ug/day and headache in one subject dosed at 45ug/day. All AEs were fully reversible with no late emergent grade 3 or greater toxicities. Evidence of T cell activation was observed in all 12 subjects with peak cytokine levels at the 30µg/day dose levels (mean±SEM): TNFα, 43±17pg/ml; IL6, 566±541pg/ml; IFNɣ, 18±12pg/ml; and IL10, 103±56pg/ml. Furthermore, T cell profiling showed an increase in cytotoxic CD8 + T cell activation marker expression during each NVG-111 treatment cycle without evidence of T cell exhaustion. Efficacy was evaluable in 11 subjects with objective clinical responses observed in 55% (6/11), including two subjects with clear evidence of single agent activity. Amongst these, three CLL subjects were rendered MRD negative in peripheral blood and one MCL subject achieved complete metabolic response by the Lugano criteria. Two subjects had stable disease but in one of these subjects there was a >50% reduction in peripheral blood lymphocytosis and a 40% reduction in lymphadenopathy. Despite time limited exposure to NVG-111, the restricted mean survival time for DoR is currently 13.6 months (SEM 3.07), the median is not yet calculable with response ongoing in four subjects. The median progression-free survival currently is 18.7 months (95% CI 2.6 - not calculable). Conclusion: These data provide clinical proof of concept for selective targeting of ROR1 with a TCE leading to objective evidence of antitumor activity with encouraging response durability even in CLL patients known to have defective T cell function. The safety profile was consistent with the mechanism of action. Further evaluation of this promising molecule is ongoing.