Unmutated Status Research Articles

Genetic Profiling in Chronic Lymphocytic Leukemia: The Role of TP53 Mutations and IGHV Status in Treatment Decision-Making – A Case Report

Introduction. The TP53 gene encodes the p53 protein, crucial for DNA damage response, apoptosis, and cell cycle regulation. In chronic lymphocytic leukemia (CLL), TP53 loss due to 17p deletion or mutation leads to poor chemoimmunotherapy response and shorter survival. Patients with unmutated immunoglobulin heavy chain variable (IGHV) status exhibit a more aggressive disease course, poorer outcomes, and reduced response to standard chemoimmunotherapy. These genetic variations significantly affect disease progression, treatment choice, and response to therapy. Case Report. In November 2023, a 61-year-old man presented to our clinic with complaints of generalized weakness and rapid fatigue since October 2023. CLL was diagnosed in 2018 through pathohistological and immunohistochemical analysis of the bone marrow. The patient received no therapy until 2023 due to the absence of active disease signs. From March 28, 2023, to July 25, 2023, the patient received chemoimmunotherapy with the bendamustine and rituximab (BR) regimen. Five courses of therapy were administered; however, further treatment was discontinued due to side effects that occurred during the fifth course of bendamustine administration. A subsequent diagnostic evaluation aimed at assessing treatment efficacy, prognosis, and genetic profiling included a cytomorphological analysis, which revealed that lymphocytes comprised 80% of the cellular composition. Immunocytological analysis confirmed the presence of monoclonal atypical lymphocytes, accounting for 70% of the cell population. Next-generation sequencing identified a pathogenic TP53 mutation, and fragment analysis confirmed an unmutated IGHV status. The presence of the TP53 mutation and unmutated IGHV status categorizes the patient as being in the very high-risk group, for which the use of Bruton’s tyrosine kinase inhibitors (BTKIs) and/or B-cell lymphoma-2 (BCL-2) inhibitors is recommended. Conclusions. This case highlights the significance of comprehensive genetic profiling in CLL patients using techniques such as fluorescence in situ hybridization, polymerase chain reaction, and next-generation sequencing. Such profiling detects molecular genetic alterations, facilitating personalized and effective treatment.

IGHV Mutational Status in a Cohort of Bulgarian CLL Patients: High Unmutated CLL Prevalence in North-East Bulgaria.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. One of the best established CLL prognostic markers is the somatic hypermutational status of the IGHV gene which is a part of the immunoglobulin heavy chain variable region. Technology for IGHV genotyping has been optimized and has been applied in routine diagnostics for the first time in Bulgaria. A total of 105 patients with CLL from different Bulgarian regions were tested. IGHV mutational status was determined by Sanger sequencing on total genomic DNA (gDNA) or RNA extracted from mononuclear cells. All sequencing profiles were analyzed with the IMGT/V-QUEST tool. Within the course of the analysis a high percentage of IGHV unmutated status was established in the Varna district on the Black Sea (Northeast Bulgaria). In addition, the IGHV genotyping performed on gDNA revealed a rare case with multiple rearrangements. The present data from IGHV genotyping will help in choosing the proper treatment for the benefit of Bulgarian CLL patients.

A Review of Resistance Mechanisms to Bruton's Kinase Inhibitors in Chronic Lymphocytic Leukemia.

Bruton's Tyrosine Kinase (BTK) inhibitors have become one of the most vital drugs in the therapy of chronic lymphocytic leukemia (CLL). Inactivation of BTK disrupts the B-cell antigen receptor (BCR) signaling pathway, which leads to the inhibition of the proliferation and survival of CLL cells. BTK inhibitors (BTKi) are established as leading drugs in the treatment of both treatment-naïve (TN) and relapsed or refractory (R/R) CLL. Furthermore, BTKi demonstrate outstanding efficacy in high-risk CLL, including patients with chromosome 17p deletion, TP53 mutations, and unmutated status of the immunoglobulin heavy-chain variable region (IGHV) gene. Ibrutinib is the first-in-class BTKi which has changed the treatment landscape of CLL. Over the last few years, novel, covalent (acalabrutinib, zanubrutinib), and non-covalent (pirtobrutinib) BTKi have been approved for the treatment of CLL. Unfortunately, continuous therapy with BTKi contributes to the acquisition of secondary resistance leading to clinical relapse. In recent years, it has been demonstrated that the predominant mechanisms of resistance to BTKi are mutations in BTK or phospholipase Cγ2 (PLCG2). Some differences in the mechanisms of resistance to covalent BTKi have been identified despite their similar mechanism of action. Moreover, novel mutations resulting in resistance to non-covalent BTKi have been recently suggested. This article summarizes the clinical efficacy and the latest data regarding resistance to all of the registered BTKi.

A Single Center Real World Study of Outcome and Resistance of Bruton Tyrosine Kinase Inhibitors (BTKi) in Chinese Patients with Chronic Lymphocytic Leukeima/Small Lymphocytic Lymphoma

Introduction Acquired BTK/PLCG2 mutations remain to be the driver of Bruton Tyrosine Kinase inhibitor (BTKi) resistance. But the underlying mechanisms need to be further explored. In this study, we retrospectively analyzed clinical and biological characteristics of BTKi-treated CLL patients and report the outcome and resistance in our center (the First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital). Method 262 patients treated with single BTKis continuously were collected and follow up the outcome in our center. Progression-free survival (PFS) was defined as from BTKi initiation to disease progression on BTKi. Next-generation sequencing (NGS) and High sensitivity droplet digital PCR (ddPCR) acquired at treatment initiation /or at the time of disease progression were used to describe mutational landscape. Kaplan-Meier method and the log-rank test were used for analysis. Results A total of 262 patients were enrolled from January 2014 to March 2023, and the median age was 63 (range 28-88) years. Ibrutinib, Zanubrutinib, Orelabrutinib were administered in 55.3%,18.3% and 17.9% of patients respectively, in addition to 6 patients with Acalabrutinib and one with Loxo-305, among them 47.7% (125/262) received BTKi as first line treatment. With a median follow up of 27.3 months, 208 patients were in durable remission while 54 patients relapsed, the median exposure of BTKi was 26.8 (range, 1-73.8) sand 27.7 (range, 3-69.8) months respectively. The median PFS was 5.8 years (5.0-NA, 95% CI) for the whole cohort. Clinical and biological characteristics of both cohorts at initiation of BTKi treatment were described and compared in Table 1. Higher proportion of bulky disease (50.0% vs 23.5%), IGHV unmutated status (84.3% vs 50.5%), del(17p) (44.7% vs 12.9%), TP53 mutation (37.8% vs 15.2%), TP53 aberrations (62.5% vs 24.3%) and complex karyotype (40.5% vs 21.1%) were shown in the BTKi relapsed cohort as compared to responsive cohort. Inferior PFS was observed in patients with TP53 aberration vs without TP53 aberration ( 45.6 mos vs not reached, p<0.0001), unmutated IGHV vs mutated IGHV (56.2 mos vs not reached, p=0.0005), with del(17p) vs without del(17p) (36.1 mos vs not reached, p<0.0001), with complex karyotype and without complex karyotype (69.8 mos vs not reached, p=0.0401), bulky disease vs no bulky disease (45.6 mos vs 69.8 mos, p=0.0006) and elevated LDH vs normal LDH (66.5 mos vs not reached, p=0.0083). Moreover, patients with del(11q) or BTKi given as second or greater line showed a tendency of inferior PFS ( p= 0.1963, p= 0.0735, respectively). Regarding the relapsed cohort, 43 patients displayed CLL progression while 11 patients displayed Richter transformation (RT, including 1 Hodgkin lymphoma [HL]) , the median time from initiation to progression were 33.7 months and 9.5 months, respectively（p<0.0001). BTK/PLCG2 mutations were the most common mutation at the timepoint of disease progression. By integrating NGS and ddPCR results, 54.9% (28/51) relapsed patients acquired BTK/PLCG2 mutation. BTKC481S mutation was the dominant hotspot mutation in all kinds of BTKi relapsed cases. Other mutations at the C481 site included C481R, C481Y, C481F. However, BTKT474 mutation was only detected in Orelabrutinib-resistant cases (Figure 1). 6 patients presented with multi-hit mutations. Treatment after disease progression on BTKis is still challenging. In our relapsed cohort, the median PFS was 5.7 months and poorer in RT as compared with CLL progression (3.0 months vs 6.7 months, p= 0.0874). Venetoclax-based regimen might be an effective salvage therapy which could showed a benefit trend in PFS as compared to other post BTKi therapy (10.1 months vs 3.1 months, p= 0.1818). Conclusion In our real world study, patients with IGHV unmutated status, TP53 aberrations, bulky disease and elevated LDH showed inferior PFS. Acquired BTK/PLCG2 mutations remained to be key drivers of BTKis resistance and BTKC481S mutation was the dominant mutation, while BTKT474 mutation was only detected in Orelabrutinib-resistant patients. The prognosis was rather poor for relapsed patients especially for RTs, treatment strategy after disease progression remains to be optimized.

Treatment Refractoriness in Chronic Lymphocytic Leukemia: Old and New Molecular Biomarkers.

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. Despite its indolent clinical course, therapy refractoriness and disease progression still represent an unmet clinical need. Before the advent of pathway inhibitors, chemoimmunotherapy (CIT) was the commonest option for CLL treatment and is still widely used in areas with limited access to pathway inhibitors. Several biomarkers of refractoriness to CIT have been highlighted, including the unmutated status of immunoglobulin heavy chain variable genes and genetic lesions of TP53, BIRC3 and NOTCH1. In order to overcome resistance to CIT, targeted pathway inhibitors have become the standard of care for the treatment of CLL, with practice-changing results obtained through the inhibitors of Bruton tyrosine kinase (BTK) and BCL2. However, several acquired genetic lesions causing resistance to covalent and noncovalent BTK inhibitors have been reported, including point mutations of both BTK (e.g., C481S and L528W) and PLCG2 (e.g., R665W). Multiple mechanisms are involved in resistance to the BCL2 inhibitor venetoclax, including point mutations that impair drug binding, the upregulation of BCL2-related anti-apoptotic family members, and microenvironmental alterations. Recently, immune checkpoint inhibitors and CAR-T cells have been tested for CLL treatment, obtaining conflicting results. Potential refractoriness biomarkers to immunotherapy were identified, including abnormal levels of circulating IL-10 and IL-6 and the reduced presence of CD27+CD45RO- CD8+ T cells.

17th International Conference on Malignant Lymphoma, Palazzo dei Congressi, Lugano, Switzerland, 13 - 17 June, 2023.

Introduction: Patient stratification based on genomic biomarkers is critical to optimize treatment of chronic lymphocytic leukemia (CLL). Using digitized, genomically annotated peripheral blood smears (PBS) of patients with CLL, we evaluated whether deep learning can predict presence of TP53 aberrations (del[17p] and/or TP53 mutation) and unmutated IGHV status solely based on cytomorphology. Methods: The workflow consisted of sample collection and digitization, manual annotation, segmentation, morphological feature extraction, and aberration classification. Whole slide images were generated from PBS of 414 patients with previously untreated CLL (CLL14, GIVe, BAAG). Manual annotation was conducted using Qupath software (v0.3.2) with ImageJ. A tailored Stardist model was used for semantic segmentation. Morphological features were collected from each segmented white blood cell (WBC) and fed into the classification model. Two neural network (NN) models were generated for each aberration (TP53 and IGHV) based on a cohort split into 70/30% training and testing datasets. The models were evaluated using AUC (Area Under the Curve of ROC [Receiver Operating Curve]). Results: In preparation of model training, 4,962 manual cells from 18 randomly selected patients were manually annotated. For the TP53 classifier, 141,873 WBC from 52 patients were segmented using the Stardist model. For the IGHV classifier, 131,410 WBC from 57 patients were segmented. The model was trained on 256 × 256 pixels patches obtained from original images with 200 epochs and 100 batch_size whilst making use of data augmentation. An intersection over union (IoU) value of 89.6% confirmed good model performance, i.e. accurate WBC segmentation. Lymphocyte cells were then segmented on each frame image. In total, 28 single-cell morphological features were captured and 8 best representatives fed into the NN model. The collected metadata vector features were randomly assigned to non-overlapping training and testing sets. Separate datasets were used for the TP53 and IGHV classifier. On a single-cell level, the models achieved an AUC of 86% for TP53 aberrations and IGHV status, respectively. For independent validation, the TP53 and IGHV classifiers were tested on a set of unseen images of 33 and 22 patients, respectively. AUC values of 78% and 72%, respectively, were achieved, confirming good model performance. To classify individual patients, a threshold of ≥50% positive cells/image was used to either classify a patient as TP53 aberrated or IGHV unmutated. Using this approach, 70% of patients with TP53 aberration and 68% with IGHV unmutated status were accurately classified. Keywords: Bioinformatics, Chronic Lymphocytic Leukemia (CLL), Computational and Systems Biology, Diagnostic and Prognostic Biomarkers No conflicts of interests pertinent to the abstract.

17th International Conference on Malignant Lymphoma, Palazzo dei Congressi, Lugano, Switzerland, 13 - 17 June, 2023.

Introduction: BTK inhibitors (BTKi) monotherapy has introduced the concept of continuous treatment in CLL/SLL until disease progression, leading to several concerns like lack of deep remission, increasing risk of toxic effects and substantial cost. Therefore, time-limited treatment strategies as first line treatment of CLL/SLL were comprehensively explored and BTKi combined with chemoimmunotherapy was one of these options which could induce durable responses in young fit patients. Methods: CLL/SLL patients who were treated with iFCR as initial therapy in the First Affiliated Hospital of Nanjing Medical University were included without any genomic restrictions. Ibrutinib (420 mg daily) was given continuously for 2 years and intravenously rituximab (375 mg/m2 in day 0 of cycle 1; 500 mg/m2 in day 0 of cycle 2–6), fludarabine (25 mg/m2, days 1–3) and cyclophosphamide (250 mg/m2, days 1–3) were administered every 28-day cycle, up to maximal 6 cycles. Patients who achieved complete remission or complete remission with incomplete recovery (CR/CRi) and bone marrow (BM) undetectable MRD (uMRD) 2 years after iFCR initiation were feasible to discontinue ibrutinib maintenance. Results: 34 previously untreated, young fit CLL/SLL patients who received iFCR regimen between January 2019 and March 2021 were included in our cohort. The median age was 55 years (IQR: 48–56). IGHV was unmutated in 21 of 34 (61.8%) patients; complex karyotype was present in 11 of 34 (32.4%) patients; TP53 mutation or del(17p) was detected in 6 of 34 (17.6%) patients. CR/CRi rate and BM uMRD rate was 35.3% (12/34) and 41.2% (14/34) after 3 cycles of iFCR and increased to 55.9% (19/34) 2 months after 6 cycles in both patients who received 3 or 4 and 6 cycles of iFCR. The best CR/CRi and BM uMRD rate were both 73.5% (25/34). With the median follow-up of 33 months (range 7–42 months), the 3-year PFS and OS rate was 80.0% and 95.5% respectively. CR/CRi rate and BM uMRD rate was comparable between patients with IGHV mutated and unmutated status without TP53 aberration, while all patients with TP53 aberration failed to achieve sustainable CR/CRi or BM uMRD. Patients who achieved MRD 10-6 negative post 3 cycles of iFCR sustained remission and discontinued ibrutinib maintenance. The most common hematological adverse events were neutropenia (25/34, 73.5%) and thrombocytopenia (24/34, 70.6%), grade 3–4 neutropenia and thrombocytopenia occurred in 67.6% (23/34) and 35.3% (12/34) patients respectively. The most common non-hematological adverse events were nausea (21/34, 61.8%), fatigue (16/34, 47.1%) and vomiting (15/34, 44.1%). Conclusion: The iFCR regimen could achieve high response rate and uMRD rate as initial treatment for young fit CLL/SLL patient without TP53 aberrations with acceptable tolerability. MRD-guided iFCR courses adjustment in patients who achieved early phase remission could achieved sustainable response and reduced toxicity. Encore Abstract - previously submitted to regional or national meetings (up to <1’000 attendees) The research was funded by: This study was supported by National Natural Science Foundation of China (Grant No. 82170166, No. 82100207, No. 82170186, No. 81970146, No. 81900167), Translational Research Grant of National Clinical Research Center for Hematology (2020ZKZB01), Six Talent Peaks Project in Jiangsu Province 2019 (Grant No. WSN-001) and Youth Talent support Project in Jiangsu Province Hospital (Grant No. YNRCQN035). Keywords: Chronic Lymphocytic Leukemia (CLL), Combination Therapies No conflicts of interests pertinent to the abstract.

Approach to relapsed CLL including Richter Transformation

Approach to relapsed CLL including Richter Transformation

Analysis of racial disparities accounting for treatment received in chronic lymphocytic leukemia: A real-world cohort analysis.

7533 Background: Recent population-based studies have shown that Black patients (pts) with CLL have worse overall survival (OS) than White pts with CLL. These studies could not account for the use of modern therapies, CLL prognostic variables, or comorbidity and thus the root cause of this disparity remains unclear. Here, we use the Flatiron Health Database (FHD) to study this disparity, while accounting for disease-specific variables and treatment (tx) received. Methods: Retrospective analysis of pts with CLL in the FHD treated between 2002 to 2022 was performed. Pt characteristics such as age at diagnosis (dx), year (yr) of dx, months (mos) from dx to first tx, race, sex, IGHV status, ECOG performance status (PS), and use of small molecule inhibitors at any time (including BTK inhibitors, venetoclax, PI3K inhibitors, and lenalidomide) were collected and analyzed. OS was measured from tx start. Multivariable cox regression (MVA) was used to determine adjusted odds of survival. Results: 13646 pts with CLL were identified. Mean age at dx was 65.3 yrs, and mean time from dx to tx was 32.3 mos. 81.2%, 8.4%, and 10.4% of pts were White, Black, or other race, respectively, and 63.2% of pts were male. 61.4% of pts were IGHV unmutated, and 89.1% of pts had a ECOG PS 0/1. 58.7% of pts were treated with a small molecule inhibitor at any point during their tx. After a median follow-up of 5.3 yrs, the median OS was 10.5 yrs (95% CI: 10.2-10.8). Black pts were younger at dx (63.1 vs 65.4), had shorter time to first tx (23.6 mo vs 34 mo), were more likely to be IGHV unmutated than White pts (83% vs 60.1%), and had more small molecule inhibitor use (69% vs 58.5%). These differences were all statistically significant (p &lt;0.01). 90.8% and 89.1% of Black and White pts had an ECOG PS of 0/1, respectively. Median OS for Black pts was 10 yrs (95% CI: 9.1-11.1) vs 10.5 yrs (95% CI: 10.2-10.8) for White pts. On MVA, Black pts had higher risk of death than White pts of the same age despite increased use of small molecule inhibitor (Table). However, the interaction between age and race was also significant, indicating a decreasing disparity between Black and White race as pts aged. Time to first tx, IGHV unmutated status, and ECOG PS were also independently associated with worse OS. Conclusions: Black race especially at younger age was independently associated with worse OS despite the use of small molecule inhibitors, IGHV status, and ECOG PS. [Table: see text]

Obinutuzumab in combination with chlorambucil in first line treatment of elderly patients with chronic lymphocytic leukemia

Introduction. Optimal therapy for elderly patients with chronic lymphocytic leukemia (CLL) is the subject of intensive research.Aim – to study the safety of obinutuzumab, as well as the selection of the optimal scheme of its use in patients with CLL, complicated by diabetes mellitus, renal insuffi ciency, cardiac comorbidity.Materials and methods. The study included primary patients with CLL having indications requiring therapy. The inclusion criteria were: Cumulative Illness Rating Scale, CIRS) (CIRS) &gt; 6 and or glomerular fi ltration rate (GFR) &lt; 70 mL/min, the lower limit of GFR was not restricted. The study focused on patients with diabetes mellitus, renal failure and signifi cant cardiac pathology. Patients with Richter’s syndrome, CNS involvement, HBs-antigen, and 17p deletion were not included. In the fi rst cycle obinutuzumab was administered at a dose of 100 or 25 mg on the fi rst day and 900 or 975 mg on the second day, then at a dose of 1000 mg on days 8 and 15. For all subsequent cycles, obinutuzumab was given at a dose of 1000 mg on day 1. The dosage of chlorambucil was 10 mg/m2 from days 1 to 7. Treatment cycles in totals of 6 were repeated every 28 days.Results. The study included 90 patients. Median age was 73.5 years, range – 60–89 years, there were 49 men (54 %) and 41 women (46 %). Twenty-four patients (27 %) had stage C, IGHV unmutated status was detected in 76 % of patients. The median creatinine clearance was 48.6 mL/min (25–110). The median CIRS score was 3 (range – 1–14). Thirty-one patients (34 %) had signifi cant cardiovascular comorbidity (previous myocardial infarction, coronary artery stenting or bypass, HF ≥ II NYHA, peripheral artery disease) as well as hemodynamically signifi cant valvular disease. Fifteen patients (17 %) had diabetes mellitus and 71 patients (79 %) had creatinine clearance &lt; 70 ml/min. Infusion reactions to obinutuzumab grade ≥ II were reported in 29 patients (32 %). Hospitalization on the day of administration or the next day after the fi rst administration was required in 5 cases (5.5 %). Twenty-seven (30 %) patients could not complete 6 cycles. The largest number of patients (14 people, 15.5 %) stopped treatment after 1 course. The causes were the development of persistent cytopenia (n = 4), grade IV reaction to obinutuzumab (n = 3), patient’s refusal (n = 2), infectious complications (n = 2), severe tumor lysis syndrome (n = 1), acute pancreatitis (n = 1) and toxicodermia (n = 1). The leading cause of premature discontinuation on subsequent cycles was persistent neutropenia. Progression during treatment occurred in 3 patients only. Overall survival was signifi cantly predicted by CIRS (maximum discriminatory value of 3, p = 0.013) as well as GFR &lt; 50 mL/min (p = 0.03). No other associations were identifi ed. At least 1 episode of grade III–IV neutropenia occurred in 41 % of patients. Grade IV neutropenia was associated with creatinine clearance &lt; 60 mL/min (p = 0.05), baseline neutrophil level &lt; 2 × 109/L (p = 0.0001), baseline monocyte level &lt; 0.3 × 109/L (p = 0.007) and age &gt; 70 years (p = 0.01). The effectiveness of treatment was evaluated in patients who completed at least 3 cycles of therapy. Complete remission was achieved in 26 patients (35 %), partial remission – in 41 (54 %), stabilization – in 4 (5 %), progression was noted in 3 (4 %). Sixteen patients (18 %) were not available to respond to the assessment. Minimal residual disease &lt; 0.01 % in the bone marrow after completion of treatment was found in 17 patients (19 %), within 0.01–0.9 % – in 25 (28 %) patients. The median follow-up from the date of therapy initiation was 39.7 months (range – 0.6–72 months). The median relapse-free survival was not reached, and 2- and 3-year survival rates were 81 and 62 %, respectively. Poor relapse-free survival signifi cantly correlated with unmutated IGHV genes (HR = 2.4, 95 % CI: 1.12–5.0, p = 0.02) and partial response as opposed to complete response (HR = 3.35; 95 % CI: 1.45–7.7, p = 0.03).Conclusion. The results of our study have practical implications as obinutuzumab is actively integrated into modern treatment regimens. Infusion reactions pose a high risk of complications in elderly patients. The dose of obinutuzumab on day 1 of administration in elderly patients, should not exceed 25 mg. The G-Clb regimen may not be optimal in patients over 75 years of age due to the unpredictable risk of complications. In patients at high risk of neutropenia, it may be appropriate to consider primary prophylaxis. ClbG is an effective regimen that resulted in high rate of MRD-negative responses and prolonged relapse-free survival.

A Fixed-Duration Immunochemotherapy Approach Combined with Ibrutinib in CLL Produces Deep and Sustained MRD Responses: 5.5-Year Results from the Icll-07 Filo Trial

Introduction In previously untreated, medically fit patients with chronic lymphocytic leukemia (CLL), the availability of targeted agents has led to research interest in achieving deep, durable remissions and improving survival outcomes. The phase II ICLL-07 (NCT02666898) trial by the French Innovative Leukemia Organization (FILO) evaluated a fixed-duration (15-month) immunochemotherapy approach (no more than 4 fludarabine/cyclophosphamide [FC]-obinutuzumab cycles). Primary analysis showed the approach was safe and 62.2% (84/135) of all patients enrolled achieved complete response (CR) with bone marrow (BM) minimal residual disease (MRD) <0.01% (Michallet et al Lancet Haematol 2019;6:e470-9). Follow-up at median 37 months from treatment start showed a persistent MRD benefit beyond end of treatment, high survival rates, and low long-term toxicity (Michallet et al Blood 2021;137:1019-23). Here we report long-term results at median 64 months from treatment start (data cut-off 20 May 2022). Methods Between 27 October 2015 and 16 May 2017, 135 previously untreated, medically fit patients with CLL were enrolled from 27 FILO centers. All received obinutuzumab 1000 mg (8 infusions over 6 cycles) plus ibrutinib (420 mg/day for 9 months). Following evaluation at D1 M9 (N=130 evaluable), those in CR with BM MRD <0.01% then continued only ibrutinib 420 mg/day for 6 additional months (I arm; n=10); otherwise, patients received 4 cycles of FC-obinutuzumab 1000 mg alongside continuing ibrutinib 420 mg/day for 6 additional months (I-FCG arm; n=115). Beyond end of treatment, patients were followed for peripheral blood (PB) MRD every 6 months, response every 3 months, progression-free/overall survival (PFS/OS), and safety. MRD was assessed by 8-color flow cytometry, using a highly sensitive (10-6) technique developed by the FILO group that enables subdivision of classical MRD <0.01% into low-level positive MRD <0.01% and undetectable MRD. Results At D1 M16, undetectable PB MRD rates were 80.0% (8/10) in the I arm and 92.5% (99/107) in the I-FCG arm. Beyond end of treatment, in the I arm the undetectable PB MRD rate decreased rapidly, and by M40 all patients had PB MRD positivity (≥0.01% or low-level positive <0.01%). In the I-FCG arm, the undetectable PB MRD rate was 76.3% (61/80) at M40, and of patients currently investigated at M64, 50/62 (80%) still had undetectable PB MRD (Figure 1). Four relapses occurred beyond end of treatment, including 2 CLL progressions (both Richter's syndrome). Throughout follow-up, no differences in undetectable PB MRD rates were apparent in the I-FCG arm according to the IGHV -mutated versus unmutated status (currently at M64: 20/27 versus 25/35, P=0.26). Overall 4-year PFS and OS rates (95% confidence intervals) were 95.5% (92% to 99 %) and 96.2% (93% to 99.5%), respectively. Of 12 deaths overall, 7 occurred beyond end of treatment, with 5 since last publication due to Richter's syndrome at M50, COVID at M50, lung cancer at M50, myelodysplastic syndrome at M60, and acute myeloid leukemia at M69. Other serious adverse events since last publication were metastatic prostate adenocarcinoma at M50 and suspicion of cerebrovascular accident at M65. Conclusion Long-term results from the ICLL-07 trial in previously untreated, medically fit patients with CLL demonstrated that that our fixed-duration (15-month) immunochemotherapy approach produced deep and sustained undetectable PB MRD responses that were correlated to PFS, without excess toxicity. These long-term MRD results remain the best to date even compared to the new targeted therapy combinations ie ibrutinib +veneteclax or obinutuzumab + venetoclax A randomized trial is needed to compare our approach with a chemotherapy-free strategy. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Survival, response rates, and post-transplant outcomes in patients with Acute Myeloid Leukemia aged 60-75 treated with high intensity chemotherapy vs. lower intensity targeted therapy

The United States Food and Drug Administration has approved several oral, targeted therapies for the treatment of Acute Myeloid Leukemia (AML) in recent years. These agents are approved in patients with relapsed/refractory disease or as frontline therapy in patients who are ineligible for intensive chemotherapy based on age, performance status, or comorbidities. They are also being increasingly utilized frontline in patients of all ages and fitness levels through clinical trials and off label prescribing, but comparative treatment outcomes associated with intensive versus targeted therapy have not been extensively studied. We conducted a single center, retrospective analysis to address the impact of treatment intensity on survival in patients with AML aged 60-75 at diagnosis. This study included 127 patients, 73 of whom received high intensity chemotherapy at any point during treatment (any HiC) and 54 of whom received only low intensity targeted therapy (LITT only). Overall survival (OS) from treatment initiation did not differ significantly between the any HiC and LITT only groups (hazard ratio (HR) for death, 0.67; 95% CI, 0.41 to 1.09; P=0.11). The only three variables that were independently associated with superior OS were lower European Leukemia Net (ELN) risk classification, TP53 unmutated status, and receipt of transplant. Our data suggest that baseline genomic features and receipt of transplant are more important than treatment intensity in predicting survival in this patient population. They also highlight the vital role of transplant in older patients with AML regardless of treatment intensity utilized for remission induction. Larger studies are needed to further address this question, including prospective randomized trials.

P682: NEMTABRUTINIB (MK-1026), A NON-COVALENT INHIBITOR OF WILD-TYPE AND C481S MUTATED BRUTON TYROSINE KINASE FOR B-CELL MALIGNANCIES: EFFICACY AND SAFETY OF THE PHASE 2 DOSE-EXPANSION BELLWAVE-001 STUDY

Background: For patients (pts) with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and certain B-cell neoplasms, resistance to Bruton tyrosine kinase inhibitors (BTKi) develops primarily through mutations at the cysteine binding site (C481) or PLCγ2 mutations. Nemtabrutinib (MK-1026, formerly ARQ-531) is a non-covalent, potent inhibitor of both wild type and C481-mutated BTK. Aims: In the phase 1/2 dose-escalation and dose-expansion BELLWAVE-001 study (NCT03162536), the preliminary recommended phase 2 dose (RP2D) of nemtabrutinib was determined to be 65 mg once daily. The efficacy and safety of nemtabrutinib in patients (pts) with CLL/SLL and B-cell non-Hodgkin lymphoma (NHL) were also evaluated at a higher dose during the dose-expansion phase. Methods: In this open-label, single-arm phase 2 study, 9 expansion cohorts were initiated following determination of preliminary nemtabrutinib RP2D. Approximately 10-25 eligible pts were enrolled into Cohort A (relapsed/refractory (r/r) CLL/SLL, with ≥2 prior therapies including covalent BTKi, with documented C481 mutation), Cohort B (r/r CLL/SLL progressed on/intolerant to a BTKi, with ≥2 prior therapies without C481 mutation), Cohort C (Richter transformation with ≥1 prior therapy), Cohort D-H (follicular lymphoma, mantle cell lymphoma, marginal zone lymphoma, high-grade B cell lymphoma with known MYC, BCL-2 or BCL-6 translocations, and Waldenström macroglobulinemia [WM], respectively, who received ≥2 prior therapies), Cohort I (food-effect cohort including pts with B-cell NHL, CLL/SLL, and WM). Primary end point was ORR (per iwCLL criteria, by investigator) for participants with CLL/SLL. Secondary end points included DOR and safety and tolerability. Results: Among 118 pts enrolled, 44 had B-cell NHL, 68 CLL/SLL, and 4 WM. Of these, 94 (79.6%) were treated at the preliminary RP2D, including 51 (54.3%) participants with CLL/SLL. Pts with CLL/SLL had a median (range) number of prior therapies of 4 (1-18), 43 (84%) had prior BTKi therapy, 12 (23%) had del17p, 30 (59%) had IGHV unmutated status, and 32 (63%) had C481S BTK mutation. At data cut-off (April 7, 2021), median (range) follow-up was 4.6 mo (0.1-26.7) for all treated pts. ORR was 57.9% (22/38; 1 CR, 21 PR/PRL) per iwCLL criteria in the efficacy-evaluable population of pts with CLL/SLL treated at preliminary RP2D. Median duration of response was not estimable [NE] (range, 8.3 mo-NE). Among all treated participants, 114 (97%) had a treatment-emergent adverse event (TEAE), with 78 (66%) having a drug-related TEAE, and 9 (8%) having a drug-related TEAE that led to discontinuation. Common TEAEs (≥ 20%) included fatigue (33%), constipation (31%), dysgeusia (28%), cough (25%), nausea (25%), pyrexia (25%), dizziness (23%), hypertension (23%), peripheral edema (22%), diarrhea (21%), and arthralgia (20%). Grade ≥3 TEAEs occurred in 80 (68%) participants. Grade 5 TEAEs occurred in 7 (6%) participants and included death following disease progression 3 (3%), sepsis 1 (1%), dyspnea 1 (1%), and respiratory failure 2 (2%). Common drug-related TEAEs (≥10%) included dysgeusia (15%), nausea (11%), fatigue (11%), and decreased neutrophil count (10%). Grade 3-4 drug-related TEAEs occurred in 31 (26%) participants. No drug-related TEAEs led to death. Summary/Conclusion: Nemtabrutinib has promising antitumor activity with a manageable safety profile in pts with CLL/SLL exposed to multiple lines of therapy, including in those who had progression of disease on prior covalent BTKi. Further evaluation of nemtabrutinib in B-cell malignancies is ongoing.

Expression of lipoprotein lipase and SORL1 genes in patients with chronic lymphocytic leukemia

Introduction. Leukemic cells of patients with chronic lymphocytic leukemia (CLL) are characterized by high expression of the lipoprotein lipase (LPL) gene in unmutated (UM) status of the variable region of the immunoglobulin heavy chain (IGHV) genes and low expression of the SORL1 gene. SORL1 protein promotes the degradation of LPL in nervous cells in vitro that has been previously shown. Objective: to study SORL1 gene expression in CLL patients depending on LPL gene expression and mutational status of IGHV genes. Materials and methods. Analysis was performed in the group of 61 CLL patients. The IGHV gene mutational status was studied by polymerase chain reaction (PCR) followed by direct sequencing. LPL and SORL1 expression was evaluated by Quantitative Real-time PCR. Results. Relative LPL expression levels in CLL samples ranged from 0.5 to 119.5 (mean 23.65 ± 5.19) and correlated with IGHV mutational status (p &lt; 0.01). The average relative SORL1 expression level was 1.71 ± 0.55. No association between SORL1 expression and IGHV mutational status was found (p = 0.358). Among unmutated IGHV cases, negative correlation between LPL and SORL1 gene expression levels was identified (r = -0.764; p = 0.036). Conclusion. The obtained data support the involvement of SORL1 in the post-translational regulation of LPL levels in leukemic cells in CLL. Ketwords: chronic lymphocytic leukemia, lipoprotein lipase, SORL1.

Long-Term Efficacy and Safety of Ibrutinib in the Treatment of CLL Patients: A Real Life Experience.

Ibrutinib has demonstrated a significant clinical impact in patients with de novo and relapsed/refractory chronic lymphocytic leukemia (CLL), even in cases with unfavorable cytogenetics and molecular markers. All CLL patients’ data treated at our Institute with ibrutinib have been retrospectively reviewed. Forty-six patients received ibrutinib either as frontline (10) or second or more advanced treatment (36). Five patients presented with TP53 mutations; 11 had the deletion of chromosome 17p; 17 displayed an unmutated immunoglobulin variable heavy chain status. The median number of cycles administered was 26. Among patients treated frontline, the best overall response rate (ORR) was 90.0%. In patients receiving ibrutinib as a second or later line ORR was 97.2%. Median progression-free survival was 28.8 and 21.1 months for patients treated frontline and as second/later line, respectively. Median overall survival was not reached for those treated frontline and resulted in 4.9 years for patients treated as second/later line. Grade 3–4 hematological toxicities were neutropenia, thrombocytopenia, and anemia. Grade 3–4 extrahematological toxicities included diarrhea, cutaneous rash, utero-vesical prolapse, vasculitis, and sepsis. Ibrutinib is effective and well tolerated in CLL. Responses obtained in a real-life setting are durable and the safety profile of the drug is favorable.

Preliminary Efficacy and Safety of MK-1026, a Non-Covalent Inhibitor of Wild-Type and C481S Mutated Bruton Tyrosine Kinase, in B-Cell Malignancies: A Phase 2 Dose Expansion Study

Preliminary Efficacy and Safety of MK-1026, a Non-Covalent Inhibitor of Wild-Type and C481S Mutated Bruton Tyrosine Kinase, in B-Cell Malignancies: A Phase 2 Dose Expansion Study

Lymphocyte Doubling Time As A Key Prognostic Factor To Predict Time To First Treatment In Early-Stage Chronic Lymphocytic Leukemia.

The prognostic role of lymphocyte doubling time (LDT) in chronic lymphocytic leukemia (CLL) was recognized more than three decades ago when the neoplastic clone’s biology was almost unknown. LDT was defined as the time needed for the peripheral blood lymphocyte count to double the of the initial observed value. Herein, the LDT prognostic value for time to first treatment (TTFT) was explored in our prospective O-CLL cohort and validated in in two additional CLL cohorts. Specifically, newly diagnosed Binet stage A CLL patients from 40 Italian Institutions, representative of the whole country, were prospectively enrolled into the O-CLL1-GISL protocol (clinicaltrial.gov identifier: NCT00917540). Two independent cohorts of newly diagnosed CLL patients recruited respectively at the Division of Hematology in Novara, Italy, and at the Hospital Clinic in Barcelona, Spain, were utilized as validation cohorts. In the training cohort, TTFT of patients with LDT >12 months was significantly longer related to those with a shorter LDT. At Cox multivariate regression model, LDT ≤ 12 months maintained a significant independent relationship with shorter TTFT along with IGHV unmutated (IGHVunmut) status, 11q and 17p deletions, elevated β2M, Rai stage I-II, and NOTCH1 mutations. Based on these statistics, two regression models were constructed including the same prognostic factors with or without the LDT. The model with the LTD provided a significantly better data fitting (χ2 = 8.25, P=0.0041). The risk prediction developed including LDT had better prognostic accuracy than those without LDT. Moreover, the Harrell’C index for the scores including LDT were higher than those without LDT, although the accepted 0.70 threshold exceeded in both cases. These findings were also confirmed when the same analysis was carried out according to TTFT’s explained variation. When data were further analyzed based on the combination between LDT and IGHV mutational status in the training and validation cohorts, IGHVunmut and LDT>12months group showed a predominant prognostic role over IGHVmut LTD ≤ 12 months (P=0.006) in the O-CLL validation cohort. However, this predominance was of borden-line significance (P=0.06) in the Barcelona group, while the significant prognostic impact was definitely lost in the Novara group. Overall, in this study, we demonstrated that LDT could be re-utilized together with the more sophisticated prognostic factors to manage the follow-up plans for Binet stage A CLL patients.

A Phase I Study Of The Oral Btk Inhibitor ONO-4059 In Patients With Relapsed/Refractory and High Risk Chronic Lymphocytic Leukaemia (CLL)

IntroductionThe B-cell receptor (BCR) pathway plays a central role in signal transduction pathways that regulate survival, activation, proliferation and differentiation of B-lineage lymphoid cells. Bruton's tyrosine kinase (Btk) is a critical kinase in BCR signal transduction and recent studies support that targeting Btk is effective in the treatment of B-cell malignancies. ONO-4059 is a highly potent and selective oral Btk inhibitor with an IC50 in the sub-nmol/L range that has demonstrated anti-tumour activity in several pre-clinical models (Yasuhiro T et al, AACR 2013). MethodsThis Phase I study was initiated to determine the safety, tolerability, dose-limiting toxicity (DLT), pharmacokinetics and pharmacodynamics of ONO-4059 given as monotherapy to patients with relapsed/refractory, high risk CLL for whom no therapy of higher priority was available. In this safety-driven, dose-escalating 3+3 design, ONO-4059 was administered as an oral, daily dose (flat dose) given continuously initially for up to 6 months, with the option of additional dosing up to 2 years. We present the safety and efficacy data on 16 evaluable patients, median age 67 yrs (range 40-77), with high risk cytogenetics (17p [38% (6/16)] or 11q [19% (3/16)], 12/16 displaying unmutated IgVH status, 8/16 displaying TP53 mutation), median baseline tumour burden 4,534mm2 [461-14,492 mm2]. Patients had received a median of 3 prior therapies [2-7], including fludarabine (16/16) and rituximab-containing therapy (13/16). Baseline median haematology parameters included hemoglobin 11.3 g/dL [8.5 -15.2], WBC 56.02 x 109/L [2.06-394.74], platelets 95.5 x 109/L [23-173], lymphocytes 50.6 x 109/L [0.5-390], neutrophils 2.46 x 109/L [0.5-11.1]. Patients were treated with ONO-4059 at doses ranging from 20mg-320mg (cohorts 1-5) and the study is currently ongoing with additional dose escalation cohorts to be completed. ResultsONO-4059 was found to be well tolerated, with no dose limiting toxicities (DLTs). A total of 15 ONO-4059-related Grade 1 (n=10) and 2 (n=5) adverse events were reported in 8 out of 16 patients, including one event of diarrhea (G2) and two events of rash (G1, G2). ONO-4059-related G3 or G4 haematological toxicities were infrequent and independent of dose; neutropenia (n=3 [G4 x1, G3 x 2]), febrile neutropenia (n=1 [G3]) occurring in 2 patients at the 20mg dose level only. Only one Grade 3 ONO-4059-related non-haematological event (pyrexia) was reported. Infection rate was low with only one event of bronchitis reported (G2, related). Three ONO-4059-related SAEs were reported in two patients (febrile neutropenia [G3] and pyrexia [G3] in one patient [20 mg]; rash [G2] in another [80 mg]). The pharmacokinetics of ONO-4059 reflects rapid absorption and elimination, a half-life of ∼6 hours, a dose dependent increase in exposure with no accumulation of ONO-4059 exposure and low inter- or intra-patient variability; with Btk occupancy in peripheral blood (as measured by phosphorylated Btk) being maintained for at least 24 hours across all dose levels.Responses have occurred across all dose levels. All patients experienced rapid reductions in lymphadenopathy observed early in treatment, between D1-D28 of the first cycle, accompanied by an increase in absolute lymphocyte count in some, but not all patients. Best overall response rate according to IWCLL criteria (including modified PR with lymphocytosis) was 70% [based on CT-scan and P/E for 7/10 evaluable patients]; with 2 PR, 5 PR with lymphocytosis (For 7 responding patients, median reduction of lymph nodes was 67% [Range 61%-79%]), 2 SD, 1 patient PD (possible Richter's). All patients showed an improvement in haematological parameters after ≥3 months on treatment. Patients (ONO-4059 20mg [1pt] and 40mg [1pt] respectively) who had grade 3 thrombocytopenia at study baseline had a significant improvement in platelet count (>100 x 109/L) with ONO-4059 treatment. To date, 15 of 16 patients remain on treatment with a median progression-free survival of 99 days [Range 8-268].In conclusion, ONO-4059 is a highly potent and selective oral Btk inhibitor with a favourable safety profile along with promising efficacy in this heavily pre-treated population, with responses observed in relapsed, refractory and 17p deleted patients. Disclosures:Salles:Janssen: Honoraria; Gilead: Honoraria; Celgene: Honoraria. Karlin:Janssen: Honoraria; Celgene: Honoraria. Morschhauser:ONO Pharma: Honoraria; Roche: Honoraria; Celgene: Honoraria; Mundipharma: Honoraria. Dyer:ONO Pharma: Honoraria, Research Funding. Hutchinson:ONO Pharma: Research Funding. Fegan:ONO Pharma: Honoraria. Cartron:ONO Pharma: Honoraria. Knurowski:ONO Pharma: Consultancy. Saunders:ONO Pharma: Consultancy; Pharmacyclics: Consultancy. Wright:ONO Pharma: Consultancy. Honda:ONO Pharma: Employment. Mazur:ONO Pharma: Consultancy. Yoshizawa:Ono Pharma: Employment. Kawabata:Ono Pharmaceutical Co., Ltd.: Employment. Birkett:Ono Pharma UK: Employment.

Bcl-2 Inhibitor ABT-199 (GDC-0199) Monotherapy Shows Anti-Tumor Activity Including Complete Remissions In High-Risk Relapsed/Refractory (R/R) Chronic Lymphocytic Leukemia (CLL) and Small Lymphocytic Lymphoma (SLL)

Introduction Novel agents are needed for CLL/SLL patients (pts) R/R to standard therapies. The intrinsic apoptotic pathway is often dysregulated in relapsed CLL/SLL due to a deficiency in pro-apoptotic proteins such as TP53 and overexpression of anti-apoptotic proteins such as Bcl-2. ABT-199 is a selective, potent, orally bioavailable, small molecule Bcl-2 inhibitor that can trigger apoptosis in vitro , even in del(17p) CLL cells, making it a promising agent for the treatment of pts with CLL/SLL. Methods The primary objectives of this phase I, dose-escalation study were to evaluate the safety, pharmacokinetics (PK), determine a maximum tolerated dose, and a recommended phase 2 dose of ABT-199. Secondary objectives were to assess efficacy and to explore biomarkers for response. Pts received a single dose of ABT-199 on Week1 Day -3 or -7 (W1D-3, W1D-7), followed by continuous once-daily dosing from W1D1, until disease progression or unacceptable toxicity. Modifications were made to the dose escalation scheme and tumor lysis syndrome (TLS) prophylaxis and monitoring schedule after TLS was observed in some pts. Evaluations included adverse events (AE; NCI-CTCAE-V4), Cairo-Bishop definitions of laboratory and clinical TLS, PK parameters and response. Results As of July 4, 2013, 56 pts were enrolled in cohorts at doses from 150 to 1200 mg, with a median time on study of 10.0 months (range 0-21.0). 17 (38%) pts had del(17p) and 18 (32%) had fludarabine (F)-refractory disease. 12 of 27 (44%) pts had beta-2 microglobulin levels >3 mg/L and 20 of 24 (83%) had IGVH unmutated status. 22 pts discontinued (D/C) ABT-199: 8 due to AEs, 12 due to progressive disease, 2 for other reasons (1 had a pulmonary embolus requiring Coumadin and 1 went to transplant in response). The most common AEs (All grades, ≥25% pts) were diarrhea (46%), neutropenia (43%), fatigue (34%), upper respiratory tract infection (29%), and cough (25%). Grade (G) 3/4 AEs occurring in ≥4 pts were neutropenia (41%), TLS (11%), thrombocytopenia (10%), hyperglycemia (10%), anemia (7%), and febrile neutropenia (7%). 7 DLTs have occurred to date: 5 TLS (1 G3 laboratory at 50 mg; 1 G4 clinical at 50 mg; 1 G3 laboratory at 100 mg and 2 at 200 mg); 1 G4 neutropenia (600 mg); and sudden death (1200 mg) in the setting of G4 (clinical) TLS. After a single dose of ABT-199 with food, Tmax and T1/2 values were approximately 6 and 17 hrs, respectively, supporting daily dosing. Preliminary efficacy data are summarized in the table below. In pts achieving CR/CRi, minimal residual disease (MRD) was quantified with 4 color flow cytometry using local lab methods (aiming to analyze >200,000 nucleated cells) and interpretation. 8 pts have evaluable results with no detectable MRD in 4 (2 with suboptimal cells analyzed) and low level MRD was found in 4 (0.05, 0.7, 0.75%; quantification pending in 1). Of the pts who had no detectable MRD, 1 pt was F-refractory and del(17p) and 2 pts were F-refractory. Conclusions ABT-199 showed activity in pts with R/R CLL with a response rate of 84% for the study population, including 20% CR/CRi. Pts with high-risk CLL showed similar efficacy with a response rate of 82% in del(17p) and 78% in F-refractory disease. Notably, 3 of the 4 pts who had no detectable MRD and achieved a CR/CRi were high-risk disease pts. This study is continuing enrollment using a revised dosing schedule designed to reduce the identified risk of TLS. A phase 2 monotherapy study in pts with relapsed del(17p) CLL has commenced as well as combination studies with either rituximab or obinutuzumab in pts with relapsed CLL. Disclosures: Seymour Genentech: Consultancy, Membership on an entity’s Board of Directors or advisory committees. Kahl: AbbVie, Inc.: Research Funding; Genentech: Consultancy, Research Funding. Wierda: AbbVie, Inc.: Research Funding; Genentech: Consultancy, Research Funding, Speakers Bureau. Gerecitano: AbbVie: Research Funding; Genentech: Research Funding. Kipps: AbbVie, Inc.: Consultancy, Research Funding. Anderson: AbbVie, Inc.: Research Funding; Genentech: Research Funding; Walter and Eliza Hall Institute of Medical Research: Employee, which recieves commercial income related to ABT-199, Employee, which recieves commercial income related to ABT-199 Other. Huang: AbbVie, Inc.: Research Funding; Genentech: Research Funding; Walter and Eliza Hall Institute of Medical Research: Employee, recieves commercial income related to ABT-199, Employee, recieves commercial income related to ABT-199 Other, Employment. Rudersdorf: AbbVie, Inc.: Employment, Stock Other. Gressick: AbbVie, Inc: Employment, Stock Other. Montalvo: AbbVie, Inc.: Employment, Stock Other. Yang: AbbVie, Inc.: Employment, Stock Other. Busman: AbbVie, Inc.: Employment, Stock Other. Dunbar: AbbVie, Inc.: Employment, Stock Other. Cerri: AbbVie, Inc.: Employment, Stock Other. Enschede: AbbVie, Inc.: Employment, Stock Other. Humerickhouse: AbbVie, Inc.: Employment, Stock Other. Roberts: AbbVie, Inc.: Research Funding; Genentech: Research Funding; Walter and Eliza Hall Institute of Medical Research: Employee, recieves commercial income related to ABT-199, Employee, recieves commercial income related to ABT-199 Other, Employment. View this table: Table: Patient Characteristics and Response Rates (iwCLL 2008 criteria)

A Case of Chronic Lymphocytic Leukemia with Unmutated Variable Region of the Immunoglobulin Heavy Chain Gene with Markedly High Lactate Dehydrogenase Responding to Ibrutinib

Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. Several prognostic factors exist that help stratify patients into different risk categories. Unmutated status of the immunoglobulin heavy chain (IGHV) gene has been shown to be among the most important high-risk prognostic factors in CLL. Elevated serum level of lactate dehydrogenase has also been shown to be associated with worst outcomes. Recently, the management of CLL has progressed favorably and improved outcomes were seen with the use of the small-molecule Bruton's tyrosine kinase inhibitor, ibrutinib, when compared with traditional chemotherapy. Here, we present a CLL case with an unmutated IGHV gene status presenting with markedly elevated LDH and responding dramatically to ibrutinib.