Immunoglobulin Heavy Chain Variable Gene Research Articles

#2991 Two cases of chronic lymphocytic leukemia associated immunotactoid glomerulopathy: variable clinical presentation, close hematological collaboration

Abstract Background and Aims Immunotactoid glomerulopathy (ITG) is a very rare disease, observable in less than 0.1% of native kidney biopsy samples. It is most often associated with hematological diseases. We confirmed ITG in two cases among our 850 kidney biopsy patients in the past 9 years. In both patients, chronic lymphocytic leukemia (CLL) was the underlying cause. Method Case 1, a 56-year-old man was admitted due to severely increased proteinuria (2 g/day) with preserved renal function, while case 2, a 57-year-old-man was referred with rapidly decreasing eGFR (20 ml/min/1.73m2) with nephrotic syndrome (serum albumin level was 24 g/l). In case 1, no previous history of hematological disease was known, in case 2, CLL - that did not require treatment - was diagnosed half a year before admission. He still had no kidney involvement even 3 months after the CLL diagnosis. We performed kidney biopsy. Light microscopy revealed mesangial proliferative-atypical membranous pattern in case 1, and membranoproliferative pattern in case 2. Immunofluorescence microscopy showed IgG1-lambda deposition, electron microscopy confirmed the organised deposits, microtubular structures with a diameter of 44 nanometers in both cases. Neither monoclonal gammopathy nor systemic immune disease was confirmed. In case 2, low titer ANA positivity, low C3 and high anti-C1q antibody titer was detected, lupus nephritis was ruled out. Previously, lymphocyte count was slightly increased in case 1, CLL was confirmed after kidney biopsy. The immunoglobulin heavy chain variable region gene somatic hypermutation status was borderline in case 1, while in the other case it was unmutated. Fluorescein in situ hybridisation revealed trisomy 12 in both cases. In case 1, chemotherapy was not used due to Rai stage 0, and with appropriate antihypertensive treatment, we could preserve kidney function, and proteinuria was persistently low (below 1 g/day). In case 2, due to Rai stage 1, and progressive renal and lymph node involvement, immunochemotherapy was started (obinutuzumab-venetoclax). Three months later eGFR stabilized at 27 ml/min/1.73 m2, proteinuria decreased below 1 g/day, the C3 level normalized. Conclusion ITG can develop in the early stages of CLL, but it can also indicate CLL progression. The light microscopy histological pattern and, in parallel, the clinical appearance can be of varying severity. Immunochemotherapy resulting reduction of CLL tumor burden and cessation of complement damage, both play a role of improving renal status. Our cases also draw attention to the need for close collaboration with hematologists.

Acalabrutinib-based regimens in frontline or relapsed/refractory higher-risk CLL: pooled analysis of 5 clinical trials

AbstractBefore targeted therapies, patients with higher-risk chronic lymphocytic leukemia (CLL), defined as del(17p) and/or TP53 mutation (TP53m), unmutated immunoglobulin heavy chain variable region genes (uIGHV), or complex karyotype (CK), had poorer prognosis with chemoimmunotherapy. Bruton tyrosine kinase inhibitors (BTKis) have demonstrated benefit in higher-risk patient populations with CLL in individual trials. To better understand the impact of the second-generation BTKi acalabrutinib, we pooled data from 5 prospective clinical studies of acalabrutinib as monotherapy or in combination with obinutuzumab (ACE-CL-001, ACE-CL-003, ELEVATE-TN, ELEVATE-RR, and ASCEND) in patients with higher-risk CLL in treatment-naive (TN) or relapsed/refractory (R/R) cohorts. A total of 808 patients were included (TN cohort, n = 320; R/R cohort, n = 488). Median follow-up was 59.1 months (TN cohort) and 44.3 months (R/R cohort); 51.3% and 26.8% of TN patients and those with R/R, respectively, remained on treatment at last follow-up. In the del(17p)/TP53m, uIGHV, and CK subgroups in the TN cohort, median progression-free survival (PFS) and median overall survival (OS) were not reached (NR). In the del(17p)/TP53m, uIGHV, and CK subgroups in the R/R cohort, median PFS was 38.6 months, 46.9 months, and 38.6 months, respectively, and median OS was 60.6 months, NR, and NR, respectively. The safety profile of acalabrutinib-based therapy in this population was consistent with the known safety profile of acalabrutinib in a broad CLL population. Our analysis demonstrates long-term benefit of acalabrutinib-based regimens in patients with higher-risk CLL, regardless of line of therapy.

Hairy cell leukemia 2024: Update on diagnosis, risk-stratification, and treatment-Annual updates in hematological malignancies.

Hairy cell leukemia (HCL) and HCL-like disorders, including HCL variant (HCL-V) and splenic diffuse red pulp lymphoma (SDRPL), are a very heterogenous group of mature lymphoid B-cell disorders characterized by the identification of hairy cells, a specific genetic profile, a different clinical course and the need for appropriate treatment. Diagnosis of HCL is based on morphological evidence of hairy cells, an HCL immunologic score of 3 or 4 based on the CD11c, CD103, CD123, and CD25 expression, the trephine biopsy which makes it possible to specify the degree of tumoral bone marrow infiltration and the presence of BRAFV600E somatic mutation. Progression of patients with HCL is based on a large splenomegaly, leukocytosis, a high number of hairy cells in the peripheral blood, and the immunoglobulin heavy chain variable region gene mutational status. VH4-34 positive HCL cases are associated with a poor prognosis, as well as HCL with TP53 mutations and HCL-V. Patients should be treated only if HCL is symptomatic. Chemotherapy with risk-adapted therapy purine analogs (PNAs) are indicated in first-line HCL patients. The use of chemo-immunotherapy combining cladribine (CDA) and rituximab (R) represents an increasingly used therapeutic approach. Management of relapsed/refractory disease is based on the use of BRAF inhibitors (BRAFi) plus R, MEK inhibitors (MEKi), recombinant immunoconjugates targeting CD22, Bruton tyrosine kinase inhibitors (BTKi), and Bcl-2 inhibitors (Bcl-2i). However, the optimal sequence of the different treatments remains to be determined.

Low incidence of tumor lysis syndrome in elderly patients with chronic lymphocytic leukemia treated with venetoclax under real-world conditions: results from the prospective observational VeRVe study.

Venetoclax is active in both frontline and relapsed/refractory settings for the treatment of chronic lymphocytic leukemia (CLL). Although the prevalence and severity of tumor lysis syndrome (TLS) are well characterized in clinical trials, laboratory and clinical TLS remain relatively unexplored in real-world clinical practice.In this prospective, real-world observational study, we aimed to determine the incidence and outcomes of TLS in patients with CLL receiving venetoclax outside a clinical trial. The study (VeRVe) was conducted in centers in Austria, Germany, and Switzerland.Two hundred and thirty-nine patients were treated according to local label with at least one dose of venetoclax. Patient demographics, baseline characteristics, and blood chemistry at baseline were documented, and descriptive statistical analyses were conducted.Seventy eight patients (33%) were treated with venetoclax monotherapy, 101 (42%) with venetoclax in combination with rituximab and 60 (25%) with venetoclax in combination with obinutuzumab. In all cases, the TLS risk mitigation strategy adhered to the ramp-up protocol. Median age was 73 years and 66% of patients were male. The majority of patients (75%) had relapsed/refractory CLL, 63/192 (32.8%) patients tested had a del(17p) and 93/134 (69.4%) patients tested had unmutated immunoglobulin heavy chain variable region gene (IGHV). Clinical TLS occurred in 5 patients (2.1%) and laboratory TLS occurred in 15 patients (6.3%). Ten patients received specific treatment, of which 6 were hospitalized. There were no deaths due to a TLS event and venetoclax was well-tolerated. Of the 5 clinical TLS events reported, none were fatal or resulted in renal failure (NCT03342144, registered on Nov 10, 2017).

Risk Factors for Fragility Fractures in Chronic Lymphocytic Leukemia.

Abnormal bone health and fragility fractures (FF) are more common in patients with chronic lymphocytic leukemia (CLL). We hypothesize that there may be risk factors in CLL patients with osteoporosis that increasethe risk of FFs. We conducted a cohort study encompassing all patients diagnosed with CLL from January 1, 2000, to July 31, 2020, utilizing International Classification of Diseases (ICD) codes related to abnormal bone health (osteopenia, osteoporosis, and/or presence of FF) within a single tertiary care institution.Of the 89 patients included, 55 (62%) were female with a mean age of 68 ± 11 years at cohort entry. Fifty-nine (66%) had at least one FF present (pFF) and 30 (34%) did not have an FF (nFF). There were no differences in IGHV (Immunoglobulin heavy chain variable region gene) mutation status, chromosomal abnormalities, or the presence of a complex karyotype. The spine accounted for 81% of identified FF. T-score <-2.5 was more common in those without FF (pFF 38% vs. nFF 71%, P= 0.02). DXA evaluation was not conducted for 36 (40%)individuals within the cohort. Risk factors for fragility fractures included male sex (relative risk [RR] 8.1, 95% confidence interval [CI] 2.1-31.7), diabetes mellitus (RR 1.4, 95% CI 1.04-1.8), smoking (RR 1.3, 95% CI 1.02-1.8), Rai stage >0 (RR 1.4, 95% CI 1.04-1.9), and T-score >-2.5 (RR 1.8, 95% CI 1.1-3.1).There is a high frequency of vertebral FFs in people with CLL despite T-scores not being in the osteoporotic range. Increased awareness to screen and treat vertebral FFs in people with CLL is needed.

Association of Cytogenetics Aberrations and IGHV Mutations with Outcome in Chronic Lymphocytic Leukemia Patients in a Real-World Clinical Setting.

Immunoglobulin heavy chain variable ( IGHV ) region mutations, TP53 mutation, fluorescence in situ hybridization (FISH), and cytogenetic analysis are the most important prognostic biomarkers used in chronic lymphocytic leukemia (CLL) patients in our daily practice. In real-life environment, there are scarce studies that analyze the correlation of these factors with outcome, mainly referred to time to first treatment (TTFT) and overall survival (OS). This study aimed to typify IGHV mutation status, family usage, FISH aberrations, and complex karyotype (CK) and to analyze the prognostic impact in TTFT and OS in retrospective study of 375 CLL patients from a Spanish cohort. We found unmutated CLL (U-CLL) was associated with more aggressive disease, shorter TTFT (48 vs. 133 months, p < 0.0001), and shorter OS (112 vs. 246 months, p < 0.0001) than the mutated CLL. IGHV3 was the most frequently used IGHV family (46%), followed by IGHV1 (30%) and IGHV4 (16%). IGHV5-51 and IGHV1-69 subfamilies were associated with poor prognosis, while IGHV4 and IGHV2 showed the best outcomes. The prevalence of CK was 15% and was significantly associated with U-CLL. In the multivariable analysis, IGHV2 gene usage and del13q were associated with longer TTFT, while VH1-02, +12, del11q, del17p, and U-CLL with shorter TTFT. Moreover, VH1-69 usage, del11q, del17p, and U-CLL were significantly associated with shorter OS. A comprehensive analysis of genetic prognostic factors provides a more precise information on the outcome of CLL patients. In addition to FISH cytogenetic aberrations, IGHV and TP53 mutations, IGHV gene families, and CK information could help clinicians in the decision-making process.

Enrichment in Metabolic Pathway Activation Corresponds to Immunoglobulin Gene Diversity across B Cell Developmental Stages in B-Lymphoblastic Leukemia

Background: Intraclonal genetic variation in the immunoglobulin heavy chain variable gene (IGHV) has been widely documented in B-lymphoblastic leukemia (B-ALL), but its biologic significance as a presumed reflection of the B cell stage of leukemic transformation has not been systematically evaluated. Using ultradeep, targeted sequencing of the rearranged IgH gene in 22 patients with B-ALL, we previously demonstrated that there are subsets of patients with either extensive or minimal diversity in recombination activating gene (RAG)-mediated variable (V), diversity (D), and joining (J) gene rearrangements and that gene expression profiling (GEP) reveals enrichment of oxidative phosphorylation (OXPHOS), glycolysis, and fatty acid metabolism Hallmark pathways among cases with V-DJ rearrangement diversity (Fries et al. ASH 2022). We observed enrichment in these same metabolic signatures among leukemia cells with a pre-B cell phenotypic signature found to be predictive of relapse (Good et al. Nat Med 2018; Liu et al. ASH 2021). To understand the functional implications of this metabolic activation observed among cases with IgH diversity, we applied cytometry by time of flight (CyTOF) phenotyping to determine if IgH clonal composition reflects the metabolic and proliferative activation inherent to B cell stage of origin which may have relevance to disease behavior and outcome. Methods: Using viably-frozen, pre-treatment bone marrow (BM) and/or peripheral blood (PB) biospecimens from a cohort of 18 patients with B-ALL with known IgH clonal composition (7 with extensive V-DJ diversity, 8 without diversity, and 3 lacking any dominant clonal sequence), we performed deep phenotyping by mass cytometry and compared signaling pathway activation patterns between cohorts and compared to healthy controls. Samples were analyzed by mass cytometry with a 40-marker panel including B cell developmental phenotypic and metabolic proteins. Developmental classification was performed as previously described (Good et al. 2018). To test statistical significance in frequency of each subpopulation between two groups, we applied a multiple unpaired t-test with correction by Holm-Sidak method. Results: We discovered that all leukemia samples - regardless of IgH clonal composition - were significantly enriched for phenotypic features reflecting a pro-BII cell state, whereas enrichment of other more or less mature cell stages varied according to IgH composition. Developmental classification demonstrated that cases lacking a clonal IgH rearrangement (N=3) - presumed to have derived from a B cell stage preceding an initial DJ joining event - were enriched at the pro-BII population (P&amp;lt;0.0001), as were cases with extensive V-DJ diversity (N=7; P=0.019), and those lacking in diversity (N=8; P=0.0007) compared to healthy BM. However, cases with V-DJ diversity were uniformly enriched for OXPHOS, glycolytic, and pentose phosphate pathway (PPP)-associated protein expression compared to those without V-DJ diversity. In cells with a pro-BII phenotype, differentially expressed proteins between diverse and non-diverse cases included proteins essential for glycolysis (GLUT1, ENO1, PKM1), PPP (PGD, TKT), and OXPHOS (SDHA, CS, ATPA5, CytC). Conclusions: Cellular metabolism is a known hallmark of cancer proliferation, leukemia stem cell maintenance, and therapeutic escape, just as genetic diversification is integral to tumor evolution. Using primary B-ALL specimens, we show that metabolic pathway activation coincides with extensive RAG-mediated IGHV gene diversification across B cell developmental phenotypes. Contrary to the canonical assumption in B-ALL that V-DJ rearrangement and diversity is tied to developmental state, our analysis suggests that all cases are enriched at the proB-preB transition, but with differences in cellular metabolism that distinguish the diverse from homogeneous rearrangement state. These data suggest that IgH composition is not merely a passive genetic signature exploitable for tracking purposes in B-ALL, but may also inherently reflect underlying biology relevant to clinical outcomes.

Broad Superiority of Zanubrutinib (Zanu) Over Bendamustine + Rituximab (BR) Across Multiple High-Risk Factors: Biomarker Subgroup Analysis in the Phase 3 SEQUOIA Study in Patients With Treatment-Naive (TN) Chronic Lymphocytic Leukemia (CLL)/Small Lymphocytic Lymphoma (SLL) without del(17p)

Introduction Zanu is a Bruton tyrosine kinase (BTK) inhibitor with high potency, selectivity, and efficacy and a favorable toxicity profile. In the phase 3 SEQUOIA study (NCT03336333; Tam et al. Lancet Oncol. 2022), zanu treatment demonstrated superior progression-free survival (PFS) in TN patients (pts) with CLL/SLL and without del(17p) (cohort 1) compared with BR treatment (hazard ratio [HR], 0.42; 95% CI, 0.28-0.63; 2-sided P&amp;lt;.0001). We evaluated PFS in both treatment arms in pt subgroups based on various biomarkers, including several known negative prognostic factors for CLL. Methods Details of the SEQUOIA study were described previously (Tam et al. Lancet Oncol. 2022). A total of 479 pts in cohort 1 were randomized to either zanu (n=241) or BR (n=238). Blood (CLL) or bone marrow (SLL) samples collected at screening were used for fluorescence in situ hybridization for chromosome abnormalities, cytogenetic analysis for complex karyotype (CK), next-generation sequencing (NGS) per the European Research Initiative on CLL (ERIC) for immunoglobulin heavy chain variable (IGHV) gene mutations and expressed clones, and ultrasensitive targeted NGS for mutation analysis of 106 genes. For NGS, all pathogenic mutations with variant allele frequency ≥1% were analyzed. The association between biomarkers and PFS was quantified using the log-rank test and HR and summarized by the Kaplan-Meier method. Data cutoff was October 31, 2022. Results Overall, the CLL features analyzed were similarly distributed between both treatment arms (Table). In pts with cytogenetic abnormalities, zanu demonstrated significantly better PFS than BR in those with del(11q) ( P&amp;lt;.001), del(13q) ( P&amp;lt;.001), trisomy 12 ( P&amp;lt;.01), or CKT ≥3 ( P&amp;lt;.01) (Table). Furthermore, zanu treatment conferred a similar PFS benefit to pts with the negative prognostic factor, del(11q) ( P=.05) or intermediate prognostic factor, trisomy 12 ( P=.40), compared to those without these abnormalities (Table). Notably, in the zanu arm, CKT ≥3 was not associated with worse PFS ( P=.18; Table). Pts with either mutated IGHV (mIGHV) or unmutated IGHV (uIGHV) in the zanu arm had significantly better PFS than pts in the BR arm (uIGHV: P&amp;lt;.0001; mIGHV: P&amp;lt;.01; Table); analysis was confirmed by an ERIC-certified provider. Furthermore, PFS was unaffected by IGHV mutational status in pts treated with zanu ( P=.12). In pts with uIGHV, IGHV1-69 was the most prevalent expressed clone in both arms (zanu: 24.6% [31/126]; BR: 30.7% [39/127]). In the present study, pts with uIGHV harboring IGHV1-69 clones showed significantly better PFS with zanu vs BR ( P&amp;lt;.0001). Across all pts, the most frequently mutated genes were ATM (zanu: 11%; BR: 16%), SF3B1 (zanu: 17%; BR: 21%), NOTCH1 (zanu: 20%; BR: 20%), and BRAF (zanu: 11%; BR: 7%; Table). Pts with mutations associated with poor prognosis in CLL had significantly better PFS with zanu than with BR (eg, ATM [ P=.02], BRAF [ P=.01], NOTCH1 [ P&amp;lt;.001], SF3B1 [ P&amp;lt;.001]; Table). Furthermore, zanu-treated pts with or without mutations in ATM ( P=.58), NOTCH1 ( P=.38), and SF3B1 ( P=.39) had similar PFS. Conclusions TN del(17p)-negative pts with CLL/SLL were evenly distributed between zanu and BR arms in SEQUOIA cohort 1 based on the biomarkers analyzed. PFS in zanu-treated pts was superior to that of BR-treated pts in all biomarker subgroups analyzed, including some known negative prognostic markers in CLL such as del11q, CKT≥3, and uIGHV. Importantly, within the zanu-treatment arm, pts with negative prognostic biomarkers showed comparable PFS benefit to pts without those markers. Like with other BTK inhibitors, ibrutinib and acalabrutinib, IGHV mutational status did not affect PFS outcome (Bartosz et al. Hematology in Clinical Practice 2022). However, contrary to what has been reported for TN or relapsed/refractory pts treated with ibrutinib-based regimens, CKT ≥3 was not associated with worse PFS in zanubrutinib-treated patients (Rigolin et al. Blood. 2021; Thompson et al. Cancer. 2015). This study provides further evidence that zanu is a valuable first-line treatment option for pts with CLL/SLL.

Acalabrutinib ± Obinutuzumab Vs Obinutuzumab + Chlorambucil in Treatment-Naive Chronic Lymphocytic Leukemia: 6-Year Follow-up of Elevate-TN

Background: Previous reports of ELEVATE-TN (NCT02475681) at median follow-up of up to 58.2 months (mo) demonstrated superior efficacy of acalabrutinib (A) ± obinutuzumab (O) compared with O + chlorambucil (Clb) in patients (pts) with treatment-naive (TN) chronic lymphocytic leukemia (CLL). Herein, updated results at 74.5 mo of follow-up are reported. Methods: Pts received A monotherapy, A+O, or O+Clb. Pts who progressed on O+Clb could cross over to A monotherapy. Investigator (INV)-assessed progression-free survival (PFS), INV-assessed overall response rate (ORR), overall survival (OS), and safety were evaluated. All analyses are ad-hoc and P-values are descriptive. Results: A total of 535 pts (A, n=179; A+O, n=179; O+Clb, n=177) were randomized: median age was 70 years, 63% had unmutated immunoglobulin heavy chain variable region genes (uIGHV), and 14% had del(17p) and/or TP53 mutation ( TP53m). At a median follow-up of 74.5 mo (range, 0.0-89.0; data cutoff March 3, 2023), median PFS was not reached (NR) for A+O and A vs 27.8 mo for O+Clb (hazard ratio [HR] vs O+Clb: 0.14 and 0.23, respectively; P&amp;lt;0.0001 for both; HR A+O vs A: 0.58; P=0.0229); estimated 72-mo PFS rates were 78%, 62%, and 17%, respectively (Figure 1). For the 79 pts who crossed over from O+Clb to A, median PFS2 (time to second disease progression or death) was NR; estimated 72-mo PFS2 rate was 54%. Median OS was NR in any treatment arm and was significantly longer with A+O vs O+Clb (HR: 0.62; P=0.0349); estimated 72-mo OS rates were 84% for A+O, 76% for A, and 75% for O+Clb ( Figure 2). In 337 pts with uIGHV, median PFS was NR in both the A+O and A arms vs 22.2 mo for O+Clb (HR: 0.08 and 0.12, respectively; P&amp;lt;0.0001 for both), and estimated 72-mo PFS rates were 75%, 60%, and 5%, respectively, with median OS NR in all treatment arms and estimated 72-mo OS rates of 84%, 76%, and 74%, respectively. In 73 pts with del(17p) and/or TP53m, median PFS was 73.1 mo for A+O and NR for A vs 17.5 mo for O+Clb (HR: 0.28 and 0.23, respectively; P≤0.0009 for both), and estimated 72-mo PFS rates were 56%, 56%, and 18%, respectively. Median OS was NR in both the A+O and A arms vs 74.9 mo for O+Clb (HR: 0.53 and 0.46, respectively, neither statistically significant) and estimated 72-mo OS rates were 68%, 72%, and 53%, respectively. ORR was significantly higher with A+O (96%; 95% confidence interval [CI]: 92-98; P&amp;lt;0.0001) and A (90%; 95% CI: 85-94; P=0.0499) vs O+Clb (83%; 95% CI: 77-88). Combined complete response (CR) plus CR with incomplete hematologic recovery rates were higher with A+O (37%) and A (19%) vs O+Clb (14%; P≤0.0499 for both). Median treatment exposure was 74.4 mo and 72.0 mo for A in the A+O and A arms, respectively; 5.5 mo and 5.6 mo for O in the A+O and O+Clb arms, respectively; and 5.5 mo for Clb in O+Clb arm. Adverse events (AEs) for the O+Clb arm have been previously reported. The most common (≥5% of pts) grade ≥3 AEs for A+O and A, respectively, were neutropenia (31% and 12%), thrombocytopenia (8% and 3%), diarrhea (6% and 1%), COVID-19 (9% and 7%), pneumonia (7% and 6%), syncope (5% and 2%), and hypertension (4% and 5%). For events of clinical interest, grade ≥3 atrial fibrillation, hypertension, and secondary primary malignances were reported in 2%, 4%, and 10% of pts treated with A+O and 2%, 5%, and 5% of pts treated with A, respectively. Treatment is ongoing in 54% (A+O; n=96) and 47% (A; n=84) of pts; the most common reasons for treatment discontinuation were AEs, observed in 21% (n=38) of pts treated with A+O and 18% (n=32) of pts treated with A, and progressive disease, observed in 6% (n=10) of pts treated with A+O and 14% (n=25) of pts treated with A. For pts who crossed over from O+Clb to A, 41% (n=32) discontinued A due to AEs in 13% (n=10) of pts and progressive disease in 16% (n=13) of pts. Conclusions: With a median follow-up of 74.5 mo, the efficacy and safety of A+O and A monotherapy were maintained in pts with TN CLL, including in pts with high-risk genetic features. At 6 years of follow-up, PFS was significantly longer in pts treated with A+O vs A. Median OS was NR in any treatment arm and was significantly longer in pts treated with A+O vs O+Clb.

Lisocabtagene Maraleucel (liso-cel) in R/R CLL/SLL: 24-Month Median Follow-up of TRANSCEND CLL 004

Background:Patients with R/R CLL/SLL who experience intolerance to or disease progression after Bruton tyrosine kinase inhibitor (BTKi) and venetoclax treatment have no established standard of care and poor outcomes, indicating a critical unmet need. Liso-cel, an autologous, CD19-directed, 4-1BB CAR T cell product, has demonstrated efficacy in large B-cell lymphoma and CLL/SLL. In the primary analysis of the phase 1/2, single-arm, multicenter TRANSCEND CLL 004 (NCT03331198) study, a single administration of liso-cel demonstrated rapid, deep, and durable responses and a manageable safety profile in patients with R/R CLL/SLL, including those with progression on previous BTKi and venetoclax failure (Siddiqi T, et al. Lancet 2023). The primary endpoint was met in the prespecified subset of efficacy-evaluable patients with disease progression on BTKi and venetoclax failure (primary efficacy analysis set [PEAS]) at a target dose of 100 × 10 6 CAR + T cells (null hypothesis: ≤ 5%) with the rate of complete response/remission (CR) and CR with incomplete marrow recovery (CRi) by an independent review committee (IRC) per 2018 International Workshop on CLL (iwCLL) criteria at 18.4% ( P = 0.0006). Here we report results from TRANSCEND CLL 004 with a median follow-up of 23.5 months. Methods: Patients must have received ≥ 2 prior lines of therapy, including a BTKi. Eligible patients received liso-cel at a target dose of either 50 × 10 6 (dose level [DL] 1) or 100 × 10 6 (DL2) CAR + T cells after lymphodepleting chemotherapy. The primary endpoint was CR/CRi in the PEAS at DL2. Key secondary endpoints were ORR and rate of undetectable MRD (uMRD; 10 −4 by next-generation sequencing) in blood. All null hypotheses were tested at the primary analysis and not retested in this analysis. Results:Of 137 leukapheresed patients, 118 received liso-cel (safety set), 97 (DL1 = 9; DL2 = 88) were efficacy evaluable, and 54 (DL1 = 4; DL2 = 50) were in the PEAS. In the safety set, median (range) age was 65 years (49-82), 83% had high-risk cytogenetics (del[17p], 42%; TP53 mutation, 47%; unmuted immunoglobulin heavy-chain variable gene, 47%; ≥ 3 chromosomal aberrations, 61%), median (range) lines of prior therapy was 5 (2-14), and all patients had prior BTKi. As of data cutoff (February 28, 2023), median (range) on-study follow-up was 23.5 months (0.4-59.6) for the safety set. In the PEAS at DL2, CR/CRi rate was 20% (95% CI, 10.0-33.7; Table 1). ORR was 44% (95% CI, 30.0-58.7). One patient who had best overall response (BOR) of partial response/remission (PR) at primary analysis had deepened to CR/CRi at 18 months without any additional therapy. Of 9 patients who had BOR of CR/CRi at the primary analysis, 8 had ongoing CR/CRi and 1 completed the study with the last assessment as CR/CRi. The uMRD rate was 64% (95% CI, 49.2-77.1) in blood and 60% (95% CI, 45.2-73.6) in marrow. Median (95% CI) duration of response was 35.3 months (12.4-not reached [NR]) and median duration of CR/CRi was NR. Median (95% CI) PFS was 11.9 months (5.7-26.2). Median (95% CI) OS was 30.3 months (15.0-NR). The efficacy outcomes were similar in the full population at DL2. Of 16 patients who had BOR of CR/CRi at primary analysis, 10 had ongoing CR/CRi. In the safety set, rates of any-grade and grade ≥ 3 treatment-emergent AEs were similar across age groups (Table 2). The rate of any-grade cytokine release syndrome (CRS) was 85% (grade 3, 8%; no grade 4/5) and neurological events (NE) was 45% (grade 3, 18%; grade 4, 1%; no grade 5); 69% received tocilizumab and/or corticosteroids for CRS/NEs. Median (range) time to onset and resolution was 4 days (1-18) and 6 days (2-37) for CRS and 7 days (1-21) and 7 days (1-83) for NEs, respectively. Prolonged cytopenia (grade ≥ 3 at Day 30 after liso-cel infusion), grade ≥ 3 infections, hypogammaglobulinemia, tumor lysis syndrome, second primary malignancy, and macrophage activation syndrome occurred in 54%, 18%, 15%, 11%, 9%, and 3%, respectively. Forty-five (33%) of 137 leukapheresed patients died after liso-cel infusion (disease progression, n = 27 [20%]; AE, n = 6 [4%]; other reasons, n = 12 [9%]). Conclusions: With longer follow-up, liso-cel continued to demonstrate durable CR/CRi, high uMRD rates, and a manageable safety profile in patients with heavily pretreated, high-risk R/R CLL/SLL. The safety results from longer follow-up were similar to those reported in the primary analysis with no new safety signals and were consistent across age groups.

Sustained remissions in CLL after frontline FCR treatment with very-long-term follow-up

AbstractChemoimmunotherapy with fludarabine, cyclophosphamide, and rituximab (FCR) achieves durable remissions, with flattening of the progression-free survival (PFS) curve in patients with mutated immunoglobulin heavy chain variable gene (IGHV-M). We updated long-term follow-up results from the original 300-patient FCR study initiated at MD Anderson in 1999. The current median follow-up is 19.0 years. With this extended follow-up, the median PFS for patients with IGHV-M was 14.6 years vs 4.2 years for patients with unmutated IGHV (IGHV-UM). Disease progression beyond 10 years was uncommon. In total, 16 of 94 (17%) patients in remission at 10 years subsequently progressed with the additional follow-up compared with the patients in our prior report in 2015. Only 4 of 45 patients (9%) with IGHV-M progressed beyond 10 years. Excluding Richter transformation, 96 of 300 patients (32%) developed 106 other malignancies, with 19 of 300 (6.3%) developing therapy-related myeloid neoplasms (tMNs), which were fatal in 16 of 19 (84%). No pretreatment patient characteristics predicted the risk of tMNs. In summary, FCR remains an option for patients with IGHV-M chronic lymphocytic leukemia (CLL), with a significant fraction achieving functional cure of CLL. A risk-benefit assessment is warranted when counseling patients, balancing potential functional cure with the risk of late relapses and serious secondary malignancies.

Affinity-matured homotypic interactions induce spectrum of PfCSP structures that influence protection from malaria infection

The generation of high-quality antibody responses to Plasmodium falciparum (Pf) circumsporozoite protein (PfCSP), the primary surface antigen of Pf sporozoites, is paramount to the development of an effective malaria vaccine. Here we present an in-depth structural and functional analysis of a panel of potent antibodies encoded by the immunoglobulin heavy chain variable (IGHV) gene IGHV3-33, which is among the most prevalent and potent antibody families induced in the anti-PfCSP immune response and targets the Asn-Ala-Asn-Pro (NANP) repeat region. Cryo-electron microscopy (cryo-EM) reveals a remarkable spectrum of helical antibody-PfCSP structures stabilized by homotypic interactions between tightly packed fragments antigen binding (Fabs), many of which correlate with somatic hypermutation. We demonstrate a key role of these mutated homotypic contacts for high avidity binding to PfCSP and in protection from Pf malaria infection. Together, these data emphasize the importance of anti-homotypic affinity maturation in the frequent selection of IGHV3–33 antibodies and highlight key features underlying the potent protection of this antibody family.

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.

THE ASSOCIATION OF THE EMERGING TICK‐BORNE BACTERIAL PATHOGEN NEOEHRLICHIA MIKURENSIS WITH MALIGNANT B CELL LYMPHOMA

The development of some lymphomas has been associated with infections caused by bacterial species discovered in the 1980s, for example, Helicobacter pylori and Borrelia burgdorferi s.l. The first cases of human infection with a bacterial species that was first described in 2004, the tick-borne bacterium Neoehrlichia mikurensis were published in 2010. Patients with malignant B cell lymphomas emerged as a risk group for severe cases of infection, presenting with fever of unknown cause and venous thromboembolism. The infection is missed by routine microbiologic diagnostic procedures such as blood culture and can only be detected by PCR. Vascular endothelium is a likely target of N. mikurensis infection. Asymptomatic carriage of the infection for months to years appears to occur. We hypothesized that N. mikurensis causes latent infections that can reactivate when B cell defenses are compromised. It was whilst conducting a study of patients with malignant B cell lymphomas scheduled to receive treatment with rituximab that we discovered several patients who had the infection already before the start of treatment. This led us to hypothesize that persistent latent infections with N. mikurensis might contribute to the development of certain cases of malignant B cell lymphoma. Splenic engagement, restricted repertoires of the Immunoglobulin heavy chain variable (IGHV) regions, and mutations of the IGHV regions from the germline configuration featured among these cases of lymphoma, which encompassed chronic lymphocytic leukemia, splenic marginal zone lymphoma, mantle cell lymphoma and non-classified indolent splenic lymphoma. Remarkably, three out of five patients could cease lymphoma therapy after eradication of the infection. Our aim is to confirm and expand these findings of a possible causality between N. mikurensis infection and the development of malignant B cell lymphomas. To this end, we are starting a prospective study of the prevalence of N. mikurensis infection in newly diagnosed patients with malignant B cell lymphomas, and the response of such lymphomas to eradication of the infection. We will also attempt to identify a genetic signature of N. mikurensis infection by studying IGHV gene usage, the mutations induced by somatic hypermutations, as well as the physicochemical properties of the complementarity-determining region 3 (CDR3), the most hypervariable part of the B cell receptor of infected patients. This will help establish if it is mainly post-germinal center B cells that undergo malignant B cell transformation in cases of N. mikurensis-associated lymphoma. The research was funded by: the Swedish Research Council, the Swedish Cancer Society, the Swedish state under the agreement between the Swedish government and the county councils, the ALF-agreement, and the Cancer and Allergy Foundation. Keywords: indolent non-Hodgkin lymphoma, tumor biology and heterogeneity, chronic lymphocytic leukemia (CLL) No conflicts of interests pertinent to the abstract.

Empirical Study on Exploring the Role of CD180 and MD-1 Prognostic Indicators for the Chronic Lymphocytic Leukaemia (CLL) Disease.

&amp;lt;b&amp;gt;Background and Objective:&amp;lt;/b&amp;gt; Chronic Lymphocytic Leukaemia (CLL) is a frequent type of leukaemia disease. This study was focused on investigating the role of prognostic indicators, such as CD180 and MD-1 for Chronic Lymphocytic Leukaemia (CLL) pathogenesis because they involve cell signalling and proliferation. &amp;lt;b&amp;gt;Materials and Methods:&amp;lt;/b&amp;gt; A total of 12 normal controls and 52 patients were taken to determine the expressions of CD180 and MD-1 with different variations in comparison with the IgVH (Immunoglobulin Heavy Chain variable region gene) mutational status, FISH (fluorescence &amp;lt;i&amp;gt;in situ&amp;lt;/i&amp;gt; hybridization) and Rai staging. &amp;lt;b&amp;gt;Results:&amp;lt;/b&amp;gt; The quantitative data findings were evident that CD180 and MD-1 expressions showed insignificant differences among CLL patients at the protein level based on SPSS results. On the contrary, they resulted in significant differences for subgroups of established biomarkers like Rai staging (stages 0, I, II and III), FISH (13q and non-13q deletions) and IgVH (mutated and unmutated). &amp;lt;b&amp;gt;Conclusion:&amp;lt;/b&amp;gt; The CD180 and MD-1 have been used as prognostic indicators to evaluate the outcomes relevant to the cell cycle and survival rate of CLL cells.

Immunoglobulin genes and stereotyped antigenic receptors in chronic lymphocytic leukemia and other lymphoproliferative diseases

Introduction. The mutational status of immunoglobulin heavy chain variable region genes (IGHV) is the most important prognostic factor in chronic lymphocytic leukemia (CLL). Furthermore, a significant narrowing of the IGHV gene repertoire is found in CLL and other lymphoproliferative diseases. Aim — to review the publication data on the IGHV genes repertoire and mutational status in CLL and other lymphoproliferative diseases regarding their clinical significance. General information. Nucleotide sequence of rearranged IGHV genes is a unique marker of a tumor clone. CLL patients with unmutated IGHV genes have an extremely unfavorable disease outcome in contrast to the patients with mutated IGHV genes. Patients with mutated IGHV genes benefit from conventional immunochemotherapy, while non-mutated IGHV patients require therapy escalation with new targeted drugs. The study of IGHV genes and stereotyped antigen receptors repertoire makes possible to identify additional groups of CLL patients with specific genetic and clinical features. Stereotype receptors are also detected in other lymphoproliferative diseases, but their clinical significance has not yet been defined. However, stereotyped receptors are found to be disease-specific.

A genome-wide association study for allergen component sensitizations identifies allergen component-specific and allergen protein group-specific associations.

Allergic diseases are some of the most common diseases worldwide. Genome-wide association studies (GWASs) have been conducted to elucidate the genetic factors of allergic diseases. However, no GWASs for allergen component sensitization have been performed. We sought to detect genetic variants associated with differences in immune responsiveness against allergen components. The participants of the present study were recruited from the Tokyo Children's Health, Illness, and Development study, and allergen component-specific IgE level at age 9 years was measured by means of allergen microarray immunoassays. We performed GWASs for allergen component sensitization against each allergen (single allergen component sensitization, number of allergen components analyzed, n= 31), as well as against allergen protein families (allergen protein group sensitization, number of protein groups analyzed, n= 16). We performed GWAS on 564 participants of the Tokyo Children's Health, Illness, and Development study and found associations between Amb a 1 sensitization and the immunoglobulin heavy-chain variable gene on chromosome 14 and between Phl p 1 sensitization and the HLA class II region on chromosome 6 (P< 5.0×10-8). AGWAS-significant association was also observed between the HLA class II region and profilin sensitization (P< 5.0×10-8). Our data provide the first demonstration of genetic risk for allergen component sensitization and show that this genetic risk is related to immune response genes including immunoglobulin heavy-chain variable gene and HLA.

Clonotypic analysis of immunoglobulin heavy chain sequences among 44 patients with Waldenström macroglobulinemia

To analyze the correlation between the mutational status of immunoglobulin heavy chain variable (IGHV) gene with the prognosis of patients with Waldenström macroglobulinemia (WM). Immunoglobulin heavy chain gene (IGH) clonotypic sequence analysis was carried out to assess the mutational status of IGHV in the blood and/or bone marrow samples from 44 WM patients. The usage characteristics of IGHV-IGHD-IGHJ gene was explored. The most common IGHV subgroup was IGHV3, which was similar to the data from the Institute of Hematology of Chinese Academy of Medical Science. IGHV3-23 (20.45% vs. 15.44%) and IGHV3-74 (11.36% vs. 7.35%) were the main fragments used, which was followed by IGHV4 gene family (15.91% vs. 24.26%). However, no significant correlation was found between the IGHV4 usage and the prognosis of the patients. Should 98% be taken as the cut-off value for the IGHV mutation status, only 5 patients had no IGHV variant, and there was no correlation with the prognosis. Based on the X-tile analysis, 92.6% was re-selected as the cut-off value for the IGHV variant status in such patients. LDH was increased in 26 patients (59.1%) without IGHV variant (P < 0.05), whilst progression-free survival (P < 0.05) and overall survival (P < 0.05) were significantly shorter compared with those with IGHV variants. The usage characteristics of IGHV-IGHD-IGHJ in our patients was similar to reported by the Institute of Hematology of Chinese Academy of Medical Science, albeit that no correlation was found between the IGHV4 usage and the prognosis of the patients. Furthermore, 98% may not be appropriate for distinguishing the IGHV variant status in WM patients.

Frequent use of IGHV3-30-3 in SARS-CoV-2 neutralizing antibody responses.

The antibody response to SARS-CoV-2 shows biased immunoglobulin heavy chain variable (IGHV) gene usage, allowing definition of genetic signatures for some classes of neutralizing antibodies. We investigated IGHV gene usage frequencies by sorting spike-specific single memory B cells from individuals infected with SARS-CoV-2 early in the pandemic. From two study participants and 703 spikespecific B cells, the most used genes were IGHV1-69, IGHV3-30-3, and IGHV3-30. Here, we focused on the IGHV3-30 group of genes and an IGHV3-30-3-using ultrapotent neutralizing monoclonal antibody, CAB-F52, which displayed broad neutralizing activity also in its germline-reverted form. IGHV3-30-3 is encoded by a region of the IGH locus that is highly variable at both the allelic and structural levels. Using personalized IG genotyping, we found that 4 of 14 study participants lacked the IGHV3-30-3 gene on both chromosomes, raising the question if other, highly similar IGHV genes could substitute for IGHV3-30-3 in persons lacking this gene. In the context of CAB-F52, we found that none of the tested IGHV3-33 alleles, but several IGHV3-30 alleles could substitute for IGHV3-30-3, suggesting functional redundancy between the highly homologous IGHV3-30 and IGHV3-30-3 genes for this antibody.

Genetic and Clinical Characteristics of Korean Chronic Lymphocytic Leukemia Patients with High Frequencies of MYD88 Mutations.

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia in Western countries. However, CLL is relatively rare in Asia; its genetic features are rarely studied. Here, we aimed to genetically characterize Korean CLL patients and to elucidate the genetic and clinical associations based on data obtained from 113 patients at a single Korean institute. We used next-generation sequencing to explore the multi-gene mutational data and immunoglobulin heavy chain variable gene clonality with somatic hypermutation (SHM). MYD88 (28.3%), including L265P (11.5%) and V217F (13.3%), was the most frequently mutated gene, followed by KMT2D (6.2%), NOTCH1 (5.3%), SF3B1 (5.3%), and TP53 (4.4%). MYD88-mutated CLL was characterized by SHM and atypical immunophenotype with fewer cytogenetic abnormalities. The 5-year time to treatment (TTT) of the overall cohort was 49.8% ± 8.2% (mean ± standard deviation) and the 5-year overall survival was 86.2% ± 5.8%. Patients with SHM, isolated del(13q), TP53-wild type, and NOTCH1-wild type showed better results than those without these conditions. In the subgroup analyses, patients with SHM and L265P presented shorter TTT than patients with SHM but not L265P. In contrast, V217F was associated with a higher SHM percentage and showed a favorable prognosis. Our study revealed the distinct characteristics of Korean CLL patients with high frequencies of MYD88 mutations and their clinical relevance.