Long-term analysis of the RiBVD phase II trial reveals the unfavorable impact of TP53 mutations and hypoalbuminemia in older adults with mantle cell lymphoma; for the LYSA group

Between 2011 and 2012, a phase II trial evaluated the use of the RiBVD (Rituximab, Bendamustine, Velcade and Dexamethasone) combination as first-line treatment for mantle cell lymphoma (MCL) patients aged over 65. We have now re-examined the classic prognostic factors, adding an assessment of the mutation status of TP53. Patients (n=74; median age 73 years) were treated with the RiBVD combination. Median Progression Free Survival (mPFS) was 79 months, and median Overall Survival (mOS) was 111 months. TP53 mutation status was available for 54/74 (73%) patients. TP53 mutations (TP53mt) were found in 12 patients (22.2%). In multivariate analysis, among the prognostic factors (PF) evaluated, only TP53mt and an albumin level below 3.6 g/dL (Alb<3.6 g/dL) were independently associated with a shorter mPFS. A hazard ratio (HR) of 3.16 (1.3-9.9, p=0.014) was obtained for TP53mt versus TP53wt, and 3.6 (1.39-9.5, p=0.009) for Alb<3.6 g/dL vs Alb≥3.6 g/dL. In terms of mOS, multivariate analysis identified three PFs: TP53mt (HR: 5.9 (1.77-19.5, p=0.004)), Alb<3.6 g/dL (HR: 5.2 (1.46-18.5, p=0.011)), and ECOG=2 (HR: 3.7 (1.31-10.6, p=0.014)). Finally, a score combining TP53 status and albumin level distinguished three populations based on the presence of 0, 1, or 2 PF. For these populations, mPFS was 7.8 years, 28 months and 2.5 months, respectively. Our prolonged follow-up confirmed the efficacy of the RiBVD regimen, comparing it favorably to other regimens. TP53mt and hypoalbuminemia emerge as strong PF that can be easily integrated into prognostic scores for older adult patients with MCL.

Infections occurring following IL6 blockade for the management of cytokine release syndrome in onco-hematology patients

BACKGROUND

Cytokine release syndrome (CRS) is a common adverse event of CAR T cell or bispecific antibody (bsAb) therapy. Anti-IL6/IL6R drugs are used in the management of auto-immune diseases. Some reports showed increased risk of bacterial infection in this context. In onco-hematology, there are few data about the occurrence of infection after administration of an anti-IL6/IL6R for CRS.

METHODS

We retrospectively reviewed all consecutive patients treated in Gustave Roussy Cancer Campus between 2018 and 2021, who received anti-IL6/IL6R for CRS due to bsAb in phase I clinical trials or adoptive cellular therapy (ACT). We constituted a control group including all the patients treated in the same clinical trials or standard of care ACT, naïve of anti-IL6/IL6R.

RESULTS

Fifty-two patients have been included. In the anti-IL6/IL6R group (n = 26), five patients developed a grade 2 to 5 infection within a month after anti-IL6/IL6R treatment, including two grade 5 infections. In the control group (n = 26), only one patient had a grade 3 infection. The two patients who had grade 5 infections were treated for diffuse large B cell lymphoma (DLBCL), one with bsAb and the other with CAR T cell. Fifty percent (3/6) of DLBCL patients who received an anti-IL6/IL6R presented an infection, one of which was a grade 5. In solid tumor patients treated with bsAb and anti-IL6/IL6R, only one patient (/9, 11%) developed a grade 2 viral infection.

CONCLUSION

It seems that the use of anti-IL6/IL6R in CRS secondary to bsAb administration in solid tumors patients does not significantly increase the risk of infection, as opposed to DLBCL patients where secondary infection might be a concern.

Liquid Biopsies for Circulating Tumor DNA Detection May Reveal Occult Hematologic Malignancies in Patients With Solid Tumors

PURPOSE

High-risk clonal hematopoiesis (CH) is frequently incidentally found in patients with solid tumors undergoing plasma cell-free DNA sequencing. Here, we aimed to determine if the incidental detection of high-risk CH by liquid biopsy may reveal occult hematologic malignancies in patients with solid tumors.

MATERIALS AND METHODS

Adult patients with advanced solid cancers enrolled in the Gustave Roussy Cancer Profiling study (ClinicalTrials.gov identifier: NCT04932525) underwent at least one liquid biopsy (FoundationOne Liquid CDx). Molecular reports were discussed within the Gustave Roussy Molecular Tumor Board (MTB). Potential CH alterations were observed, and patients referred to hematology consultation in the case of pathogenic mutations in JAK2, MPL, or MYD88, irrespective of the variant allele frequency (VAF), or in DNMT3A, TET2, ASXL1, IDH1, IDH2, SF3B1, or U2AF1 with VAF ≥ 10%, while also considering patient cancer-related prognosis. TP53 mutations were discussed case-by-case.

RESULTS

Between March and October 2021, 1,416 patients were included. One hundred ten patients (7.7%) carried at least one high-risk CH mutation: DNMT3A (n = 32), JAK2 (n = 28), TET2 (n = 19), ASXL1 (n = 18), SF3B1 (n = 5), IDH1 (n = 4), IDH2 (n = 3), MPL (n = 3), and U2AF1 (n = 2). The MTB advised for hematologic consultation in 45 patients. Overall, 9 patients of 18 actually addressed had confirmed hematologic malignancies that were occult in six patients: two patients had myelodysplastic syndrome, two essential thrombocythemia, one a marginal lymphoma, and one a Waldenström macroglobulinemia. The other three patients were already followed up in hematology.

CONCLUSION

The incidental findings of high-risk CH through liquid biopsy may trigger diagnostic hematologic tests and reveal an occult hematologic malignancy. Patients should have a multidisciplinary case-by-case evaluation.

Abstract A19: Integrated single cell analysis reveals co-evolution of malignant B cells and the tumor microenvironment in transformed follicular lymphoma

Introduction: Histological transformation from follicular lymphoma (FL) to aggressive B-cell lymphoma (tFL) is a disease course altering event linked to poor prognosis for affected patients. From a biological point of view, it is paradigmatic of disease dynamics with distinct clinical stages that project onto genetically and phenotypically divergent states. Aim: By applying a series of high-dimensional single cell (sc)RNA and DNA profiling techniques, we aimed to characterize the clonal and phenotypic evolution of tumor B cells and to reveal dynamic interactions with components of the tumor microenvironment (TME) during transformation. Methods: We included 11 tFL patients with paired FL (tFL-FL) and DLBCL (tFL-DLBCL) timepoint biopsies, and 11 indolent FL controls (with &gt; 6y of follow-up without evidence of progression or transformation). Single cell whole transcriptome (scWTS) and BCR sequencing was performed for all samples and single cell whole genome sequencing (scWGS) for transformation pairs. Results: In each transformation pair, BCR sequencing confirmed the clonal relationship between FL and DLBCL timepoints. Clustering of scRNA data from each pair showed an inverse correlation between transcriptional similarity and time between the two biopsies. Some tFL-FL cells could always be found within the tFL-DLBCL clusters. Therefore, we labeled these cells as presumed “early-DLBCL cells”. Phylogenetic analysis using scWGS data showed distinct FL and DLBCL clones, and “mixed-clones” composed of cells from both timepoints in most pairs. FL cells in DLBCL clones were favored to represent precursor cells of transformation. DLBCL cells in FL clones likely represent residual FL cells after transformation, and could be found in the majority of the pairs. Divergent evolution from FL to DLBCL with specific copy number abnormalities unique to each timepoint was the most common mode of evolution during transformation, and only one pair showed linear evolution. Integrative analysis of scRNA and scDNA data highlighted that samples with the fewest genomic changes showed the least transcriptomic changes and vice versa. Differential expression and gene set enrichment analysis of malignant cells identified “MYC targets V1“ as the main pathway enriched in tFL-DLBCL cells in comparison to tFL-FL cells. Cells from the indolent control FL cases had a significantly lower MYC score than cells from pre-transformed FL. In parallel to the insights into tumor cell evolution, scRNAseq analysis also revealed significant shifts in TME composition, from T cells with a TFH and central memory phenotype in tFL-FL samples, to cells with an exhausted cytotoxic phenotype in tFL-DLBCL samples. Conclusion: Applying high-dimensional scRNA and DNA profiling techniques we identified precursor cell populations of transformation at the genomic and phenotypic level and linked genomic and phenotypic evolution with shifting TME composition in a comprehensive disease evolution model of transformation.

Citation Format: Clementine Sarkozy, Shaocheng Wu, Katsuyoshi Takata, Tomohiro Aoki, Susana B Neriah, Katy Milne, Brad Nelson, Andrew Weng, David Scott, Jeffrey W Craig, Christian Steidl, Andrew Roth. Integrated single cell analysis reveals co-evolution of malignant B cells and the tumor microenvironment in transformed follicular lymphoma [abstract]. In: Proceedings of the Third AACR International Meeting: Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2022 Jun 23-26; Boston, MA. Philadelphia (PA): AACR; Blood Cancer Discov 2022;3(5_Suppl):Abstract nr A19.

474 Phase 1 study of SEA-TGT, a human, nonfucosylated anti-TIGIT monoclonal antibody with enhanced immune-effector function, in patients with advanced malignancies (SGNTGT-001, trial in progress)

Background

T-cell immunoreceptor with immunoglobulin and immunoreceptor tyrosine-based inhibitory domains (TIGIT), and costimulatory receptor CD226 competitively bind 2 ligands, CD155 and CD112, which are expressed by tumor cells and antigen-presenting cells in the tumor microenvironment.1 2 Dual TIGIT/programmed cell death protein-1 (PD-1) blockade increased tumor antigen-specific CD8+ T-cell expansion and function in vitro and promoted potent antitumor response in vivo.3 4 TIGIT/PD-1 dual blockade using a TIGIT monoclonal antibody (mAb) with intact Fc produced clinical responses in advanced cancer.5 SEA-TGT is an investigational, human, nonfucosylated mAb directed against TIGIT. SEA-TGT binds to TIGIT, blocking inhibitory checkpoint signals directed at T cells. SEA-TGT enhances binding to activating FcγRIIIa and decreases binding to inhibitory FcγRIIb; this depletes immunosuppressive regulatory T cells and amplifies naive and memory T cells, potentially augmenting PD-1 inhibition effects. Preclinically, at suboptimal doses, SEA-TGT plus anti-PD-1 mAbs had superior antitumor activity than either agent alone.6

Methods

Safety and antitumor activity of SEA TGT in ~377 adults (≥18 years) will be evaluated in this phase 1, multicenter, open-label, dose-escalation/expansion study. Part A will assess the safety/tolerability of SEA TGT to determine maximum tolerated and recommended doses. Part B will assess the safety and antitumor activity of the recommended dose in disease-specific expansion cohorts. Part C will assess SEA-TGT plus sasanlimab in dose-expansion cohorts after an initial safety run-in. Patients with histologically/cytologically confirmed relapsed/refractory/progressive metastatic solid tumors including non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (HNSCC), gastric/gastroesophageal junction carcinoma, cutaneous melanoma, bladder, cervical, ovarian or triple-negative breast cancer, or selected lymphomas will be eligible for Parts A and B. Part C will enroll patients with histologically confirmed advanced NSCLC (high [tumor proportion score (TPS) ≥50%] and low [TPS=1–49%] PD ligand 1 [PD-L1] expression), cutaneous melanoma, and HNSCC without previous anti–PD-1/PD-L1 therapy exposure. SEA TGT will be administered on Day 1 of 21-day cycles.Laboratory abnormalities, adverse events, dose-limiting toxicities, and dose-level safety and activity are primary endpoints. Secondary endpoints are objective response (OR) and complete response (CR) rates, duration of OR/CR, progression-free survival, overall survival, pharmacokinetics (PK), and antidrug antibodies. Exploratory analysis will include pharmacodynamics (PD), PK/PD relationships, biomarkers, and resistance to SEA-TGT. This trial is recruiting in Europe and North America.

Trial Registration

NCT04254107

References

Blake SJ, Dougall WC, Miles JJ, et al. Molecular pathways: Targeting CD96 and TIGIT for cancer immunotherapy. Clin Cancer Res 2016;22(21):5183–5188.

Chauvin JM, Zarour HM. TIGIT in cancer immunotherapy. J ImmunoTher Cancer 2020;8:e000957.

Johnston RJ, Comps-Agrar L, Hackney J, et al. The immunoreceptor TIGIT regulates antitumor and antiviral CD8+ T cell effector function. Cancer Cell 2014;26(6):923–937.

Chauvin JM, Pagliano O, Fourcade J, et al. TIGIT and PD-1 impair tumor antigen-specific CD8+ T cells in melanoma patients. J Clin Invest 2015;125(5):2046–2058.

Rodriguez-Abreu D, Johnson ML, Hussein MA, et al. Primary analysis of a randomized, double-blind, phase 2 study of the anti-TIGIT antibody tiragolumab (tira) plus atezolizumab (atezo) versus placebo plus atezo as first-line (1L) treatment in patients with PD-L1-selected NSCLC (CITYSCAPE). J Clin Oncol 2020;38(15 suppl):9503.

Smith A, Zeng W, Lucas S, et al. Poster 1583. SEA-TGT is an empowered anti-TIGIT antibody that displays superior combinatorial activity with several therapeutic agents. Presented at: American Association for Cancer Research Annual Meeting; April 9–14, 2021; Virtual Meeting.

Ethics Approval

Institutional review boards or independent ethics committees of participating sites approved the trial, which will be conducted in compliance with the Declaration of Helsinki and International Conference on Harmonisation Guidelines for Good Clinical Practice. All patients will provide written informed consent.

Single Cell Phenotypic Profiling of 27 DLBCL Cases Reveals Marked Intertumoral and Intratumoral Heterogeneity

Diffuse large B-cell lymphoma (DLBCL) is the most common histologic subtype of non-Hodgkin lymphoma and is notorious for its clinical heterogeneity. Patient outcomes can be predicted by cell-of-origin (COO) classification, demonstrating that the underlying transcriptional signature of malignant B-cells informs biological behavior in the context of standard combination chemotherapy regimens. In the current study, we used mass cytometry (CyTOF) to examine tumor phenotypes at the protein level with single cell resolution in a collection of 27 diagnostic DLBCL biopsy specimens from treatment naïve patients. We found that malignant B-cells from each patient occupied unique regions in 37-dimensional phenotypic space with no apparent clustering of samples into discrete subtypes. Interestingly, variable MHC class II expression was found to be the greatest contributor to phenotypic diversity. Within individual tumors, a subset of cases showed multiple phenotypic subpopulations, and in one case, we were able to demonstrate direct correspondence between protein-level phenotypic subsets and DNA mutation-defined subclones. In summary, CyTOF analysis can resolve both intertumoral and intratumoral heterogeneity among primary samples and reveals that each case of DLBCL is unique and may be comprised of multiple, genetically distinct subclones. © 2019 International Society for Advancement of Cytometry.

Abstract 3765: Somatic JAK-STAT mutations in subtypes of aggressive B-cell lymphomas with DLBCL morphology

Aberrant activation of the JAK-STAT pathway is a hallmark of a variety of lymphomas and can alter the lymphoma cells secretome and the composition of the tumor microenvironment (TME). The up-regulation of the immune regulatory chemokine CCL17 has been shown to be mediated by STATs-dependent mechanism in primary mediastinal B cell lymphoma (PMBCL). Here, we assembled a cohort of 340 R-CHOP-treated aggressive lymphomas with diffuse large B cell lymphoma (DLBCL) morphology to investigate JAK-STAT mutations (targeted gene sequencing), copy number (CN) alterations (SNP arrays), gene expression (RNAseq) and TME composition (IHC). The cohort was evaluated using FISH for BCL2, BCL6 and MYC rearrangements and the molecular classification assay, Lymph2Cx, to distinguish ABC vs GBC vs double-hit lymphomas with DLBCL morphology (DH-DLBCL). Among the 317 evaluable cases, 26 were DH-DLBCLs, 101 ABC, 155 GCB and 35 unclassified. In addition, we used the recently published Lymph3Cx assay (Mottok A. et al., Blood 2018) to identify cases with a molecular PMBCL (mPMBCL) expression signature within the GCB-DLBCL group (6.5%, 10/155 cases). Twenty-five of 155 GCB cases (16.1%) were classified as ‘uncertain PMBCL/DLBCL’. Mutational analysis of all cases (n=340) revealed the presence of JAK-STAT pathway mutations at the following frequencies: SOCS1 21.6%, STAT6 4.8%, IL4R 5.3% and 9p24 amplification 11.3%. These mutations were significantly enriched in the mPMBCL (n=10) group compared to the bona fide GCB (n=118) and intermediate phenotype group (uncertain PMBCL/DLBCL) (n=25) (p&lt;0.05). The relative frequency of any JAK-STAT mutations was 100% (10/10) in mPMBCL, 29.2% (35/118) in bona fide GCB and 56% (14/25) in uncertain PMBCL/DLBCL. Among the GCB samples with follow-up data (n=107, incl. bona fide GCB and mPMBCL), cases carrying mutations in IL4R (n=11, 10.3%) had an inferior disease-specific survival (p=0.011) and time to progression (p=0.0048) after R-CHOP therapy. Interestingly, IL4R mutations were also detected in the DH-DLBCL group with an incidence of 11.5% (3/26 cases). Mutations in the extracellular and transmembrane domains of IL4R resulted in gain-of-function mutations leading to constitutive activation of the JAK-STAT pathway in vitro. IL4R gain-of-function increased CCL17 expression through a STAT6-dependent mechanism in vitro. Similarly, gene expression analysis of primary patient samples carrying activating IL4R mutations displayed increased CCL17expression (p&lt;0.05), which positively correlated with the level of the T-regulatory marker FOXP3 (p&lt;0.05) by IHC. In summary, aberrant JAK-STAT activation driven by alterations, such as activating IL4R mutations, plays a significant role in altering chemokine expression profiles and TME changes. Our data strongly suggest the biological and clinical relevance of Lymph3Cx to define a subgroup of aggressive lymphoma harboring a molecular PMBCL signature.

Citation Format: Elena Vigano, Gerben Duns, Daisuke Ennishi, Clementine Sarkozy, Bruce Woolcock, Faith Cheung, Elizabeth Chavez, Stacy S. Hung, Katsuyoshi Takata, Anja Mottok, Randy Gascoyne, Kerry J. Savage, Ryan Morin, David W. Scott, Christian Steidl. Somatic JAK-STAT mutations in subtypes of aggressive B-cell lymphomas with DLBCL morphology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3765.

A phase 2 study of rituximab, bendamustine, bortezomib and dexamethasone for first-line treatment of older patients with mantle cell lymphoma

We present results of a prospective, multicenter, phase II study evaluating rituximab, bendamustine, bortezomib and dexamethasone as first-line treatment for patients with mantle cell lymphoma aged 65 years or older. A total of 74 patients were enrolled (median age, 73 years). Patients received a maximum of six cycles of treatment at 28-day intervals. The primary objective was to achieve an 18-month progression-free survival rate of 65% or higher. Secondary objectives were to evaluate toxicity and the prognostic impact of mantle cell lymphoma prognostic index, Ki67 expression, [¹⁸F]fluorodeoxyglucose-positron emission tomography and molecular minimal residual disease, in peripheral blood or bone marrow. With a median follow-up of 52 months, the 24-month progression-free survival rate was 70%, hence the primary objective was reached. After six cycles of treatment, 91% (54/59) of responding patients were analyzed for peripheral blood residual disease and 87% of these (47/54) were negative. Four-year overall survival rates of the patients who did not have or had detectable molecular residual disease in the blood at completion of treatment were 86.6% and 28.6%, respectively (P<0.0001). Neither the mantle cell lymphoma index, nor fluorodeoxyglucose-positron emission tomography nor Ki67 positivity (cut off of ≥30%) showed a prognostic impact for survival. Hematologic grade 3-4 toxicities were mainly neutropenia (51%), thrombocytopenia (35%) and lymphopenia (65%). Grade 3-4 non-hematologic toxicities were mainly fatigue (18.5%), neuropathy (15%) and infections. In conclusion, the tested treatment regimen is active as frontline therapy in older patients with mantle cell lymphoma, with manageable toxicity. Minimal residual disease status after induction could serve as an early predictor of survival in mantle cell lymphoma. ClinicalTrials.gov: NCT 01457144.

Early event status informs subsequent outcome in newly diagnosed follicular lymphoma

Recent advances in follicular lymphoma (FL) have resulted in prolongation of overall survival (OS). Here we assessed if early events as defined by event-free survival (EFS) at 12 and 24 months from diagnosis (EFS12/EFS24) can inform subsequent OS in FL. 920 newly diagnosed grade 1-3A FL patients enrolled on the University of Iowa/Mayo Clinic Lymphoma SPORE Molecular Epidemiology Resource (MER) from 2002-2012 were initially evaluated. EFS was defined as time from diagnosis to progression, relapse, re-treatment, or death due to any cause. OS was compared to age-and-sex-matched survival in the general US population using standardized mortality ratios (SMR) and 95% confidence intervals (CI). We used a cohort of 412 FL patients from two Lyon, France hospital registries for independent replication. Patients who failed to achieve EFS12 had poor subsequent OS (MER SMR = 3.72, 95%CI: 2.78-4.88; Lyon SMR = 8.74, 95%CI: 5.41-13.36). Conversely, patients achieving EFS12 had no added mortality beyond the background population (MER SMR = 0.73, 95%CI: 0.56-0.94, Lyon SMR = 1.02, 95%CI: 0.58-1.65). Patients with early events after immunochemotherapy had especially poor outcomes (EFS12 failure: MER SMR = 17.63, 95%CI:11.97-25.02, Lyon SMR = 19.10, 95%CI:9.86-33.36; EFS24 failure: MER SMR = 13.02, 95%CI:9.31-17.74, Lyon SMR = 7.22, 95%CI:4.13-11.74). In a combined dataset of all patients from both cohorts, baseline FLIPI was no longer informative in EFS12 achievers. Reassessment of patient status at 12 months from diagnosis in follicular lymphoma patients, or at 24 months in patients treated with immunochemotherapy, is a strong predictor of subsequent overall survival in FL. Early event status provides a simple, clinically relevant endpoint for studies assessing outcome in FL. Am. J. Hematol. 91:1096-1101, 2016. © 2016 Wiley Periodicals, Inc.