Ding, Wei

Purpose Venetoclax-based treatment for chronic lymphocytic leukemia (CLL) can be a logistically burdensome regimen due to extensive required monitoring of tumor lysis syndrome (TLS). The purpose of this study was to evaluate the feasibility and safety of pharmacist and registered nurse (RN) driven management of venetoclax ramp-up in CLL. Methods This was a prospective, pilot program for patients receiving venetoclax-based therapy for CLL. Patients had nine weekly visits during the first three cycles of therapy, of which five visits were independently performed by a pharmacist or RN. Laboratory tests to evaluate TLS were ordered and monitored independently by the RN in collaboration with clinicians (physician, nurse practitioner, physician assistant). Results Thirty CLL patients, median age 67 years, 73% treated in the frontline setting, started venetoclax between May 2022 and January 2023. After the initial three weeks of obinutuzumab treatment, TLS risk prior to venetoclax initiation had improved to low (93%), medium (3%), and high (3%). There was zero incidence of laboratory or clinical TLS by Howard criteria during the venetoclax ramp-up for all patients. Pharmacist and RNs performed 139 independent visits and monitored 197 sets of TLS labs. Conclusion Use of independent pharmacist and RN visits for toxicity checks and TLS monitoring during weekly venetoclax dose ramp-up did not lead to increased incidence of TLS in patients with CLL. These visits increased both access and efficiency within the CLL clinic. This concept has the potential to be applied in other cancer care settings with a variety of treatment regimens.

7050 Background: The management of Richter transformation (RT) of CLL represents an unmet clinical need. We previously reported modest efficacy of pembrolizumab monotherapy in an initial cohort of patients with RT (Ding, et al, Blood 2017). Here we report updated results of this trial, including an expansion cohort and a combination therapy cohort. Methods: Patients with biopsy proven RT to diffuse large B-cell lymphoma were enrolled and treated with single agent pembrolizumab (200 mg IV Q3W). Patients with progressive disease (PD) or stable disease (SD) after 3 months of pembrolizumab monotherapy were allowed to add a B-cell receptor (BCR) kinase inhibitor. The primary end point was overall response rate (ORR). Results: A total of 26 patients with RT were enrolled (9 in initial cohort and 17 in expansion cohort). The median age was 68.5 years. Ten (38%) patients had del(17p) or TP53 mutation. The median number of prior lines of therapy was 3 (range 1-10). Fifteen (58%) patients had received ibrutinib previously (14 of whom had PD on ibrutinib). With pembrolizumab monotherapy (n=26), the ORR was 23.1%, with 2 (7.7%) complete response (CR), 4 (15.4%) partial response (PR), and 7 (26.9%) SD. Of the 6 patients with confirmed CR or PR, responses occurred after a median of 2 cycles of monotherapy. The median duration of response (DOR) was 3.2 months (95% CI 2.8-NA). The median progression-free survival (PFS) was 2.6 months (95% CI 1.6-3.6). Sixteen patients went on to receive a BCR kinase inhibitor (ibrutinib [n=15], idelalisib [n=1]) in combination with pembrolizumab, after SD or PD on pembrolizumab monotherapy. The ORR to combination therapy was 62.5%, with 4 (25.0%) CR and 6 (37.5%) PR. Of the 10 patients with confirmed CR or PR to combination therapy, responses occurred after a median of 4 cycles of therapy. The median DOR was 4.5 months (95% CI 1.6-NA). The median PFS was 7.6 months (95% CI 2.3-13.3). After a median follow-up of 50.4 (95% CI 34.0-56.0) months, the median overall survival (OS) for all 26 patients with RT was 11.6 months (95% CI 7.5-20.1), and the 2-year OS rate was 27%. Treatment-related adverse events (TRAEs) of any grade occurred in 24 (92%) patients, including anemia (54%), thrombocytopenia (58%), neutropenia (54%), leukopenia (35%), lymphopenia (23%), dyspnea (23%), diarrhea (19%), and nausea (23%). Treatment-related grade 3 or above AEs occurred in 21 (81%) patients, including neutropenia (38%), leukopenia (31%), thrombocytopenia (27%), anemia (15%), febrile neutropenia (12%), and lung infection (12%). Conclusions: This expanded analysis confirmed that pembrolizumab has modest single agent activity in RT. Combination therapy with pembrolizumab and a BCR kinase inhibitor is associated with increased efficacy (ORR >60%), similar to other reports. These results support further investigation of immune checkpoint inhibitor-based combination therapy in RT. Clinical trial information: NCT02332980 .

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

Background: Richter Transformation (RT) refers to the development of an aggressive lymphoma in the setting of chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL). Small molecule inhibitors (SMI), such as the Bruton tyrosine kinase inhibitors (BTKi) and BCL2 inhibitors (BCL2i), have revolutionized the treatment of CLL/SLL. Prior studies evaluated outcomes of patients (pts) with RT in an era where chemoimmunotherapy (CIT) was typically used to treat CLL/SLL. Now that SMI are standard of care, fewer pts with CLL/SLL receive CIT, therefore we sought to determine which variables predict survival in pts who developed RT without prior CIT exposure for CLL/SLL. Methods: We conducted an international multicenter retrospective study of pts from 11 academic centers. Pts with RT occurring as large B-cell lymphoma who did not previously receive CIT (e.g., fludarabine, cyclophosphamide, bendamustine, chlorambucil) for their CLL/SLL were included. We collected pt, disease, and treatment (tx) characteristics. RT was categorized into 3 groups: “Concurrent RT,” defined as RT and CLL/SLL diagnosed simultaneously (within 3 months [mos]); “RT w/o prior CLL/SLL tx,” defined as RT and CLL/SLL diagnosed >3 mos apart with the CLL/SLL never treated; and “RT with prior non-CIT tx for CLL/SLL” defined as having received prior CLL/SLL tx. Overall survival (OS) was measured from RT diagnosis (Dx) and estimated using the Kaplan-Meier method. Cox regression model was used to identify prognostic factors associated with OS. Results: 242 pts were identified. At CLL/SLL Dx, 66% of pts had unmutated IGHV, 37% had del17p/ TP53 disruption, and 20% had trisomy 12. At RT Dx, 56% of the RT with prior non-CIT tx for CLL/SLL group had a del17p/ TP53 disruption versus 27% for the concurrent RT group and 18% for the RT w/o prior CLL/SLL tx groups. Median time from CLL/SLL Dx to RT Dx was 47 mos (range 3-394) for RT w/o prior CLL/SLL tx and 46 mos (range 4-218) for RT with prior non-CIT tx for CLL/SLL. Pts with prior non-CIT tx for CLL/SLL received a median of 1 (range 1-5) prior tx. 86% of pts previously received a BTKi or a BCL2i for tx of CLL/SLL (54% BTKi only, 5% BCL2i only, 27% both). The remaining 14% had been treated with an anti-CD20 monoclonal antibody (MoAb), steroids, lenalidomide, radiation, or alemtuzumab. 85% of pts developed RT while on active tx with SMI. Median age at RT Dx was 69 years (range 37-92). At RT Dx, 38% and 21% of pts had del17p/ TP53 disruption, and trisomy 12 in CLL/SLL tissue, respectively. At RT Dx, there was no difference in highest SUV on PET (median 16, range 2.9-65.6), LDH (median 325, range 103-8162, ULN range 180-271), largest lymph node in diameter (median 4.9 cm, range 0-17.1), Ki-67 (median 80%, range 5%-100%), rate of GCB subtype (27%), presence of MYC translocation (20%), or CLL/SLL and RT clonal relationship (81%) for those pts tested amongst the 3 groups ( Table). The most common 1 st line tx for RT was CIT with or w/o radiation and/or steroids (76%), followed by CIT plus SMI (13%), SMI single agent or combination (7%), and other (4%, which includes anti-CD20 MoAb). Median follow-up from RT Dx was 42.3 mos; the median OS for the entire cohort was 25.8 mos (95% CI: 16.8-49.1). Pts with RT after non-CIT tx for CLL/SLL had a significantly worse OS (median 8.2 mos [95% CI: 5.6-14.3]) than pts with concurrent RT (median 46.3 mos [95% CI: 23.8-96.9]) and RT w/o prior CLL/SLL tx (median 63.5 mos [95% CI: 28.3-70.3]) ( Figure). From an exploratory univariable analysis, we found RT after non-CIT tx for CLL/SLL compared to concurrent RT (HR 2.32 [95% CI: 1.55-3.46]), RT Dx age (HR for 5-year increase 1.14 [95% CI: 1.05-1.23]), del17p/ TP53 disruption (HR 2.27 [95% CI: 1.45-3.56]), and LDH (HR for 2-fold increase 1.37 [95% CI: 1.20-1.58]) were prognostic for worse OS. Conclusions: This is the largest cohort of pts who developed RT having received only SMI with no CIT for their CLL reported, thus reflecting the current treatment landscape. Despite being CIT-naïve, pts in our series who received tx for their CLL/SLL and then developed RT had a short OS, underscoring the need to develop better therapies for these pts. In contrast, as in other published analyses (Wang Haematologica 2020), pts w/o prior tx for CLL/SLL had more favorable outcomes, with a median OS of approximately 5 years. Further analysis to determine PFS and OS by tx for RT for pts who have been treated with SMI for their CLL/SLL is ongoing.

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

Abstract Richter's transformation (RT) is a clinically challenging and aggressive transformation of CLL (Chronic lymphocytic leukemia) to lymphoma. Immune-checkpoint therapy has improved outcomes in selective lymphoma types. Nearly 40% of RT patients respond to anti-PD1, while the underlying CLL do not show any response, and 10% of CLL patients progress post-anti-PD1 treatment. Previous studies mostly focused on T-cell responses elicited by anti-PD1, however, intrinsic changes in CLL and RT B-cells induced by the treatment remains elusive. We hypothesized that pre-existing active transcriptional circuitry and distinct B-cell subsets in the CLL and RT B-cells may determine the response to anti-PD1 treatment. Peripheral blood mononuclear cells (PBMCs) from 3 patients who received pembrolizumab(anti-PD1) as a single agent. Samples were obtained at baseline and 3 months post-treatment initiation. Among these patients, 2 are progressors while 1 is a responder. We performed single-cell RNAseq (10X Genomics) on B-cells enriched from PBMCs derived from 3 samples (1 Responder: RS2, 2 progressors: CLL14 and CLL17) before and after treatment using chromium single cell 3' gene expression library. A total of ~10000 cells were captured with an average detection of 1000 genes/sample. To delineate the transcriptional changes upon the anti-PD1 treatment, we first integrated the single-cell data from 6 samples (before and after Pembro) and performed unsupervised clustering analysis using UMAP (Uniform Manifold Approximation and projection). We identified 8 different clusters based on highly expressed marker genes. Cluster 2(C2) was increased in the responder as compared to the progressors post-pem treatment. To determine the activated pathways in each cluster, we performed gene-set enrichment analysis (GSEA) using the Enrichr method. This analysis revealed upregulation of distinct pathways related to IFNG/MYC(C1), IFNG(C2), ER stress(C3), B-cell dependent T cell activation related pathway(C4), MYC targets/TNFα(C5,6,7) indicating intra-tumor transcriptional heterogeneity. To decipher the intratumor cell differentiation changes, we performed pseudotime trajectory analysis using Monocle 2 coupled with B cell developmental stage markers. We identified 7 different states, with distinct changes of state in responder sample RS2 (State 4,5, 6, and 7 were increased in RS2 post-treatment) while CLL samples(progressors) did not have distinct changes. Integration with B cell development revealed that aggressive B cells with CD38 expression were highly induced upon anti-PD1 in responder RS2 while regulatory (CD1d) and memory B cells (CD27) remained the same, suggesting PD1 induced intrinsic changes contributing to the disease response. We identified distinct transcriptional states in B cells within responders and progressors which may govern the intra-tumor and inter-tumor heterogeneity to the anti-PD1 response. Citation Format: Prajish Sundaram Iyer, Lu Yang, Yang Zhi Zhang, Hyo Jin Kim, Charla Secreto, Sutapa Sinha, Neil Kay, Stephen Ansell, Wei Ding, Lili Wang. Tumor intrinsic changes determine immune-checkpoint response in Richter's transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1612.

Recent successes and FDA approvals of CD19 redirected chimeric antigen receptor T cell (CART19) therapy have been achieved in pivotal clinical trials in patients with B cell malignancies. However, durable response rates in non-Hodgkin B cell lymphoma (B-NHL) and chronic lymphocytic leukemia (CLL) are low. Tumor-associated macrophages have emerged as key mediators of tumor-induced CART cell immunosuppression. Axl receptor tyrosine kinase (Axl-RTK) is overexpressed in various human cancers including B-NHL or CLL and correlates with poor overall survival. Thus, several Axl-RTK inhibitors are currently being investigated in clinical trials. We have previously reported that the Axl-RTK inhibitor TP-0903 modulates CART19 function by Th1 polarization. Moreover, we observed a significant reduction in myeloid-derived cytokines in preclinical models. This led us to hypothesize that Axl-RTK inhibition also modulates monocytes which in turn affects CART function. To test our hypothesis, we interrogated the interactions between Axl-RTK inhibition, monocytes, and CART. First, we isolated CD14+ monocytes from peripheral mononuclear cells (PBMCs) from healthy donors by magnetic negative selection. Flow cytometric analysis revealed a robust Axl expression on monocytes (Fig.1A). Monocytes were maintained in ImmunoCult Macrophage Medium (STEMCELL Technologies) and differentiated with lipopolysaccharide and interferon-γ for M1-type and interleukin (IL)-4 for M2-type macrophages. After confirming the macrophage phenotypes, cells were assessed for Axl expression. Flow cytometric analysis demonstrated that M2-type macrophages expressed higher Axl compared to M1 macrophages (Fig.1B). Then, we treated PBMCs from healthy donors with TP-0903 for 24 hours to determine the specific cell types affected by Axl-RTK inhibition. Flow cytometric analysis revealed that monocytes were significantly inhibited by TP-0903 compared to B cells or T cells (Fig.1C). Having demonstrated that TP-0903 strongly suppresses monocytes and that M2-type macrophages express Axl on their surface, we then performed a cytotoxicity assay against CD19+ mantle cell lymphoma cell line, JeKo-1, to study the impact of Axl-RTK inhibition on monocyte-induced CART suppression. We used CART19 generated in our laboratory (FMC63-41BBζ). CART19, JeKo-1, and M2-type macrophages were co-cultured at 1:2:1 ratio and incubated for 3 days. The data revealed that M2-type macrophages strongly suppress CART19 killing (Fig.1D) which could be overcome with TP-0903 (Fig.1E). Next we studied monocyte-induced CART19 suppression with antigen-specific proliferation. CART19, JeKo-1, and monocytes were co-cultured at 1:5:1 ratio and incubated for 5 days. Flow cytometric analysis revealed that in the presence of monocytes, antigen-specific proliferation of CART19 was significantly suppressed, which was reversed in the presence of TP-0903 (Fig.1F). To assess how Axl inhibition modulates myeloid cell-derived cytokines/chemokines, we performed Multiplex (Millipore-Sigma) with the supernatants obtained from these co-culture assays. The presence of monocytes resulted in a significant increase in IL-17a, IL-6, IL-1 receptor agonist, IL-1β, and soluble CD40 ligand. However, Axl-RTK inhibition resulted in selective reduction of those cytokines/chemokines (Fig.1G) while preserving other effector cytokines. Finally, we tested whether Axl-RTK inhibition with TP-0903 could overcome the negative effects of monocytes in vivo. Here, immunocompromised NSG mice were injected with 1x106 luciferase+ JeKo-1 cells intravenously. Ten days later, mice were injected with freshly isolated monocytes derived from a healthy donor. Two weeks after JeKo-1 inoculation, tumor burden was assessed with bioluminescence imaging. Mice were then randomized according to the tumor burden to receive 0.5x106 CART19 as a monotherapy or in combination with 20 mg/kg/day of oral TP-0903. The combination therapy resulted in superior anti-tumor effects and overall survival compared to CART19 monotherapy (Fig.1H-I). In summary, Axl-RTK inhibition with TP-0903 demonstrates a direct suppression of inhibitory monocytes, which in turn enhances CART cell function. Our findings support the strategy of further refining and testing the novel and potent combination of Axl-RTK inhibition and CART cell therapy for the treatment of B cell malignancies. Figure 1 Disclosures Sakemura: Humanigen: Patents & Royalties. Cox:Humanigen: Patents & Royalties. Mouritsen:Sumitomo Dainippon Pharma Oncology, Inc.: Current Employment. Foulks:Tolero Pharmaceuticals, Inc.: Current Employment. Warner:Tolero Pharmaceuticals, Inc.: Current Employment. Ding:Merck: Membership on an entity's Board of Directors or advisory committees, Research Funding; DTRM: Research Funding; Astra Zeneca: Research Funding; Abbvie: Research Funding; Octapharma: Membership on an entity's Board of Directors or advisory committees; MEI Pharma: Membership on an entity's Board of Directors or advisory committees; alexion: Membership on an entity's Board of Directors or advisory committees; Beigene: Membership on an entity's Board of Directors or advisory committees. Parikh:GlaxoSmithKline: Honoraria; Verastem Oncology: Honoraria; Genentech: Honoraria; Ascentage Pharma: Research Funding; AbbVie: Honoraria, Research Funding; Merck: Research Funding; TG Therapeutics: Research Funding; AstraZeneca: Honoraria, Research Funding; Janssen: Honoraria, Research Funding; MorphoSys: Research Funding; Pharmacyclics: Honoraria, Research Funding. Kay:Pharmacyclics: Membership on an entity's Board of Directors or advisory committees, Research Funding; MEI Pharma: Research Funding; Abbvie: Research Funding; Tolero Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding; Bristol Meyer Squib: Membership on an entity's Board of Directors or advisory committees, Research Funding; Acerta Pharma: Research Funding; Sunesis: Research Funding; Astra Zeneca: Membership on an entity's Board of Directors or advisory committees; Agios Pharma: Membership on an entity's Board of Directors or advisory committees; Cytomx: Membership on an entity's Board of Directors or advisory committees; Morpho-sys: Membership on an entity's Board of Directors or advisory committees; Rigel: Membership on an entity's Board of Directors or advisory committees; Oncotracker: Membership on an entity's Board of Directors or advisory committees; Dava Oncology: Membership on an entity's Board of Directors or advisory committees; Juno Theraputics: Membership on an entity's Board of Directors or advisory committees. Kenderian:Mettaforge: Patents & Royalties; Lentigen: Research Funding; MorphoSys: Research Funding; Sunesis: Research Funding; Tolero: Research Funding; BMS: Research Funding; Juno: Research Funding; Gilead: Research Funding; Kite: Research Funding; Novartis: Patents & Royalties, Research Funding; Torque: Consultancy; Humanigen: Consultancy, Patents & Royalties, Research Funding.