Citations

Despite the remarkable outcomes of CD19-directed chimeric antigen receptor T (CART19) cell therapy in B-cell malignancies, the durable responses in diffuse large B-cell lymphoma are less than 40%, and strategies to enhance this response are desperately needed. Inhibition of AXL RTK with TP0903, a high-affinity AXL inhibitor has been found to induce robust apoptosis of malignant B cells. Here, we aimed to examine the role of AXL RTK inhibition with TP0903 on T-cell function in B-cell malignancies. First, we investigated the influence of TP0903 on CART19 cell phenotype and functions. Here, we used 41BB costimulated, lentiviral-transduced CART cells. AXL inhibition led to polarization of CART cells into a Th1 phenotype when T cells were stimulated with the CD19+ mantle cell lymphoma (MCL) cell line Jeko or with leukemic B cells isolated from patients with chronic lymphocytic leukemia (CLL), in the presence of TP0903 (Fig 1A). Exposure of activated CART cells to TP0903 also resulted in significant downregulation of inhibitory receptors on activated CART cells (Fig 1B), a reduction of conical cytokines known to be associated with the development of cytokine release syndrome (CRS) (Fig 1C). To investigate the effect of AXL RTK inhibition of CART cells with TP0903 in vivo, we established MCL xenografts through the injection of 1.0x106 of Jeko into NSG mice. A week later, mice were treated with either vehicle alone, TP0903 (20 mg/kg/day) alone, 0.5x106 of CART19 alone, or TP0903 (20mg/kg/day)+0.5x106 of CART19. Three weeks after the treatment, mice were rechallenged with 1.0x106 of Jeko. Mice treated with CART19 and TP0903 rejected the tumor challenge while mice previously treated with CART19 alone redeveloped MCL, suggesting that AXL inhibition enhanced CART cell persistence (Fig 1D). Finally, we validated our preclinical findings in correlative analyses of phase 1 clinical trial of TP0903 in patients with solid tumors (NCT02729298). Similar to our findings, there was a significant reduction in Tregs, reduction of inhibitory receptors and polarization to a Th1 phenotype. These findings will be further investigated in a planned phase 1 clinical trial of TP0903 in relapsed/refractory CLL (NCT03572634) In summary, we demonstrated for the first time that AXL inhibition polarizes T cells into a Th1 phenotype, downregulates inhibitory receptors, and synergizes with CART cells in B-cell malignancies. These findings encourage further study of TP0903 as an enhancer of T-cell immunotherapies.

The prevalence, clinicopathologic correlates, and outcomes of previously untreated chronic lymphocytic leukemia (CLL) patients with IGH‐BCL2 and IGH‐BCL3 translocations are not well known. Using the Mayo Clinic CLL database, we identified patients seen between March 1, 2002 and September 30, 2016 who had FISH testing performed within 3 years of CLL diagnosis. The prognostic profile, time to first therapy (TTT), and overall survival (OS) of patients with IGH‐BCL2 and IGH‐BCL3 translocation were compared to patients without these abnormalities (non‐IGH group). Of 1684 patients who met the inclusion criteria, 38 (2.2%) had IGH‐BCL2, and 16 (0.9%) had IGH‐BCL3 translocation at diagnosis. Patients with IGH‐BCL3 translocation were more likely to have high and very‐high CLL‐International Prognostic Index, compared to patients with IGH‐BCL2 translocation and the non‐IGH group. The 5‐year probability of requiring therapy was significantly higher for IGH‐BCL3 compared to IGH‐BCL2 and non‐IGH groups (84% vs 33% vs 29%, respectively, P < 0.0001). The 5‐year OS was significantly shorter for IGH‐BCL3 compared to IGH‐BCL2 and non‐IGH groups (45% vs 89% vs 86%, respectively, P < 0.0001). On multivariable analyses, IGH‐BCL3 translocation was associated with a shorter TTT (hazard ratio [HR] = 2.7; P = 0.005) and shorter OS (HR = 5.5; P < 0.0001); IGH‐BCL2 translocation did not impact TTT and OS. In conclusion, approximately 3% of all newly diagnosed CLL patients have either an IGH‐BCL2 or IGH‐BCL3 translocation. Patients with IGH‐BCL3 translocations have a distinct prognostic profile and outcome. These results support the inclusion of an IGH probe during the routine evaluation of FISH abnormalities in newly diagnosed CLL.

Abstract Infection is a common cause of death in patients with advanced cirrhosis. We aimed to develop a predictive model in Child–Turcotte–Pugh (CTP) class C cirrhotics hospitalized with infection for optimizing treatment and improving outcomes. Clinical information was retrospectively abstracted from 244 patients at Tianjin Third Central Hospital, China (cohort 1). Factors associated with mortality were determined using logistic regression. The model for predicting 90-day mortality was then constructed by decision tree analysis. The model was further validated in 91 patients at Mayo Clinic, Rochester, MN (cohort 2) and 82 patients at Seoul St. Mary's Hospital, Korea (cohort 3). The predictive performance of the model was compared with that of the CTP, model for end-stage liver disease (MELD), MELD-Na, Chronic Liver Failure–Sequential Organ Failure Assessment, and the North American consortium for the Study of End-stage Liver Disease (NACSELD) models. The 3-month mortality was 58%, 58%, and 54% in cohort 1, 2, and 3, respectively. In cohort 1, respiratory failure, renal failure, international normalized ratio, total bilirubin, and neutrophil percentage were determinants of 3-month mortality, with odds ratios of 16.6, 3.3, 2.0, 1.1, and 1.03, respectively (P < .05). These parameters were incorporated into the decision tree model, yielding area under receiver operating characteristic (AUROC) of 0.804. The model had excellent reproducibility in the U.S. (AUROC 0.808) and Korea cohort (AUROC 0.809). The proposed model has the highest AUROC and best Youden index of 0.488 and greatest overall correctness of 75%, compared with other models evaluated. The proposed model reliably predicts survival of advanced cirrhotics with infection in both Asian and U.S. populations.

SummaryThe effects of ibrutinib on the natural history of autoimmune cytopenias (AIC) among chronic lymphocytic leukaemia (CLL) patients treated in routine clinical practice require further investigation. Using the Mayo Clinical CLL Database, 193 CLL patients treated with ibrutinib between November 2013 and January 2017 outside the context of a clinical trial were identified; complete review of their medical records was performed for details of past history of AIC and treatment‐emergent AIC. We identified 29/193 (15%) patients with history of AIC prior to ibrutinib start. Of 12 patients requiring AIC therapy at ibrutinib start, 8 (67%) were able to discontinue or de‐escalate AIC treatment, and no patient had worsening of their AIC after initiating ibrutinib. Eleven (6%) patients developed treatment‐emergent AIC after a median of 59 (range, 6–319) days following the initiation of ibrutinib, 7 of whom (64%) were able to continue ibrutinib. Overall and event‐free survival from time of ibrutinib start were not significantly different between patients with history of AIC and those with no history of AIC. Treatment‐emergent AIC were seen exclusively in patients with unmutated IGHV and were associated with a shorter EFS. These results suggest a low rate of treatment‐emergent AIC and improvement in patients with existing AIC.

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a low-grade B-cell neoplasm and ∼2% to 9% patients develop an aggressive lymphoma, most commonly diffuse large B-cell lymphoma (Richter transformation, DLBCL-RT). Programmed death-1 (PD-1) pathway plays a crucial role in tumor host immunity evasion and its blockade has emerged as an effective anti-cancer immunotherapy. PD-L1 and PD-1 expression has shown predictive value in anti-PD cancer immunotherapy; however, it has not been well documented in CLL/SLL and DLBCL-RT. We evaluated PD-1 and PD-L1 expression by immunohistochemistry in 39 CLL/SLL, 15 DLBCL-RT, and 26 other DLBCL. In CLL/SLL, neoplastic B-cell PD-1 expression was weak and restricted to prolymphocytes/paraimmunoblasts within proliferation centers (PCs) and accentuated PCs of all sizes. Neoplastic B-cell PD-1 expression was highly prevalent and demonstrated increased intensity in DLBCL-RT, but in contrast was only rarely seen in other DLBCL (12/15 vs. 1/26; P<0.0001). An excellent correlation (90% concordance) was observed between neoplastic B-cell PD-1 immunohistochemistry positivity and molecularly defined CLL/SLL clonal relatedness in DLBCL-RT. PD-L1 expression was observed on the neoplastic B cells in rare DLBCL-RT and other DLBCL cases (1/15 vs. 1/26; P>0.05) as well as background histiocytes and dendritic cells. Overall survival of DLBCL-RT was significantly inferior to that of the other DLBCL (median, 16.9 vs. 106.1 mo; P=0.002). Our findings suggest a biological continuum from prolymphocytes/paraimmunoblasts in CLL/SLL PCs to the neoplastic B-cells in DLBCL-RT. The characteristic PD-1 expression in DLBCL-RT makes it a potential surrogate marker for determining clonal relatedness to CLL/SLL, which may have important prognostic and therapeutic implications.