Adverse events in lymphoma patients treated with phosphoinositide 3 kinase Inhibitor in clinical trials: a meta-analysis.

BACKGROUND: Malignant lymphomas are one of the most common cancers worldwide and with high biologic heterogeneity, while the phosphoinositide 3 kinase (PI3K)/mTOR pathway is crucial in maintaining cell growth and survival both in physiological and in pathological conditions (i.e., lymphoma). PI3K inhibitors have been proven to be effective in several subtypes of lymphomas. However, the high incidence of treatment-related adverse events as well as the special safety profile in PI3K inhibitors draws great attention. Thus, this meta-analysis was conducted to compare adverse events in PI3K inhibitors to conventional regimens in lymphoma patients. METHODS: Articles were retrieved from PubMed, Cochrane, and Embase to identify randomized controlled trials and phase III clinical trials that used PI3K inhibitors comparing with non-PI3K inhibitors in lymphoma patients. To achieve the appropriate results, we calculated the risk ratio and 95% confidence intervals. RESULTS: Four trials with 1399 patients that met our criteria were included. The PI3K inhibitors group significantly increased the risk of all-grade adverse events (AEs) (RR 0.95, 95% CI: 0.92-0.98) and high-grade AEs (RR 0.63, 95% CI: 0.57-0.70), compared with the non-PI3K inhibitors group. Besides, the incidence of neutropenia (RR 0.81, 95% CI: 0.74-0.90), pneumonia (RR 0.62, 95% CI: 0.46-0.83), and diarrhea (RR 0.40, 95% CI: 0.32-0.49) were significantly high in the PI3Ki group, while the incidence of anemia (RR 0.78, 95% CI: 0.50-1.20) and thrombocytopenia (RR 0.85, 95% CI: 0.51-1.42) had no statistic significant. CONCLUSION: PI3K inhibitors increased the risk of certain AEs in lymphoma patients.

Low-dose triptolide enhances antitumor effect of JQ1 on acute myeloid leukemia through inhibiting RNA polymerase II in vitro and in vivo.

The bromodomain and extra-terminal (BET) domain inhibitor JQ1 exerts potent anticancer activity in various cancer cells. However, the resistance to BET inhibitors in leukemia stem cells limits its implication in acute myeloid leukemia (AML). High concentration of triptolide (TPL) presents anticancer activities but with adverse effects. Here, we investigated whether the combination of low-dose TPL with JQ1 could help to circumvent the dilemma of drug resistance and side effect in treating AML. AML cell lines, primary cells from 10 AML patients with different status, as well as AML mice model were subjected to different treatments and apoptotic related protein expression were evaluated. Data showed that low-dose TPL combined with JQ1 effectively killed AML cell lines and primary cells from AML patients without exerting significantly greater lethal activity against normal cells. Mechanism study revealed that low-dose TPL combined with JQ1 triggered reactive oxygen species production and induced mitochondrial-mediated apoptosis in AML cells, in which the inhibition of RNA polymerase II to downregulate c-Myc was mainly responsible for the enhanced activity of TPL in combination with JQ1. In vivo study presented that cotreatment with low-dose TPL and JQ1 significantly reduced tumor burden of the NOD/SCID mice engrafted with MOLM-13 cells. In conclusion, low-dose TPL enhanced the antitumor effect of JQ1 on AML without increasing the side effects, supporting a potential option for AML treatment.

Impairment of Vα24-Jα18+Vß11+ natural killer T cells in adult acute lymphoblastic leukemia patients.

Type I natural killer T (NKT) cells are attractive candidates for cancer immunotherapy. In this study, we examined the characteristics of type I NKT cells in patients with adult B-cell acute lymphoblastic leukemia (ALL). We first identified type I NKT cells as Vα24-Jα18 and Vß11 double-positive CD3+ lymphocytes. Using this method, we found that the adult B-cell ALL patients presented significantly lower level of type I NKT cells than the age- and sex-matching control subjects. The expression of IL-21 by type I NKT cells was then examined using intracellular flow cytometry, which showed that with α-GalCer stimulation, the adult B-cell ALL patients presented significantly lower level of IL-21+ type I NKT cells than control subjects. By both flow cytometry and ELISA, we found that the vast majority of IL-21-expressing type I NKT cells expressed IL-21R, which was also reduced in adult B-cell ALL patients. Using an in vitro co-culture system, we demonstrated that IL-21R+, but not IL-21R-, type I NKT cells could promote the IFN-γ, granzyme B, and perforin expression by CD8 T cells in an IL-21-dependent fashion. This type I NKT cell-mediated stimulatory effect was reduced in adult B-cell ALL patients than in control subjects. In addition, we observed a positive correlation between the frequency of IL-21R+ type I NKT cells and the frequencies of IFN-γ-, granzyme B-, and perforin-expressing circulating CD8 T cells in adult B-cell ALL patients directly ex vivo. Overall, this study identified an IL-21-related impairment in type I NKT cells from adult B-cell ALL patients.

CD4+ T cell-mediated cytotoxicity is associated with MHC class II expression on malignant CD19+ B cells in diffuse large B cell lymphoma.

Diffuse large B cell lymphoma (DLBCL) is a common B cell malignancy with approximately 30% of patients present relapsed or refractory disease after first-line therapy. Research of further treatment options is needed. Cytotoxic CD4+ T cells express cytolytic molecules and have potential antitumor function. Here, we showed that the CD19+ cells from DLBCL patients presented significantly reduced expression of MHC II molecules than those from healthy controls. Three years after the first-line treatment, patients that presented relapsed disease had significantly lower MHC II expression on their CD19+ cells than patients who did not show recurrence. Examining cytotoxic CD4+ T cells show that DLBCL patients presented significantly elevated frequencies of granzyme A-, granzyme B-, and/or perforin-expressing cytotoxic CD4+ T cells. Also, frequency of cytotoxic CD4+ T cells in DLBCL patients was positively correlated with the MHC II expression level. Subsequently, the cytotoxic potential of CD4+ T cells against autologous CD19+ cells was investigated. We found that the cytotoxic potential of CD4+ T cells was highest in MHC II-high, intermediate in MHC II-mid, and lowest in MHC II-low patients. The percentage of MHC II-expressing viable CD19+ cells presented a significant reduction after longer incubation with cytotoxic CD4+ T cells, suggesting that cytotoxic CD4+ T cells preferentially eliminated MHC II-expressing CD19+ cells. Blocking MHC II on CD19+ cells significantly reduced the cytolytic capacity of CD4+ T cells. Despite these discoveries, the frequency of cytotoxic CD4+ T cells did not predict the clinical outcome of DLBCL patients. Together, these results demonstrated that cytotoxic CD4+ T cells presented an MHC II-dependent cytotoxic potential against autologous CD19+ cells and could potentially represent a future treatment option for DLBCL.

Radiation-induced Bystander Effects on Glioblastoma Tumor Cells via NMDA Receptor Signaling.

Proton therapy has been widely applied on treating inaccessible and inoperable tumors, such as tumors deep within the brain or close to the critical brain stem. Nevertheless, the damaging effect of radiation for central nervous system (CNS) tumors is difficult to be confined within the irradiated region and has led to decline of neurological function in especially children with congenital CNS tumors. Currently, the involvement of n-methyl-d-aspartate (NMDA) receptors or secretary cytokines and chemokines in proton-induced bystander effects remains unclear. To understand the modulatory effects of NMDA receptor inhibition on the survival and proliferation of glioblastoma-derived cells, mesenchymal-like U373 cells were applied along with U87 neural glioblastoma cells for single doses of proton radiation at different LET in the presence or absence of pretreatment with memantine and/or collimation. Under collimation, neuronal tumor cells that are not directly irradiated (i.e., bystander cells) encounter similar biological effects potentially through cell coupling and synaptic transmission. Furthermore, whether proton LET plays a role in the mediation of bystander effect awaits to be elucidated. From this study, synaptic transmission was found to play differential roles in the proliferation of U373 and U87 cells after exposure to collimated radiation. Also, radiation-induced cell proliferation at the late stage was more correlated with bystander cell survival than early manifested γH2AX foci, suggesting that proton-induced glutamatergic synapse may act as a more important contributor than proton-induced direct effect on DNA double-stranded breaks to the late-stage responses of glioblastoma cells.

[The Effecacy and Safety of Daratumumab Based Regimens in Relapsed/Refractory Multiple Myeloma: A Single-Center Real-World Data Analysis].

OBJECTIVE: To investigate the efficacy and safety of daratumumab based regimens in relapse and/or refractory multiple myeloma (RRMM) in the real world, as well as the impact of daratumumab on stem cell collection and engraftment. METHODS: The clinical data of patients with RRMM who received daratumumab in hematology department of the First Affiliated Hospital of Xiamen University from February 2019 to March 2023 and had evaluable efficacy were retrospective analysis. RESULTS: All 43 RRMM patients were treated with daratumumab-based combination regimens, including Dd, DVd, DRd, Dkd, DId, and Dara-DECP. With median follow-up time 10.1 (2.1-36.6) months, the best overall response rate (ORR) was 74.4% and a best complete response rate (CR) was 25.6%. 1-year overall survival rate (OS) was 84.5%. The most common severe hematologic adverse events (Grade>3) are 3/4 grade leukopenia（18.6%）, and the most common severe non-hematologic adverse events were infusion-related reactions (IRRs， 20.9%) and infections（7.0%）. Multivariate prognostic analysis showed that extramedullary infiltration was an independent adverse prognostic factor affecting OS （P =0.004）. The use of daratumumab has no effect on stem cell collection, or engraftment. CONCLUSION: Daratumumab is safe and effective in RRMM.

The role of central nervous system (CNS) prophylaxis in preventing DLBCL patients from CNS relapse: A network meta-analysis.

BACKGROUND: Secondary central nervous system (CNS) relapses are an uncommon yet devastating complication in diffuse large B cell lymphoma (DLBCL). Although several prophylaxis attempts were employed clinically in order to reduce the CNS relapse rate, the optimal management remained uncertain. METHODS: We employed conventional meta-analysis along with Network meta-analysis to investigate an optimal prophylactic strategy. The primary outcome was CNS relapse rate. RESULTS: A total of thirty-six studies comprising 5 RCTs, one clinical trial and 30 observational studies were included. Rituximab overall was superior in reducing CNS relapse rate, and the statistical significance exists (RR 0.79(0.68-0.93), p = 0.004). In rituximab era, none of intravenous, intrathecal administration or novel target agents could significantly decrease CNS relapse rate in high CNS risk patients. Intensive chemotherapy regimen containing HD-MTX with HD-Ara-C (SUCRA 93.4 %) was ranked as the first in reducing CNS relapse rate followed by no prophylaxis (SUCRA 57.5 %), HD-MTX (SUCRA 53.1 %), IT (SUCRA 34.5 %) and lenalidomide maintenance (SUCRA 11.5 %). In addition, intercalated HD-MTX had a trend of reducing CNS relapse but without statistical significance (RR 0.86(0.44-1.68), p = 0.67). However, i-HD-MTX was associated with increased grade 3-4 toxicities and prolonged inpatient stay. Early HD-MTX exposure also increased the treatment related death. CONCLUSION: Our network meta-analysis provides an overview of the relative efficacy of all available CNS prophylaxis strategies in DLBCL. In rituximab era, none of intravenous, intrathecal administration or novel target agents could significantly decrease CNS relapse rate in high CNS risk patients. Further studies with prospective, randomized clinical trials as well as with more focus on novel target agents that could spread blood-brain barriers are suggested.

Vδ2 T cell subsets, defined by PD-1 and TIM-3 expression, present varied cytokine responses in acute myeloid leukemia patients.

Vδ2 T cells represent the major γδ T cell subset in humans and can serve as an important early source of TNF-α and IFN-γ during inflammatory responses. In acute myeloid leukemia (AML) patients receiving allogeneic stem cell transplantation, higher γδ T cell count predicted better prognosis. The impact of PD-1 and TIM-3 expression on the function of Vδ2 T cells is yet unclear. In this study, we showed that the frequencies of PD-1+TIM-3- Vδ2 T cells were comparable between healthy controls and AML patients, but the frequencies of PD-1-TIM-3+ Vδ2 T cells and of PD-1+TIM-3+ Vδ2 T cells were significantly higher in AML patients than in healthy controls. Both PD-1 and TIM-3 were upregulated upon phosphoantigen + IL-2 activation, but the relative differences in the frequencies of various PD-1 vs. TIM-3 subsets between AML patients and healthy controls remained. Interestingly, among all PD-1 vs. TIM-3 subsets, the PD-1+TIM-3- subset presented the highest TNF-α and IFN-γ expression, while the PD-1+TIM-3+ subset presented the lowest TNF-α and IFN-γ expression. Anti-PD-1 inhibition did not significantly affect the production of TNF-α or IFN-γ, but anti-TIM-3 inhibition and anti-PD-1/TIM-3 dual inhibition significantly elevated the production of TNF-α and IFN-γ. Interestingly, anti-PD-1 blocking antibodies had significantly increased the frequency of TIM-3+ cells in Vδ2 T cells, suggesting a compensatory TIM-3 upregulation. In addition, the levels of PD-L1 and HMGB-1 were significantly higher in AML patients than in healthy subjects. In summary, this study provides knowledge on the cytokine expression patterns by PD-1 and/or TIM-3-expressing Vδ2 T cells in AML patients, and indicates that the upregulation of PD-1 alone is insufficient to indicate functional impairment, and Vδ2 T cells may require anti-TIM-3 inhibition for functional revival.

IL-21-mediated expansion of Vγ9Vδ2 T cells is limited by the Tim-3 pathway.

Vγ9Vδ2 T cells are the main γδ T subset in the peripheral blood and lymphoid organs. Previous studies have shown that Vγ9Vδ2 T cells could expand in the presence of phosphoantigens and IL-2 and exert antitumor functions. However, their potency was limited because sustained proliferation could not be achieved, possibly due to exhaustion caused by prolonged antigenic stimulation. In this study, we examined the proliferative response of Vγ9Vδ2 T cells to IL-21, a cytokine previously shown to promote NK cell and CD8 T cell cytotoxicity. We found that IL-21 could significantly improve the proliferation of phosphoantigen-stimulated Vγ9Vδ2 T cells in a dose-dependent manner. However, in acute myeloid leukemia (AML) patients, the efficacy of IL-21 was significantly reduced. Vγ9Vδ2 T cells from AML patients exhibited lower expression of IL-21R, and required higher levels of IL-21 for expansion. IL-21-treated Vγ9Vδ2 T cells from AML patients presented lower increase in STAT1 phosphorylation than Vγ9Vδ2 T cells from healthy volunteers. Interestingly, AML Vγ9Vδ2 T cells presented significantly higher Tim-3 expression than healthy Vγ9Vδ2 T cells. IL-21 treatment further induced Tim-3 upregulation. Blocking Tim-3 increased the proliferation and the STAT phosphorylation in Vγ9Vδ2 T cells in response to IL-21. Together, these results demonstrated that IL-21 could significantly expand the Vγ9Vδ2 T cells, but its efficacy was limited since it also increased the expression of checkpoint molecule Tim-3.