Relapsed and refractory aggressive NHL: time for a change

Reduced-intensity conditioning with fludarabine/busulfan versus fludarabine/low-dose melphalan in patients with non-Hodgkin lymphoma undergoing allogeneic haematopoietic stem cell transplantation

Reduced-intensity conditioning regimens are commonly used in allogeneic haematopoietic cell transplantation for non-Hodgkin lymphoma (NHL); however, the optimal regimen remains unknown. In this study, the outcomes of adult patients with NHL who received fludarabine plus reduced-dose busulfan (6.4 mg/kg; Flu/Bu2) (n = 286) and fludarabine plus low-dose melphalan (80 or 100 mg/m2; Flu/Mel80-100) (n = 283) between January 2009 and December 2020 were compared using Japanese registry data. The primary end-point was the 5-year overall survival (OS). The 5-year OS was 53.8% (95% CI, 47.6-59.6) and 42.4% (95% CI, 35.6-49.0) in the Flu/Bu2 and Flu/Mel80-100 groups respectively (p = 0.030). After inverse probability of treatment weighting adjustment, the adjusted HR of Flu/Bu2 compared with Flu/Mel80-100 group for 5-year OS was 0.77 (95% CI, 0.60-0.99, p = 0.046), 0.97 (95% CI, 0.78-1.21, p = 0.798) for 5-year progression-free survival, 0.65 (95% CI, 0.45-0.94, p = 0.022) for 5-year cumulative risk of non-relapse mortality and 1.25 (95% CI, 0.95-1.64, p = 0.115) for 5-year cumulative risk of relapse. In this study, patients with NHL who received Flu/Bu2 were associated with better OS and lower non-relapse mortality than those who received Flu/Mel80-100.

A phase IV, randomized, multicenter, open-label trial comparing efficacy and systemic exposure for a standard weight-based dose versus a fixed dose of plerixafor in combination with G-CSF in patients with Non-Hodgkin's lymphoma weighing ≤70 kg

A randomized, multicenter, open-label study explored the effect of a fixed-dose (FD) of plerixafor versus the approved weight-based (WB) dose for the mobilization of hematopoietic stem cells (HSCs) in patients with non-Hodgkin's lymphoma and a body weight of ≤70 kg. After mobilization with granulocyte colony-stimulating factor (G-CSF) 10 μg/kg/day for 4 days, patients were randomized 1:1 to either plerixafor FD 20 mg (n = 30) or WB 0.24 mg/kg (n = 31) on the evening of Day 4. Co-primary endpoints were the proportion of patients achieving ≥5 × 106 CD34+ cells/kg in ≤4 days of apheresis, and total systemic exposure to plerixafor (area under the concentration-time curve from 0 to 10 h [AUC0-10]). There was no statistically significant difference between the proportion of patients attaining the primary efficacy endpoint (60% FD arm, 55% WB arm; P = 0.395). Exposure to plerixafor was greater in the FD arm relative to the WB arm; however, there was no appreciable difference regarding fold increases of peripheral blood CD34+ cells. The safety profile was similar between treatment groups. These results suggest there is no statistically significant difference in HSC mobilization with a standard WB dosing regimen of plerixafor plus G-CSF in patients with low body weight compared with an FD regimen.

CRISPR-Cas9 technology and its application in haematological disorders

The recent advent of the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR associated protein 9 (Cas9) system for precise genome editing has revolutionized methodologies in haematology and oncology studies. CRISPR-Cas9 technology can be used to remove and correct genes or mutations, and to introduce site-specific therapeutic genes in human cells. Inherited haematological disorders represent ideal targets for CRISPR-Cas9-mediated gene therapy. Correcting disease-causing mutations could alleviate disease-related symptoms in the near future. The CRISPR-Cas9 system is also a useful tool for delineating molecular mechanisms involving haematological malignancies. Prior to the use of CRISPR-Cas9-mediated gene correction in humans, appropriate delivery systems with higher efficiency and specificity must be identified, and ethical guidelines for applying the technology with controllable safety must be established. Here, the latest applications of CRISPR-Cas9 technology in haematological disorders, current challenges and future directions are reviewed and discussed.

Targeting B-cell malignancies through human B-cell receptor specific CD4+ T cells

The B-cell receptor (BCR) expressed by a clonal B cell tumor is a tumor specific antigen (idiotype). However, the T-cell epitopes within human BCRs which stimulate protective immunity still lack detailed characterization. In this study, we identified 17 BCR peptide-specific CD4⁺ T-cell epitopes derived from BCR heavy and light chain variable region sequences. Detailed analysis revealed these CD4⁺ T-cell epitopes stimulated normal donors' and patients' Th1 CD4⁺ T cells to directly recognize the autologous tumors by secretion of IFNγ, indicating the epitopes are processed and presented by tumor cells. One BCR peptide-specific CD4⁺ T cell line was also cytotoxic and lysed autologous tumor cells through the perforin pathway. Sequence analysis of the epitopes revealed that 10 were shared by multiple primary patients' tumors, and 16 had the capacity to bind to more than one HLA DRB1 allele. T cells stimulated by shared epitopes recognized primary tumors expressing the same sequences on multiple HLA DRB1 alleles. In conclusion, we identified 17 BCR-derived CD4⁺ T-cell epitopes with promiscuous HLA DRB1 binding affinity that are shared by up to 36% of patients, suggesting a strategy to overcome the requirement for individual preparation of therapeutic agents targeting idiotype.

Persistent Disparities Among Patients With T-Cell Non-Hodgkin Lymphomas and B-Cell Diffuse Large Cell Lymphomas Over 40 Years: A SEER Database Review

BACKGROUND

As of 2013, more than 550,000 people are living with non-Hodgkin lymphoma (NHL).

PATIENTS AND METHODS

We undertook a large Surveillance Epidemiology and End Results (SEER) based analysis to describe outcome disparities in different subgroups of aggressive T-cell and B-cell NHL patients, with a focus on various ethnicities.

RESULTS

The final analysis included 7662 patients with T-cell and 84,910 with B-cell NHL. Survival analysis revealed that male sex and increasing age were independent predictors of worse overall survival (OS; P < .001). For aggressive T-cell NHL, there was no significant improvement in median OS between 1973 and 2011 (P = .081), and ethnic minorities (Asians, Hispanics, and African Americans) had significantly worse OS than whites (P < .001). There were similar trends for age, sex, and race for diffuse large B-cell NHL, but a significant improvement in median OS was seen over time (P < .001).

CONCLUSION

These results are the first to elicit outcomes in a broad classification of ethnic minorities and underscore the urgency for development of novel therapeutics, especially in T-cell NHL. In addition, in-depth studies of disease biology and health care utilization are required for better triage of health care resources, especially for ethnic minorities.

Predictive Modeling of Drug Response in Non-Hodgkin's Lymphoma

We combine mathematical modeling with experiments in living mice to quantify the relative roles of intrinsic cellular vs. tissue-scale physiological contributors to chemotherapy drug resistance, which are difficult to understand solely through experimentation. Experiments in cell culture and in mice with drug-sensitive (Eµ-myc/Arf-/-) and drug-resistant (Eµ-myc/p53-/-) lymphoma cell lines were conducted to calibrate and validate a mechanistic mathematical model. Inputs to inform the model include tumor drug transport characteristics, such as blood volume fraction, average geometric mean blood vessel radius, drug diffusion penetration distance, and drug response in cell culture. Model results show that the drug response in mice, represented by the fraction of dead tumor volume, can be reliably predicted from these inputs. Hence, a proof-of-principle for predictive quantification of lymphoma drug therapy was established based on both cellular and tissue-scale physiological contributions. We further demonstrate that, if the in vitro cytotoxic response of a specific cancer cell line under chemotherapy is known, the model is then able to predict the treatment efficacy in vivo. Lastly, tissue blood volume fraction was determined to be the most sensitive model parameter and a primary contributor to drug resistance.

CC-122, a pleiotropic pathway modifier, mimics an interferon response and has antitumor activity in DLBCL

Cereblon (CRBN), a substrate receptor of the Cullin 4 RING E3 ubiquitin ligase complex, is the target of the immunomodulatory drugs lenalidomide and pomalidomide. Recently, it was demonstrated that binding of these drugs to CRBN promotes the ubiquitination and subsequent degradation of 2 common substrates, transcription factors Aiolos and Ikaros. Here we report that CC-122, a new chemical entity termed pleiotropic pathway modifier, binds CRBN and promotes degradation of Aiolos and Ikaros in diffuse large B-cell lymphoma (DLBCL) and T cells in vitro, in vivo, and in patients, resulting in both cell autonomous as well as immunostimulatory effects. In DLBCL cell lines, CC-122-induced degradation or short hairpin RNA-mediated knockdown of Aiolos and Ikaros correlates with increased transcription of interferon (IFN)-stimulated genes independent of IFN-α, -β, and -γ production and/or secretion and results in apoptosis in both activated B-cell (ABC) and germinal center B-cell DLBCL cell lines. Our results provide mechanistic insight into the cell-of-origin independent antilymphoma activity of CC-122, in contrast to the ABC subtype selective activity of lenalidomide.

Management of patients with non-Hodgkin's lymphoma: focus on adoptive T-cell therapy

Non-Hodgkin’s lymphoma (NHL) represents a heterogeneous group of malignancies with high diversity in terms of biology, clinical responses, and prognosis. Standard therapy regimens produce a 5-year relative survival rate of only 69%, with the critical need to increase the treatment-success rate of this patient population presenting at diagnosis with a median age of 66 years and many comorbidities. The evidence that an impaired immune system favors the development of NHL has opened the stage for new therapeutics, and specifically for the adoptive transfer of ex vivo-expanded antigen-specific T-cells. In this review, we discuss how T-cells specific for viral-associated antigens, nonviral-associated antigens expressed by the tumor, T-cells redirected through the expression of chimeric antigen receptors, and transgenic T-cell receptors against tumor cells have been developed and used in clinical trials for the treatment of patients with NHLs.

Salvage therapy with mitoxantrone, etoposide, bleomycin and dexamethasone for refractory or relapsed aggressive non-Hodgkin's lymphoma patients with a poor performance status or comorbidity

The treatment of refractory or relapsed aggressive non-Hodgkin's lymphoma (NHL) in patients in a state of poor health is difficult due to their ineligibility to receive intensive salvage chemotherapy. In the present study, 16 refractory or relapsed aggressive NHL patients with a poor performance status or comorbidities were treated with mitoxantrone, etoposide, bleomycin and dexamethasone (MEBD) therapy. The treatment consisted of 10 mg/m² intravenous (IV) mitoxantrone on day 1, 75 mg/m² IV etoposide on days 1-3, 20 mg IV dexamethasone on days 1-4 and 15 mg intramuscular bleomycin on days 1, 4, 8 and 12, every 21 days. The efficacy and toxicity of the regimen were evaluated. The overall response rate was 68.8%, with a complete response rate of 18.8% and a partial response rate of 50.0%. The efficacy of the treatment for B-cell lymphoma was greater than that for T-cell lymphoma. The median progression-free survival time for the patients was 16.7 months and the median overall survival time was 22.4 months. The one-year overall survival rate was 62.5% and the two-year overall survival rate was 43.8%. The most common toxicity symptom was myelosuppression. In conclusion, refractory or relapsed aggressive NHL patients with a poor performance status or comorbidity are eligible for chemotherapy. MEBD therapy is an effective and feasible salvage regimen for NHL patients in a state of poor health.