CD20 is a differentiation related cell surface phosphoprotein that is expressed during early pre-B cell stages until plasma cell differentiation, and is a suitable molecular target for B-cell ...malignancies by monoclonal antibodies such as rituximab, ofatumumab, obinutuzumab and others. CD20 expression is confirmed in most B-cell malignancies; however, the protein expression level varies in each patient, even in de novo tumors, and down-modulation of CD20 expression after chemoimmunotherapy with rituximab, resulting in rituximab resistance, has been recognized in the clinical setting. Recent reports suggest that genetic and epigenetic mechanisms are correlated with aberrantly low CD20 expression in de novo tumors and relapsed/refractory disease after using rituximab. Furthermore, some targeting drugs, such as lenalidomide, bortezomib and ibrutinib, directly or indirectly affect CD20 protein expression. CD20-negative phenotypically-changed DLBCL after rituximab use tends to show an aggressive clinical course and poor outcome with resistance to not only rituximab, but also conventional salvage chemo-regimens. Understanding of the mechanisms of CD20-negative phenotype may contribute to establish strategies for overcoming chemo-refractory B-cell malignancies. In this manuscript, recent progress of research on molecular and clinical features of CD20 protein and CD20-negative B-cell malignancies was reviewed.
Since the introduction of all-
trans
retinoic acid (ATRA) and arsenic trioxide (As
2
O
3
) for the treatment of acute promyelocytic leukemia (APL), the overall survival rate has improved ...dramatically. However, relapse/refractory patients showing resistance to ATRA and/or As
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O
3
are recognized as a clinically significant problem. Genetic mutations resulting in amino acid substitution in the retinoic acid receptor alpha (RARα) ligand binding domain (LBD) and the PML-B2 domain of PML-RARα, respectively, have been reported as molecular mechanisms underlying resistance to ATRA and As
2
O
3
. In the LBD mutation, ATRA binding with LBD is generally impaired, and ligand-dependent co-repressor dissociation and degradation of PML-RARα by the proteasome pathway, leading to cell differentiation, are inhibited. The PML-B2 mutation interferes with the direct binding of As
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3
with PML-B2, and PML-RARα SUMOylation with As
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O
3
followed by multimerization and degradation is impaired. To overcome ATRA resistance, utilization of As
2
O
3
provides a preferable outcome, and recently, a synthetic retinoid Am80, which has a higher binding affinity with PML-RARα than ATRA, has been tested in the clinical setting. However, no strategy attempted to date has been successful in overcoming As
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O
3
resistance. Detailed genomic analyses using patient samples harvested repeatedly may help in predicting the prognosis, selecting the effective targeting drugs, and designing new sophisticated strategies for the treatment of APL.
Purpose Hodgkin Reed-Sternberg cells harbor alterations in chromosome 9p24.1, leading to overexpression of programmed death-ligand 1 (PD-L1) and PD-L2. Pembrolizumab, a programmed death 1-blocking ...antibody, demonstrated a high overall response rate (ORR) in patients with relapsed or refractory classic Hodgkin lymphoma (rrHL) in phase I testing. Methods KEYNOTE-087 ( ClinicalTrials.gov identifier, NCT02453594) was a single-arm phase II study of pembrolizumab in three cohorts of patients with rrHL, defined on the basis of lymphoma progression after (1) autologous stem cell transplantation (ASCT) and subsequent brentuximab vedotin (BV); (2) salvage chemotherapy and BV, and thus, ineligible for ASCT because of chemoresistant disease; and (3) ASCT, but without BV after transplantation. Patients received pembrolizumab 200 mg once every 3 weeks. Response was assessed every 12 weeks. The primary end points were ORR by central review and safety. Results A total of 210 patients were enrolled and treated (69 in cohort 1, 81 in cohort 2, and 60 in cohort 3). At the time of analysis, patients received a median of 13 treatment cycles. Per central review, the ORR was 69.0% (95% CI, 62.3% to 75.2%), and the complete response rate was 22.4% (95% CI, 16.9% to 28.6%). By cohort, ORRs were 73.9% for cohort 1, 64.2% for cohort 2, and 70.0% for cohort 3. Thirty-one patients had a response ≥ 6 months. The safety profile was largely consistent with previous pembrolizumab studies. Conclusion Pembrolizumab was associated with high response rates and an acceptable safety profile in patients with rrHL, offering a new treatment paradigm for this disease.
Programmed death-1 inhibitors are approved for patients with relapsed or refractory classic Hodgkin lymphoma (RRcHL). We present the 2-year follow-up of the phase 2 KEYNOTE-087 study of pembrolizumab ...in 210 patients, based on HL progression after autologous stem cell transplantation (ASCT) and subsequent brentuximab vedotin (BV; cohort 1); salvage chemotherapy and BV, with ineligibility for SCT owing to chemorefractory disease (cohort 2); and progression after SCT without BV (cohort 3). With a median follow-up of 27.6 months, the objective response rate (ORR) by blinded independent central review was 71.9% (95% CI, 65.3-77.9), the complete response rate (CRR) was 27.6%, and the partial response (PR) rate was 44.3%. Median duration of response was 16.5 months (range, 0.0+ to 27.0+ +, no progressive disease at last assessment) in all patients, 22.1 months in cohort 1, 11.1 months in cohort 2, and 24.4 months in cohort 3. Median progression-free survival was not reached in all patients with CR: 13.8 months (95% CI, 12.0-22.1) for patients with PR and 10.9 months (95% CI, 5.6-11.1) for patients with stable disease. Median overall survival was not reached in all patients or in any cohort. Treatment-related adverse events (TRAEs) of any grade occurred in 153 (72.9%) patients; grades 3 and 4 occurred in 25 (12.0%) patients; none resulted in death. Results confirmed effective antitumor activity, durability of response, and manageable safety of pembrolizumab monotherapy in RRcHL, regardless of prior treatment and including chemoresistant cHL. This trial was registered at www.clinicaltrials.gov as #NCT02453594.
•Pembrolizumab provided durable and deep responses with acceptable tolerability in a broad spectrum of RRcHL.•Pembrolizumab was also effective in difficult-to-treat chemorefractory cHL.
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Cancer‐associated fibroblasts (CAF) are a key component in the tumor microenvironment and play functional roles in tumor metastasis and resistance to chemotherapies. We have previously reported that ...CAF isolated from lymphoma samples increase anaerobic glycolysis and decrease intracellular production of reactive oxygen species, promoting the survival of tumor cells. Herein, we analyzed the mechanisms underlying this support of tumor‐cell survival by CAF. As direct contact between lymphoma cells and CAF was not indispensable to survival support, we identified that the humoral factor pyruvate was significantly secreted by CAF. Moreover, survival of lymphoma cells was promoted by the presence of pyruvate, and this promotion was canceled by inhibition of monocarboxylate transporters. Metabolome analysis of lymphoma cells in coculture with CAF demonstrated that intermediates in the citric acid cycle were significantly increased, indicating that tumor cells produced energy by aerobic metabolism. These findings indicate that energy production in lymphoma cells is regulated in coordination not only with anaerobic glycolysis, but also with aerobic metabolism termed the reverse‐Warburg effect, involving the secretion of pyruvate from CAF resulting in increased use of the citric acid cycle in lymphoma cells.
Figure 2 shows that CAF and conditioned media support survival of primary lymphoma cells. We show CAF support survival of various disease types and lineages of primary lymphoma cells in Figure 2.
Viral infection induces potent cellular immunity and activated intracellular signaling, which may dictate the driver events involved in immune escape and clonal selection of virus-associated cancers, ...including Epstein-Barr virus (EBV)-positive lymphomas. Here, we thoroughly interrogated PD-L1/PD-L2-involving somatic aberrations in 384 samples from various lymphoma subtypes using high-throughput sequencing, particularly focusing on virus-associated lymphomas. A high frequency of PD-L1/PD-L2-involving genetic aberrations was observed in EBV-positive lymphomas 33 (22%) of 148 cases, including extranodal NK/T-cell lymphoma (ENKTL, 23%), aggressive NK-cell leukemia (57%), systemic EBV-positive T-cell lymphoproliferative disorder (17%) as well as EBV-positive diffuse large B-cell lymphoma (DLBCL, 19%) and peripheral T-cell lymphoma-not otherwise specified (15%). Predominantly causing a truncation of the 3'-untranslated region, these alterations represented the most prevalent somatic lesions in ENKTL. By contrast, the frequency was much lower in EBV-negative lymphomas regardless of histology type 12 (5%) of 236 cases. Besides PD-L1/PD-L2 alterations, EBV-positive DLBCL exhibited a genetic profile distinct from EBV-negative one, characterized by frequent TET2 and DNMT3A mutations and the paucity of CD79B, MYD88, CDKN2A, and FAS alterations. Our findings illustrate unique genetic features of EBV-associated lymphomas, also suggesting a potential role of detecting PD-L1/PD-L2-involving lesions for these lymphomas to be effectively targeted by immune checkpoint blockade.
Background. There is no standard management of reactivation of hepatitis B virus (HBV) infection in HBV-resolved patients without hepatitis B surface antigen (HBsAg), but with antibodies against ...hepatitis B core antigen and/or antibodies against HBsAg (anti-HBs). Methods. We conducted a prospective observational study to evaluate the occurrence of HBV reactivation by serial monthly monitoring of HBV DNA and to establish preemptive therapy guided by this monitoring in B-cell non-Hodgkin lymphoma (B-NHL) treated with rituximab plus corticosteroid-containing chemotherapy (R-steroid-chemo). The primary endpoint was the incidence of HBV reactivation defined as quantifiable HBV DNA levels of ≥11 1U/mL. Results. With a median HBV DNA follow-up of 562 days. HBV reactivation was observed in 21 of the 269 analyzed patients. The incidence of HBV reactivation at 1.5 years was 8.3% (95% confidence interval, 5.5–12.4). No hepatitis due to HBV reactivation was observed in patients who received antiviral treatment when HBV DNA levels were between 11 and 432 IU/mL. An anti-HBs titer of <10 mIU/mL and detectable HBV DNA remaining below the level of quantification at baseline were independent risk factors for HBV reactivation (hazard ratio, 20.6 and 56.2, respectively; P<.001). Even in 6 patients with a rapid increase of HBV due to mutations, the monthly HBV DNA monitoring was effective at preventing HBV-related hepatitis. Conclusions. Monthly monitoring of HBV DNA is useful for preventing HBV reactivation–related hepatitis among B-NHL patients with resolved HBV infection following R-steroid-chemo (UMIN000001299).
Arsenic trioxide (As2O3) is a highly effective treatment for patients with refractory/relapsed acute promyelocytic leukemia (APL), but resistance to As2O3 has recently been seen. In the present ...study, we report the findings that 2 of 15 patients with refractory/relapsed APL treated with As2O3 were clinically As2O3 resistant. Leukemia cells from these 2 patients harbored missense mutations in promyelocytic leukemia gene–retinoic acid receptor-α gene (PML-RARA) transcripts, resulting in amino acid substitutions of A216V and L218P in the PML B2 domain. When wild-type or mutated PML-RARA (PR-WT and PR-B/L-mut, respectively) were overexpressed in HeLa cells, immunoblotting showed SUMOylated and/or oligomerized protein bands in PR-WT but not in PR-B/L-mut after As2O3 treatment. Protein-localization analysis indicated that PR-WT in the soluble fraction was transferred to the insoluble fraction after treatment with As2O3, but PR-B/L-mut was stably detected in fractions both with and without As2O3. Immunofluorescent microscopy analysis showed PR-WT localization as a microgranular pattern in the cytoplasm without As2O3 and as a macrogranular pattern with As2O3. PR-B/L-mut was diffusely observed in the cytoplasm with and without As2O3. Nearly identical localization patterns were observed in patients' primary cells. Therefore, B2 domain mutations may play an important role in aberrant molecular responses to As2O3 and may be critical for As2O3 resistance in APL.
The number of patients aged 80 years or older with diffuse large B-cell lymphoma (DLBCL) is increasing, and the incidence rate of the disease in this population group reaches up to 20%. The risk of ...infection is higher in older patients than in other patients. Although hypnotic drugs are frequently detected as potentially inappropriate medications, it is unclear whether hypnotic drugs affect the occurrence of infection during chemotherapy. Here, we investigated whether the use of hypnotic drugs is associated with infection during first-line chemotherapy in patients with diffuse large B-cell lymphoma (DLBCL) aged 80 years or older.
Japanese patients aged 80 years or older with diffuse large B-cell lymphoma who had received first-line chemotherapy at Fujita Health University Hospital from January 2005 to March 2020 were enrolled in this retrospective cohort study. The primary study outcome was the identification of the risk factor for infection during first-line chemotherapy.
This study included 65 patients received first-line chemotherapy. The proportion of patients with National Comprehensive Cancer Network-international prognostic index ≥ 6 was higher in the infection group than in the non-infection group. The relative dose intensity of each anticancer drug (cyclophosphamide, adriamycin, and vincristine) and dose of prednisolone did not significantly differ between the two groups. Multivariate analysis showed that the use of benzodiazepines was a risk factor for infection (odds ratio, 4.131 95% confidence interval: 1.225-13.94, P = 0.022).
DLBCL patients using benzodiazepines should be monitored for infection symptoms during chemotherapy.
Although next‐generation sequencing‐based panel testing is well practiced in the field of cancer medicine for the identification of target molecules in solid tumors, the clinical utility and clinical ...issues surrounding panel testing in hematological malignancies have yet to be fully evaluated. We conducted a multicenter prospective clinical sequencing study to verify the feasibility of a panel test for hematological tumors, including acute myeloid leukemia, acute lymphoblastic leukemia, multiple myeloma, and diffuse large B‐cell lymphoma. Out of 96 eligible patients, 79 patients (82%) showed potentially actionable findings, based on the clinical sequencing assays. We identified that genetic alterations with a strong clinical significance were found at a higher frequency in terms of diagnosis (n = 60; 63%) and prognosis (n = 61; 64%) than in terms of therapy (n = 8; 8%). Three patients who harbored a germline mutation in either DDX41 (n = 2) or BRCA2 (n = 1) were provided with genetic counseling. At 6 mo after sequencing, clinical actions based on the diagnostic (n = 5) or prognostic (n = 3) findings were reported, but no patients were enrolled in a clinical trial or received targeted therapies based on the sequencing results. These results suggest that panel testing for hematological malignancies would be feasible given the availability of useful diagnostic and prognostic information. This study is registered with the UMIN Clinical Trial Registry (UMIN000029879, multiple myeloma; UMIN000031343, adult acute myeloid leukemia; UMIN000033144, diffuse large B‐cell lymphoma; and UMIN000034243, childhood leukemia).
This multicenter prospective study investigated feasibility of target capture‐based panel testing, focusing on hematological malignancies. Our results suggest that panel testing for hematological malignancies is feasible given the availability of useful diagnostic and prognostic information.
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