Masahiro Yokoyama

Hepatic toxicity and prognosis in hepatitis C virus–infected patients with diffuse large B-cell lymphoma treated with rituximab-containing chemotherapy regimens: a Japanese multicenter analysis

The influence of hepatitis C virus (HCV) infection on prognosis and hepatic toxicity in patients with diffuse large B-cell lymphoma in the rituximab era is unclear. Thus, we analyzed 553 patients, 131 of whom were HCV-positive and 422 of whom were HCV-negative, with DLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (RCHOP)-like chemotherapy. Survival outcomes and hepatic toxicity were compared according to HCV infection. The median follow-up was 31 and 32 months for patients who were HCV-positive and HCV-negative, respectively. HCV infection was not a significant risk factor for prognosis (3-year progression-free survival, 69% vs 77%, P = .22; overall survival, 75% vs 84%, P = .07). Of 131 patients who were HCV-positive, 36 (27%) had severe hepatic toxicity (grade 3-4), compared with 13 of 422 (3%) patients who were HCV-negative. Multivariate analysis revealed that HCV infection was a significant risk factor for severe hepatic toxicity (hazard ratio: 14.72; 95% confidence interval, 6.37-34.03; P < .001). An exploratory analysis revealed that pretreatment transaminase was predictive of severe hepatic toxicity. HCV-RNA levels significantly increased during immunochemotherapy (P = .006). These results suggest that careful monitoring of hepatic function and viral load is indicated during immunochemotherapy for HCV-positive patients.

Blockade of bulky lymphoma‐associated CD55 expression by RNA interference overcomes resistance to complement‐dependent cytotoxicity with rituximab

Recently, anti‐CD20 (rituximab) and anti‐Her2/neu (trastuzumab) antibodies have been developed and applied to the treatment of malignant lymphoma and breast cancer, respectively. However, bulky lymphoma is known to be resistant to rituximab therapy, and this needs to be overcome. Fresh lymphoma cells were collected from 30 patients with non‐Hodgkins lymphoma, the expression of CD20 and CD55 was examined by flow cytometry, and complement‐dependent cytotoxicity (CDC) assays were carried out. Susceptibility to CDC with rituximab was decreased in a tumor size‐dependent manner (r = –0.895, P < 0.0001), but not in a CD20‐dependent manner (r = –0.076, P = 0.6807) using clinical samples. One complement‐inhibitory protein, CD55, contributed to bulky lymphoma‐related resistance to CDC with rituximab. A decrease in susceptibility to CDC with rituximab was statistically dependent on CD55 expression (r = –0.927, P < 0.0001) and the relationship between tumor size and CD55 expression showed a significant positive correlation (r = 0.921, P < 0.0001) using clinical samples. To overcome the resistance to rituximab by high expression of CD55 in bulky lymphoma masses, small interfering RNA (siRNA) was designed from the DNA sequence corresponding to nucleic acids 1–380 of the CD55 cDNA. Introduction of this siRNA decreased CD55 expression in the breast cancer cell line SK‐BR3 and in CD20‐positive cells of patients with recurrent lymphoma; resistance to CDC was also inhibited. This observation gives us a novel strategy to suppress bulky disease‐related resistance to monoclonal antibody treatment. (Cancer Sci 2006; 97: 72–79)

Central nervous system event in patients with diffuse large B-cell lymphoma in the rituximab era

Central nervous system (CNS) events, including CNS relapse and progression to CNS, are known to be serious complications in the clinical course of patients with lymphoma. This study aimed to evaluate the risk of CNS events in patients with diffuse large B‐cell lymphoma in the rituximab era. We performed a retrospective survey of Japanese patients diagnosed with diffuse large B‐cell lymphoma who underwent primary therapy with R‐CHOP chemoimmunotherapy between September 2003 and December 2006. Patients who had received any prophylactic CNS treatment were excluded. Clinical data from 1221 patients were collected from 47 institutions. The median age of patients was 64 years (range, 15–91 years). We noted 82 CNS events (6.7%) and the cumulative 5‐year probability of CNS events was 8.4%. Patients with a CNS event demonstrated significantly worse overall survival (P < 0.001). The 2‐year overall survival rate after a CNS event was 27.1%. In a multivariate analysis, involvement of breast (relative risk [RR] 10.5), adrenal gland (RR 4.6) and bone (RR 2.0) were identified as independent risk factors for CNS events. We conclude that patients with these risk factors, in addition to patients with testicular involvement in whom CNS prophylaxis has been already justified, are at high risk for CNS events in the rituximab era. The efficacy and manner of CNS prophylaxis in patients for each involvement site should be evaluated further. (Cancer Sci 2012; 103: 245–251)

CD5 expression is potentially predictive of poor outcome among biomarkers in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP therapy

BACKGROUND Several biomarkers indicating poor prognosis have been reassessed in patients receiving rituximab combination chemotherapy for diffuse large B-cell lymphoma (DLBCL). However, few studies have investigated outcome in relation to a combination of these biomarkers. In addition, no large-scale studies have reassessed the outcome of patients with CD5-positive DLBCL treated with rituximab. PATIENTS AND METHODS We conducted a retrospective study and investigated the predictive value of three biomarkers -- BCL2, germinal center (GC) phenotype and CD5 -- in 121 DLBCL patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone. RESULTS CD5-positive patients showed significantly poorer event-free survival (EFS) and overall survival (OS) than CD5-negative patients (2-year EFS, 18% versus 73%, P < 0.001; 2-year OS, 45% versus 91%, P = 0.001). However, no significant difference in outcome according to BCL2 or GC phenotype was observed. Multivariate analysis revealed that CD5 expression was a significant prognostic factor for EFS [hazard ratio 14.2, 95% confidence interval (CI) 4.7-43.2] and OS (hazard ratio 20.3, 95% CI 3.6-114.4). CONCLUSIONS CD5 expression was the only significant prognostic factor among the biomarkers examined in this study. Further studies with larger numbers are warranted to confirm the prognostic significance of CD5 expression for patients with DLBCL receiving rituximab-containing chemotherapy.

Lymphomatoid gastropathy: a distinct clinicopathologic entity of self-limited pseudomalignant NK-cell proliferation

Diagnostic errors in distinguishing between malignant and reactive processes can cause serious clinical consequences. We report 10 cases of unrecognized self-limited natural killer-cell proliferation in the stomach, designated as lymphomatoid gastropathy (LyGa). This study included 5 men and 5 women (age, 46-75 years) without any gastric symptoms. Gastroscopy showed elevated lesion(s) (diameter, ∼ 1 cm). Histologically, medium-sized to large atypical cells diffusely infiltrated the lamina propria and, occasionally, the glandular epithelium. The cells were CD2(+/-), sCD3(-), cCD3(+), CD4(-), CD5(-), CD7(+), CD8(-), CD16(-), CD20(-), CD45(+), CD56(+), CD117(-), CD158a(-), CD161(-), T cell-restricted intracellular antigen-1(+), granzyme B(+), perforin(+), Epstein-Barr early RNA(-), T-cell receptor αβ(-), and T-cell receptor γδ(-). Analysis of the 16 specimens biopsied from 10 patients led to a diagnosis of lymphoma or suspected lymphoma in 11 specimens, gastritis for 1 specimen, adenocarcinoma for 1 specimen, and LyGa or suspected LyGa for 3 specimens. Most lesions underwent self-regression. Three cases relapsed, but none of the patients died. According to conventional histopathologic criteria, LyGa is probably diagnosed as lymphoma, especially as extranodal natural killer/T-cell lymphoma, nasal type. However, LyGa is recognized as a pseudomalignant process because of its clinical characteristics. The concept of LyGa should be well recognized.

Increased incidence of interstitial pneumonia by CHOP combined with rituximab

Several authors have reported interstitial pneumonia (IP) during rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy, while others have encountered Pneumocystis jirovecii pneumonia during rituximab-combined bi-weekly CHOP. Herein, we report that 13 of 90 (14%) patients developed IP during R-CHOP therapy, compared with none of 105 patients treated with CHOP alone as a historical control. There were no differences in baseline data between patients undergoing the two therapies. Among R-CHOP-treated patients, serum β-d-glucan was increased in 8 of 12 (75%) IP patients compared with none of 30 non-IP patients examined. In five IP patients who underwent sputum evaluation, two were positive for P. jirovecii by the polymerase chain reaction and another two were positive for Candida albicans. No other organisms were detected as causative pathogens. Treatment with steroids, sulfamethoxazole-trimethoprim (ST), and antifungals was effective. Our results suggest that R-CHOP raises the incidence of IP, possibly through increasing the susceptibility to P. jirovecii and fungal infection. The need for prophylactic antifungals and ST during R-CHOP should be evaluated by randomized controlled trials.

Prognostic impact of extranodal involvement in diffuse large B‐cell lymphoma in the rituximab era

Extranodal involvement is considered a poor prognostic factor for patients with diffuse large B‐cell lymphoma (DLBCL); however, the prognostic impact of specific sites of involvement has not been fully elucidated.

Phase I study of inotuzumab ozogamicin (CMC-544) in Japanese patients with follicular lymphoma pretreated with rituximab-based therapy

Inotuzumab ozogamicin (CMC‐544), an antibody‐targeted chemotherapeutic agent composed of an anti‐CD22 antibody conjugated to calicheamicin, a potent cytotoxic antibiotic, specifically targets the CD22 antigen present in >90% of B‐lymphoid malignancies, rendering it useful for treating patients with B‐cell non‐Hodgkin lymphoma (B‐NHL). This phase I study evaluated the safety, tolerability, efficacy, and pharmacokinetics of inotuzumab ozogamicin in Japanese patients. Eligible patients had relapsed or refractory CD22‐positive B‐NHL without major organ dysfunction. Inotuzumab ozogamicin was administered intravenously once every 28 days (dose escalation: 1.3 and 1.8 mg/m2). All 13 patients had follicular lymphoma, were previously treated with ≥1 rituximab‐alone or rituximab‐containing chemotherapy, and were enrolled into two dose cohorts (1.3 mg/m2, three patients; 1.8 mg/m2, 10 patients). No patient had dose‐limiting toxicities, and the maximum tolerated dose, previously determined in non‐Japanese patients (1.8 mg/m2), was confirmed. Drug‐related adverse events (AEs) included thrombocytopenia (100%), leukopenia (92%), lymphopenia (85%), neutropenia (85%), elevated AST (85%), anorexia (85%), and nausea (77%). Grade 3/4 drug‐related AEs in ≥15% patients were thrombocytopenia (54%), lymphopenia (31%), neutropenia (31%), and leukopenia (15%). The AUC and Cmax of inotuzumab ozogamicin increased dose‐dependently with pharmacokinetic profiles similar to non‐Japanese. Seven patients had complete response (CR, 54%) including unconfirmed CR, four patients had partial response (31%), and two patients had stable disease (15%). The overall response rate was 85% (11/13). Inotuzumab ozogamicin was well tolerated at doses up to 1.8 mg/m2 and showed preliminary evidence of activity in relapsed or refractory follicular lymphoma pretreated with rituximab‐containing therapy, warranting further investigations. This trial was registered in ClinicalTrials.gov (NCT00717925). (Cancer Sci 2010)

Soluble interleukin-2 receptor retains prognostic value in patients with diffuse large B-cell lymphoma receiving rituximab plus CHOP (RCHOP) therapy

BACKGROUND Soluble interleukin-2 receptor (SIL-2R) is known to be a prognostic parameter in patients with diffuse large B-cell lymphoma (DLBCL) receiving cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) therapy. However, its prognostic value has not been well known since the introduction of rituximab. PATIENTS AND METHODS We retrospectively evaluated the prognostic impact of SIL-2R in 228 DLBCL patients, comparing 141 rituximab-combined CHOP (RCHOP)-treated patients with 87 CHOP-treated patients as a historical control. RESULTS Patients with high serum SIL-2R showed significantly poorer event-free survival (EFS) and overall survival (OS) than patients with low SIL-2R in both the RCHOP group (2-year EFS, 66% versus 92%, P<0.001; OS, 82% versus 95%, P=0.005) and the CHOP group (2-year EFS, 40% versus 82%; OS, 61% versus 90%, both P<0.001). Multivariate analysis including the five parameters of International Prognostic Index (IPI) and two-categorized IPI revealed that SIL-2R was an independent prognostic factor for EFS and OS in the RCHOP group as well as in the CHOP group. CONCLUSIONS Our results demonstrate that SIL-2R retains its prognostic value in the rituximab era. The prognostic value of SIL-2R in DLBCL patients receiving rituximab-combined chemotherapy should be reassessed on a larger scale and by long-term follow-up.

Identification of CD20 C-Terminal Deletion Mutations Associated with Loss of CD20 Expression in Non-Hodgkin's Lymphoma

Purpose: Rituximab is commonly incorporated into CD20-positive B-cell lymphoma therapy to improve response and prognosis. With increasing use, resistance to rituximab is a continuing concern, but CD20 mutation as a cause of resistance has not previously been reported. Experimental Design: Freshly collected lymphoma cells from 50 patients with previously untreated or relapsed/resistant non-Hodgkins B-cell lymphomas (diffuse large B cell, n = 22; follicular, n = 7; mucosa associated lymphoid tissue, n = 16; chronic lymphocytic leukemia, n = 2; small lymphocytic lymphoma, n = 1; lymphoplasmacytic, n = 1; mantle cell lymphoma, n = 1) were assessed for CD20 expression by flow cytometry, and CD20 gene sequencing was done on extracted DNA. Results: CD20 mutations were found in 11 (22.0%) of 50 patients and could be grouped as C-terminal deletion (8.0%), early termination (10.0%), and extracellular domain (2.0%) or transmembrane domain (2.0%) mutations. The mean fluorescence intensity of CD20 on fresh lymphoma cells was significantly lower for the C-terminal deletion mutation [3.26; 95% confidence interval (95% CI), 0.09-6.89] compared with wild type (30.8; 95% CI, 22.4-39.2; P < 0.05). In contrast, early termination mutations did not show significant differences in CD20 expression compared with wild type (19.5; 95% CI, 10.7-28.4; P > 0.05). Conclusions: It is possible that C-terminal deletion mutations of CD20 may be related to relapse/resistance after rituximab therapy. These mutations should be examined in patients showing progression of disease after partial remission.