Bettina Altmann

Vitamin D Deficiency Impairs Rituximab-Mediated Cellular Cytotoxicity and Outcome of Patients With Diffuse Large B-Cell Lymphoma Treated With but Not Without Rituximab

PURPOSE To investigate the impact and mechanisms of vitamin D deficiency (VDD) on the outcome of elderly patients with diffuse large B-cell lymphoma (DLBCL). PATIENTS AND METHODS Three hundred fifty-nine pretreatment 25-hydroxyvitamin D3 (25[OH]D3) serum levels from the RICOVER-60 study (Six Versus Eight Cycles of Biweekly CHOP-14 With or Without Rituximab in Elderly Patients With Aggressive CD20+ B-Cell Lymphomas) and 63 from the RICOVER-noRTh study (an amendment to the RICOVER-60 study in which patients received six cycles of cyclophosphamide, doxorubicin, vincristine, and prednisone administered at an interval of 2 weeks plus two cycles of rituximab [R-CHOP-14], but without radiotherapy) were determined by chemoluminescent immunoassay. Rituximab-mediated cellular cytotoxicity (RMCC) was assessed by lactate dehydrogenase release assay of CD20+ Daudi cells. RESULTS RICOVER-60 patients with VDD (≤ 8 ng/mL) and vitamin D levels more than 8 ng/mL treated with rituximab had 3-year event-free survival (EFS) of 59% and 79% and 3-year overall survival (OS) of 70% and 82%, respectively. These differences were significant in a multivariable analysis adjusting for International Prognostic Index risk factors with a hazard ratio (HR) of 2.1 (P = .008) for EFS and 1.9 (P = .040) for OS. EFS was not significantly different in patients with vitamin D levels ≤ 8 or more than 8 ng/mL (HR, 1.2; P = .388) treated without rituximab. This was confirmed in an independent validation set of 63 RICOVER-noRTh patients. RMCC increased significantly (P < .001) in seven of seven individuals with VDD after substitution and normalization of their vitamin D levels. CONCLUSION VDD is a risk factor for elderly patients with DLBCL treated with R-CHOP. That VDD impairs RMCC and substitution improves RMCC strongly suggests that vitamin D substitution enhances rituximab efficacy, which must be confirmed in appropriately designed prospective trials addressing VDD and substitution not only in DLBCL, but also in malignancies treated with other antibodies, of which the major mechanism of action is antibody-dependent cellular cytotoxicity (eg, trastuzumab in breast cancer and cetuximab in colorectal cancer).

USP9X stabilizes XIAP to regulate mitotic cell death and chemoresistance in aggressive B‐cell lymphoma

The mitotic spindle assembly checkpoint (SAC) maintains genome stability and marks an important target for antineoplastic therapies. However, it has remained unclear how cells execute cell fate decisions under conditions of SAC‐induced mitotic arrest. Here, we identify USP9X as the mitotic deubiquitinase of the X‐linked inhibitor of apoptosis protein (XIAP) and demonstrate that deubiquitylation and stabilization of XIAP by USP9X lead to increased resistance toward mitotic spindle poisons. We find that primary human aggressive B‐cell lymphoma samples exhibit high USP9X expression that correlate with XIAP overexpression. We show that high USP9X/XIAP expression is associated with shorter event‐free survival in patients treated with spindle poison‐containing chemotherapy. Accordingly, aggressive B‐cell lymphoma lines with USP9X and associated XIAP overexpression exhibit increased chemoresistance, reversed by specific inhibition of either USP9X or XIAP. Moreover, knockdown of USP9X or XIAP significantly delays lymphoma development and increases sensitivity to spindle poisons in a murine Eμ‐Myc lymphoma model. Together, we specify the USP9X–XIAP axis as a regulator of the mitotic cell fate decision and propose that USP9X and XIAP are potential prognostic biomarkers and therapeutic targets in aggressive B‐cell lymphoma.

Obesity negatively impacts outcome in elderly female patients with aggressive B-cell lymphomas treated with R-CHOP: results from prospective trials of the German high grade non-Hodgkin's lymphoma trial group

To study if obesity is a risk factor in elderly patients (>60 years) with aggressive B‐cell lymphoma, the outcomes of 576 elderly patients treated with rituximab in the RICOVER‐60 trial were analysed in a retrospective study with regard to body mass index (BMI) and gender. Of the 576 patients, 1% had low body weight (BMI < 18·5), 38% were normal weight (18·5 ≤ BMI < 25), 42% were overweight (25 ≤ BMI < 30) and 19% were obese (BMI ≥ 30). Event‐free (EFS), progression‐free (PFS) and overall survival (OS) according to BMI showed no significant differences for all and for male patients. EFS (P = 0·041), PFS (P = 0·038) and OS (P = 0·031) were significantly better for female non‐obese patients. A multivariate analysis adjusted for International Prognostic Index risk factors confirmed these results, with the following hazard ratios (HR) for obesity (BMI ≥ 30) for EFS/PFS/OS: all patients – 1·4/1·4/1·4 (not significant); male patients – 1·2/1·2/1·0 (not significant) and female patients – 1·7 (P = 0·032)/1·9 (P = 0·022)/2·0 (P = 0·017). In conclusion, obesity is a risk factor that influences treatment outcome in elderly female patients with aggressive B‐cell lymphoma treated with R‐CHOP (rituximab + cyclophosphamide, doxorubicin, vincristine, prednisolone). The inferior outcomes in obese female patients may be due to faster rituximab clearance in obese females.

ANTI-INFECTIVE PROPHYLAXIS WITH ACICLOVIR AND COTRIMOXAZOLE SIGNIFICANTLY REDUCES THE RATE OF INFECTIONS AND THERAPY-ASSOCIATED DEATHS IN ELDERLY PATIENTS WITH DLBCL UNDERGOING R-CHOP IMMUNOCHEMOTHERAPY

lymphoma (DLBCL) is suboptimal, and the risk of central nervous system (CNS) progression is relatively high. We investigated the efficacy of dose‐dense chemoimmunotherapy and systemic CNS prophylaxis in two completed Nordic trials including patients less than 65 years with high‐risk DLBCL. We combined individual patient data from these studies to compare clinical outcome and prognostic factors in patients treated with CNS prophylaxis given in the beginning (CHIC) vs at the end (CRY‐04) of therapy. Patients and Methods: Inclusion criteria were age 18‐65 years, primary DLBCL or grade 3 follicular lymphoma without signs of CNS involvement, WHO performance score 0‐3, age‐adjusted International Prognostic Index (aaIPI 2‐3) and/or involvement of anatomical sites associated with an increased risk for CNS recurrence (e.g. testis, facial sinuses, orbita). In CRY‐04, six courses of R‐CHOEP14 were followed by HD‐Mtx and HD‐Ara‐C. In CHIC, treatment consisted of two courses of HD‐Mtx in combination with R‐CHOP14, followed by four courses of R‐CHOEP14 and one course of R‐HD‐AraC. In addition, liposomal AraC was administered intrathecally at courses 1, 3 and 5. Primary end points were failure free survival (FFS; disease progression, discontinuation of protocolled therapy due to toxicity, death from any cause) at 3 years and CNS progression rate at 1.5 years. Secondary end points included progression‐free survival (PFS; disease progression or death from any cause) and overall survival (OS) at 3 years. Results: Among 303 patients enrolled in the trials (CRY‐04, n = 160 and CHIC, n = 143), 295 (CRY‐04, n = 154 and CHIC, n = 139) met inclusion criteria and were evaluable for baseline characteristics and primary end points. Median age (54 and 56 years, p = 0.222), male/female ratio, stage and aaIPI scores were comparable in the two cohorts. Three‐year FFSwas 63% in CRY‐04 and 77% in CHIC (p = 0.018) after a median follow‐up of 5 and 3 years, respectively. Cumulative incidence rates of CNS progression were 5.0% and 2.4% (p = 0.22), and 3‐year OS 80% and 86% (p = 0.508), respectively. Treatment in the CHIC reduced the risk of systemic progression (aaIPI adjusted RR = 0.484, 95%CI 0.300‐ 0.782, p = 0.003). PFS benefit with CHIC vs CRY‐04 was observed across pre‐specified subgroups, and particularly in patients <60 years old (p = 0.007), with low proliferation index (Ki67 expression <75%, p = 0.029), and BCL2 positivity (p = 0.006). In the subsets of patients with available PET data, Deauville score 5 at the end of treatment was associated with increased rate of progression and death in both trials (p = 0.012). Only one out of 17 biopsies from PET positive lesions (DS 3‐5) contained vital lymphoma tissue. Conclusions: Our results derived from trial data with homogenous treatment support the use of HD‐Mtx in the beginning rather than at the end of therapy. Superior outcome seems to be primarily due to better systemic control of the disease. In addition, number of CNS recurrences is reduced.

Elevated serum free light chains do not predict outcome of elderly patients with aggressive CD20+ B‐cell lymphomas

Massimo Breccia Matteo Molica Fabio Efficace Clara Minotti Roberto Latagliata Robin Fo a Francesco Lo Coco Department of Cellular Biotechnologies and Hematology, Sapienza University, Data Center and Health Outcomes Research Unit, Italian Group for Adult Hematologic Diseases (GIMEMA), and Department of Biopathology, University Tor Vergata, and Laboratory of Neuro-Oncohematology, Santa Lucia Foundation, Rome, Italy E-mail: breccia@bce.uniroma1.it