Citations

Abstract Background: Lenalidomide (Revlimid®) has been reported to show activity in non-Hodgkin’s Lymphoma (NHL). However, prognostic factors predicting an individual patient’s response were unavailable. Aim: To investigate prognostic factors for lenalidomide response in patients with relapsed/refractory aggressive NHL. Methods: Patients with relapsed/refractory aggressive NHL with measurable disease ≥2 cm after at least 1 prior treatment regimen were eligible. Patients received 25 mg lenalidomide orally once daily on Days 1-21 every 28 days and continued therapy for 52 weeks as tolerated or until disease progression. Response and progression were evaluated using the IWLRC methodology. Univariate analyses using Fisher’s exact test and multivariate analyses using logistic regression were conducted to investigate associations of prognostic variables with response. Results: Forty-nine patients received lenalidomide oral monotherapy. The median age was 65 (23-86) and 24 were female. Histology was diffuse large B-cell lymphoma (n=26), follicular center lymphoma grade 3 (n=5), mantle cell lymphoma (n=15) and transformed (n=3). Median time from diagnosis was 2.7 (0.4-32) years and median number of prior treatment regimens was 4 (1-8). Forty-five (92%) of the patients had received prior rituximab and 63% were rituximab-refractory. Seventeen patients (35%) exhibited an objective response (2 complete responses, 4 complete responses unconfirmed and 11 partial responses). Response to lenalidomide was the same for patients who were refractory to rituximab (30%) and those who were not (31%). Three of 4 patients who were rituximab naive responded. Multivariate analysis including IPI, ECOG PS, stage, LDH, # of extranodal sites, age, sex, # of prior regimens and time from diagnosis identified only time since last rituximab and tumor burden as correlated with response. Response to lenalidomide was associated with low tumor burden (52% for <50 cm2v 0% for ≥50 cm2, P=0.033, odds ratio=10.9) and longer time from rituximab to lenalidomide treatment (52% for ≥ 230 days v 6% for <230 days, P=0.031, odds ratio=6.6). Rituximab depletes normal host B-cells and the kinetics for their loss and recovery are consistent with the timing of lenalidomide activity following rituximab. This may be a basis for this effect. However other tumor/host biological factors may also play a role. Patients with favorable values for both prognostic factors (N=24) had a 67% response rate [RR] compared to a 4% RR for patients with unfavorable values (N=25; P< 0.001) and a progression free survival (ongoing) of 7.5 months v 1.9 months. Although absolute lymphocyte count was not selected as a prognostic indicator of response in the multivariate setting, a trend was evident in the univariate analysis (42% for > 0.6 × 109/L v 9% for ≤0.6 × 109/L, P=0.071). Conclusion: Tumor burden and host immune competence may determine the response of relapsed/refractory aggressive NHL to lenalidomide monotherapy.

Abstract Background: In Hodgkin’s Disease (HD), G-CSF has been used to maintain maximum dose intensity by avoiding neutropenia and treatment delays. Pre-clinical data and anecdotal reports have shown an association between G-CSF administration and bleomycin pulmonary toxicity (BPT). This complication may cause access morbidity and have a detrimental impact on survival in this otherwise good prognosis population. We embarked on a retrospective analysis to determine if G-CSF increased the incidence of this complication or had an impact on outcomes. Methods: We reviewed all patients managed for HD at Mayo Clinic, Rochester, from January 1986 to February 2003. BPT was defined by the presence of pulmonary symptoms, bilateral interstitial infiltrates, and no evidence for an infectious etiology. Patients who received G-CSF support with one or more of their bleomycin-containing chemotherapy cycles were considered as being treated with G-CSF. Results: A retrospective review identified 141 patients with HD treated with a bleomycin-containing regimen. The mean age of patients at diagnosis was 34 years. Fifty four percent were males. The histology was nodular sclerosing in 85%. The Hasenclever index was 0 in 15%, 1 in 35%, 2 in 24%, 3 in 16%, 4 in 9%, and ≥ 5 in 1%. The G-CSF and non G-CSF groups were balanced for poor prognosis risk factors including Hasenclever index. Frontline chemotherapy included ABVD in 57%, MOPP-ABV(D) in 33%, COPP-ABV in 8%, BEACOPP in 3%, and Stanford V in 2%. Forty one percent of patients received radiation. The 5-year overall survival (OS) and progression free survival (PFS) for all patients were 87% and 79% respectively. G-CSF was administered to 52% (74/141) of patients. BPT occurred in 18% of patients (25/141). A higher rate of BPT was observed in patients receiving G-CSF, 26% (19/74) versus 9% (6/67) in non G-CSF patients (p=0.0141). In this population, G-CSF administration was the only factor associated with an increased risk of BPT. There was no difference between the two groups for BPT associated risk factors including radiation, bleomycin dose, renal insufficiency, smoking history, and underlying lung disease. Additionally these risk factors showed no correlation with the development of BPT. The mortality from BPT was 4.2% (6/141) in all patients and 24% (6/25) in patients who developed the pulmonary syndrome. Of the 6 patients who died acutely, 83% (5/6) received G-CSF. CR rates were equal between the G-CSF and non G-CSF groups at 92% and 94% respectively. Five year OS and PFS were equal between the G-CSF and non G-CSF groups at 82% versus 89% (p=0.473) and 74% versus 84% (p=0.152) respectively. Conclusion: G-CSF administration increases the incidence of pulmonary toxicity in HD patients treated with bleomycin based chemotherapy. The major impact was on treatment related morbidity as 5-year OS and PFS were equal between the G-CSF and non G-CSF groups.

Abstract Background: Bleomycin-containing chemotherapy regimens have become the mainstay of treatment in Hodgkin’s Disease (HD). The risk of bleomycin pulmonary toxicity (BPT) ranges from 0–46% and mortality rates range from 0–27%. Although there is no excepted standard treatment for BPT, corticosteroid treatment, withholding bleomycin from subsequent chemotherapy, and proceeding with a non-bleomycin containing regimen is the most common approach. We reviewed our experience to better delineate outcome and appropriate treatment in these patients. Methods: We reviewed all patients managed for HD at Mayo Clinic, Rochester, from January 1986 to February 2003. BPT was defined by the presence of pulmonary symptoms, bilateral interstitial infiltrates, and no evidence for an infectious etiology. Results: A retrospective review identified 141 patients with HD treated with a bleomycin-containing regimen. The mean age of patients at diagnosis was 34 years. Fifty four percent were males. The histology was nodular sclerosing in 85%. The Hasenclever index was 0 in 15%, 1 in 35%, 2 in 24%, 3 in 16%, 4 in 9%, and >5 in 1%. Frontline chemotherapy included ABVD in 57%, MOPP-ABV(D) in 33%, COPP-ABV in 8%, BEACOPP in 3%, and Stanford V in 2%. Forty one percent of patients received radiation. The 5-year overall survival (OS) and progression free survival (PFS) for all patients were 87% and 79% respectively. BPT was observed in 18% of patients (25/141). There was a significant decrease in OS, 63% in patients with BPT versus 90% in non-BPT patients at 5 years (p=0.0013). The mortality from BPT was 4.2% (6/141) in all patients and 24% (6/25) in patients who developed the pulmonary syndrome. These 6 patients all died within 9 months of their HD diagnosis from BPT. The Hasenclever index was 3 or less in 5 of these 6 patients. CR rates were equal at 91% and 93% in BPT and non-BPT patients respectively (p=0.299). Twenty two percent (31/141) of patients, either symptomatic or asymptomatic, had bleomycin omitted at any time from their regimen with no difference in OS or PFS, 83% versus 88% (p=0.369) and 82% versus 78% (p=0.853) respectively. The mean bleomycin dose was 84 mg/m2 (range of 20–180 mg/m2). Bleomycin dose had no impact on OS or PFS. In BPT patients subsequent non-bleomycin therapy included AVD 44%, MOPP-AV 31%, or no further chemotherapy 25%. The five-year OS was equal between the AVD and MOPP-AV groups at 91%. However in patients who received no further chemotherapy 5-year OS was 30% (p=0.0001). Conclusion: Bleomycin pulmonary toxicity (BPT) results in a significant decrease in OS survival at 5 years in patients being treated for Hodgkin’s Disease. In patients who do not die acutely from pulmonary toxicity both OS and PFS appear equal despite the omission of bleomycin.

Abstract Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease with recognized variability in clinical outcome, genetic features, and cells of origin. To date, transcriptional profiling has been used to highlight similarities between DLBCL tumor cells and normal B-cell subtypes and associate genes and pathways with unfavorable outcome. Given the genetic heterogeneity in DLBCL, there are likely to be subsets of tumors with different pathogenetic mechanisms and possible treatment targets. To identify DLBCL subtypes that were sufficiently robust to be captured by multiple methods, we analyzed the profiles of 176 newly diagnosed DLBCLs using three different clustering algorithms (hierarchical clustering (HC), self-organizing maps (SOM), and probabilistic clustering (PC)), the top 5% of genes with the highest reproducibility across duplicate samples and largest variation across patient tumors, and a resampling-based method (consensus clustering) that automatically selects the most stable numbers of clusters with each algorithm. Three discrete subsets of DLBCLs -- “Oxidative Phosphorylation” (OxPhos), “B-cell Receptor/Proliferation” and “Host Response” (HR) -- were identified, characterized using gene set enrichment analysis and confirmed in an independent series of newly diagnosed DLBCLs with available array data. There was an association between cluster membership and examined genetic abnormalities in DLBCL. BCL2 translocations were more common in the OxPhos cluster whereas BCL6 translocations were more frequent in the BCR/proliferation cluster. Translocations of either type were uncommon in the HR cluster. Patients with HR DLBCLs were also significantly younger than those with OxPhos or BCR/proliferation tumors; HR patients also had a significantly higher incidence of splenic and BM involvement. The unique characteristics of HR tumors - fewer known genetic abnormalities and prominent host immune and inflammatory cell transcripts -prompted us to assess host immune cells in study tumors using morphologic and immunohistochemical approaches. HR DLBCLs contained significantly higher numbers of morphologically distinct CD2+/CD3+ tumor-infiltrating lymphocytes and interdigitating S100+/GILT+/CD1a-/CD123- dendritic cells. The HR cluster shared features of histologically defined T-cell/histiocyte-richBCL, including fewer known genetic abnormalities, younger age at presentation and frequent splenic and bone marrow involvement. The current study identifies tumor microenvironment and host inflammatory response as defining features in DLBCL, provides insights into the nature of the host immune response in a major DLBCL subtype and suggests rational treatment targets in newly identified tumor groups.

Abstract Primary mediastinal large B-cell lymphoma (MLBCL) is a clinically distinct entity that typically presents as localized, sclerotic disease in young, female patients. We previously characterized the transcriptional profiles of MLBCLs and identified important shared features with a clinically related disorder, classical Hodgkin lymphoma (cHL) (Blood 102:3871, 2003). Given the documented role of the NFkB survival pathway in Hodgkin Reed-Sternberg cells, we previously assessed NFkB activation in MLBCL by determining the subcellular location of the c-REL subunit of the NFkB heterodimer with a 2-color immunofluoresence assay. In a small pilot MLBCL series, c-REL was localized to the nucleus in the majority of examined cases, consistent with NFkB activation. In the current study, we evaluated c-REL subcellular localization in an additional series of MLBCLs and DLBCLs using a broadly applicable immunoperoxidase method. 100% of MLBCLs exhibited nuclear c-REL staining whereas DLBCL c-REL subcellular localization was more variable. Thereafter, we analyzed the transcription profiles of the 34 MLBCLs and 176 DLBCLs for coordinate expression of NFkB target genes, using literature-curated NFkB target gene lists from three independent sources and gene set enrichment analysis (GSEA). MLBCL signatures exhibited significant enrichment of 2 of the 3 NFkB target gene sets. In addition, 32 NFkB target genes from the combined set were significantly more abundant in MLBCLs than DLBCLs (> 30% more abundant and > 99th percentile in permutation analysis). Similar results were obtained in an independent series of MLBCLs and DLBCLs with available gene expression profiles (J. Exp. Med. 198:851, 2003). To assess the role of c-REL amplification in NFkB activation in our lymphoma series, we compared c-REL amplification, c-REL subcellular localization and coordinate expression of the identified NFkB target genes and classified the DLBCLs according to putative cell of origin. The majority of c-REL amplifications (67%) were found in DLBCLs of germinal center (GC) subtype, consistent with the observation that c-REL is part of the described GC signature. However, most (71%) of the examined GC DLBCLs had cytoplasmic c-REL expression and the GC DLBCLs did not have increased expression of NFkB target genes. Taken together with the MLBCL analyses, these studies indicate that: 1) NFkB is consistently activated in MLBCL; 2) c-REL amplification is not closely associated with NFkB activation in large cell lymphomas (LCLs); and 3) NFkB activation in LCL subtypes does not require amplification of the c-REL locus.

Background Frailty increases risk for complications after total joint arthroplasty (TJA). Whether this association is influenced by anesthetic administered is unknown. We hypothesized that use of neuraxial (spinal or epidural) anesthesia is associated with better outcomes compared with general anesthesia, and that the effect of anesthesia type on outcomes differs by frailty status. Methods This single-institution cohort study included all patients (≥50 years) from January 2005 through December 2016 undergoing unilateral, primary and revision TJA. Using multivariable Cox regression, we assessed relationships between anesthesia type, a preoperative frailty deficit index (FI) categorized as non-frail (FI <0.11), vulnerable (FI 0.11 to 0.20), and frail (FI >0.20), and complications (mortality, infection, wound complications/hematoma, reoperation, dislocation, and periprosthetic fracture) within 1 year after surgery. Interactions between anesthesia type and frailty were tested, and stratified models were presented when an interaction (p<0.1) was observed. Results Among 18 458 patients undergoing TJA, more patients were classified as frail (21.5%) and vulnerable (36.2%) than non-frail (42.3%). Anesthesia type was not associated with complications after adjusting for age, joint, and revision type. However, in analyzes stratified by frailty, vulnerable patients under neuraxial block had less mortality (HR=0.49; 95% CI 0.27 to 0.89) and wound complications/hematoma (HR=0.71; 95% CI 0.55 to 0.90), whereas no difference in risk by anesthesia type was observed among patients found non-frail or frail. Conclusions Neuraxial anesthesia use among vulnerable patients was associated with improved survival and less wound complications. Calculating preoperative frailty prior to TJA informs perioperative risk and enhances shared-decision making for selection of anesthesia type.

Abstract Background: Invasive lobular carcinoma (ILC) is typically strongly hormone receptor (HR) positive, with unique characteristics. It has been shown to have poor response to neoadjuvant chemotherapy (NAC) and recent studies describe the benefits of neoadjuvant endocrine therapy (NET). We sought to determine how the primary management strategy in ILC has changed over time, and the impact of ILC tumor biology on its management. Specifically, we hypothesized that use of NAC has decreased, while NET use increased. Additionally, we investigated whether NET is associated with higher rates of breast conservation surgery (BCS) than other primary management strategies. Methods: We queried the NCDB from 2010-2016 and identified all women with ILC who underwent surgical therapy. Patients with stage IV disease were excluded. First course of treatment was classified as: NAC (chemotherapy starting 31-365 days before surgery), NET (short course defined as 7-30 days before surgery; long course defined as 31-365 days before surgery), and primary surgery. Tumors were considered HR+ if they were estrogen receptor and/or progesterone receptor positive. Trends over time in first treatment strategy were compared using Cochrane-Armitage tests. The association between first treatment strategy and use of BCS was assessed using multivariable logistic regression. Results: Among 79,709 women with ILC, 94.0% were HR+/HER2-, 4.7% were HER2+, and 1.3% were triple negative. The most common primary treatment strategy was surgery (92.3%), but the percent undergoing systemic treatment before surgery increased from 7.1% in 2010 to 8.8% in 2016 (p&lt;0.001). The use of NAC increased significantly over the study period in patients with triple negative (12.1% in 2010 to 23.7% in 2016, p=0.007) and HER2+ (12.2% in 2010 to 29.1% in 2016, p&lt;0.001) ILC tumors. Among patients with HR+/HER2- tumors, however, the use of NAC decreased from 4.7% in 2010 to 4.2% in 2016, p=0.007, and the use of long course NET increased significantly, from 1.6% in 2010 to 2.7% in 2016, p&lt;0.001. The use of short course NET in HR+/HER2- patients remained very low over the study period (0.4% in 2010 to 0.5% in 2016, p=0.14). Analyzing the HR+/HER2- subset, 48.4% (295/609) of patients undergoing long course NET with a cT2 tumor underwent BCS compared to 35.3% for primary surgery, 27.3% for NAC, and 24.8% for short course NET (p&lt;0.001). Long course NET was also associated with a higher BCS rate in cT3/cT4 tumors: 22.6% BCS for long course NET, 8.3% BCS for primary surgery, 9.6% BCS for NAC, 7.8% BCS for short course NET (p&lt;0.001). In multivariable analysis including a clinical T category by treatment interaction, long course NET was the only treatment that was associated with higher rates of BCS compared to primary surgery in cT2 (OR 1.51, 95% CI: 1.27-1.79) tumors, while both long course NET (OR 2.52, 95% CI: 1.97-3.22) and NAC (OR 1.54, 95% CI: 1.27-1.88) were associated with increased use of BCS in cT3/cT4 tumors, see Table. Conclusions: The primary management of ILC is slowly evolving over time with a decrease in primary surgery. NAC use has increased appropriately in tumor subtypes with greatest potential benefit (i.e., triple negative or HER2 positive). In HR+/HER2- disease, NAC use has decreased, however NET use has increased and in cT2+ tumors NET was associated with higher rates of BCS. Variable1Odds ratio for BCS (95% CI)p-valueAge, per 1 year increase1.04 (1.03-1.04)&lt;0.001Charlson-Deyo comorbidity score&lt;0.0011 vs 00.86 (0.82-0.90)2+ vs 00.72 (0.66-0.79)Grade2&lt;0.001Moderately/Poorly vsWell Differentiated0.91 (0.88-0.95)Clinical N category2&lt;0.001cN1 vs cN00.49 (0.46-0.52)cN2/cN3 vs cN00.41 (0.35-0.47)Multicentric&lt;0.001Yes vs No0.36 (0.34-0.38)Primary treatment by clinical T category2&lt;0.001For cT1 tumorsLong course NET vs primary surgery0.65 (0.51-0.83)NAC vs Primary surgery0.31 (0.24-0.41)Short course NET vs primary surgery0.85 (0.58-1.24)For cT2 tumorsLong course NET vs primary surgery1.51 (1.27-1.79)NAC vs primary surgery1.04 (0.90-1.20)Short course NET vs primary surgery0.53 (0.33-0.85)For cT3/cT4 tumorsLong course NET vs primary surgery2.52 (1.97-3.22)NAC vs primary surgery1.54 (1.27-1.88)Short course NET vs primary surgery0.79 (0.31-2.02)1Model additionally adjusted for year of diagnosis, race, ethnicity, and insurance status.2Unknown level included in the model but not reported Citation Format: Rita A Mukhtar, Tanya L. Hoskin, Elizabeth B. Habermann, Judy C. Boughey. Trends in primary management of invasive lobular carcinoma: An analysis of the National Cancer Database (NCDB) [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-13-01.

OBJECTIVE The nature of the volume-outcome relationship in cases with severe traumatic brain injury (TBI) remains unclear, with considerable interhospital variation in patient outcomes. The objective of this study was to understand the state of the volume-outcome relationship at different levels of trauma centers in the United States. METHODS The authors queried the National Trauma Data Bank for the years 2007–2014 for patients with severe TBI. Case volumes for each level of trauma center organized into quintiles (Q1–Q5) served as the primary predictor. Analyzed outcomes included in-hospital mortality, total hospital length of stay (LOS), and intensive care unit (ICU) stay. Multivariable regression models were performed for in-hospital mortality, overall complications, and total hospital and ICU LOSs to adjust for possible confounders. The analysis was stratified by level designation of the trauma center. Statistical significance was established at p < 0.001 to avoid a type I error due to a large sample size. RESULTS A total of 122,445 patients were included. Adjusted analysis did not demonstrate a significant relationship between increasing hospital volume of severe TBI cases and in-hospital mortality, complications, and nonhome hospital discharge disposition among level I–IV trauma centers. However, among level II trauma centers, hospital LOS was longer for the highest volume quintile (adjusted mean difference [MD] for Q5: 2.83 days, 95% CI 1.40–4.26 days, p < 0.001, reference = Q1). For level III and IV trauma centers, both hospital LOS and ICU LOS were longer for the highest volume quintile (adjusted MD for Q5: LOS 4.6 days, 95% CI 2.3–7.0 days, p < 0.001; ICU LOS 3.2 days, 95% CI 1.6–4.8 days, p < 0.001). CONCLUSIONS Higher volumes of severe TBI cases at a lower level of trauma center may be associated with a longer LOS. These results may assist policymakers with target interventions for resource allocation and point to the need for careful prehospital decision-making in patients with severe TBI.

Background: Evidence-based, procedure-specific guidelines for prescribing opioids are urgently needed to optimize pain relief while minimizing excessive opioid prescribing and potential opioid diversion in our communities. A multidisciplinary panel at our institution recently developed procedure-specific guidelines for discharge opioid prescriptions for common orthopaedic surgical procedures. The purpose of this study was to evaluate postoperative opioid prescription quantities, variability, and 30-day refill rates before and after implementation of the guidelines. Methods: This retrospective cohort study was conducted at a single academic institution from December 2016 to March 2018. Guidelines were implemented on August 1, 2017, with a recommended maximum opioid prescription quantity for 14 common orthopaedic procedures. Patients who underwent these 14 procedures during the period of December 2016 to May 2017 made up the pre-guideline cohort (n = 2,223), and patients who underwent these procedures from October 2017 to March 2018 made up the post-guideline cohort (n = 2,300). Opioid prescription quantities were reported as oral morphine equivalents (OME), with medians and interquartile ranges (IQRs). Four levels were established for recommended prescription maximums, ranging from 100 to 400 OME. Results: In the pre-guideline cohort, the median amount of prescribed opioids across all procedures was 600 OME (IQR, 390 to 863 OME), which decreased by 38% in the post-guideline period, to a median of 375 OME (IQR, 239 to 400 OME) in the post-guideline cohort (p < 0.001). The 30-day refill rate did not change significantly, from a rate of 24% in the pre-guideline cohort to 25% in the post-guideline cohort (p = 0.43). Multivariable analysis demonstrated that guideline implementation was the factor most strongly associated with prescriptions exceeding guideline maximums (odds ratio [OR] = 9.9; p < 0.001). Age groups of <80 years (OR = 2.0 to 2.4; p < 0.001) and males (OR = 1.2; p = 0.025) were also shown to have higher odds of exceeding guideline maximums. Conclusions: Procedure-specific guidelines are capable of substantially decreasing opioid prescription amounts and variability. Furthermore, the absence of change in refill rates suggests that pain control remains similar to pre-guideline prescribing practices. Evidence-based guidelines are a readily employable solution that can drive rapid change in practice and enhance the ability of orthopaedic surgeons to provide responsible pain management.

7559 Background: Waldenström macroglobulinemia (WM) is a rare indolent lymphoma commonly treated with rituximab (R)-based therapy. The use of rituximab maintenance (mR) in WM is controversial. We present a case-control study of patients (pts) with WM treated with mR. Methods: Pts evaluated at Mayo Clinic, Rochester with active WM that received mR between 1/2000 & 6/2018 were included. Cases comprised pts who received mR following R-based induction as primary therapy. Cases were matched based on the time of diagnosis in 1:2 ratio with a control group treated with R-based primary induction therapy without mR. Time to event analyses were performed from initiation of R-based induction. Results: Of 776 pts with active WM, 42 (5%) cases received mR and 84 pts were selected as controls. The median follow-up and the proportion of high risk pts were comparable between the two cohorts (Table). Pts in the mR cohort show a trend toward longer time to next therapy (TTNT) and a significantly longer overall survival (OS) compared to the control group (Table). The R-based induction therapies were comparable in the two cohorts (p = 0.6). Median duration of mR was 1.9 yrs (95% CI 1.6-2) and mR was used most frequently every (q) 2 (range 1-6) months. Of the 42 mR pts, 25 (60%) received an R-based combination for induction and 17 (40%) received R monotherapy as induction. Five (12%) pts discontinued mR due to toxicity, infections were reported in 13 pts (31%) during mR therapy and 3 pts (7%) received IVIg infusions for recurrent infections. Conclusions: R-based induction followed by mR demonstrates a longer OS in WM compared to R-treated control population not receiving mR, albeit at a high rate of infections. Despite limitations of a retrospective study, with a heterogeneously treated cohort, these data add to the body of literature supporting Rituximab maintenance. Results from an ongoing randomized controlled trial are awaited. [Table: see text]