Ars2-containing bispecific, Fab- and IgG1-format BAR-bodies to target DLBCL cells.

Despite recent advances in the therapy of diffuse large B-cell lymphoma, not otherwise specified (DLBCL), around 30% of patients develop refractory disease or relapse after first-line treatment. Recently, Ars2 was reported as the auto-antigenic target of the B-cell receptor (BCR) in approximately 25% of activated B-cell DLBCL cases. Ars2 could be used to specifically target B cells expressing Ars2-reactive BCRs. However, the optimal therapeutic format to integrate Ars2 into has yet to be determined. To mimic therapeutic antibody formats, Ars2-containing bispecific and IgG1-like constructs (BCR antigens for reverse [BAR]-bodies) were developed. Two bispecific BAR-bodies connecting single-chain antibodies against CD16 or CD3 to the BCR-binding epitope of Ars2 were constructed. Both constructs showed strong binding to U2932 cells and induced effector cell-dependent and selective cytotoxicity against U2932 cells of up to 44% at concentrations of 20 µg/ml. Additionally, IgG1-format Ars2 BAR-bodies were constructed by replacing the variable heavy- and light-chain regions of a full-length antibody with the Ars2 epitope. IgG1-format Ars2 BAR-bodies also bound selectively to U2932 and OCI-Ly3 cells and induced selective cytotoxicity of up to 60% at 10 µg/ml. In conclusion, Ars2-containing bispecific and IgG1-format BAR-bodies both are new therapeutic formats to target DLBCL cells.

B-cell receptors of EBV-negative Burkitt lymphoma bind modified isoforms of autoantigens.

Burkitt lymphoma (BL) represents the most aggressive B-cell-lymphoma. Beside the hallmark of IG-MYC-translocation, surface B-cell receptor (BCR) is expressed, and mutations in the BCR pathway are frequent. Coincidental infections in endemic BL, and specific extra-nodal sites suggest antigenic triggers. To explore this hypothesis, BCRs of BL cell lines and cases were screened for reactivities against a panel of bacterial lysates, lysates of Plasmodium falciparum, a custom-made virome array and against self-antigens, including post-translationally modified antigens. An atypically modified, SUMOylated isoform of Bystin, that is, SUMO1-BYSL was identified as the antigen of the BCR of cell line CA46. SUMO1-BYSL was exclusively expressed in CA46 cells with K139 as site of the SUMOylation. Secondly, an atypically acetylated isoform of HSP40 was identified as the antigen of the BCR of cell line BL41. K104 and K179 were the sites of immunogenic acetylation, and the acetylated HSP40 isoform was solely present in BL41 cells. Functionally, addition of SUMO1-BYSL and acetylated HSP40 induced BCR pathway activation in CA46 and BL41 cells, respectively. Accordingly, SUMO1-BYSL-ETA' immunotoxin, produced by a two-step intein-based conjugation, led to the specific killing of CA46 cells. Autoantibodies directed against SUMO1-BYSL were found in 3 of 14 (21.4%), and autoantibodies against acetylated HSP40 in 1/14(7.1%) patients with sporadic Burkitt-lymphoma. No reactivities against antigens of the infectious agent spectrum could be observed. These results indicate a pathogenic role of autoreactivity evoked by immunogenic post-translational modifications in a subgroup of sporadic BL including two EBV-negative BL cell lines.

KIR2DS1-HLA-C status as a predictive marker for benefit from rituximab: a post-hoc analysis of the RICOVER-60 and CLL8 trials.

BACKGROUND: The addition of rituximab to chemotherapy has substantially improved outcomes for patients with B-cell malignancies. The mechanisms of action of rituximab include activation of natural killer cells. Killer-cell immunoglobulin-like receptors (KIRs) mediate natural killer cell function through interaction with HLA. We evaluated the clinical impact of KIR-HLA genotypes on rituximab-containing therapy. METHODS: For this post-hoc analysis, we used data from the RICOVER-60 trial (NCT00052936) as the discovery cohort and the CLL8 trial (NCT00281918) as the validation cohort. RICOVER-60 included patients aged 61-80 years with aggressive B-cell lymphoma treated with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) with or without rituximab. CLL8 included patients aged 30-81 years with chronic lymphocytic leukaemia treated with chemotherapy (fludarabine and cyclophosphamide; FC) with or without rituximab. We evaluated the KIR and HLA-C status of 519 patients with available blood samples in the RICOVER-60 trial and the KIR2DS1 and HLA-C status of 549 patients with available blood samples in the CLL8 trial, and evaluated their associations with event-free survival (RICOVER-60), progression-free survival, and overall survival (RICOVER-60 and CLL8). FINDINGS: In the RICOVER-60 trial, 201 (39%) patients were positive for KIR2DS1, 79 (15%) were homozygous for HLA-C2, and 36 (7%) were positive for KIR2DS1 and homozygous for HLA-C2. In the CLL8 trial, 206 (38%) patients were positive for KIR2DS1, 75 (14%) were homozygous for HLA-C2, and 26 (5%) were positive for KIR2DS1 and homozygous for HLA-C2. In the RICOVER-60 trial, both KIR2DS1 and HLA-C status were identified as independent risk factors for survival. KIR2DS1 positivity, homozygosity for HLA-C2, and subsequent KIR2DS1-HLA-C status were associated with adverse clinical outcome in patients receiving rituximab-containing therapy (event-free survival for patients with KIR2DS1-HLA-C2/C2 vs all other patients, HR 2·6 [95% CI 1·4-4·7], p=0·0015; progression-free survival, 2·7 [1·5-5·1], p=0·0013; overall survival, 2·8 [1·5-5·4], p=0·0016) but not in patients receiving CHOP chemotherapy only (event-free survival, 0·9 [0·5-1·7], p=0·85; progression-free survival, 1·1 [0·6-2·0], p=0·81; overall survival, 1·2 [0·6-2·4], p=0·53). A significant interaction between KIR2DS1-HLA-C status and rituximab was observed (p=0·018 for event-free survival and p=0·034 for progression-free survival). In contrast to all other patients, those positive for KIR2DS1 and homozygous for HLA-C2 did not benefit from adding rituximab to CHOP chemotherapy (event-free survival, 1·9 [0·8-4·6], p=0·16; progression-free survival, 1·4 [0·6-3·4], p=0·48; overall survival, 1·6 [0·6-4·3], p=0·33). In the CLL8 trial, KIR2DS1-HLA-C status was confirmed as a predictive marker for benefit from rituximab therapy (p=0·024 for the interaction of KIR2DS1-HLA-C status and rituximab regarding progression-free survival). In contrast to all other patients, those positive for KIR2DS1 and homozygous for HLA-C2 did not benefit from adding rituximab to FC chemotherapy (progression-free survival, 2·1 [0·9-4·9], p=0·094; overall survival, 2·6 [0·5-12·7], p=0·21). INTERPRETATION: Assessment of KIR2DS1 and HLA-C genotype might identify patients who would not benefit from rituximab, thereby allowing alternative therapies to be given. Further validation of these findings in prospective clinical trials is needed. FUNDING: F Hoffman La Roche.

The B-cell Receptor Autoantigen LRPAP1 Can Replace Variable Antibody Regions to Target Mantle Cell Lymphoma Cells.

Mantle cell lymphoma (MCL) accounts for 5%-10% of all lymphomas. The disease's genetic hallmark is the t(11; 14)(q13; q32) translocation. In younger patients, the first-line treatment is chemoimmunotherapy followed by autologous stem cell transplantation. Upon disease progression, novel and targeted agents such as the BTK inhibitor ibrutinib, the BCL-2 inhibitor venetoclax, or the combination of both are increasingly used, but even after allogeneic stem cell transplantation or CAR T-cell therapy, MCL remains incurable for most patients. Chronic antigenic stimulation of the B-cell receptor (BCR) is thought to be essential for the pathogenesis of many B-cell lymphomas. LRPAP1 has been identified as the autoantigenic BCR target in about 1/3 of all MCLs. Thus, LRPAP1 could be used to target MCL cells, however, there is currently no optimal therapeutic format to integrate LRPAP1. We have therefore integrated LRPAP1 into a concept termed BAR, for B-cell receptor antigens for reverse targeting. A bispecific BAR body was synthesized consisting of the lymphoma-BCR binding epitope of LRPAP1 and a single chain fragment targeting CD3 or CD16 to recruit/engage T or NK cells. In addition, a BAR body consisting of an IgG1 antibody and the lymphoma-BCR binding epitope of LRPAP1 replacing the variable regions was synthesized. Both BAR bodies mediated highly specific cytotoxic effects against MCL cells in a dose-dependent manner at 1-20 µg/mL. In conclusion, LRPAP1 can substitute variable antibody regions in different formats to function in a new therapeutic approach to treat MCL.

FDG PET/CT to detect bone marrow involvement in the initial staging of patients with aggressive non-Hodgkin lymphoma: results from the prospective, multicenter PETAL and OPTIMAL>60 trials.

PURPOSE: Fluorine-18 fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG PET/CT) is the standard for staging aggressive non-Hodgkin lymphoma (NHL). Limited data from prospective studies is available to determine whether initial staging by FDG PET/CT provides treatment-relevant information of bone marrow (BM) involvement (BMI) and thus could spare BM biopsy (BMB). METHODS: Patients from PETAL (NCT00554164) and OPTIMAL>60 (NCT01478542) with aggressive B-cell NHL initially staged by FDG PET/CT and BMB were included in this pooled analysis. The reference standard to confirm BMI included a positive BMB and/or FDG PET/CT confirmed by targeted biopsy, complementary imaging (CT or magnetic resonance imaging), or concurrent disappearance of focal FDG-avid BM lesions with other lymphoma manifestations during immunochemotherapy. RESULTS: Among 930 patients, BMI was detected by BMB in 85 (prevalence 9%) and by FDG PET/CT in 185 (20%) cases, for a total of 221 cases (24%). All 185 PET-positive cases were true positive, and 709 of 745 PET-negative cases were true negative. For BMB and FDG PET/CT, sensitivity was 38% (95% confidence interval [CI]: 32-45%) and 84% (CI: 78-88%), specificity 100% (CI: 99-100%) and 100% (CI: 99-100%), positive predictive value 100% (CI: 96-100%) and 100% (CI: 98-100%), and negative predictive value 84% (CI: 81-86%) and 95% (CI: 93-97%), respectively. In all of the 36 PET-negative cases with confirmed BMI patients had other adverse factors according to IPI that precluded a change of standard treatment. Thus, the BMB would not have influenced the patient management. CONCLUSION: In patients with aggressive B-cell NHL, routine BMB provides no critical staging information compared to FDG PET/CT and could therefore be omitted. TRIAL REGISTRATION: NCT00554164 and NCT01478542.

VEGFR2 and VEGFA polymorphisms are not associated with an inferior prognosis in Caucasian patients with aggressive B-cell lymphoma.

PURPOSE: Previous published data showed an impact of single-nucleotide polymorphisms in the VEGF A and VEGFR2 genes on the survival of patients with various malignancies, among others diffuse large B-cell lymphoma (DLBCL). PATIENTS AND METHODS: We investigated the role of four VEGF-A and two VEGFR-2 gene polymorphisms on the outcome of 273 patients with diffuse large B-cell lymphoma who were treated with R-CHOP within a prospective, randomized trial of the German High-Grade Non-Hodgkin Lymphoma Study Group (DSHNHL). The genomic DNA samples were analyzed using commercial DNA Probes (Applied Biosystems, USA) to detect single-nucleotide polymorphisms in the VEGF A rs699947, rs1570360, rs2010963, rs3025039 and rs1870377, and rs2305948 in the VEGFR2 receptor. Hundred healthy blood donors served as a control. RESULTS: There was no difference between the SNP allele frequencies in lymphoma patients compared to the control group for all investigated SNPs. None of the investigated SNPs was significantly associated with EFS or OS. After adjusting for the International Prognostic Index risk factors in a multivariate analysis, these results could be confirmed. CONCLUSION: Single-nucleotide polymorphisms of the VEGF and VEGFR2 were not associated with a worse outcome in Caucasian patients with DLBCL.

Identification of the atypically modified autoantigen Ars2 as the target of B-cell receptors from activated B-cell-type diffuse large B-cell lymphoma.

It has been suggested that B-cell receptor (BCRs) stimulation by specific antigens plays a pathogenic role in diffuse large B-cell lymphoma (DLBCL). Here, it was the aim to screen for specific reactivities of DLBCL-BCRs in the spectrum of autoantigens and antigens of infectious origin. Arsenite resistance protein 2 (Ars2) was identified as the BCR target of 3/5 ABC-type DLBCL cell lines and 2/11 primary DLBCL cases. Compared to controls, Ars2 was hypo-phosphorylated exclusively in cases and cell lines with Ars2-specific BCRs. In a validation cohort, hypo-phosphorylated Ars2 was found in 8/31 ABC-type, but only 1/20 germinal center B cell (GBC)-like type DLBCL. Incubation with Ars2 induced BCR-pathway activation and increased proliferation, while an Ars2/ETA-toxin conjugate induced killing of cell lines with Ars2-reactive BCRs. Ars2 appears to play a role in a subgroup of ABC-type DLBCLs. Moreover, transformed DLBCL lines with Ars2-reactive BCRs still show growth advantage after incubation with Ars2. These results provide knowledge about the pathogenic role of a specific antigen stimulating the BCR pathway in DLCBL.

Alemtuzumab plus CHOP versus CHOP in elderly patients with peripheral T-cell lymphoma: the DSHNHL2006-1B/ACT-2 trial.

PTCL patients exhibit poor survival with existing treatments. We investigated the efficacy of CHOP combined with alemtuzumab in 116 PTCL patients age 61-80 in an open-label, randomized phase 3 trial. Alemtuzumab was given on day 1, to a total of 360 mg in 21 patients, or 120 mg in 37. Hematotoxicity was increased with A-CHOP resulting in more grade ≥3 infections (40% versus 21%) and 4 versus 1 death due to infections, respectively. CR/CRu rate was 60% for A-CHOP and 43% for CHOP, and OR rate was 72% and 66%, respectively. Three-year-EFS, PFS and OS were 27% [15%-39%], 28% [15%-40%], and 37% ([23%-50%] for A-CHOP, and 24% [12%-35%], 29% [17%-41%], and 56% [44%-69%] for CHOP, respectively, showing no significant differences. Multivariate analyses, adjusted for strata and sex confirmed these results (hazard ratio HREFS: 0.7 ([95% CI: 0.5-1.1]; p = 0.094), HRPFS: 0.8 ([95% CI: 0.5-1.2]; p = 0.271), HROS: 1.4 ([95% CI: 0.9-2.4]; p = 0.154). The IPI score was validated, and male sex (HREFS 2.5) and bulky disease (HREFS 2.2) were significant risk factors for EFS, PFS, and OS. Alemtuzumab added to CHOP increased response rates, but did not improve survival due to treatment-related toxicity.

Integration of the B-Cell Receptor Antigen Neurabin-I/SAMD14 Into an Antibody Format as New Therapeutic Approach for the Treatment of Primary CNS Lymphoma.

Recently, neurabin-I and SAMD14 have been described as the autoantigenic target of approximately 66% of B-cell receptors (BCRs) of primary central nervous system lymphomas (PCNSL). Neurabin-I and SAMD14 share a highly homologous SAM domain that becomes immunogenic after atypical hyper-N-glycosylation (SAMD14 at ASN339 and neurabin-I at ASN1277). This post-translational modification of neurabin-I and SAMD14 seems to lead to a chronic immune reaction with B-cell receptor activation contributing to lymphoma genesis of PCNSLs. The selective tropism of PCNSL to the CNS corresponds well to the neurabin-I and SAMD14 protein expression pattern. When conjugated to Pseudomonas Exotoxin A (ETA´), the PCNSL reactive epitope exerts cytotoxic effects on lymphoma cells expressing a SAMD14/neurabin-I reactive BCR. Thus, the reactive epitopes of SAMD14/neurabin-I might be useful to establish additional therapeutic strategies against PCNSL. To test this possibility, we integrated the PCNSL-reactive epitope of SAMD14/neurabin-I into a heavy-chain-only Fab antibody format in substitution of the variable region. Specific binding of the prokaryotically produced SAMD14/neurabin-I Fab-antibody to lymphoma cells and their internalization were determined by flow cytometry. Since no established EBV-negative PCNSL cell line exists, we used the ABC-DLBCL cell lines OCI-Ly3 and U2932, which were transfected to express a SAMD14/neurabin-I reactive BCR. The SAMD14/neurabin-I Fab antibody bound specifically to DLBCL cells expressing a BCR with reactivity to SAMD14/neurabin-I and not to unmanipulated DLBCL cell lines. Eukaryotically produced full-length IgG antibodies are well established as immunotherapy format. Therefore, the PCNSL-reactive epitope of SAMD14/neurabin-I was cloned into a full-length IgG1 format replacing the variable domains of the light and heavy chains. The IgG1-format SAMD14/neurabin-I construct was found to specifically bind to target lymphoma cells expressing a SAMD14/neurabin-I reactive B cell receptor. In addition, it induced dose-dependent relative cytotoxicity against these lymphoma cells when incubated with PBMCs. Control DLBCL cells are not affected at any tested concentration. When integrated into the Fab-format and IgG1-format, the PCNSL-reactive epitope of SAMD14/neurabin-I functions as B-cell receptor Antigen for Reverse targeting (BAR). In particular, the IgG1-format BAR-body approach represents a very attractive therapeutic format for the treatment of PCNSLs, considering its specificity against SAMD14/neurabin-I reactive BCRs and the well-known pharmacodynamic properties of IgG antibodies.

Lymphocyte predominant cells detect Moraxella catarrhalis-derived antigens in nodular lymphocyte-predominant Hodgkin lymphoma.

Nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL) is a rare lymphoma of B-cell origin with frequent expression of functional B-cell receptors (BCRs). Here we report that expression cloning followed by antigen screening identifies DNA-directed RNA polymerase beta' (RpoC) from Moraxella catarrhalis as frequent antigen of BCRs of IgD+ LP cells. Patients show predominance of HLA-DRB1*04/07 and the IgVH genes encode extraordinarily long CDR3s. High-titer, light-chain-restricted anti-RpoC IgG1/κ-type serum-antibodies are additionally found in these patients. RpoC and MID/hag, a superantigen co-expressed by Moraxella catarrhalis that is known to activate IgD+ B cells by binding to the Fc domain of IgD, have additive activation effects on the BCR, the NF-κB pathway and the proliferation of IgD+ DEV cells expressing RpoC-specific BCRs. This suggests an additive antigenic and superantigenic stimulation of B cells with RpoC-specific IgD+ BCRs under conditions of a permissive MHC-II haplotype as a model of NLPHL lymphomagenesis, implying future treatment strategies.

Four versus six cycles of CHOP chemotherapy in combination with six applications of rituximab in patients with aggressive B-cell lymphoma with favourable prognosis (FLYER): a randomised, phase 3, non-inferiority trial.

BACKGROUND: Six cycles of R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone) are the standard treatment for aggressive B-cell non-Hodgkin lymphoma. In the FLYER trial, we assessed whether four cycles of CHOP plus six applications of rituximab are non-inferior to six cycles of R-CHOP in a population of patients with B-cell non-Hodgkin lymphoma with favourable prognosis. METHODS: This two-arm, open-label, international, multicentre, prospective, randomised phase 3 non-inferiority trial was done at 138 clinical sites in Denmark, Israel, Italy, Norway, and Germany. We enrolled patients aged 18-60 years, with stage I-II disease, normal serum lactate dehydrogenase concentration, ECOG performance status 0-1, and without bulky disease (maximal tumour diameter <7·5 cm). Randomisation was computer-based and done centrally in a 1:1 ratio using the Pocock minimisation algorithm after stratification for centres, stage (I vs II), and extralymphatic sites (no vs yes). Patients were assigned to receive either six cycles of R-CHOP or four cycles of R-CHOP plus two doses of rituximab. CHOP comprised cyclophosphamide (750 mg/m2), doxorubicin (50 mg/m2), and vincristine (1·4 mg/m2, with a maximum total dose of 2 mg), all administered intravenously on day 1, plus oral prednisone or prednisolone at the discretion of the investigator (100 mg) administered on days 1-5. Rituximab was given at a dose of 375 mg/m2 of body surface area. Cycles were repeated every 21 days. No radiotherapy was planned except for testicular lymphoma treatment. The primary endpoint was progression-free survival after 3 years. The primary analysis was done in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of assigned treatment. A non-inferiority margin of -5·5% was chosen. The trial, which is completed, was prospectively registered at ClinicalTrials.gov, NCT00278421. FINDINGS: Between Dec 2, 2005, and Oct 7, 2016, 592 patients were enrolled, of whom 295 patients were randomly assigned to receive six cycles of R-CHOP and 297 were assigned to receive four cycles of R-CHOP plus two doses of rituximab. Four patients in the four-cycles group withdrew informed consent before the start of treatment, so 588 patients were included in the intention-to-treat analysis. After a median follow-up of 66 months (IQR 42-100), 3-year progression-free survival of patients who had four cycles of R-CHOP plus two doses of rituximab was 96% (95% CI 94-99), which was 3% better (lower limit of the one-sided 95% CI for the difference was 0%) than six cycles of R-CHOP, demonstrating the non-inferiority of the four-cycles regimen. 294 haematological and 1036 non-haematological adverse events were documented in the four-cycles group compared with 426 haematological and 1280 non-haematological adverse events in the six-cycles group. Two patients, both in the six-cycles group, died during study therapy. INTERPRETATION: In young patients with aggressive B-cell non-Hodgkin lymphoma and favourable prognosis, four cycles of R-CHOP is non-inferior to six cycles of R-CHOP, with relevant reduction of toxic effects. Thus, chemotherapy can be reduced without compromising outcomes in this population. FUNDING: Deutsche Krebshilfe.

Progranulin autoantibodies in systemic sclerosis and autoimmune connective tissue disorders: A preliminary study.

OBJECTIVE: The present study aimed to investigate progranulin autoantibodies in systemic sclerosis and autoimmune connective tissue disorders. Progranulin is a physiologic tumor necrosis factor (TNF) antagonist. Progranulin antibodies decrease progranulin levels. METHODS: Serum samples of 123 patients with systemic sclerosis and various autoimmune connective tissue disorders (Sjoegren's syndrome [SjS], mixed connective tissue disorder, polymyositis [PM] and dermatomyositis [DM], antiphospholipid syndrome [APLS], and undifferentiated connective tissue disease [UCTD]) were tested for progranulin antibodies using enzyme-linked immunosorbent assay. RESULTS: Progranulin antibodies were found in 34 of 123 (27.6%) patients at least once during their disease. In detail, 2 of 8 (25%) patients with limited cutaneous systemic sclerosis, 10 of 31 (32.3%) patients with diffuse cutaneous systemic sclerosis, 9 of 22 (40.9%) patients with SjS, 1 of 3 (33.33%) patients with mixed connective tissue disease, 4 of 33 (12.1%) patients with DM or PM, 6 of 15 (40%) patients with APLS, and 2 of 11 (18.2%) patients with UCTD were positive for progranulin antibodies during the course of disease. CONCLUSIONS: Progranulin antibodies are frequently present in patients with systemic sclerosis and other autoimmune connective tissue disorders. Despite the lack of specificity for a given autoimmune disease, progranulin antibodies might not only indicate a potential subtype but also play a pathogenic role in patients with autoimmune connective disorders. Given the important role of TNF-α in inflammatory processes in autoimmune connective tissue disorders, progranulin antibodies might support the proinflammatory environment by neutralizing the TNF blocker progranulin.

LRPAP1 is a frequent proliferation-inducing antigen of BCRs of mantle cell lymphomas and can be used for specific therapeutic targeting.

The predominant usage of VH4-34 and V3-21 and reports of stereotyped CDR3s suggest a shared antigenic target of B-cell receptors (BCR) from mantle cell lymphomas (MCL). To identify the target antigens of MCL-BCRs, BCRs from 21 patients and seven MCL cell lines were recombinantly expressed and used for antigen screening. The BCRs from 8/21 patients and 2/7 MCL cell lines reacted specifically with the autoantigen low-density lipoprotein receptor-related protein-associated protein 1 (LRPAP1). High-titered and light chain-restricted anti-LRPAP1 serum antibodies were found in MCL patients, but not in controls. LRPAP1 induced proliferation by BCR pathway activation, while an LRPAP1-ETA' toxin-conjugate specifically killed MCL cells with LRPAP1-specific BCRs. Our results suggest a role of LRPAP1 in lymphomagenesis and maintenance of a considerable proportion of MCL cases by chronic autoantigenic stimulation, likely evolving from a chronic autoreactive B-cell response. Importantly, LRPAP1 can be used for a novel therapeutic approach that targets MCL with LRPAP1-reactive BCRs with high specificity.

Doubling rituximab in high-risk patients with aggressive B-cell lymphoma -results of the DENSE-R-MegaCHOEP trial.

To further improve outcome in young high-risk patients with diffuse large B-cell lymphoma (DLBCL) the number of rituximab (R) infusions was doubled in combination with standard CHOEP (cyclophosphamide, doxorubicin, etoposide, vincristine, prednisone) chemotherapy. Seventy-seven patients (aged 18-60 years) with an age-adjusted International Prognostic Index of 2-3 received 12 × R (375 mg/m2 ) on days 0, 1, 4, 8, 15, 22, 29, 43, 57, 71, 85 and 99 together with eight cycles of CHOEP-14. Results were retrospectively compared to those of patients receiving 6 × R and 8 × CHOEP-14 in the standard arm of the randomized R-MegaCHOEP trial. Two-year overall survival (OS) was 82% [95% confidence interval (CI) 73%-92%]; 2-year event-free (EFS) and progression-free survival (PFS) was 69% (95% CI 59-80%) and 76% (95% CI 66%--6%), respectively. Comparing 12 to six doses of R revealed no differences (univariate/multivariate) in EFS (at 2 years: 69% vs. 71%), PFS (76% vs. 75%) and OS (82% vs. 85%), with P = 0·766, P = 0·871 and P = 0·843, respectively. Doubling the number of R infusions concomitant to CHOEP did not improve treatment outcomes. Nonetheless, OS and PFS of young high-risk patients who received only six infusions of R combined with CHOEP remain excellent and were confirmed in an independent cohort of patients.

Allogeneic stem cell transplantation for patients with relapsed or refractory T-cell lymphoma: efficacy of lymphoma-directed conditioning against advanced disease.

Salvage chemotherapy induces disease remissions in patients with relapsed or refractory (r/r) T-cell lymphomas, but fails to provide lasting tumor control. We analyzed the outcome after peripheral blood stem and bone marrow transplantation (PBSCT, n = 80; BMT, n = 4) from matched related (MRD, n = 22) or matched and unmatched unrelated donors (MUD and MMD, n = 53 and n = 9, respectively) following conditioning with fludarabine, busulfan, and cyclophosphamide (FBC) for 84 consecutive patients with r/r T-cell malignancies. At start of conditioning LDH was elevated in 50% of cases, and residual tumor (PD, SD, PR) was detectable in 84% of patients. In total, 38% (95% CI 33-44) of the patients were alive and disease-free after a median observation time of 14.5 (range 1.8 to 114) months. Univariate and multivariate analyses identified low ECOG status, as well as occurrence of acute GvHD as favorable factors for outcome. Lymphoma-directed conditioning with fludarabin, busulfan and cyclophosphamid (FBC-12), and allogeneic stem cell transplantation resulted in long-term survival for a proportion of patients with r/r peripheral T-cell lymphoma, including those with PR and SD only after salvage therapy.

Saposin C is a frequent target of paraproteins in Gaucher disease-associated MGUS/multiple myeloma.

Patients with Gaucher disease (GD) have an increased risk of monoclonal gammopathies for which antigenic targets might play a role in their pathogenesis. Here we report the identification of saposin C (sapC) as high-titre (1:1 000 000) target structure of 7/16 GD-associated paraproteins. Anti-sapC immunoglobulin (Ig) showed identity with the paraprotein Ig type and subclass in each patient that showed anti-sapC immunoreactivity. Absorption and depletion studies completely removed the paraprotein from the sera of GD patients. No immunoreactivity against sapC was detected in healthy donors and in other plasma cell dyscrasias, demonstrating that anti-sapC reactivity is highly restricted to GD. Several uncharacterized forms of post-translational modified sapC were detected but their role in the pathogenesis is not clear. We confirm the frequent presence of low-titre (1:250) anti-lysolipid reactivities in the sera of GD patients but we could show that this immunoreactivity is not mediated by the paraprotein and is not restricted to GD patients.

Doxorubicin, vinblastine, dacarbazine and lenalidomide for older Hodgkin lymphoma patients: final results of a German Hodgkin Study Group (GHSG) phase-I trial.

About 30% of all Hodgkin lymphoma (HL) patients are ≥60 years old. As lenalidomide has promising single agent activity in multiple relapsed HL, we replaced bleomycin in ABVD with lenalidomide in this phase-I trial. Patients aged ≥60 years with early-unfavourable- or advanced-stage HL (Eastern Cooperative Oncology Group performance status ≤2, Cumulative Illness Rating Scale for Geriatrics score 0-7) received 4-8 cycles of AVD (doxorubicin, vinblastine, dacarbazine) and lenalidomide in escalation with overdose control. Dose-limiting toxicities (DLTs) included thromboembolism ≥grade 2, severe haematological toxicity, neutropenic fever and prolonged therapy delay. Twenty-five patients with a median age of 68 years were included, 68% had advanced-stage HL. A pre-defined stopping criterion for dose escalation after DLT evaluation of 20/24 patients suggested a recommended phase II dose (RPTD) of 20 mg. DLTs occurred in 10/24 evaluable patients, all treated with ≥20 mg, however, median relative dose intensity was 97% (interquartile range 49-104%). Grade 3 or higher toxicities occurred in all 22 patients at ≥20 mg lenalidomide but no treatment-related deaths occurred. Overall response rate was 80% for all patients (20/25) and 86% (19/22) at ≥20 mg lenalidomide. Three-year estimates for progression-free survival and OS were 69·7% (95% CI: 50·3-89·1%) and 83·8% (95%-CI: 69·3-98·4%), respectively. In conclusion, AVD with lenalidomide 20 mg is feasible and highly effective in older HL patients.

Hyper-N-glycosylated SAMD14 and neurabin-I as driver autoantigens of primary central nervous system lymphoma.

To address the role of chronic antigenic stimulation in primary central nervous system lymphoma (PCNSL), we searched for autoantigens and identified sterile α-motif domain containing protein 14 (SAMD14) and neural tissue-specific F-actin binding protein I (neurabin-I) as autoantigenic targets of the B-cell receptors (BCRs) from 8/12 PCNSLs. In the respective cases, SAMD14 and neurabin-I were atypically hyper-N-glycosylated (SAMD14 at ASN339 and neurabin-I at ASN1277), explaining their autoimmunogenicity. SAMD14 and neurabin-I induced BCR pathway activation and proliferation of aggressive lymphoma cell lines transfected with SAMD14- and neurabin-I-reactive BCRs. Moreover, the BCR binding epitope of neurabin-I conjugated to truncated Pseudomonas exotoxin-killed lymphoma cells expressing the respective BCRs. These results support the role of chronic antigenic stimulation by posttranslationally modified central nervous system (CNS) driver autoantigens in the pathogenesis of PCNSL, serve as an explanation for their CNS tropism, and provide the basis for a novel specific treatment approach.