OBJECTIVES:Autologous hematopoietic stem cell transplantation (aHSCT) for systemic sclerosis (SSc) is an effective treatment strategy but carries a high treatment-related mortality (TRM). Consequently, patients with severe organ dysfunction have been excluded from previous randomized trials such as ASTIS. This study aimed to evaluate the feasibility and non-inferiority of a disease-manifestation - adapted chemotherapy protocol designed to mitigate toxicity to also treat patients who would have been ASTIS-ineligible. METHODS:In this prospective, open-label, monocentric, phase II non-inferiority trial at the University Hospital Tübingen, Germany, patients with progressive SSc (disease duration≤6 years) were stratified by lung and cardiac involvement. Mobilization included 1500mg/m2 cyclophosphamide (CYC) for patients with inflammatory interstitial lung disease (iILD) versus 1000mg/m2 otherwise, both reduced compared to the ASTIS protocol. Conditioning comprised rabbit anti-thymocyte globulin (4×10mg/kg); patients without cardiac involvement additionally received CYC 4×50mg/kg. In those with cardiac involvement, CYC was reduced by 50% and thiotepa (2×5mg/kg) was added. RESULTS:Between 09/2012 and 07/2022, 35 patients were treated (no iILD/cardiac involvement: n=14; iILD only: n=3; cardiac only: n=12; both: n=6). Three-year overall survival (OS) was 77%, meeting non-inferiority compared to EBMT registry data (80%). TRM within 100 days was 11% (n=4) in the whole group. CONCLUSIONS:This adapted regimen showed comparable 3y-OS in patients with advanced organ involvement who would have been excluded from prior trials. While feasibility is demonstrated, aHSCT in this high-risk population remains associated with substantial risk, and efficacy cannot be definitively established. Further studies are warranted.

BACKGROUND:Adding ibrutinib to standard, first-line immunochemotherapy improves failure-free survival in adult patients aged 18-65 years with mantle cell lymphoma, according to the first results from the TRIANGLE trial. With prolonged follow-up, we investigated whether the addition of autologous stem-cell transplantation (ASCT) to an ibrutinib-containing regimen improves failure-free survival, and evaluated effects on overall survival. METHODS:We conducted a three-arm, randomised, open-label, phase 3 superiority trial (TRIANGLE) in 165 secondary or tertiary clinical centres, with experience in mantle cell lymphoma treatment and the capability to perform ASCT or an association with such a centre, in 13 European countries and Israel. Patients aged 18-65 years with untreated, stage II-IV mantle cell lymphoma and suitable for ASCT were randomly assigned (1:1:1) to control group A or experimental groups A + I or I. Randomisation was done using computer-generated random numbers and stratified by study groups and Mantle Cell Lymphoma International Prognostic Index risk groups. Treatment in group A consisted of six alternating, 21-day cycles of R-CHOP (intravenous rituximab 375 mg/m2 on day 0 or 1, cyclophosphamide 750 mg/m2 on day 1, doxorubicin 50 mg/m2 on day 1, vincristine 1·4 mg/m2 on day 1 [up to a maximum of 2 mg], and oral prednisone 100 mg on days 1-5) and R-DHAP or R-DHAOx (intravenous rituximab 375 mg/m2 on day 0 or 1, intravenous or oral dexamethasone 40 mg on days 1-4, high-dose intravenous cytarabine 2 × 2 g/m2 for 3 h every 12 h on day 2, plus either intravenous cisplatin 100 mg/m2 over 24 h on day 1 [R-DHAP] or intravenous oxaliplatin 130 mg/m2 on day 1 [R-DHAOx]), followed by ASCT. In group A + I, oral ibrutinib (560 mg daily) was added on days 1-19 of R-CHOP cycles and as 2-year maintenance after ASCT. In group I, ibrutinib was given the same way, but ASCT was omitted. Rituximab maintenance was allowed in all treatment groups according to national guidelines. Three pairwise, one-sided, log-rank tests for the primary outcome (failure-free survival) were statistically monitored. The primary analysis was by intention to treat and included all randomly assigned patients, ignoring protocol deviations. Safety was assessed in randomly assigned patients who started any trial treatment component of the respective treatment phase. The trial is registered with ClinicalTrials.gov (NCT02858258) and is complete. FINDINGS:Between July 29, 2016, and Dec 28, 2020, 870 patients (662 [76%] were male, 208 [24%] were female) were randomly assigned to group A (n=288), group A + I (n=292), or group I (n=290). After median follow-up of 54·9 months (95% CI 54·4-56·0), group A + I did not show superiority over group I, with 4-year failure-free survival of 82% (95% CI 78-87) versus 81% (76-86; hazard ratio [HR] 0·86 [one-sided 98·33% CI 0·00-1·27]; one-sided p=0·21). Group A + I remained superior to group A (82% [78-87] vs 70% [65-76]; HR 0·63 [one-sided 98·33% CI 0·00-0·89]; one-sided p=0·0026) and, as before, group A did not show superiority over group I (70% [65-76] vs 81% [76-86]; HR 1·45 [one-sided 98·33% CI 0·00-2·02]; one-sided p=0·99). 4-year overall survival was 88% (95% CI 84-92) in group A + I versus 81% (76-85) in group A (HR 0·59 [95% CI 0·38-0·92], p=0·0036) and 90% (87-94) in group I versus 81% (76-85) in group A (0·57 [0·36-0·90], p=0·0019). During maintenance or follow-up, the most common grade 3-5 adverse events were haematological disorders, reported in 127 (54%) of 234 patients in group A + I versus 74 (28%) of 269 in group I and 56 (23%) of 240 patients in group A, and infections, reported in 80 (34%) of 234 patients in group A + I versus 71 (26%) of 269 in group I and 37 (15%) of 240 patients in group A. Infections and infestations were the most common fatal adverse events during maintenance or follow-up, occurring in four (2%) of 234 patients in group A + I and five (2%) of 269 patients in group I. INTERPRETATION:After a prolonged follow-up of 55 months, both ibrutinib-containing groups showed relevant improvements not only in failure-free survival-a modified form of progression-free survival-but also in overall survival. In contrast, the addition of ASCT to an ibrutinib-containing regimen had no supplementary benefit but increased toxicity. Induction treatment with ibrutinib and R-CHOP plus R-DHAP (or R-DHAOx), followed by 2 years of maintenance treatment with ibrutinib, should be considered as a new standard of care for younger patients with mantle cell lymphoma. FUNDING:Janssen.

The TRIANGLE trial established an ibrutinib-containing therapy without autologous stem-cell transplantation (ASCT) as the new standard for younger, treatment-naïve patients with mantle cell lymphoma (MCL). However, the benefit of rituximab maintenance (RM) within this novel standard is unclear. We investigated whether RM improves progression-free survival (PFS) and overall survival (OS) with acceptable toxicity when added to the experimental arms of TRIANGLE. This secondary analysis of TRIANGLE included patients randomly assigned to ibrutinib-containing therapy without (I) or with (A + I) ASCT who responded to induction/ASCT. RM was given per national and center practice. PFS and OS of patients with and without RM were compared with inverse probability of treatment weighted Kaplan-Meier curves and log-rank tests. Among responders after induction/ASCT (I: 274; A + I: 237), RM was given to 61% (I) and 64% (A + I). RM prolonged PFS in ibrutinib-containing treatment arms (I: log-rank test: P = .003, 4-year PFS probability RM v no RM, 85% v 73%; A + I: P < .001, 90% v 75%). There were trends toward prolonged OS in RM groups. RM groups were at higher risk of grade 3 to 5 infectious toxicity (I: 34% v 11%; A + I: 41% v 18%). Our findings support adding RM to BTK inhibitor treatments in younger, untreated patients with MCL to achieve prolonged remission.

BACKGROUND:Therapeutic T-cell activation to induce tumour-specific immune responses promises sustainable cancer control. However, this treatment is not yet widely used because of the challenges of personalised drug design and a shortage of mutation-derived neoepitopes. This study aimed to evaluate the immunogenicity, safety, and toxicity of iTAC-XS15-CLL01, a personalised warehouse-based multipeptide T-cell activator combined with the Toll-like receptor 1/2 ligand XS15, in patients with chronic lymphocytic leukaemia who were undergoing Bruton's tyrosine kinase inhibitor (BTKi)-based regimes. METHODS:This open-label, single-centre, phase 1 study, conducted in Germany, enrolled patients aged 18 years or older who had chronic lymphocytic leukaemia with an Eastern Cooperative Oncology Group score of 2 or lower and were due to receive a BTKi-based regimen either as monotherapy or in combination (eg, with anti-CD20). The patients' HLA allotype had to match at least one of the corresponding HLA alleles of peptides included in the peptide warehouse. To begin treatment with iTAC-XS15-CLL01, patients had to have reached at least partial remission with remaining minimal residual disease after 6-8 months of BTKi therapy. iTAC-XS15-CLL01 comprised eight chronic lymphocytic leukaemia-specific peptides, selected for the individual patient from a peptide warehouse on the basis of HLA allotyping and immunopeptidomics. Participants received three monthly doses of iTAC-XS15-CLL01 (consisting of 300 μg of each peptide plus 50 μg XS15, emulsified in Montanide ISA 51 VG), injected subcutaneously. The primary endpoints were induction of a T-cell response after application of iTAC-XS15-CLL01 compared with baseline, as assessed with IFNγ ELISpot assays, and the frequency and severity of adverse events from the first application of iTAC-XS15-CLL01 to end of treatment. All analyses were done per protocol. This study was registered with ClinicalTrials.gov (NCT04688385) and is now closed. FINDINGS:Between Jan 21, 2021, and July 7, 2023, 30 patients with chronic lymphocytic leukaemia were screened, and 20 were recruited to enter the iTAC-XS15-CLL01 treatment phase and followed up for 6 months. All patients were of White ethnicity; six (30%) patients were female, and 14 (70%) were male. Median age was 56·5 years (IQR 49·5-65·5). The most common grade 3 adverse events were injection-site erythema (three [15%] of 20 patients), granuloma (two [10%] of 20), and ulceration (one [5%] of 20). There were no grade 4 adverse events, treatment-related serious adverse events, or deaths. T-cell responses targeting multiple peptides were induced in 19 (95% [95% CI 75·1-99·9]) of 20 patients at end of treatment and persisted in 16 (84%) of 19 at 6 months follow-up, with the intensity of responses increasing until end of study. INTERPRETATION:Our findings indicate that iTAC-XS15-CLL01 could be a potent immunotherapeutic agent in patients with chronic lymphocytic leukaemia and should be further evaluated in phase 2 trials. FUNDING:Medical Faculty, Tübingen University.

Vitreoretinal large B-cell lymphoma (VR-LBCL) is a rare hematologic malignancy. It is classified as primary (PVR-LBCL) or secondary (SVR-LBCL) based on the initial site of manifestation. Owing to limited prospective data and absent standardized guidelines, treatment remains challenging. This dual-center retrospective study aimed to evaluate outcomes of methotrexate (MTX) intravitreal (itv.), Rituximab itv., or combinatorial itv. therapy (R-MTX) and assess the impact of additional systemic immunochemotherapy. Among 65 patients (median age 72 years) included, 55.4% (n = 36) had PVR-LBCL. The median time to diagnosis was 31 days (1-2805). Over a median follow-up of 23.2 months, 35 patients relapsed. MTX itv. showed a trend toward better ocular relapse-free-survival than Rituximab itv. (P = 0.07). Intriguingly, patients receiving R-MTX itv. experienced no relapses throughout follow-up. In general, addition of systemic therapy was associated with significantly longer relapse-free-survival compared to itv. monotherapy (P = 0.05). Keratopathy and elevated intraocular pressure were common side effects with MTX itv. and Rituximab itv., respectively. Despite compelling findings and being one of the largest cohorts published to date, the heterogeneity of the patient population and small subgroups limit direct clinical translation. Nonetheless, this study provides a strong foundation for the design of future clinical trials.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive, poor-prognostic, and CD123-overexpressing orphan hematologic malignancy for which tagraxofusp, a CD123-targeted fusion protein, is the only approved drug. In this retrospective study, safety and efficacy of tagraxofusp were assessed through real-world clinical practice data, collected in patients with BPDCN who received tagraxofusp via a European Named Patient Program (2019–2024). Twenty-six adults with treatment-naïve BPDCN received 12 µg/kg tagraxofusp intravenously daily on days 1–5 (or by day 10) of a 21-day cycle. Primary endpoints were complete response (CR) rates and incidence/severity of capillary leak syndrome (CLS). Secondary endpoints included hematopoietic stem cell transplantation (HSCT), overall survival (OS), and safety. At a median follow-up of 13.5 months, the overall response rate (ORR) was 90

Introduction. Primary vitreoretinal lymphoma (PVRL) is a distinct subset of primary central nervous system lymphoma (PCNSL), characterized by its emergence within the intraocular environment without initial brain involvement. The pathogenesis of PVRL remains unclear, though it is hypothesized to originate outside the CNS, subsequently migrating to ocular regions where an immune-permissive microenvironment facilitates its manifestation. Diagnostically, PVRL presents significant challenges due to its clinical mimicry of uveitis and the fragility of lymphoma cells in the vitreous. The treatment of PVRL is demanding as well, with diverse and heterogeneous strategies, encompassing localized intravitreal therapy, radiotherapy, systemic chemotherapy, and targeted therapy. However, as a rare disease, data on PVRL are limited, and prospective trials are largely absent. Through collaboration between two European centers, we conducted a comprehensive retrospective analysis of PVRL cases to evaluate treatment outcomes and relapse behavior, aiming to enhance understanding of this challenging condition. Methods. A retrospective analysis of PVRL cases was performed at the University Hospital Tübingen and the Medical University Graz. Electronic health records were analyzed for demographic data, clinical presentation, diagnostic procedure, treatments and outcome, relapse manifestations and adverse events. Descriptive statistics are provided for the entire cohort and center-specific cohorts. Statistical comparisons using SPSS were performed where possible. Results. A total of 65 cases with intraocular lymphoma involvement were identified (Tübingen n=34, Graz n=31), comprising 40 cases of primary vitreoretinal lymphoma (PVRL), 9 cases of primary central nervous system lymphoma (PCNSL) with later ocular involvement, 5 cases of PCNSL with simultaneous eye infiltration, and 11 cases of systemic diffuse large B-cell lymphoma (DLBCL) at initial diagnosis. The mean age at diagnosis was 72.7 years (range 49-96), 55.4% were female, and the median follow-up time was 18 months. The median time to diagnosis from the onset of the first symptoms was 31 days (range 1-2805). There was considerable heterogeneity in treatment modalities and clinical management. Intravitreal (itv.) treatment primarily involved Rituximab (n=34), Methotrexate (n=19), or combinations thereof (n=5). Intravitreal Methotrexate resulted in clinically significant keratopathy in 11 of 12 cases (91.7%), while Rituximab caused increased intraocular pressure in 9 of 34 cases (26.4%). Intravitreal treatment (n=58) resulted in 55.2% complete responses, and 34.6% partial responses, without a significant difference between modalities. A total of 69.2% (n=45) of patients received systemic chemotherapy at some point, including 11 patients who received systemic immunochemotherapy despite having exclusive eye manifestations. Despite intensive therapy, 70% of cases developed a single documented relapse of any kind, while 52.4% developed a second relapse, considering high rates of patients lost to follow-up (n=25). Conclusions. This retrospective analysis of a large cohort highlights the significant heterogeneity in treatment approaches for PVRL. The study found no significant differences in overall outcomes between intravitreal rituximab and intravitreal methotrexate. However, each treatment had distinct adverse effects, with methotrexate causing keratopathy and rituximab associated with increased intraocular pressure. Despite diverse treatment strategies, the high rate of relapses underscores the need for standardized treatment protocols. Future prospective trials are essential to optimize therapeutic strategies and improve long-term outcomes for PVRL patients, addressing both intraocular disease control and CNS relapse prevention.

Background Treatment with high-dose chemotherapy followed by autologous hematopoietic stem cell transplantation (aHSCT) is an intensive treatment option for patients with severe forms of systemic sclerosis (SSc). Even though associated with a high treatment related mortality, the results in this high-risk population are generally favourable. The knowledge on the potential mechanism of action of this therapy and how it can improve patients with SSc is crucial to better select the right patients for aHSCT. Methods This is a monocentric retrospective study from Tübingen, Germany, including 32 patients who underwent aHSCT. Peripheral blood samples were analysed for different lymphocyte subsets at various timepoints before and after aHSCT. Patients were divided into responders and non-responders according to the modified Rodnan skin score and lung function test in the three years following aHSCT. Results Responders showed significantly lower levels of cluster of differentiation (CD)4 positive T cells in the first months after aHSCT (month 1 and 3), B cells (month 3 and 6 after aHSCT) and natural killer cells (month 1). Mantel-cox test showed a significant deviation of the probability curves, i.e. patients with lower CD4 + T cells and natural killer cells one month and B cells after 3 months after stem cell transplantation had a higher probability to belong to the responder group. Conclusions Taken together, this study supports the theory that a profound CD4 + T cell and B cell lymphopenia is important for patients with SSc to achieve a sustained response after aHSCT.

IntroductionBlastic plasmacytoid dendritic cell neoplasia (BPDCN) is a rare, aggressive hematologic malignancy. Until recently, the only curative treatment consisted of intensive chemotherapy, followed by hematopoietic cell transplantation (HCT) in eligible adult cases. Tagraxofusp, a CD123-targeted protein-drug conjugate and the first approved targeted treatment for BPDCN, might enhance outcomes especially in patients not eligible for intensive therapies.MethodsHere, we report real-world outcomes of five male patients with a median age of 79 years who received tagraxofusp as first-line treatment for BPDCN.ResultsTagraxofusp was found to be well-tolerated in this elderly cohort, with only one patient requiring discontinuation. Three patients responded to the treatment (two patients achieved a CR and one patient achieved a partial response), of which two subsequently underwent allogeneic (allo) HCT. One patient is alive and well after ≥ 4 years after alloHCT, and one patient shows sustained CR after now 13 cycles of tagraxofusp. The other three patients died of progressive disease 4-11 months after initiation of treatment.DiscussionIn line with results from 13 published cases outside clinical trials in the literature, sustained responses were associated with CR after tagraxofusp treatment and subsequent alloHCT. Our results provide real-world evidence for safety and efficacy of tagraxofusp as first-line treatment for BPDCN.

BACKGROUND:Adding ibrutinib to standard immunochemotherapy might improve outcomes and challenge autologous stem-cell transplantation (ASCT) in younger (aged 65 years or younger) mantle cell lymphoma patients. This trial aimed to investigate whether the addition of ibrutinib results in a superior clinical outcome compared with the pre-trial immunochemotherapy standard with ASCT or an ibrutinib-containing treatment without ASCT. We also investigated whether standard treatment with ASCT is superior to a treatment adding ibrutinib but without ASCT. METHODS:The open-label, randomised, three-arm, parallel-group, superiority TRIANGLE trial was performed in 165 secondary or tertiary clinical centres in 13 European countries and Israel. Patients with previously untreated, stage II-IV mantle cell lymphoma, aged 18-65 years and suitable for ASCT were randomly assigned 1:1:1 to control group A or experimental groups A+I or I, stratified by study group and mantle cell lymphoma international prognostic index risk groups. Treatment in group A consisted of six alternating cycles of R-CHOP (intravenous rituximab 375 mg/m2 on day 0 or 1, intravenous cyclophosphamide 750 mg/m2 on day 1, intravenous doxorubicin 50 mg/m2 on day 1, intravenous vincristine 1·4 mg/m2 on day 1, and oral prednisone 100 mg on days 1-5) and R-DHAP (or R-DHAOx, intravenous rituximab 375 mg/m2 on day 0 or 1, intravenous or oral dexamethasone 40 mg on days 1-4, intravenous cytarabine 2 × 2 g/m2 for 3 h every 12 h on day 2, and intravenous cisplatin 100 mg/m2 over 24 h on day 1 or alternatively intravenous oxaliplatin 130 mg/m2 on day 1) followed by ASCT. In group A+I, ibrutinib (560 mg orally each day) was added on days 1-19 of R-CHOP cycles and as fixed-duration maintenance (560 mg orally each day for 2 years) after ASCT. In group I, ibrutinib was given the same way as in group A+I, but ASCT was omitted. Three pairwise one-sided log-rank tests for the primary outcome of failure-free survival were statistically monitored. The primary analysis was done by intention-to-treat. Adverse events were evaluated by treatment period among patients who started the respective treatment. This ongoing trial is registered with ClinicalTrials.gov, NCT02858258. FINDINGS:Between July 29, 2016 and Dec 28, 2020, 870 patients (662 men, 208 women) were randomly assigned to group A (n=288), group A+I (n=292), and group I (n=290). After 31 months median follow-up, group A+I was superior to group A with 3-year failure-free survival of 88% (95% CI 84-92) versus 72% (67-79; hazard ratio 0·52 [one-sided 98·3% CI 0-0·86]; one-sided p=0·0008). Superiority of group A over group I was not shown with 3-year failure-free survival 72% (67-79) versus 86% (82-91; hazard ratio 1·77 [one-sided 98·3% CI 0-3·76]; one-sided p=0·9979). The comparison of group A+I versus group I is ongoing. There were no relevant differences in grade 3-5 adverse events during induction or ASCT between patients treated with R-CHOP/R-DHAP or ibrutinib combined with R-CHOP/R-DHAP. During maintenance or follow-up, substantially more grade 3-5 haematological adverse events and infections were reported after ASCT plus ibrutinib (group A+I; haematological: 114 [50%] of 231 patients; infections: 58 [25%] of 231; fatal infections: two [1%] of 231) compared with ibrutinib only (group I; haematological: 74 [28%] of 269; infections: 52 [19%] of 269; fatal infections: two [1%] of 269) or after ASCT (group A; haematological: 51 [21%] of 238; infections: 32 [13%] of 238; fatal infections: three [1%] of 238). INTERPRETATION:Adding ibrutinib to first-line treatment resulted in superior efficacy in younger mantle cell lymphoma patients with increased toxicity when given after ASCT. Adding ibrutinib during induction and as maintenance should be part of first-line treatment of younger mantle cell lymphoma patients. Whether ASCT adds to an ibrutinib-containing regimen is not yet determined. FUNDING:Janssen and Leukemia & Lymphoma Society.

PDF file - 184K, (A) The RANKL antibodies MIH23 and MIH24 specifically bind to RANKL. Binding of MIH23 and MIH24 to surface expressed RANKL was determined by FACS using RANKL transfectants (L-RANKL) and control cells (L cells). Shaded peaks, specific mAb (MIH23 and MIH24); open peaks, isotype controls (mouse IgM and mouse IgG2b, respectively). (B) MIH23 and MIH24 block RANK-RANKL interaction. RANKL transfectants and the parental controls were stained with RANK-Ig (shaded peaks) or human IgG1 (open peaks) followed by anti-human-PE and investigated by FACS. Dotted line: staining after preincubation with the indicated RANKL mAb; dashed line: after preincubation with mouse IgM and mouse IgG2b as respective isotype controls. (C) Sensitivity and specificity of the sandwich ELISA for detection of sRANKL. The indicated serial dilutions of rRANKL in culture medium were analyzed as described in the methods section. X represents 100ng/ml rGITRL as control. The dotted line represents the chosen detection limit of 0.05ng/ml. Means of triplicates with standard deviations are shown. (D, E) MM cell lines do not display RANKL protein on the surface despite expression of mRANKL mRNA. The indicated MM cell lines were analyzed for RANKL surface and mRNA expression by FACS (D) and RT-PCR (E) as described in the methods section. Results obtained with RANKL transfectants and parental cells are shown as controls.

Introduction: The FORT trial demonstrated a higher complete remission (CR) rate using 12 × 2 Gy compared to 2 × 2 Gy in Follicular Lymphoma (FL) (67% vs. 47%). This benefit resulted also in an improved progression free survival (PFS). The TROG 99.03 trial and the MIR study showed an improved PFS with the addition of Rituximab to radiation therapy of 30–40 Gy in early stage FL. Preclinical data suggest that the anti-CD20 antibody may act synergistic with radiation therapy and therefore enhance the radiation effect of low dose radiotherapy. The prospective, multicentric phase II GAZAI study of the German Lymphoma Alliance (GLA) investigated the efficacy of low dose radiation therapy (2 × 2 Gy) in combination with the anti-CD20 antibody Obinutuzumab in early stage nodal FL. The primary endpoint was the metabolic complete remission at the end of therapy. Methods: Patients with early stage FL grade 1/2 were recruited in 11 German centers. Ann Arbor stage I or II was confirmed by FDG-PET/CT. Patients received 1000 mg Obinutuzumab flat dose intravenously in weeks 1, 2, 3, 4, 8, 12 and 16. An interim CT scan was performed in week 7 for response evaluation and subsequent treatment planning. Radiation therapy was applied to the initial involved sites (site of diagnostic surgical intervention and PET positive sites) in week 9. The radiation dose was 2 x 2 Gy on two succeeding days. A FDG-PET/CT was performed at the end of therapy in week 18 for evaluation of the metabolic and morphologic response. Minimal detectable/residual disease (MRD) in peripheral blood was monitored at baseline and at week 18 by allel-specific RQ PCR targeting t(14;18) translocations and clonal immunoglobulin heavy chain (IGH) rearrangements. Results: Of 89 patients included in the study, 54 entered the treatment phase showing FDG-PET-positive lymph nodes qualifying for the primary endpoint. At week 18, metabolic CR (Deauville score (DS) <3) was seen in 46/53 patients (87%; one patient only had a CT without FDG-PET). Partial metabolic remission with a DS 3 was seen in 3 patients (6%) and 3 patients showed a DS 4. Morphologic (CT based) CR/CRu according to Cheson 1999 criteria was seen in 21/54 patients (39%) at week 7 and in 49/54 patients (91%) at week 18. Morphologic PR was seen in 17 patients (32%) at week 7 and in 4 patients (7%) at week 18; one patient (2%) showed progressive disease (metabolic and morphologic) outside of the radiation field. 13/54 patients (24%) were initially MRD positive. All but one patient converted to MRD negativity at week 18. Conclusions: Low dose radiation therapy using 2 × 2 Gy in combination with Obinutuzumab is highly effective in early stage FL. Longer follow-up is necessary to investigate if this effectivity also results in a prolonged PFS. Currently, the FORTplus trial is looking for non-inferiority of this regimen in comparison to a conventional radiation dose (12 × 2 Gy) combined with Rituximab. The research was funded by: Roche Pharma Keywords: combination therapies, indolent non-Hodgkin lymphoma, radiation therapy Conflicts of interests pertinent to the abstract K. Herfarth Research funding: Roche Pharma Educational grants: Roche Pharma C. W. Scholz Consultant or advisory role: Roche Pharma Honoraria: Speakers Honoraria Roche Pharma Educational grants: Roche Pharma K. Hübel Consultant or advisory role: Scientific advisory board Roche Pharma Honoraria: Speaker Honoraria Roche Pharma Research funding: Roche Pharma C. Buske Consultant or advisory role: Roche Pharma Honoraria: Roche Pharma Research funding: Roche Pharma J. Dürig Consultant or advisory role: Scientific advisory board Roche Pharma Honoraria: Speakers Honoraria Roche Pharma Educational grants: Roche Pharma G. Lenz Consultant or advisory role: Advisory board Roche Pharma Honoraria: Speakers honoraria Roche Pharma Research funding: Roche Pharma C. Pott Research funding: Roche Pharma M. Dreyling Consultant or advisory role: Roche Pharma Honoraria: Speakers Honoraria Roche Pharma Research funding: Roche Pharma

PURPOSE The outcome of older patients with mantle cell lymphoma (MCL) has improved by the introduction of immunochemotherapy, followed by rituximab (R)-maintenance. Assessment of minimal residual disease (MRD) represents a promising tool for individualized treatment decisions and was a prospectively planned part of the European MCL Elderly trial. We investigated how MRD status influenced the efficacy of R-maintenance and how MRD can enable tailored consolidation strategies. PATIENTS AND METHODS Previously untreated patients with MCL age 60 years or older have been randomly assigned to R versus interferon-alpha maintenance after response to rituximab, fludarabine, cyclophosphamide (R-FC) versus rituximab, cyclophosphamide, doxorubicin, vincristine, prednisone (R-CHOP). MRD monitoring was performed by real-time quantitative polymerase chain reaction (qPCR) following EuroMRD guidelines. RESULTS A qPCR assay with a median sensitivity of 1 × 10 −5 could be generated in 80% of 288 patients in an international, multicenter, multilaboratory setting. More extensive tumor dissemination facilitated the identification of a molecular marker. The efficacy of R-maintenance in clinical remission was confirmed for MRD-negative patients at the end of induction in terms of progression-free survival (PFS; hazard ratio [HR], 0.38 [95% CI, 0.21 to 0.63]) and overall survival (OS; HR, 0.37 [95% CI, 0.20 to 0.68]), particularly in R-CHOP–treated patients (PFS-HR, 0.23 [95% CI, 0.10 to 0.52]; OS-HR, 0.19 [95% CI, 0.07 to 0.52]). R-maintenance appeared less effective in MRD-positive patients (PFS-HR, 0.51 [95% CI, 0.26 to 1.02]) overall and after R-CHOP induction (PFS-HR, 0.59 [95% CI, 0.28 to 1.26]). R-FC achieved more frequent and faster MRD clearance compared with R-CHOP. MRD positivity in clinical remission after induction was associated with a short median time to clinical progression of approximately 1-1.7 years. CONCLUSION The results confirm the strong efficacy of R-maintenance in patients who are MRD-negative after induction. Treatment de-escalation for MRD-negative patients is discouraged by our results. More effective consolidation strategies should be explored in MRD-positive patients to improve their long-term prognosis.

PDF file - 264K, (A) The ability of MM cells to release sRANKL does not influence NK reactivity induced by RANK-Fc-ADCC. The increase in cytotoxicity (left) and cytokine production (right) of allogeneic NK cells using RANKL surface-positive MM cells that do (+sRANKL) or do not (-sRANKL) release sRANKL as targets upon treatment with RANK-Fc-ADCC was calculated. To this end, specific lysis (E:T ratio 40:1) or cytokine release (E:T ratio 1:1) of NK cells in the presence of isotyp control-treated target cells was set to 1 in each individual data set. No statistically significant difference (p=0.39 and p=1, respectively; Mann-Whitney U-Test) was observed upon analysis of results from 8 (cytotoxicity) and 6 (cytokine release) independent experiments. (B) Surface levels of RANKL do not correlate with induction of NK reactivity by RANK-Fc-ADCC. Expression of RANKL on patient MM (circles) and CLL cells (triangles) was correlated with the increase in cytotoxicity (left) and cytokine production (right) of allogeneic NK cells upon treatment with RANK-Fc-ADCC calculated by as described in A. Each symbol represents the result of one independent experiment. The number of independent experiments, correlation coefficients (Pearson correlation) and p values (T-Test) are indicated. (C) NK reactivity against RANKL surface-negative MM cells is not affected by the fusion proteins. RPMI 8226 MM cells (left) and primary MM cells (right) that lack RANKL surface expression were incubated with allogeneic NK cells in the presence or absence of 10mug/ml of the indicated RANK fusion proteins or isotype control. Cytotoxicity was determined by 2h Europium release assays (upper panels) and IFN-gamma levels in supernatants were analyzed after 24h by ELISA (lower panels). (D) RANKL transfectants were cultured with allogeneic NK cells in the presence or absence of RANK-Fc-ADCC or isotype control (10g/ml each) and the indicated concentrations of rRANKL. Cytotoxicity was determined by 2h Europium release assays (left) and IFN- levels in supernatants were analyzed after 24h by ELISA (right). One repesentative experiment each of a total of three with similar results is shown in C and D.