ALBERT

Description: Leukemia relapse occurring in donor cells, so called donor cell leukemia (DCL) after allogeneic hematopoietic stem cell transplantation has been previously reported in the literature. Some authors have suggested that the development of DCL is perhaps a more common occurrence than traditionally thought. Donor cell myeloma (DCM) seems to be less frequent than DCL. This 46-year old male when first seen in 2000 was diagnosed with stage IIIa multiple myeloma. A monoclonal IgA kappa spike was recorded at diagnosis. Treatment with melphalan and prednisone was delivered every four to six weeks for a total of 22 courses. Fourty months after the initial diagnosis, an M2 acute myelogenous leukemia was identified. Treatment with chemotherapy resulted in complete remission. Matched UCB cells were localized at the London Cord Blood Bank. The UCB belonged to a male product of a white western European mother and a black Nigerian father who was a carrier of hemoglobin S. Hemoglobins A, F and S were detected in the UCB, consonant with sickle cell trait. The patient was allografted employing the "Mexican" NST conditioning regimen, granulocyte count recovered to more than 0.5 x 109/L on day 14, with the platelet count never dropping below 20 x 109/L. On day +40, the polymorphic microsatellite markers revealed mixed chimerism. The hemoglobin S gene was identified on day +20 and on day +60, full chimerism was shown. Cyclosporine A was stopped on day +350. The patient returned 170 months after the transplant with low back pain and the bone marrow aspiration disclosed 80% abnormal plasma cells, an IgA kappa monoclonal spike of 3.1 gr/dl, and complete chimerism. Malignant plasma cells were sorted by means of flow cytometry before genetic fingerprinting; cells were stained with an admixture of fluorescent monoclonal antibodies and cells co-expressing dim CD45, bright CD38 and CD56 were sorted out to ≥99% purity. Sorted cells were shown to have donor origin (Figure 1). The patient was treated with thalidomide, dexamethasone and bortezomib and the monoclonal spike disappeared; an autologous stem cell transplant is planned. Most people consider that the development of a malignancy in the cells of the donor is a rare event and very few prospective studies have analyzed the real prevalence of this phenomenon. Prospectively, we have found that 7% (95% CI 2.9 to 13.6%) of patients with leukemic activity after an allogeneic graft do have a donor cell-derived leukemia; this figure contrasts with those described elsewhere in non-prospective studies. A major problem in the analysis of donor cell derived malignancies is that demonstration of the donor cell origin of malignant activity. In this case, the demonstration of DNA of the donor in the fluorescence-activated sorted malignant plasma cells is indicative of the origin of the myeloma cells. Interestingly, the immunoglobulin type produced by the initial myeloma cells is the same as that of the donor-cell myeloma; Despite being two myelomas producing the same immunoglobulin subtype, both should be considered as de novomalignancies and as such, treated; we have previously shown that donor cell leukemias do have a response when treated as de novo, non-secondary leukemias. To our best knowledge, this is the second report of DCM following allogeneic HSCT. Prior to this case, Kim et al reported a DCM after an allogeneic transplant in a patient with refractory anemia with ringed sideroblasts. Previously, two cases have been reported of donor-origin MM, but they occurred in patients who underwent solid organ transplantation of the kidney and heart-lung. Kumar et alreported a case of DCM developing after unrelated allogeneic HSCT in the both donor and recipient but they did not conducted a comprehensive molecular cytogenetic study. In the case published by Maestas et al, an abnormal proliferation of plasma cells was identified in the donor, thus making possible that a malignant plasma cell clone was already present in the donor stem cells. In summary, we have clearly shown that this patient has had three different malignancies: 1) De novomultiple myeloma, 2) Secondary acute myelogenous leukemia and 3) De novodonor cell-derived multiple myeloma. The mechanisms involved in these episodes could be useful to better understand tumorigenesis. Disclosures No relevant conflicts of interest to declare.

Description: Introduction. Efficacy and safety of daratumumab monotherapy (DARA mono) in relapsed/refractory multiple myeloma (rrMM) has been shown in the single-arm phase I/II trial GEN501 and the single-arm phase II trial SIRIUS (1, 2). Since then, several indirect treatment comparisons of DARA mono versus comparator therapies have been published showing consistent results with an overall survival benefit for DARA mono (3, 4, 5, 6). This analysis compares efficacy and for the first time also safety of DARA mono data versus an international historic control group, adjusting for differences in patient populations based on individual patient level data (IPD). Methods. IPD from the SIRIUS trial and from the International Myeloma Foundation (IMF)-cohort (7), a retrospective, multicenter cohort, were compared using a multivariate Cox proportional hazards model, on the endpoints of efficacy (overall survival (OS)) and safety (discontinuation due to adverse events (DISCONAE)). The IMF-cohort included patients with rrMM who received at least three prior lines of therapy, were refractory to both an immunomodulator (IMiD) and a proteasome inhibitor (PI), and were exposed to an alkylating agent. An inclusion criterion for the historic control group in this analysis was treatment with EU approved regimens. Baseline covariates adjusted for in the regression model included age, gender, prior lines of therapy, albumin, beta-2 microglobulin, prior exposure to pomalidomide and carfilzomib, and PI/IMiD refractory status. Several sensitivity analyses were run, including multiple imputation of missing values. Results. Data from 106 patients treated with DARA mono (16 mg/kg) were available from SIRIUS; 258 patients from the IMF chart review fulfilled the inclusion criteria; most frequent treatment regimens contained pomalidomide plus dexamethasone (PomDex) (n=172), bortezomib (n=31), carfilzomib (n=21), cyclophosphamide (n=14) and lenalidomide (n=9). The adjusted HR for OS was 0.41 [0.25, 0.69], p

Description: Introduction: Transformed B-cell lymphomas (t-BCL) harbor features of indolent and aggressive disease and it is assumed that transformation conveys an unfavorable prognosis. Because of the ambiguous pathological findings these lymphomas are rarely included into clinical trials. As a result, there is a lack of information about t-BCL patients' short-term and long-term outcomes although very recently a large retrospective analysis detailed the outcomes of transformed follicular lymphoma (t-FL) (Blood June 23, 2015; DOI 10.1182/blood-2015-01-621375). t-BCLs can be separated into a primary type, i.e. transformation at the time of diagnosis, and a secondary type, i.e. transformation after a previous diagnosis of indolent BCL. The present study reports the outcome of patients with t-BCL and also includes indolent lymphomas other than FL. Methods: This is a retrospective, single center analysis of patients with t-BCL seen at the Dept. of Hematology and the Dept. of Medical Oncology at the University Hospital Essen between 1999 and 2015. The departments' archives were screened for patients with primary or secondary t-BCL. A lymphoma was considered transformed when the diagnosis of indolent lymphoma (FL grade 1, 2, 3A; extranodal marginal zone lymphoma (EMZL), nodal marginal zone lymphoma (NMZL), splenic marginal zone lymphoma (SMZL), small lymphocytic lymphoma (SLL), lymphoplasmacytic lymphoma (LPL)) preceded a diffuse large B-cell lymphoma (DLBCL) or other aggressive lymphoma or was simultaneously present. Lymphomas were classified according to WHO 2008 terminology whenever possible. FL with simultaneous grade 3A and grade 3B portions were classified as primary t-BCL. Central pathology review was not performed. Demographic parameters, treatment history, response and outcome data were collected. Survival analyses were performed using the Kaplan-Meier method. The log rank test was used to calculate survival differences, p values 〉 0,05 were considered statistically significant. Multivariable Cox regression analysis was used where appropriate. The ethics committee of the faculty of medicine, University of Duisburg-Essen, approved this study (14-5497-BO). Results: 92 patients treated between 1999 and 2015 were identified. 47 (51 %) were female. 38 (41%) suffered from primary and 54 (59%) from secondary t-BCL. Median age at transformation was 60 years (30-87). For secondary t-BCL, time to transformation spanned 2-275 months with a median of 40.5. The treatment approach influenced time to transformation: 33.3 (median) months for observation only (n=20) and 66 months (median) for chemotherapy or rituximab-chemotherapy (n=20; p=0.02). After radiation therapy (n=10) median time to transformation was 32 months. 4 patients received chemotherapy and radiation therapy. FL grade1-3 was diagnosed in 67 patients (73%). Other diagnoses included EMZL (n=9), LPL (n=5), NMZL (n=3) SLL (n=3), SMZL (n=2) and other low-grade lymphomas (n=3). Histology at transformation was DLBCL in 86 patients. FL grade 3B, Burkitt-like lymphoma and aggressive lymphoma, unclassified, were diagnosed in 2 patients each. In primary t-BCL Ann Arbor stages III or IV were found in 25 patients (63 %), extranodal disease was present in 13 (34%), and 7 (18%) suffered from B symptoms. In secondary t-BCL Ann Arbor stages III or IV were found in 41 patients (66 %), extranodal disease was present in 12 (22%), and 11 (20%) suffered from B symptoms. Follicular Lymphoma International Prognostic Index high risk categories at time of transformation were evaluable for 42/67 FL patients and more frequent in secondary t-FL (n=33 (79%)) than in primary t-BCL (n=9 (21%)). Treatment of primary vs secondary t-BCL included CHOP (5/5), R-CHOP (29/23), R-ASHAP (0/10), Burkitt-type protocol (1/2), R-GemOx (0/2), R-ICE (0/2), radiation only (6/0), BEAM + ASCT (0/8), and other regimens. Overall survival (OS) at 5 years was dependent on remission status after first treatment of transformation with 86% for patients in CR, 66% for PR (CR vs PR p=n.s.) and 6% [CI=4.6-38.3] for PD (CR vs PD: p

Description: Introduction: T-cell engaging immunotherapies such as bispecific T-cell recruiting antibodies such as the recently approved blinatumomab, or chimeric antigen receptor T-cells (CAR-T) have emerged as highly active therapeutics in patients with refractory or relapsed hematological malignancies such as ALL or NHL. However, a relevant number of heavily pretreated patients progress or do not respond to these novel therapies. The objective of this study was to determine whether patients´ treatment history impacts the T-cell engagement of novel immunotherapies by analyzing activity of AFM11 - a CD19-directed tandem diabody (TandAb®) construct with T-cells obtained from patients after different chemotherapeutic regimens (R-Bendamustine, R-CHOP, HD-BEAM). Methods: T-cells were isolated and enriched from NHL patients 4-6 weeks after different therapeutic regimens and characterized side by side with T-cells enriched from healthy volunteers by flow cytometry. The responsiveness of T-cells from NHL patients to AFM11 was compared with T-cells from healthy volunteers in proliferation and cytokine release assays. In addition, enriched T-cells were used as effector cells at limiting effector-to-target (E:T) ratios in heterologous cytotoxicity assays with NALM-6 target cells in the presence of AFM11 or an appropriate control TandAb. Results: We found less CD3+ cells (median 148.1 cells/µL in patient group vs. 1232.2 cells/µL in healthy donors), less NK-cells (median 35.9 in patient group vs. 217.8 cells/µL in healthy donors), and no B-cells in the selected patients. Among memory T-cells, the percentages of both central (CD45RO+/CD62L+) and effector memory (CD45RO+/CD62L-) CD4+ and CD8+ cells were significantly increased in patient PBMC. Finally, we examined the percentages of regulatory T-cells (Treg) among the CD4+ T-cells of patients and healthy donors. Overall, patients contained higher proportions of Treg. Patients who received R-Bendamustine or HD-BEAM treatment had more Treg, while the percentage of Treg in patients after R-CHOP was comparable to healthy donors. Whereas CD8+ T-cells from patients and healthy volunteers showed similar proliferative response upon AFM11 stimulation in the presence of target cells, CD4+ T-cells from patients proliferated significantly more than CD4+ T-cells from healthy volunteers. No difference was observed among the patient groups with different prior chemotherapeutic regimens. T-cells from patients produced significantly higher amounts of IFN-γ than T-cells of healthy donors upon stimulation with AFM11 and target cells. In contrast, the production of IL-10 was significantly lower by T-cells from patients when compared to healthy donors. Surprisingly, most of the T-cells from healthy donors and patients did not produce IL-6. In heterologous cytotoxicity assays T-cells from healthy donors induced statistically significant higher specific lysis of NALM-6 in the presence of AFM11. There was no statistically significant difference between T-cells isolated from patients after different chemotherapies at an E:T ratio of 1:2. However, at lower E:T ratios there was statistically significant difference among T-cells from patients after different chemotherapy regimens. T-cells isolated from patients who received R-CHOP treatment had the strongest lysis capacity compared to the two other groups. The lowest efficacy of AFM11-mediated target cell lysis was observed with T-cells from patients after treatment with HD-BEAM. Conclusions: In conclusion, T-cells of NHL patients after different chemotherapy regimens are reduced in number and have functional defects. However, AFM11 is able to activate patient T-cells for potent target cell lysis with similar efficacy as T-cells from healthy volunteers at higher E:T ratios. Only at limiting effector cell counts a lower efficacy was observed for T-cells from patients. T-cells from R-CHOP treated patients are the most active among the tested treatment groups and display similar responsiveness as T-cells from healthy donors. Lower activity was measured with T-cells from R-Bendamustine pretreated patients and substantial lower cytotoxic activity for T-cells from patients after HD-BEAM treatment. The correlation of these findings with in vivo response will be evaluated in an ongoing Phase I trial with AFM11. Disclosures Reusch: Affimed: Employment, Patents & Royalties: Patents. Einsele:Celgene: Consultancy, Honoraria, Speakers Bureau; Janssen: Consultancy, Honoraria, Speakers Bureau; Novartis: Consultancy, Honoraria; Amgen: Consultancy, Honoraria, Speakers Bureau. Treder:Affimed: Employment.