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The activating receptor natural killer group 2, member D (NKG2D) represents an attractive target for immunotherapy as it exerts a crucial role in cancer immunosurveillance by regulating the activity of cytotoxic lymphocytes. In this study, a panel of novel NKG2D-specific single-chain fragments variable (scFv) were isolated from naïve human antibody gene libraries and fused to the fragment antigen binding (Fab) of rituximab to obtain [CD20×NKG2D] bibodies with the aim to recruit cytotoxic lymphocytes to lymphoma cells. All bispecific antibodies bound both antigens simultaneously. Two bibody constructs, [CD20×NKG2D#3] and [CD20×NKG2D#32], efficiently activated natural killer (NK) cells in co-cultures with CD20+ lymphoma cells. Both bibodies triggered NK cell-mediated lysis of lymphoma cells and especially enhanced antibodydependent cell-mediated cytotoxicity (ADCC) by CD38 or CD19 specific monoclonal antibodies suggesting a synergistic effect between NKG2D and FcgRIIIA signaling pathways in NK cell activation. The [CD20×NKG2D] bibodies were not effective in redirecting CD8+ T cells as single agents, but enhanced cytotoxicity when combined with a bispecific [CD19×CD3] T cell engager, indicating that NKG2D signaling also supports CD3-mediated T cell activation. In conclusion, engagement of NKG2D with bispecific antibodies is attractive to directly activate cytotoxic lymphocytes or to support their activation by monoclonal antibodies or bispecific T cell engagers. As a perspective, cotargeting of two tumor antigens may allow fine-tuning of antibody cancer therapies. Our proposed combinatorial approach is potentially applicable for many existing immunotherapies but further testing in different preclinical models is necessary to explore the full potential. [ABSTRACT FROM AUTHOR]

To identify new antibodies for the treatment of plasma cell disorders including multiple myeloma (MM), a single-chain Fragment variable (scFv) antibody library was generated by immunizing mice with patient-derived malignant plasma cells. To enrich antibodies binding myeloma antigens, phage display with cellular panning was performed. After depleting the immune library with leukocytes of healthy donors, selection of antibodies was done with L-363 plasma cell line in two consecutive panning rounds. Monitoring the antibodies' enrichment throughout the panning by next-generation sequencing (NGS) identified several promising candidates. Initially, 41 unique scFv antibodies evolving from different B cell clones were selected. Nine of these antibodies strongly binding to myeloma cells and weakly binding to peripheral blood mononuclear cells (PBMC) were characterized. Using stably transfected Chinese hamster ovary cells expressing individual myeloma-associated antigens revealed that two antibodies bind CD38 and intercellular adhesion molecule-1 (ICAM-1), respectively, and 7 antibodies target yet unknown antigens. To evaluate the therapeutic potential of our new antibodies, in a first proof-of-concept study the CD38 binding scFv phage antibody was converted into a chimeric IgG1. Further analyses revealed that #5-CD38-IgG1 shared an overlapping epitope with daratumumab and isatuximab and had potent anti-myeloma activity comparable to the two clinically approved CD38 antibodies. These results indicate that by phage display and deep sequencing, new antibodies with therapeutic potential for MM immunotherapy can be identified. [ABSTRACT FROM AUTHOR]

ULBP2:HER2-scFv simultaneously bound to HER2 and NKG2D and triggered NK cells to kill HER2-expressing tumor cells in the nanomolar concentration range. Keywords: ADCC; antibody therapy; EGFR; NK cells; NKG2D EN ADCC antibody therapy EGFR NK cells NKG2D 545 556 12 04/12/22 20220401 NES 220401 Introduction Exploiting natural killer (NK) cells is a promising approach in cancer immunotherapy. ULBP2:HER2-scFv induces NK cell cytotoxicity To analyze whether ULBP2:HER2-scFv was able to trigger NK cell cytotoxicity SP 51 sp Cr release experiments were performed (Figure 3A). [Extracted from the article]

Objective: A post hoc subgroup analysis of two phase III trials (NCT00416273, NCT00416208) was carried out to investigate the influence of 100/140 and 200 mg/m² melphalan as well as single/double autologous stem cell transplantation (ASCT) on progression‐free survival (PFS). Additionally, the effect of bortezomib consolidation on PFS was analyzed. Methods: Following induction therapy and high‐dose melphalan with subsequent ASCT, patients with newly diagnosed multiple myeloma (NDMM) were randomized 1:1 to either four 35‐day cycles of bortezomib consolidation (1.6 mg/m² IV on days 1, 8, 15, 22) or observation. Results: Of the 340 patients included in this analysis, 13.5% received 1 × MEL100/140, 22.9% 2 × MEL100/140, 31.2% 1 × MEL200, and 32.4% 2 × MEL200. With higher cumulative melphalan dose, PFS improved (P =.0085). PFS curves of patients treated with 2 × MEL100/140 and 1 × MEL200 were very similar. The superior dose effect of MEL200 over MEL100/140 was non‐existent in the bortezomib consolidation arm but pronounced in the observation arm (P =.0015). Similarly, double ASCT was only beneficial in patients without bortezomib consolidation (P =.0569). Conclusions: Full dose melphalan and double transplantation seem advantageous only as long as patients are not receiving bortezomib consolidation afterwards. [ABSTRACT FROM AUTHOR]

Background: Combined therapy with carfilzomib, bendamustine, and dexamethasone was evaluated in this multicenter phase 1/2 trial conducted within the European Myeloma Network (EMN09 trial). Methods: Sixty‐three patients with relapsed/refractory multiple myeloma who had received ≥2 lines of prior therapy were included. The phase 1 portion of the study determined the maximum tolerated dose of carfilzomib with bendamustine set at 70 mg/m2 on days 1 and 8. After 8 cycles, responding patients received maintenance therapy with carfilzomib and dexamethasone until progression. Results: On the basis of the phase 1 results, the recommended phase 2 dose for carfilzomib was 27 mg/m2 twice weekly in weeks 1, 2, and 3. Fifty‐two percent of patients achieved a partial response or better, and 32% reached a very good partial response or better. The clinical benefit rate was 93%. After a median follow‐up of 21.9 months, the median progression‐free survival was 11.6 months, and the median overall survival was 30.4 months. The reported grade ≥3 hematologic adverse events (AEs) were lymphopenia (29%), neutropenia (25%), and thrombocytopenia (22%). The main nonhematologic grade ≥3 AEs were pneumonia, thromboembolic events (10%), cardiac AEs (8%), and hypertension (2%). Conclusions: In heavily pretreated patients who have relapsed/refractory multiple myeloma, combined carfilzomib, bendamustine, and dexamethasone is an effective treatment option administered in the outpatient setting. Infection prophylaxis and attention to patients with cardiovascular predisposition are required. In patients with heavily pretreated relapsed/refractory multiple myeloma, combined carfilzomib, bendamustine, and dexamethasone is an effective, well tolerated, and affordable treatment option safely administered in the outpatient setting. However, infection prophylaxis and attention to patients with cardiovascular predisposition are required. [ABSTRACT FROM AUTHOR]

Summary: Optimal donor choice for a second allogeneic haematopoietic cell transplant (allo‐HCT) in relapsed acute myeloid leukaemia (AML) remains unknown. We compared overall survival (OS) using registry data from the Acute Leukemia Working Party (ALWP) of the European Society for Blood and Marrow Transplantation (EBMT) involving 455 adults who received a second allo‐HCT from a human leucocyte antigen (HLA)‐matched unrelated (MUD) (n = 320) or a haploidentical (n = 135) donor. Eligibility criteria required adults aged ≥18 years who received a second allo‐HCT for treating AML relapse between 2005 and 2019. The primary end‐point was OS. There was no statistically significant difference in the median (interquartile range) age between the groups, MUD 46 (35–58) versus haploidentical 44 (33–53) years (P = 0·07). The median OS was not different between the MUD and the haploidentical groups (10 vs. 11 months, P = 0·57). Similarly, the 2‐year OS was 31% for the MUD and 29% for the haploidentical donor groups. The OS was worse if the procedure was performed with active AML [hazard ratio (HR) 1·42, 95% confidence interval (CI) 1·07–1·89; P = 0·02]. Conversely, a longer time from first allo‐HCT to relapse (>13·2 months) was associated with better OS (HR 0·50, 95% CI 0·37–0·69; P < 0·0001). The results of the present analysis limit the ability to recommend one donor type over another when considering a second allo‐HCT for relapsed AML. Our findings highlight that best OS is achieved when receiving the second allo‐HCT in complete remission. [ABSTRACT FROM AUTHOR]

Purpose: The optimal dose intensity for conditioning prior to allogeneic hematopoietic stem cell transplantation (alloHSCT) for chronic lymphocytic leukemia (CLL) is unknown. Methods: We retrospectively compared outcomes of patients who received a first alloHCST after non-myeloablative (NMA) and reduced intensity conditioning (RIC). Data of 432 patients with a median age of 55 years were included, of which 86 patients underwent NMA and 346 RIC. Results: The median follow-up after alloHSCT was 4.3 years. Compared to the RIC group, more NMA patients had purine-analog-sensitive disease, were in complete remission and received matched related donor transplantation. After RIC, the probabilities for 5-year OS, EFS, CIR, and NRM were 46%, 38%, 28%, and 35% and after NMA the respective probabilities were 52%, 43%, 25%, and 32%. In multivariate analysis, remission status prior to conditioning but not RIC versus NMA conditioning had a significant impact on CIR, EFS, and OS. Conclusion: Presumed higher anti-leukemic activity of RIC versus NMA conditioning did not translate into better outcomes after alloHSCT, but better remission status prior to conditioning did. Effective pathway inhibitor-based salvage therapies combined with NMA conditioning might thus represent the most attractive contemporary approach for alloHSCT for patients with CLL. [ABSTRACT FROM AUTHOR]

Objective: A post hoc analysis of two phase III trials was carried out to explore the influence of age and treatment factors on the effect of bortezomib consolidation on progression‐free survival (PFS) post autologous stem cell transplantation (ASCT). Methods: Patients with newly diagnosed multiple myeloma were assigned to one of two trials (ClinicalTrials.gov IDs: NCT00416273, NCT00416208), which were conducted in parallel, based on age (18‐60 or 61‐75 years, respectively). Following induction and ASCT, patients were randomized 1:1 to four 35‐day cycles of bortezomib consolidation (1.6 mg/m2 IV on days 1, 8, 15, 22) or observation only. Results: Median PFS with bortezomib consolidation vs observation was 33.6 vs 29.0 months (P = 0.3599) in patients aged 18‐60 years (n = 202), and 33.4 vs 26.4 months (P = 0.0073) in patients aged 61‐75 years (n = 155), respectively. Bortezomib consolidation post‐ASCT appeared to equalize outcomes between older and younger patients who received prior treatment of differing intensity. This suggests that the effect of consolidation may be relative and may depend on the composition and intensity of induction and high‐dose therapy. Conclusion: Older patients receiving less intensive prior treatment could experience a larger PFS benefit from bortezomib consolidation. [ABSTRACT FROM AUTHOR]