Real-world analysis of teclistamab in 123 RRMM patients from Germany

Teclistamab, a B-cell maturation antigen (BCMA) × CD3 directed bispecific antibody, has shown high response rates and durable remissions in the MAJESTEC-1 trial in patients with relapsed and refractory multiple myeloma (RRMM). We retrospectively assessed efficacy and tolerability in 123 patients treated at 18 different German centers to determine whether outcome is comparable in the real-world setting. Most patients had triple-class (93%) or penta-drug (60%) refractory disease, 37% of patients had received BCMA-directed pretreatment including idecabtagene vicleucel (ide-cel) CAR-T cell therapy (21/123, 17.1%). With a follow-up of 5.5 months, we observed an overall response rate (ORR) of 59.3% and a median progression-free survival (PFS) of 8.7 months. In subgroup analyses, we found significantly lower ORR and median PFS in patients with extramedullary disease (37%/2.1 months), and/or an ISS of 3 (37%/1.3 months), and ide-cel pretreated patients (33%/1.8 months). Nonetheless, the duration of response in ide-cel pretreated patients was comparable to that of anti-BCMA naive patients. Infections and grade ≥3 cytopenias were the most frequent adverse events. In summary, we found that teclistamab exhibited a comparable efficacy and safety profile in the real-world setting as in the pivotal trial.

Meeting report of the 7th Heidelberg Myeloma Workshop: today and tomorrow

PURPOSE

The 7th Heidelberg Myeloma Workshop was held on April 5th and 6th, 2019 at the University Hospital Heidelberg.

METHODS AND RESULTS

Main topics of the meeting were (1) diagnostics and prognostic factors, (2) role of immunotherapy in multiple myeloma (MM), (3) current therapy of MM, (4) biology and genomics of MM as well as (5) novel treatment concepts. A debate on the status of minimal residual disease (MRD) driven therapy was held.

CONCLUSION

Diagnostics and treatment of newly diagnosed and relapsed MM are continuously evolving. While advances in the field of (single cell) genetic analysis now allow for characterization of the disease at an unprecedented resolution, immunotherapeutic approaches and MRD testing are at the forefront of the current clinical trial landscape.

Bortezomib before and after high-dose therapy in myeloma: long-term results from the phase III HOVON-65/GMMG-HD4 trial

The Dutch-Belgian Cooperative Trial Group for Hematology Oncology Group-65/German-speaking Myeloma Multicenter Group-HD4 (HOVON-65/GMMG-HD4) phase III trial compared bortezomib (BTZ) before and after high-dose melphalan and autologous stem cell transplantation (HDM, PAD arm) compared with classical cytotoxic agents prior and thalidomide after HDM (VAD arm) in multiple myeloma (MM) patients aged 18-65 years. Here, the long-term follow-up and data on second primary malignancies (SPM) are presented. After a median follow-up of 96 months, progression-free survival (censored at allogeneic transplantation, PFS) remained significantly prolonged in the PAD versus VAD arm (hazard ratio (HR)=0.76, 95% confidence interval (95% CI) of 0.65-0.89, P=0.001). Overall survival (OS) was similar in the PAD versus VAD arm (HR=0.89, 95% CI: 0.74-1.08, P=0.24). The incidence of SPM were similar between the two arms (7% each, P=0.73). The negative prognostic effects of the cytogenetic aberration deletion 17p13 (clone size ⩾10%) and renal impairment at baseline (serum creatinine >2 mg dl^-1) on PFS and OS remained abrogated in the PAD but not VAD arm. OS from first relapse/progression was similar between the study arms (HR=1.02, P=0.85). In conclusion, the survival benefit with BTZ induction/maintenance compared with classical cytotoxic agents and thalidomide maintenance is maintained without an increased risk of SPM.

Molecular signaling in multiple myeloma: association of RAS/RAF mutations and MEK/ERK pathway activation

Multiple myeloma (MM) is a plasma cell malignancy that is still considered to be incurable in most cases. A dominant mutation cluster has been identified in RAS/RAF genes, emphasizing the potential significance of RAS/RAF/MEK/ERK signaling as a therapeutic target. As yet, however, the clinical relevance of this finding is unclear as clinical responses to MEK inhibition in RAS-mutant MM have been mixed. We therefore assessed RAS/RAF mutation status and MEK/ERK pathway activation by both targeted sequencing and phospho-ERK immunohistochemistry in 180 tissue biopsies from 103 patients with newly diagnosed MM (NDMM) and 77 patients with relapsed/refractory MM (rrMM). We found a significant enrichment of RAS/BRAF mutations in rrMM compared to NDMM (P=0.011), which was mainly due to an increase of NRAS mutations (P=0.010). As expected, BRAF mutations were significantly associated with activated downstream signaling. However, only KRAS and not NRAS mutations were associated with pathway activation compared to RAS/BRAF^wt (P=0.030). More specifically, only KRAS^G12D and BRAF^V600E were consistently associated with ERK activation (P<0.001 and P=0.006, respectively). Taken together, these results suggest the need for a more specific stratification strategy consisting of both confirmation of protein-level pathway activation as well as detailed RAS/RAF mutation status to allow for a more precise and more effective application of targeted therapies, for example, with BRAF/MEK inhibitors in MM.

Role of Growth arrest-specific gene 6-Mer axis in multiple myeloma

Multiple myeloma is a mostly incurable malignancy characterized by the expansion of a malignant plasma cell (PC) clone in the human bone marrow (BM). Myeloma cells closely interact with the BM stroma, which secretes soluble factors that foster myeloma progression and therapy resistance. Growth arrest-specific gene 6 (Gas6) is produced by BM-derived stroma cells and can promote malignancy. However, the role of Gas6 and its receptors Axl, Tyro3 and Mer (TAM receptors) in myeloma is unknown. We therefore investigated their expression in myeloma cell lines and in the BM of myeloma patients and healthy donors. Gas6 showed increased expression in sorted BMPCs of myeloma patients compared with healthy controls. The fraction of Mer(+) BMPCs was increased in myeloma patients in comparison with healthy controls whereas Axl and Tyro3 were not expressed by BMPCs in the majority of patients. Downregulation of Gas6 and Mer inhibited the proliferation of different myeloma cell lines, whereas knocking down Axl or Tyro3 had no effect. Inhibition of the Gas6 receptor Mer or therapeutic targeting of Gas6 by warfarin reduced myeloma burden and improved survival in a systemic model of myeloma. Thus, the Gas6-Mer axis represents a novel candidate for therapeutic intervention in this incurable malignancy.

Targeted treatments to improve stem cell outcome: old and new drugs

Thalidomide, lenalidomide and bortezomib have been approved for the treatment of relapsed or refractory multiple myeloma in the recent years. These agents are now being increasingly integrated into therapeutic regimens for newly diagnosed patients. First data are available on the promising activity of these novel agents in induction therapy, as well as maintenance treatment to improve outcome after stem cell transplantation. Whether these early results will lead to prolonged overall survival and thereby ultimately redefine the role of stem cell transplantation in first-line treatment of multiple myeloma will be one of the most important questions to be answered in the coming years. Bone Marrow Transplantation (2007) 40, 1129-1137; doi:10.1038/sj.bmt.1705829; published online 3 September 2007.

Thalidomide in newly diagnosed multiple myeloma: influence of thalidomide treatment on peripheral blood stem cell collection yield

In a phase III randomized, multicenter study, the German-speaking Myeloma-Multicenter Group (GMMG) and the Dutch-Belgian Hemato-Oncology Cooperative Group (HOVON) group investigated the influence of thalidomide (Thal) on the outcome of peripheral blood stem cell (PBSC) collection in multiple myeloma (MM) before peripheral autologous blood stem cell transplantation (ABSCT). We analyzed the data of 398 myeloma patients after induction with Thal, doxorubicin and dexamethasone (TAD) in comparison with vincristine, doxorubicin and dexamethasone (VAD) followed by mobilization with cyclophosphamide, doxorubicin, dexamethasone (CAD) and PBSC collection. Within both the study groups, patients treated with TAD showed to collect significantly fewer CD34(+) cells compared with VAD (GMMG, TAD: median 9.8 x 10(6)/kg; range 2.0-33.6; VAD: median 10.9 x 10(6)/kg range 3.0-36.0; P=0.02) (HOVON, TAD: median 7.4 x 10(6)/kg; range 2.0-33.0; VAD: median 9.4 x 10(6)/kg; range 0.0-48.7; P=0.009). However, engraftment after peripheral autologous stem cell transplantation showed no difference between Thal and VAD groups. We conclude that Thal as a part of induction regimen is associated with better response rates (GMMG-HD3: CR/PR 79%, VAD: CR/PR 58%; HOVON-50: TAD: CR/PR 81%, VAD: CR/PR 61%), but significantly affects the yield of PBSC collection. Nevertheless, the number of total CD34(+) cells collected was sufficient for double autologous transplantation in 82% of the Thal patients, with at least 2.5 x 10(6)/kg CD34(+) cells.

Lenalidomide and bortezomib induce osteoclast cytotoxicity and decrease BAFF secretion in osteoclasts in human multiple myeloma: Clinical implications

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Background: Myeloma bone disease is caused by an enhanced osteoclast (OCL) activation, leading to osteolytic bone lesions. OCL have recently been reported to produce abundant B-cell activating factor (BAFF) in the bone marrow microenvironment that is important for myeloma cell growth and survival (Blood 106, 1021–30, 2005; ASH2005, #627). The proteasome inhibitor bortezomib (PS341, Velcade) has potent anti-myeloma activity with impressive clinical responses. A recent study indicated that bortezomib has inhibitory effects on OCL (ASH 2005, #2488). Lenalidomide (CC-5013, Revlimid) is an immunomodulatory derivative of thalidomide that has shown promising anti-myeloma effects in patients with relapsed or refractory multiple myeloma (MM) (ASH 2005, #6 & #1565). However, the effect of lenalidomide on human OCL lineage is unknown. Therefore, the aim of this study is to investigate the effect of lenalidomide and bortezomib on human OCL. Methods: OCL formation from healthy donors and MM patients were stimulated with RANKL (50ng/ml) and GM-CSF (10ng/ml) in 20% FBS/RPMI. Cells were incubated with lenalidomide 2μM or bortezomib 2nM, alone and in combination, for two weeks followed by [3H]thymidine uptake assay to measure growth inhibition of OCL. Similar experiments were also performed in cocultures of CD138-purified cells from MM patients with OCL, in the presence or absence of lenalidomide and bortezomib. In addition, ELISA was performed to measure cytokine release of BAFF produced by OCL in these cultures. Results: OCL growth was decreased by lenalidomide (n=6) (median 49.2%, range 20–62.5%; coculture: 53% and 35%) as well as bortezomib (96 and 49%; coculture 63 and 59%) and by the combination of both drugs (95 and 55%; coculture 42 and 44%). BAFF secretion was dramatically decreased in cultures treated with lenalidomide 2μM (n=3) (median 72%, range 61–75.9%). Conclusions: These results indicate that lenalidomide and bortezomib inhibit OCL growth and survival. Importantly, lenalidomide and bortezomib also block growth and survival of MM cells cocultured with OCL, suggesting that lenalidomide may inhibit OCL growth and survival through inhibition of BAFF and may prevent development of osteolytic lesions in MM.

No significant financial relationships to disclose.

Molecular monitoring of tumour load kinetics predicts disease progression after non-myeloablative allogeneic stem cell transplantation in multiple myeloma

BACKGROUND

Non-myeloablative allogeneic stem cell transplantation followed by immunomodulatory therapies is considered a potentially curative approach in the treatment of multiple myeloma and most effective in a minimal residual disease setting.

PATIENTS AND METHODS

The aim of this study was to find the most sensitive real-time PCR assay (TaqMan), based on the IGH rearrangement, to quantify the tumour load of 11 patients with multiple myeloma after non-myeloablative allogeneic transplantation. Patient-allele specific primers (ASO) and the TaqMan probe were derived from CDR2 and CDR3 hypervariable regions of IGH, while consensus primers were located within the FR3 and FR4/JH regions. Four different approaches of primer combinations were tested.

RESULTS

ASO-forward and -reverse primers together with the clone-specific TaqMan probe were the most sensitive approach compared with the JH (P=0.071) or the FR3 consensus primer (P <0.001). The detection limit amounted to 1/10(4)-1/10(5) cells. Consecutively, 120 samples from 11 patients prior and post allogeneic transplantation were analysed. Three patients reached complete clinical remission accompanied by molecular remission. Disease progression or relapse was seen in six patients. In five, molecular progressive disease was detected prior to the clinical diagnosis of progression or relapse.

CONCLUSION

Patient-specific real-time IGH-PCR provides the opportunity for earlier treatment intervention.

The immunogenic glycoprotein gp35-37 of human herpesvirus 8 is encoded by open reading frame K8.1

Human herpesvirus 8 (HHV-8) is likely to be involved in the pathogenesis of Kaposi's sarcoma (KS) and body cavity-based lymphomas (BCBLs). The HHV-8 genome is primarily in a latent state in BCBL-derived cell lines like BCBL-1, but lytic replication can be induced by phorbol esters (R. Renne, W. Zhang, B. Herndier, M. McGrath, N. Abbey, D. Kedes, and D. E. Ganem, Nat. Med. 2:342-346, 1996). A 35- to 37-kDa glycoprotein (gp35-37) is the polypeptide most frequently and intensively recognized by KS patient sera on Western blots with induced BCBL-1 cells. Its apparent molecular mass is reduced to 30 kDa by digestion with peptide-N-glycosidase F. By searching the known HHV-8 genomic sequence for open reading frames (ORF) with the potential to encode such a glycoprotein, an additional, HHV-8-specific reading frame was identified adjacently to ORF K8. This ORF, termed K8.1, was found to be transcribed primarily into a spliced mRNA encoding a glycoprotein of 228 amino acids. Recombinant K8.1 was regularly recognized by KS patient sera in Western blots, and immunoaffinity-purified antibodies to recombinant K8.1 reacted with gp35-37. This shows that the immunogenic gp35-37 is encoded by HHV-8 reading frame K8.1, which will be a useful tool for studies of HHV-8 epidemiology and pathogenesis.

A theory for the origin of a self-replicating chemical system. II. Computer simulation of the autogen

In order to better understand the feasibility and limitations of the autogen (White 1980), a computer simulation based on the fluctuating clay environment was used to test whether autocatalytic growth would occur under various conditions. The results suggest that overall accuracies of replication and translation in the range of 90% and 10%, and protoenzyme turnover numbers of 10--120 monomers/protoenzyme/day are adequate for exponential growth. Nucleation of the components of the autogen from random background oligomers would be extremely rapid if oligomers lengths 2--6 were adequately functional, whereas oligomer lengths much greater than 10 are prohibited. The autogen would most likely nucleate and grow to dominance either rapidly (10--100 cycles of roughly 1 day each) or not at all.