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16
result(s) for
"Bargou, Ralf Christian"
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Association of ADAM family members with proliferation signaling and disease progression in multiple myeloma
2024
Multiple myeloma (MM) is a hematological malignancy whose curability is greatly challenged by recurrent patient relapses and therapy resistance. We have previously proposed the high expression of
ADAM8
,
ADAM9
and
ADAM15
(A Disintegrin And Metalloproteinase 8/9/15) as adverse prognostic markers in MM. This study focused on the so far scarcely researched role of ADAM8/9/15 in MM using two patient cohorts and seven human MM cell lines (HMCL). High
ADAM8
/
9
/
15
expression was associated with high-risk cytogenetic abnormalities and extramedullary disease. Furthermore,
ADAM8
/
15
expression increased with MM progression and in relapsed/refractory MM compared to untreated patient samples. RNA sequencing and gene set enrichment analysis comparing
ADAM8
/
9
/
15
high/low
patient samples revealed an upregulation of proliferation markers and proliferation-associated gene sets in
ADAM8
/
9
/
15
high
patient samples. High
ADAM8
/
9
/
15
expression correlated with high Ki67 and high
ADAM8
/
15
expression with high MYC protein expression in immunohistochemical stainings of patient tissue. Conversely, siRNA-mediated knockdown of
ADAM8
/
9
/
15
in HMCL downregulated proliferation-related gene sets. Western blotting revealed that
ADAM8
knockdown regulated IGF1R/AKT signaling and
ADAM9
knockdown decreased mTOR activation. Lastly, high
ADAM8
/
9
/
15
expression levels were verified as prognostic markers independent of Ki67/MYC expression and/or high-risk abnormalities. Overall, these findings suggest that ADAM8/9/15 play a role in MM progression and proliferation signaling.
Journal Article
Exon-4 Mutations in KRAS Affect MEK/ERK and PI3K/AKT Signaling in Human Multiple Myeloma Cell Lines
2020
Approximately 20% of multiple myeloma (MM) cases harbor a point mutation in KRAS. However, there is still no final consent on whether KRAS-mutations are associated with disease outcome. Specifically, no data exist on whether KRAS-mutations have an impact on survival of MM patients at diagnosis in the era of novel agents. Direct blockade of KRAS for therapeutic purposes is mostly impossible, but recently a mutation-specific covalent inhibitor targeting KRASp.G12C entered into clinical trials. However, other KRAS hotspot-mutations exist in MM patients, including the less common exon-4 mutations. For the current study, the coding regions of KRAS were deep-sequenced in 80 newly diagnosed MM patients, uniformely treated with three cycles of bortezomib plus dexamethasone and cyclophosphamide (VCD)-induction, followed by high-dose chemotherapy and autologous stem cell transplantation. Moreover, the functional impact of KRASp.G12A and the exon-4 mutations p.A146T and p.A146V on different survival pathways was investigated. Specifically, KRASWT, KRASp.G12A, KRASp.A146T, and KRASp.A146V were overexpressed in HEK293 cells and the KRASWT MM cell lines JJN3 and OPM2 using lentiviral transduction and the Sleeping Beauty vector system. Even though KRAS-mutations were not correlated with survival, all KRAS-mutants were found capable of potentially activating MEK/ERK- and sustaining PI3K/AKT-signaling in MM cells.
Journal Article
Functional Investigation of IGF1R Mutations in Multiple Myeloma
by
Bayrhof, Otto-Jonas
,
Steinbrunn, Torsten
,
Schwarzfischer, Marlene
in
Bortezomib
,
Care and treatment
,
Carfilzomib
2024
High expression of the receptor tyrosine kinase (RTK) insulin-like growth factor-1 receptor (IGF1R) and RTK mutations are associated with high-risk/worse prognosis in multiple myeloma (MM). Combining the pIGF1R/pINSR inhibitor linsitinib with the proteasome inhibitor (PI) bortezomib seemed promising in a clinical trial, but IGF1R expression was not associated with therapy response. Because the oncogenic impact of IGF1R mutations is so far unknown, we investigated the functional impact of IGF1R mutations on survival signaling, viability/proliferation and survival response to therapy. We transfected four human myeloma cell lines (HMCLs) with IGF1RWT, IGF1RD1146N and IGF1RN1129S (Sleeping Beauty), generated CRISPR-Cas9 IGF1R knockouts in the HMCLs U-266 (IGF1RWT) and L-363 (IGF1RD1146N) and tested the anti-MM activity of linsitinib alone and in combination with the second-generation PI carfilzomib in seven HMCLs. IGF1R knockout entailed reduced proliferation. Upon IGF1R overexpression, survival signaling was moderately increased in all HCMLs and slightly affected by IGF1RN1129S in one HMCL, whereby the viability remained unaffected. Expression of IGF1RD1146N reduced pIGF1R-Y1135, especially under serum reduction, but did not impact downstream signaling. Linsitinib and carfilzomib showed enhanced anti-myeloma activity in six out of seven HMCL irrespective of the IGF1R mutation status. In conclusion, IGF1R mutations can impact IGF1R activation and/or downstream signaling, and a combination of linsitinib with carfilzomib might be a suitable therapeutic approach for MM patients potentially responsive to IGF1R blockade.
Journal Article
Pasotuxizumab, a Bite ® Immune Therapy for Castration-Resistant Prostate Cancer: Phase I, Dose-Escalation Study Findings
by
Wittemer-Rump, Sabine
,
Goebeler, Maria-Elisabeth
,
Stienen, Sabine
in
Aged
,
Aged, 80 and over
,
Androgens
2021
We report results of a first-in-human study of pasotuxizumab, a PSMA bispecific T-cell engager (BiTE
) immune therapy mediating T-cell killing of tumor cells in patients with advanced castration-resistant prostate cancer.
We assessed once-daily subcutaneous (SC) pasotuxizumab. All SC patients developed antidrug antibodies; therefore, continuous intravenous (cIV) infusion was assessed.
A total of 47 patients received pasotuxizumab (SC: n = 31, 0.5-172 μg/d; cIV: n = 16, 5-80 μg/d). The SC maximum tolerated dose was 172.0 μg/d. A sponsor change stopped the cIV cohort early; maximum tolerated dose was not determined. PSA responders occurred (>50% PSA decline: SC, n = 9; cIV, n = 3), including two long-term responders.
Data support pasotuxizumab safety in advanced castration-resistant prostate cancer and represent evidence of BiTE monotherapy efficacy in solid tumors. Clinical trial registration: NCT01723475 (ClinicalTrials.gov).
Journal Article
Characterization and root cause analysis of immunogenicity to pasotuxizumab (AMG 212), a prostate-specific membrane antigen-targeting bispecific T-cell engager therapy
by
Penny, Hweixian Leong
,
Wittemer-Rump, Sabine
,
Bargou, Ralf C.
in
Amino acid sequence
,
Androgens
,
Antibodies
2023
IntroductionIn oncology, anti-drug antibody (ADA) development that significantly curtails response durability has not historically risen to a level of concern. The relevance and attention ascribed to ADAs in oncology clinical studies have therefore been limited, and the extant literature on this subject scarce. In recent years, T cell engagers have gained preeminence within the prolific field of cancer immunotherapy. These drugs whose mode of action is expected to potently stimulate anti-tumor immunity, may potentially induce ADAs as an unintended corollary due to an overall augmentation of the immune response. ADA formation is therefore emerging as an important determinant in the successful clinical development of such biologics.MethodsHere we describe the immunogenicity and its impact observed to pasotuxizumab (AMG 212), a prostate-specific membrane antigen (PSMA)-targeting bispecific T cell engager (BiTE®) molecule in NCT01723475, a first-in-human (FIH), multicenter, dose-escalation study in patients with metastatic castration-resistant prostate cancer (mCRPC). To explain the disparity in ADA incidence observed between the SC and CIV arms of the study, we interrogated other patient and product-specific factors that may have explained the difference beyond the route of administration.ResultsTreatment-emergent ADAs (TE-ADA) developed in all subjects treated with at least 1 cycle of AMG 212 in the subcutaneous (SC) arm. These ADAs were neutralizing and resulted in profound exposure loss that was associated with contemporaneous reversal of initial Prostate Surface Antigen (PSA) responses, curtailing durability of PSA response in patients. Pivoting from SC to a continuous intravenous (CIV) administration route remarkably yielded no subjects developing ADA to AMG 212. Through a series of stepwise functional assays, our investigation revealed that alongside a more historically immunogenic route of administration, non-tolerant T cell epitopes within the AMG 212 amino acid sequence were likely driving the high-titer, sustained ADA response observed in the SC arm.DiscussionThese mechanistic insights into the AMG 212 ADA response underscore the importance of performing preclinical immunogenicity risk evaluation as well as advocate for continuous iteration to better our biologics.
Journal Article
Allogeneic transplantation in multiple myeloma: long-term follow-up and cytogenetic subgroup analysis
by
Jung, Wolfram
,
Frickhofen, Norbert
,
Liebisch, Peter
in
38/32
,
631/67/1990/804
,
692/699/67/1990/804
2019
This phase 3 trial compared tandem autologous stem cell transplantation (autoSCT) versus autoSCT followed by reduced-intensity conditioning allogeneic stem cell transplantation (auto/alloSCT) in patients with newly diagnosed multiple myeloma (MM) with deletion of (del) chromosome 13q (del13q). The availability/absence of a human leukocyte antigen-matched-related or matched-unrelated donor (MUD) determined the nature of the second SCT. The primary endpoint was progression-free survival (PFS) in the intention-to-treat population (
n
=
199). Auto/alloSCT was performed in 126 patients; 74 received MUD allografts. After 91 months median follow-up, median PFS with auto/allo versus tandem autoSCT was 34.5 versus 21.8 months (
P
= 0.003; adjusted hazard ratio 0.55, 95% confidence interval 0.36–0.84). Median overall survival (OS) was 70.2 versus 71.8 months (
P
=
0.856). Two-year non-relapse mortality with auto/allo versus tandem autoSCT was 14.3% versus 4.1% (
P
=
0.008). In patients harboring both del13q and del17p, median PFS and OS were 37.5 and 61.5 months with auto/allo (
n
=
19) versus 6.1 and 23.4 months with tandem autoSCT (
n
= 6) (
P
=
0.0002 and 0.032). Our findings suggest that auto/alloSCT significantly extends PFS versus tandem autoSCT in del13q MM, and indicate some survival benefit for first-line alloSCT in high-risk MM.
Journal Article
Cancer care in German centers of excellence during the first 2 years of the COVID-19 pandemic
by
Lordick, Florian
,
Stilgenbauer, Stephan
,
Baumann, Michael
in
Aftercare
,
Cancer
,
Cancer Research
2023
Purpose
An increasing number of international studies demonstrate serious negative effects of the COVID-19 pandemic on the timely diagnosis of cancer and on cancer treatment. Our study aimed to quantitatively and qualitatively evaluate the capacities of German Comprehensive Cancer Centers (CCCs) in different areas of complex oncology care during the first 2 years of the COVID-19 pandemic.
Methods
Prospective panel survey over 23 rounds among 18 CCCs in Germany between March 2020 and June 2022.
Results
The COVID-19 pandemic substantially affected the oncological care system in Germany during the first 2 years. Persistent limitations of care in CCCs primarily affected follow-up (− 21%) and psycho-oncologic care (− 12%), but also tumor surgery (− 9%). Substantial limitations were also reported for all other areas of multidisciplinary oncological care.
Conclusions
This study documents the limitations of oncological care during the COVID-19 pandemic and highlights the need to develop strategies to avoid similar limitations in the future.
Journal Article