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135
result(s) for
"Stilgenbauer Stephan"
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Resistance Mechanisms for the Bruton's Tyrosine Kinase Inhibitor Ibrutinib
by
Yilmaz, Ayse Selen
,
Buggy, Joseph J
,
Dave, Sandeep S
in
Adenine - analogs & derivatives
,
Agammaglobulinaemia Tyrosine Kinase
,
Aged
2014
In some patients with CLL, resistance to the BTK inhibitor ibrutinib develops. Two classes of resistance mutations have been found: the more common involves alteration of the drug-binding site to make binding reversible; the less common activates a downstream kinase that effectively bypasses BTK.
The development of B-cell–receptor antagonists has been a therapeutic advance in chronic lymphocytic leukemia (CLL). Although B-cell–receptor ligation in normal cells induces proliferation, apoptosis, or anergy,
1
pathway dysregulation in CLL results in the propagation of proliferative and prosurvival signals.
2
,
3
Several agents targeting the B-cell–receptor pathway are in development, including the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib. Although
BTK
is not recurrently mutated in CLL,
4
,
5
it is up-regulated at the transcript level and is constitutively active.
6
,
7
Ibrutinib irreversibly binds BTK at the C481 residue, rendering it kinase-inactive, inducing modest CLL-cell apoptosis, and abolishing proliferation and B-cell–receptor signaling in . . .
Journal Article
Obinutuzumab plus Chlorambucil in Patients with CLL and Coexisting Conditions
2014
Obinutuzumab, a glycoengineered anti-CD20 antibody with increased killing capacity, outperformed rituximab when used in combination with chlorambucil in patients with chronic lymphocytic leukemia who had coexisting illnesses.
Chronic lymphocytic leukemia (CLL), which is characterized by a neoplastic accumulation of B lymphocytes,
1
is the most common leukemia in Western countries. The majority of patients with CLL are older than 70 years of age, and many present with coexisting conditions.
2
,
3
In the past, CLL was treated with chemotherapy without improving survival.
4
–
8
The addition of the monoclonal anti-CD20 antibody rituximab to fludarabine and cyclophosphamide has been shown to prolong overall survival in physically fit patients with previously untreated CLL.
9
–
11
However, randomized trials have not shown that targeting the CD20 antigen in patients with CLL and coexisting conditions . . .
Journal Article
Revolution of Chronic Lymphocytic Leukemia Therapy: the Chemo-Free Treatment Paradigm
2020
Purpose of ReviewOver the last years, targeted anticancer therapy with small molecule inhibitors and antibodies has much replaced chemoimmunotherapy, which has been the gold standard of care for patients with chronic lymphocytic leukemia (CLL). Here we give an overview of novel targeted agents used in therapy of chronic lymphocytic leukemia, as well as efforts to overcome resistance development, focusing on approved drugs since they gained high relevance in clinical practice.Recent FindingsNovel agents moved to the forefront as a treatment strategy of CLL due to their outstanding efficacy, almost irrespectively of the underlying genetic features. Inhibition of Bruton’s tyrosine kinase (BTK), a key molecule in the B cell receptor pathway, achieved dramatic efficacy even in poor-risk and chemo-refractory patients. Further success was accomplished with venetoclax, which specifically inhibits anti-apoptotic BCL2 and induces apoptosis of CLL cells.SummaryInhibition of BTK or BCL2 is very effective and induces prolongation of progression-free and overall survival. Approved combination treatments such as venetoclax or ibrutinib with obinutuzumab show high responses rates and long remission durations. However, evolution and selection of subclones with continuous treatment leads to resistance towards these novel drugs and disease relapse. Hence, comparison of sequential treatment with combinations and discontinuation of therapy are important aspects which need to be investigated.
Journal Article
repDilPCR: a tool for automated analysis of qPCR assays by the dilution-replicate method
by
Reichenzeller, Michaela
,
Stilgenbauer, Stephan
,
Mertens, Daniel
in
Algorithms
,
Analysis
,
Assaying
2024
Background
The dilution-replicate experimental design for qPCR assays is especially efficient. It is based on multiple linear regression of multiple 3-point standard curves that are derived from the experimental samples themselves and thus obviates the need for a separate standard curve produced by serial dilution of a standard. The method minimizes the total number of reactions and guarantees that Cq values are within the linear dynamic range of the dilution-replicate standard curves. However, the lack of specialized software has so far precluded the widespread use of the dilution-replicate approach.
Results
Here we present repDilPCR, the first tool that utilizes the dilution-replicate method and extends it by adding the possibility to use multiple reference genes. repDilPCR offers extensive statistical and graphical functions that can also be used with preprocessed data (relative expression values) obtained by usual assay designs and evaluation methods. repDilPCR has been designed with the philosophy to automate and speed up data analysis (typically less than a minute from Cq values to publication-ready plots), and features automatic selection and performance of appropriate statistical tests, at least in the case of one-factor experimental designs. Nevertheless, the program also allows users to export intermediate data and perform more sophisticated analyses with external statistical software, e.g. if two-way ANOVA is necessary.
Conclusions
repDilPCR is a user-friendly tool that can contribute to more efficient planning of qPCR experiments and their robust analysis. A public web server is freely accessible at
https://repdilpcr.eu
without registration. The program can also be used as an R script or as a locally installed Shiny app, which can be downloaded from
https://github.com/deyanyosifov/repDilPCR
where also the source code is available.
Journal Article
Venetoclax in relapsed or refractory chronic lymphocytic leukaemia with 17p deletion: a multicentre, open-label, phase 2 study
2016
Deletion of chromosome 17p (del[17p]) in patients with chronic lymphocytic leukaemia confers very poor prognosis when treated with standard chemo-immunotherapy. Venetoclax is an oral small-molecule BCL2 inhibitor that induces chronic lymphocytic leukaemia cell apoptosis. In a previous first-in-human study of venetoclax, 77% of patients with relapsed or refractory chronic lymphocytic leukaemia achieved an overall response. Here we aimed to assess the activity and safety of venetoclax monotherapy in patients with relapsed or refractory del(17p) chronic lymphocytic leukaemia.
In this phase 2, single-arm, multicentre study, we recruited patients aged 18 years and older with del(17p) relapsed or refractory chronic lymphocytic leukaemia (as defined by 2008 Modified International Workshop on Chronic Lymphocytic Leukemia guidelines) from 31 centres in the USA, Canada, UK, Germany, Poland, and Australia. Patients started once daily venetoclax with a weekly dose ramp-up schedule (20, 50, 100, 200, 400 mg) over 4–5 weeks. Patients were then given daily 400 mg continuous dosing until disease progression or discontinuation for another reason. The primary endpoint was the proportion of patients achieving an overall response, assessed by an independent review committee. Activity and safety analyses included all patients who received at least one dose of study drug (per protocol). This study is registered with ClinicalTrials.gov, number NCT01889186. Follow-up is ongoing, and patients are still receiving treatment.
Between May 27, 2013, and June 27, 2014, 107 patients were enrolled into the study. At a median follow-up of 12·1 months (IQR 10·1–14·2), an overall response by independent review was achieved in 85 (79·4%; 95% CI 70·5–86·6) of 107 patients. The most common grade 3–4 adverse events were neutropenia (43 [40%]), infection (21 [20%]), anaemia (19 [18%]), and thrombocytopenia (16 [15%]). Serious adverse events occurred in 59 (55%) patients, irrespective of their relationship to treatment, with the most common (≥5% of patients) being pyrexia and autoimmune haemolytic anaemia (seven [7%] each), pneumonia (six [6%]), and febrile neutropenia (five [5%]). 11 patients died in the study within 30 days of the last dose of venetoclax; seven due to disease progression and four from an adverse event (none assessed as treatment related).
Results of this trial show that venetoclax monotherapy is active and well tolerated in patients with relapsed or refractory del(17p) chronic lymphocytic leukaemia, providing a new therapeutic option for this very poor prognosis population. Additionally, in view of the distinct mechanism-of-action of venetoclax, combinations or sequencing with other novel targeted agents should be investigated to further advance treatment of del(17p) chronic lymphocytic leukaemia.
AbbVie and Genentech.
Journal Article
Idelalisib and Rituximab in Relapsed Chronic Lymphocytic Leukemia
by
Kipps, Thomas J
,
Ma, Shuo
,
Aiello, Maria
in
1-Phosphatidylinositol 3-kinase
,
Aged
,
Aged, 80 and over
2014
A placebo-controlled study of idelalisib in patients with relapsed chronic lymphocytic leukemia who were receiving rituximab was stopped early because of significant improvement in rates of response, progression-free survival, and overall survival with idelalisib.
Chronic lymphocytic leukemia (CLL) is the most prevalent leukemia among adults. Standard treatments include combinations of purine analogues, alkylating agents, and monoclonal antibodies. In younger patients without major coexisting illnesses, these regimens can provide high response rates of durable length but have substantial toxic effects. As a result, these treatments often have unacceptable side effects in older patients and those with coexisting illnesses.
1
Patients with relapsed CLL often have limited options because of the development of resistance to, or persisting toxic effects of, previous therapies. This is particularly true for elderly patients and those with coexisting illnesses.
2
For these patients, . . .
Journal Article
Venetoclax plus obinutuzumab versus chlorambucil plus obinutuzumab for previously untreated chronic lymphocytic leukaemia (CLL14): follow-up results from a multicentre, open-label, randomised, phase 3 trial
by
Kipps, Thomas J
,
Tandon, Maneesh
,
Fischer, Kirsten
in
Bone marrow
,
Chemotherapy
,
Chlorambucil
2020
Venetoclax plus obinutuzumab has been established as a fixed-duration treatment regimen for patients with chronic lymphocytic leukaemia. We compared the long-term efficacy after treatment cessation of the combination of venetoclax plus obinutuzumab with chlorambucil plus obinutuzumab in patients with previously untreated chronic lymphocytic leukaemia.
CLL14 is a multicentre, randomised, open-label, phase 3 trial done at 196 sites in 21 countries. Eligible patients were aged 18 years or older, had untreated chronic lymphocytic leukaemia, and coexisting conditions with a cumulative illness rating scale greater than 6, a creatinine clearance of 30–69 mL/min, or both. Patients were randomly assigned (1:1) via a web and voicemail system with allocation concealment and based on a computer-generated randomisation schedule with a block size of six and stratified by Binet stage and geographical region. Patients received either venetoclax plus obinutuzumab (oral venetoclax initiated on day 22 of cycle 1 [28-day cycles], with a 5-week dose ramp-up [20 mg, 50 mg, 100 mg, and 200 mg, then 400 mg daily for 1 week], thereafter continuing at 400 mg daily until completion of cycle 12; combined with intravenous obinutuzumab for six cycles starting with 100 mg on day 1 and 900 mg on day 2 [or 1000 mg on day 1], 1000 mg on days 8 and day 15 of cycle 1, and subsequently 1000 mg on day 1 of cycles 2 through 6) or chlorambucil plus obinutuzumab (oral chlorambucil at 0·5 mg/kg bodyweight on days 1 and 15 of each cycle for 12 cycles combined with the same obinutuzumab regimen). The primary endpoint was investigator-assessed progression-free survival in the intention-to-treat population. Safety was assessed in all patients who received at least one dose of study treatment. Patient enrolment is complete, and the study is registered with ClinicalTrails.gov, NCT02242942.
Between Aug 7, 2015, and Aug 4, 2016, 432 patients were enrolled and randomly assigned to receive either venetoclax plus obinutuzumab (n=216) or chlorambucil plus obinutuzumab (n=216). All patients had been off treatment for at least 24 months at data collection. At a median follow-up of 39·6 months (IQR 36·8–43·0), patients given venetoclax plus obinutuzumab had a significantly longer progression-free survival than did patients given chlorambucil plus obinutuzumab (HR 0·31, 95% CI 0·22–0·44; p<0·0001). Median progression-free survival was not reached (95% CI not estimable to not estimable) in the venetoclax plus obinutuzumab group vs 35·6 months (33·7–40·7) in the chlorambucil plus obinutuzumab group. The most common grade 3 or 4 adverse event in both groups was neutropenia (112 [53%] of 212 patients in the venetoclax plus obinutuzumab group versus 102 [48%] of 214 patients in the chlorambucil plus obinutuzumab group). Serious adverse events occurred in 115 (54%) of 212 patients in the venetoclax plus obinutuzumab group and 95 (44%) of 214 patients in the chlorambucil plus obinutuzumab group. Venetoclax or chlorambucil treatment-related deaths were reported in one (1%) of 212 patients in the venetoclax plus obinutuzumab group (n=1 sepsis) and two (1%) of 214 patients in the chlorambucil plus obinutuzumab group (n=1 septic shock, n=1 metastatic skin squamous carcinoma).
2 years after treatment cessation, venetoclax plus obinutuzumab continues to significantly improve progression-survival compared with chlorambucil plus obinutuzumab, thereby providing a limited duration treatment option for patients with previously untreated chronic lymphocytic leukaemia.
F Hoffmann-La Roche and AbbVie.
Journal Article
Targeting BTK with Ibrutinib in Relapsed or Refractory Mantle-Cell Lymphoma
by
Kunkel, Lori A
,
Kahl, Brad S
,
Dreyling, Martin
in
Administration, Oral
,
Adult
,
Agammaglobulinaemia Tyrosine Kinase
2013
Mantle-cell lymphoma is often refractory to treatment, especially in response to second-line therapy. Inhibition of the Bruton's tyrosine kinase with ibrutinib produced responses in two thirds of patients in a phase 2 study; 21% of patients had a complete response.
Mantle-cell lymphoma is a distinct subtype of non-Hodgkin's lymphoma that has an aggressive clinical course and a poor prognosis.
1
Current frontline combination chemotherapies
2
and intensive chemoimmunotherapy followed by stem-cell transplantation have improved the outcome for patients with this disease.
3
,
4
Although these regimens have high initial response rates, most patients eventually have a relapse and die from mantle-cell lymphoma. More effective agents are needed.
Constitutive activation of B-cell receptor signaling appears to be essential for the survival and proliferation of malignant B cells, an observation that has led to the design of inhibitors of B-cell receptor–associated kinases.
3
–
5
Bruton's tyrosine . . .
Journal Article
Transcriptomic profiles and 5-year results from the randomized CLL14 study of venetoclax plus obinutuzumab versus chlorambucil plus obinutuzumab in chronic lymphocytic leukemia
2023
Data on long-term outcomes and biological drivers associated with depth of remission after BCL2 inhibition by venetoclax in the treatment of chronic lymphocytic leukemia (CLL) are limited. In this open-label parallel-group phase-3 study, 432 patients with previously untreated CLL were randomized (1:1) to receive either 1-year venetoclax-obinutuzumab (Ven-Obi, 216 patients) or chlorambucil-Obi (Clb-Obi, 216 patients) therapy (NCT02242942). The primary endpoint was investigator-assessed progression-free survival (PFS); secondary endpoints included minimal residual disease (MRD) and overall survival. RNA sequencing of CD19-enriched blood was conducted for exploratory post-hoc analyses. After a median follow-up of 65.4 months, PFS is significantly superior for Ven-Obi compared to Clb-Obi (Hazard ratio [HR] 0.35 [95% CI 0.26–0.46],
p
< 0.0001). At 5 years after randomization, the estimated PFS rate is 62.6% after Ven-Obi and 27.0% after Clb-Obi. In both arms, MRD status at the end of therapy is associated with longer PFS. MRD + ( ≥ 10
−4
) status is associated with increased expression of multi-drug resistance gene
ABCB1 (MDR1)
, whereas MRD6 (< 10
−6
) is associated with
BCL2L11
(
BIM
) expression. Inflammatory response pathways are enriched in MRD+ patient solely in the Ven-Obi arm. These data indicate sustained long-term efficacy of fixed-duration Ven-Obi in patients with previously untreated CLL. The distinct transcriptomic profile of MRD+ status suggests possible biological vulnerabilities.
The CLL14 study (NCT02242942) explored the activity of obinutuzumab (anti-CD20) plus venetoclax (Bcl2 inhibitor) versus obinutuzumab plus chlorambucil in patients with previously untreated chronic lymphocytic leukemia (CLL). Here the authors report the 5-year long-term results of the clinical trial and transcriptional profiles associated with response to therapies.
Journal Article