Jakub Krejcik

Bio: Jakub Krejcik is an academic researcher from University of Southern Denmark. The author has contributed to research in topics: Daratumumab & Multiple myeloma. The author has an hindex of 11, co-authored 15 publications receiving 1729 citations. Previous affiliations of Jakub Krejcik include VU University Medical Center.

Targeting CD38 with daratumumab monotherapy in multiple myeloma

Abstract: BACKGROUND Multiple myeloma cells uniformly overexpress CD38. We studied daratumumab, a CD38-targeting, human IgG1κ monoclonal antibody, in a phase 1–2 trial involving patients with relapsed myeloma or relapsed myeloma that was refractory to two or more prior lines of therapy. METHODS In part 1, the dose-escalation phase, we administered daratumumab at doses of 0.005 to 24 mg per kilogram of body weight. In part 2, the dose-expansion phase, 30 patients received 8 mg per kilogram of daratumumab and 42 received 16 mg per kilogram, administered once weekly (8 doses), twice monthly (8 doses), and monthly for up to 24 months. End points included safety, efficacy, and pharmacokinetics. RESULTS No maximum tolerated dose was identified in part 1. In part 2, the median time since diagnosis was 5.7 years. Patients had received a median of four prior treatments; 79% of the patients had disease that was refractory to the last therapy received (64% had disease refractory to proteasome inhibitors and immunomodulatory drugs and 64% had disease refractory to bortezomib and lenalidomide), and 76% had received autologous stem-cell transplants. Infusion-related reactions in part 2 were mild (71% of patients had an event of any grade, and 1% had an event of grade 3), with no dose-dependent adverse events. The most common adverse events of grade 3 or 4 (in ≥5% of patients) were pneumonia and thrombocytope nia. The overall response rate was 36% in the cohort that received 16 mg per kilogram (15 patients had a partial response or better, including 2 with a complete response and 2 with a very good partial response) and 10% in the cohort that received 8 mg per kilogram (3 had a partial response). In the cohort that received 16 mg per kilogram, the median progression-free survival was 5.6 months (95% confidence interval [CI], 4.2 to 8.1), and 65% (95% CI, 28 to 86) of the patients who had a response did not have progression at 12 months. CONCLUSIONS Daratumumab monotherapy had a favorable safety profile and encouraging efficacy in patients with heavily pretreated and refractory myeloma. (Funded by Janssen Research and Development and Genmab; ClinicalTrials.gov number, NCT00574288.)

Monocytes and granulocytes reduce CD38 expression levels on myeloma cells in patients treated with daratumumab

Abstract: Purpose: Daratumumab treatment results in a marked reduction of CD38 expression on multiple myeloma cells. The aim of this study was to investigate the clinical implications and the underlying mechanisms of daratumumab-mediated CD38 reduction.Experimental Design: We evaluated the effect of daratumumab alone or in combination with lenalidomide-dexamethasone, on CD38 levels of multiple myeloma cells and nontumor immune cells in the GEN501 study (daratumumab monotherapy) and the GEN503 study (daratumumab combined with lenalidomide-dexamethasone). In vitro assays were also performed.Results: In both trials, daratumumab reduced CD38 expression on multiple myeloma cells within hours after starting the first infusion, regardless of depth and duration of the response. In addition, CD38 expression on nontumor immune cells, including natural killer cells, T cells, B cells, and monocytes, was also reduced irrespective of alterations in their absolute numbers during therapy. In-depth analyses revealed that CD38 levels of multiple myeloma cells were only reduced in the presence of complement or effector cells, suggesting that the rapid elimination of CD38high multiple myeloma cells can contribute to CD38 reduction. In addition, we discovered that daratumumab-CD38 complexes and accompanying cell membrane were actively transferred from multiple myeloma cells to monocytes and granulocytes. This process of trogocytosis was also associated with reduced surface levels of some other membrane proteins, including CD49d, CD56, and CD138.Conclusions: Daratumumab rapidly reduced CD38 expression levels, at least in part, through trogocytosis. Importantly, all these effects also occurred in patients with deep and durable responses, thus excluding CD38 reduction alone as a mechanism of daratumumab resistance.The trials were registered at www.clinicaltrials.gov as NCT00574288 (GEN501) and NCT1615029 (GEN503). Clin Cancer Res; 23(24); 7498-511. ©2017 AACR.

Daratumumab for the Treatment of Multiple Myeloma.

Abstract: This mini-review will summarize the present state of development of the CD38 antibody daratumumab for the treatment of multiple myeloma.

Daratumumab, Bortezomib, and Dexamethasone for Multiple Myeloma

Abstract: BackgroundDaratumumab, a human IgGκ monoclonal antibody that targets CD38, induces direct and indirect antimyeloma activity and has shown substantial efficacy as monotherapy in heavily pretreated patients with multiple myeloma, as well as in combination with bortezomib in patients with newly diagnosed multiple myeloma. MethodsIn this phase 3 trial, we randomly assigned 498 patients with relapsed or relapsed and refractory multiple myeloma to receive bortezomib (1.3 mg per square meter of body-surface area) and dexamethasone (20 mg) alone (control group) or in combination with daratumumab (16 mg per kilogram of body weight) (daratumumab group). The primary end point was progression-free survival. ResultsA prespecified interim analysis showed that the rate of progression-free survival was significantly higher in the daratumumab group than in the control group; the 12-month rate of progression-free survival was 60.7% in the daratumumab group versus 26.9% in the control group. After a median follow-up period ...

Daratumumab, Lenalidomide, and Dexamethasone for Multiple Myeloma

Abstract: BackgroundDaratumumab showed promising efficacy alone and with lenalidomide and dexamethasone in a phase 1–2 study involving patients with relapsed or refractory multiple myeloma. MethodsIn this phase 3 trial, we randomly assigned 569 patients with multiple myeloma who had received one or more previous lines of therapy to receive lenalidomide and dexamethasone either alone (control group) or in combination with daratumumab (daratumumab group). The primary end point was progression-free survival. ResultsAt a median follow-up of 13.5 months in a protocol-specified interim analysis, 169 events of disease progression or death were observed (in 53 of 286 patients [18.5%] in the daratumumab group vs. 116 of 283 [41.0%] in the control group; hazard ratio, 0.37; 95% confidence interval [CI], 0.27 to 0.52; P<0.001 by stratified log-rank test). The Kaplan–Meier rate of progression-free survival at 12 months was 83.2% (95% CI, 78.3 to 87.2) in the daratumumab group, as compared with 60.1% (95% CI, 54.0 to 65.7) in t...

Targeting CD38 with daratumumab monotherapy in multiple myeloma

Abstract: BACKGROUND Multiple myeloma cells uniformly overexpress CD38. We studied daratumumab, a CD38-targeting, human IgG1κ monoclonal antibody, in a phase 1–2 trial involving patients with relapsed myeloma or relapsed myeloma that was refractory to two or more prior lines of therapy. METHODS In part 1, the dose-escalation phase, we administered daratumumab at doses of 0.005 to 24 mg per kilogram of body weight. In part 2, the dose-expansion phase, 30 patients received 8 mg per kilogram of daratumumab and 42 received 16 mg per kilogram, administered once weekly (8 doses), twice monthly (8 doses), and monthly for up to 24 months. End points included safety, efficacy, and pharmacokinetics. RESULTS No maximum tolerated dose was identified in part 1. In part 2, the median time since diagnosis was 5.7 years. Patients had received a median of four prior treatments; 79% of the patients had disease that was refractory to the last therapy received (64% had disease refractory to proteasome inhibitors and immunomodulatory drugs and 64% had disease refractory to bortezomib and lenalidomide), and 76% had received autologous stem-cell transplants. Infusion-related reactions in part 2 were mild (71% of patients had an event of any grade, and 1% had an event of grade 3), with no dose-dependent adverse events. The most common adverse events of grade 3 or 4 (in ≥5% of patients) were pneumonia and thrombocytope nia. The overall response rate was 36% in the cohort that received 16 mg per kilogram (15 patients had a partial response or better, including 2 with a complete response and 2 with a very good partial response) and 10% in the cohort that received 8 mg per kilogram (3 had a partial response). In the cohort that received 16 mg per kilogram, the median progression-free survival was 5.6 months (95% confidence interval [CI], 4.2 to 8.1), and 65% (95% CI, 28 to 86) of the patients who had a response did not have progression at 12 months. CONCLUSIONS Daratumumab monotherapy had a favorable safety profile and encouraging efficacy in patients with heavily pretreated and refractory myeloma. (Funded by Janssen Research and Development and Genmab; ClinicalTrials.gov number, NCT00574288.)

Lenalidomide, Bortezomib, and Dexamethasone with Transplantation for Myeloma

Abstract: BackgroundHigh-dose chemotherapy plus autologous stem-cell transplantation has been the standard treatment for newly diagnosed multiple myeloma in adults up to 65 years of age. However, promising data on the use of combination therapy with lenalidomide, bortezomib, and dexamethasone (RVD) in this population have raised questions about the role and timing of transplantation. MethodsWe randomly assigned 700 patients with multiple myeloma to receive induction therapy with three cycles of RVD and then consolidation therapy with either five additional cycles of RVD (350 patients) or high-dose melphalan plus stem-cell transplantation followed by two additional cycles of RVD (350 patients). Patients in both groups received maintenance therapy with lenalidomide for 1 year. The primary end point was progression-free survival. ResultsMedian progression-free survival was significantly longer in the group that underwent transplantation than in the group that received RVD alone (50 months vs. 36 months; adjusted hazar...

Guidelines for the use of flow cytometry and cell sorting in immunological studies (second edition)

Abstract: These guidelines are a consensus work of a considerable number of members of the immunology and flow cytometry community. They provide the theory and key practical aspects of flow cytometry enabling immunologists to avoid the common errors that often undermine immunological data. Notably, there are comprehensive sections of all major immune cell types with helpful Tables detailing phenotypes in murine and human cells. The latest flow cytometry techniques and applications are also described, featuring examples of the data that can be generated and, importantly, how the data can be analysed. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid, all written and peer-reviewed by leading experts in the field, making this an essential research companion.