ABSTRACT
Introduction: Despite several studies, the impact of coronavirus disease 2019 on patients with multiple myeloma remains uncertain. Material(s) and Method(s): We performed a survey that covered the period of the first and second waves of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in 23 centers inseven countries. Out of 352 patients with myeloma and SARS-CoV-2, 23% died. Results/Conclusions: Logistic regression showed a lower risk of death among patients treated with proteasome inhibitor and a higher risk of death for those who had a severe or a very severe course of disease.Copyright © 2023 Sciendo. All rights reserved.
ABSTRACT
Proteasome inhibitors are among the most potent classes of drugs in multiple myeloma treatment. One of the main challenges in myeloma therapy is acquired resistance to drugs. Several theories have been proposed to describe the mechanisms responsible for resistance to the most commonly used proteasome inhibitors bortezomib and carfilzomib. This study aimed to describe functional differences between sensitive myeloma cells (MM1S WT) and their daughter cell lines resistant to either bortezomib (MM1S/R BTZ) or carfilzomib (MM1S/R CFZ), as well as between both resistant cell lines. Bortezomib- and carfilzomib-resistant cell lines were successfully generated by continuous exposure to the drugs. When exposed to different drugs than during the resistance generation period, MM1S/R BTZ cells showed cross-resistance to carfilzomib, whereas MM1S/R CFZ cells were similarly sensitive to bortezomib as MM1S WT cells. Following proteomic profiling, unsupervised principal component analysis revealed that the MM1S/R BTZ and MM1S/R CFZ cell lines differed significantly from the MM1S WT cell line and from each other. Canonical pathway analysis showed similar pathways enriched in both comparisons - MM1S WT vs. MM1S/R CFZ and MM1S WT vs. MM1S/R BTZ. However, important differences were present in the statistical significance of particular pathways. Key alterations included the ubiquitin-proteasome system, metabolic pathways responsible for redox homeostasis and the unfolded protein response. In functional studies, both drugs continued to reduce chymotrypsin-like proteasome activity in resistant cells. However, the baseline activity of all three catalytic domains of the proteasome was higher in the resistant cells. Differences in generation of reactive oxygen species were identified in MM1S/R BTZ (decreased) and MM1S/CFZ cells (increased) in comparison to MM1S WT cells. Both baseline and drug-induced activity of the unfolded protein response were higher in resistant cells than in MM1S WT cells and included all three arms of this pathway: IRE1α/XBP1s, ATF6 and EIF2α/ATF4 (downstream effectors of PERK). In conclusion, contrary to some previous reports, resistant MM1S cells show upregulation of unfolded protein response activity, reflecting the heterogeneity of multiple myeloma and prompting further studies on the role of this pathway in resistance to proteasome inhibitors.
ABSTRACT
Introduction: Multiple myeloma (MM) is the leading indication for autologous stem cell transplantation (ASCT), with over 12,000 transplants per year in Europe. Due to low toxicity, an entirely outpatient procedure or an early discharge after ASCT can be considered as alternatives to inpatient transplantation. Thus, we launched an Early Discharge Program (EDP) for patients qualified for ASCT due to MM who were under 60 years of age, without significant comorbidities, who had a caregiver available 24/7, and who lived within a 60-minute drive of our hospital. Material and methods: Patients spent 72 hours in the hospital being administered melphalan 200 mg/m2 intravenous followed by an infusion of hematopoietic stem cells. They were eventually discharged and remained under outpatient care. The program was launched in September 2019 and was temporarily halted due to the coronavirus disease 19 (COVID-19) pandemic in early 2020. Five patients were enrolled to the EDP. Results: Non-hematological toxicity was mild and manageable in an outpatient setting. Only one patient was readmitted due to exacerbation of ulcerative colitis that was probably not related to ASCT. We observed neither infections nor bleeding. Due to hematological toxicity, three of the five patients received platelet transfusion on the 6th day after ASCT as outpatients. No packed erythrocytes were transfused. The EDP demonstrated lower costs compared to an inpatient approach. Conclusions: We believe that early discharge, which is an intermediate step to full at-home transplantation due to patients' wellbeing, reduction of infections caused by resistant microorganisms, and costs, will eventually replace a full inpatient procedure for a significant population of patients suffering from multiple myeloma and indeed other diseases.