scholarly journals Plitidepsin has a positive therapeutic index in adult patients with COVID-19 requiring hospitalization.

2021 ◽  
Author(s):  
Jose F. Varona ◽  
Pedro Landete ◽  
Jose A Lopez-Martin ◽  
Vicente Estrada ◽  
Roger Paredes ◽  
...  
Keyword(s):  
Cyclic Peptide ◽  
Elongation Factor ◽  
Therapeutic Index ◽  
Adult Patients ◽  
Host Protein ◽  
Dose Effect ◽  
Dependent Manner ◽  
Eukaryotic Translation ◽  
Discharge Rates ◽  
Grade 3

Plitidepsin is a marine-derived cyclic-peptide that inhibits SARS-CoV-2 replication at low nanomolar concentrations by the targeting of host protein eEF1A (eukaryotic translation-elongation-factor-1A). We evaluated a model of intervention with plitidepsin in hospitalized COVID-19 adult patients where three doses were assessed (1.5, 2 and 2.5 mg/day for 3 days, as a 90-minute intravenous infusion) in 45 patients (15 per dose-cohort). Treatment was well tolerated, with only two Grade 3 treatment-related adverse events observed (hypersensitivity and diarrhea). The discharge rates by Days 8 and 15 were 56.8% and 81.8%, respectively, with data sustaining dose-effect. A mean 4.2 log10 viral load reduction was attained by Day 15. Improvement in inflammation markers was also noted in a seemingly dose-dependent manner. These results suggest that plitidepsin impacts the outcome of patients with COVID-19.

scholarly journals Preclinical and randomized phase I studies of plitidepsin in adults hospitalized with COVID-19

2022 ◽  
Vol 5 (4) ◽  
pp. e202101200
Author(s):  
Jose F Varona ◽  
Pedro Landete ◽  
Jose A Lopez-Martin ◽  
Vicente Estrada ◽  
Roger Paredes ◽  
...  
Keyword(s):  
Viral Load ◽  
Adverse Events ◽  
Cyclic Peptide ◽  
Elongation Factor ◽  
Primary Objective ◽  
Host Protein ◽  
Dose Selection ◽  
Open Label ◽  
Eukaryotic Translation ◽  
Grade 3

Plitidepsin, a marine-derived cyclic-peptide, inhibits SARS-CoV-2 replication at nanomolar concentrations by targeting the host protein eukaryotic translation elongation factor 1A. Here, we show that plitidepsin distributes preferentially to lung over plasma, with similar potency against across several SARS-CoV-2 variants in preclinical studies. Simultaneously, in this randomized, parallel, open-label, proof-of-concept study (NCT04382066) conducted in 10 Spanish hospitals between May and November 2020, 46 adult hospitalized patients with confirmed SARS-CoV-2 infection received either 1.5 mg (n = 15), 2.0 mg (n = 16), or 2.5 mg (n = 15) plitidepsin once daily for 3 d. The primary objective was safety; viral load kinetics, mortality, need for increased respiratory support, and dose selection were secondary end points. One patient withdrew consent before starting procedures; 45 initiated treatment; one withdrew because of hypersensitivity. Two Grade 3 treatment-related adverse events were observed (hypersensitivity and diarrhea). Treatment-related adverse events affecting more than 5% of patients were nausea (42.2%), vomiting (15.6%), and diarrhea (6.7%). Mean viral load reductions from baseline were 1.35, 2.35, 3.25, and 3.85 log10 at days 4, 7, 15, and 31. Nonmechanical invasive ventilation was required in 8 of 44 evaluable patients (16.0%); six patients required intensive care support (13.6%), and three patients (6.7%) died (COVID-19-related). Plitidepsin has a favorable safety profile in patients with COVID-19.

scholarly journals Plitidepsin has potent preclinical efficacy against SARS-CoV-2 by targeting the host protein eEF1A

Science ◽  
2021 ◽  
Vol 371 (6532) ◽  
pp. 926-931 ◽  
Author(s):  
Kris M. White ◽  
Romel Rosales ◽  
Soner Yildiz ◽  
Thomas Kehrer ◽  
Lisa Miorin ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Elongation Factor ◽  
Resistant Mutant ◽  
Host Protein ◽  
Translation Elongation Factor ◽  
Translation Elongation ◽  
Eukaryotic Translation ◽  
Drug Resistant Mutant

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral proteins interact with the eukaryotic translation machinery, and inhibitors of translation have potent antiviral effects. We found that the drug plitidepsin (aplidin), which has limited clinical approval, possesses antiviral activity (90% inhibitory concentration = 0.88 nM) that is more potent than remdesivir against SARS-CoV-2 in vitro by a factor of 27.5, with limited toxicity in cell culture. Through the use of a drug-resistant mutant, we show that the antiviral activity of plitidepsin against SARS-CoV-2 is mediated through inhibition of the known target eEF1A (eukaryotic translation elongation factor 1A). We demonstrate the in vivo efficacy of plitidepsin treatment in two mouse models of SARS-CoV-2 infection with a reduction of viral replication in the lungs by two orders of magnitude using prophylactic treatment. Our results indicate that plitidepsin is a promising therapeutic candidate for COVID-19.

Virtual Screening, Molecular Modelling and Biochemical Studies to Exploit PF14_0660 as a Target to Identify Novel Anti-malarials

2019 ◽  
Vol 16 (4) ◽  
pp. 417-426
Author(s):  
Vimee Raturi ◽  
Kumar Abhishek ◽  
Subhashis Jana ◽  
Subhendu Sekhar Bag ◽  
Vishal Trivedi
Keyword(s):  
Virtual Screening ◽  
Phosphatase Activity ◽  
Molecular Modelling ◽  
Drug Target ◽  
Antimalarial Activity ◽  
Biochemical Study ◽  
Tyrosine Phosphatase ◽  
Host Protein ◽  
Dependent Manner ◽  
Multiple Sequence

Background: Malaria Parasite relies heavily on signal transduction pathways to control growth, the progression of the life cycle and sustaining stress for its survival. Unlike kinases, Plasmodium's phosphatome is one of the smallest and least explored for identifying drug target for clinical intervention. PF14_0660 is a putative protein present on the chromosome 14 of Plasmodium falciparum genome. Methods: Multiple sequence alignment of PF14_0660 with other known protein phosphatase indicate the presence of phosphatase motif with specific residues essential for metal binding, catalysis and providing structural stability. PF14_0660 is a mixed α/β type of protein with several β -sheet and α-helix arranged to form βαβαβα sub-structure. The surface properties of PF14_0660 is conserved with another phosphate of this family, but it profoundly diverges from the host protein tyrosine phosphatase. PF14_0660 was cloned, over-expressed and protein is exhibiting phosphatase activity in a dose-dependent manner. Docking of Heterocyclic compounds from chemical libraries into the PF14_0660 active site found nice fitting of several candidate molecules. Results: Compound PPinh6, PPinh 7 and PPinh 5 are exhibiting antimalarial activity with an IC50 of 1.4 ± 0.2µM, 3.8 ± 0.3 µM and 9.4 ± 0.6&#181M respectively. Compound PPinh 6 and PPinh 7 are inhibiting intracellular PF14_0660 phosphatase activity and killing parasite through the generation of reactive oxygen species. Conclusion: Hence, a combination of molecular modelling, virtual screening and biochemical study allowed us to explore the potentials of PF14_0660 as a drug target to design anti-malarials.

scholarly journals Activation of mitochondrial TUFM ameliorates metabolic dysregulation through coordinating autophagy induction

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Dasol Kim ◽  
Hui-Yun Hwang ◽  
Eun Sun Ji ◽  
Jin Young Kim ◽  
Jong Shin Yoo ◽  
...  
Keyword(s):  
Metabolic Regulation ◽  
Elongation Factor ◽  
Dependent Manner ◽  
Diet Induced Obesity ◽  
Metabolic Dysregulation ◽  
Autophagy Induction ◽  
Transcription Factor Eb ◽  
Mitochondrial Elongation

AbstractDisorders of autophagy, a key regulator of cellular homeostasis, cause a number of human diseases. Due to the role of autophagy in metabolic dysregulation, there is a need to identify autophagy regulators as therapeutic targets. To address this need, we conducted an autophagy phenotype-based screen and identified the natural compound kaempferide (Kaem) as an autophagy enhancer. Kaem promoted autophagy through translocation of transcription factor EB (TFEB) without MTOR perturbation, suggesting it is safe for administration. Moreover, Kaem accelerated lipid droplet degradation in a lysosomal activity-dependent manner in vitro and ameliorated metabolic dysregulation in a diet-induced obesity mouse model. To elucidate the mechanism underlying Kaem’s biological activity, the target protein was identified via combined drug affinity responsive target stability and LC–MS/MS analyses. Kaem directly interacted with the mitochondrial elongation factor TUFM, and TUFM absence reversed Kaem-induced autophagy and lipid degradation. Kaem also induced mitochondrial reactive oxygen species (mtROS) to sequentially promote lysosomal Ca2+ efflux, TFEB translocation and autophagy induction, suggesting a role of TUFM in mtROS regulation. Collectively, these results demonstrate that Kaem is a potential therapeutic candidate/chemical tool for treating metabolic dysregulation and reveal a role for TUFM in autophagy for metabolic regulation with lipid overload.

scholarly journals A phase I study of combined trabectedin and pegylated liposomal doxorubicin therapy for advanced relapsed ovarian cancer

2021 ◽  
Author(s):  
Shunji Takahashi ◽  
Munetaka Takekuma ◽  
Kenji Tamura ◽  
Kazuhiro Takehara ◽  
Hiroyuki Nomura ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Phase I ◽  
Liposomal Doxorubicin ◽  
Advanced Ovarian Cancer ◽  
Pegylated Liposomal Doxorubicin ◽  
Japanese Patients ◽  
Pharmacokinetic Analysis ◽  
Dependent Manner ◽  
Drug Concentrations ◽  
Grade 3

Abstract Background Advanced relapsed ovarian cancer has a poor prognosis, and treatment options are limited. Methods This phase I trial investigated the dosage, safety, pharmacokinetics and efficacy of trabectedin plus pegylated liposomal doxorubicin (PLD) in Japanese patients with advanced relapsed ovarian, fallopian tube, or primary peritoneal cancer. Patients received trabectedin 0.9 or 1.1 mg/m2 immediately after PLD 30 mg/m2; both drugs were given by intravenous infusion. Treatment was repeated every 21 days until disease progression or unacceptable toxicity. The maximum tolerated dose (MTD) was determined in an initial dose escalation phase, and this was used in a subsequent safety assessment phase. Safety and tumor response were monitored throughout the trial, and drug concentrations for pharmacokinetic analysis were measured during cycle 1. Results Eighteen patients were included. The MTD of trabectedin was determined as 1.1 mg/m2. Gastrointestinal adverse events were experienced by all patients, but were mostly grade 1 or 2 in intensity. Most patients had grade ≥ 3 elevations in transaminase levels or grade ≥ 3 reductions in neutrophil count, but these events were generally manageable through dose reduction and/or supportive therapies, as appropriate. There were no deaths during the trial. Trabectedin exposure increased in a dose-dependent manner. The overall response rate was 27.8%. Conclusions Trabectedin, in combination with PLD, may have clinical benefits in Japanese patients with relapsed advanced ovarian cancer. The recommended dosage of trabectedin for further study in this population is 1.1 mg/m2 once every 21 days. Clinical trial registration number: JapicCTI-163164

Functional analysis of a stable transcription arrest site in the first intron of the murine adenosine deaminase gene

1993 ◽  
Vol 13 (5) ◽  
pp. 2718-2729
Author(s):  
S F Kash ◽  
J W Innis ◽  
A U Jackson ◽  
R E Kellems
Keyword(s):  
Rna Polymerase Ii ◽  
Adenosine Deaminase ◽  
Functional Characterization ◽  
Gel Filtration ◽  
Point Mutations ◽  
Elongation Factor ◽  
Dependent Manner ◽  
First Intron ◽  
Intron 1

Transcription arrest plays a role in regulating the expression of a number of genes, including the murine adenosine deaminase (ADA) gene. We have previously identified two prominent arrest sites at the 5' end of the ADA gene: one in the first exon and one in the first intron (J. W. Innis and R. E. Kellems, Mol. Cell. Biol. 11:5398-5409, 1991). Here we report the functional characterization of the intron 1 arrest site, located 137 to 145 nucleotides downstream of the cap site. We have determined, using gel filtration, that the intron 1 arrest site is a stable RNA polymerase II pause site and that the transcription elongation factor SII promotes read-through at this site. Additionally, the sequence determinants for the pause are located within a 37-bp fragment encompassing this site (+123 to +158) and can direct transcription arrest in an orientation-dependent manner in the context of the ADA and adenovirus major late promoters. Specific point mutations in this region increase or decrease the relative pausing efficiency. We also show that the sequence determinants for transcription arrest can function when placed an additional 104 bp downstream of their natural position.

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