Platelet Aggregation Analysis of AMG 531 in a Randomized, Placebo-Controlled Study in Healthy Japanese Subjects.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1071-1071
Author(s):  
Yuji Kumagai ◽  
Tomoe Fujita ◽  
Machiko Ozaki ◽  
Kunihiko Sahashi ◽  
Masayuki Ohkura ◽  
...  

Abstract AMG 531 is a novel thrombopoiesis-stimulating peptibody currently being investigated for the treatment of chronic immune thrombocytopenic purpura. This study was a double-blind, phase 1 evaluation of safety (including a platelet aggregation analysis), pharmacodynamics, and pharmacokinetics of AMG 531 in healthy Japanese men. Thirty subjects were randomly assigned 4:1 (AMG 531:placebo) to each of 3 sequential dose cohorts (0.3, 1, and 2 μg/kg) of 10 subjects each. A single dose of AMG 531 or placebo was administered by subcutaneous injection, and subjects were evaluated for 6 weeks. Concentrations of 0.2 and 2 μg/mL collagen and 0.5 and 2 μmol/L adenosine phosphate were used as reagents in the platelet aggregation analysis conducted on day -1, day 2, day 15, and at the end of the study. No enhancement or reduction in platelet aggregation was detected in samples collected from subjects treated with AMG 531 compared with either pretreatment or placebo samples. Overall, adverse events were similar between the AMG 531 and placebo groups. Treatment-related adverse events (headache, “feeling hot,” migraine without aura, and/or malaise) were reported for 5 of 24 subjects treated with AMG 531. Four of 8 subjects who received the 1 μg/kg dose and 7 of 8 subjects who received the 2 μg/kg dose had platelet count increases ≥ 1.5-fold over baseline, and 3 of 8 subjects who received the 2 μg/kg dose had platelet count increases ≥ 2-fold over baseline, a pharmacodynamic effect similar to that seen in previous studies of non-Japanese subjects. Serum concentrations of AMG 531 were below the lower limit of quantification in all but 2 subjects who received the 2 μg/kg dose. In summary, platelets in subjects treated with AMG 531 functioned normally compared with pretreatment and placebo samples. AMG 531 was generally well tolerated and was effective at raising platelet counts after a single subcutaneous administration.

Vaccines ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 296
Author(s):  
Irina Kiseleva ◽  
Irina Isakova-Sivak ◽  
Marina Stukova ◽  
Marianna Erofeeva ◽  
Svetlana Donina ◽  
...  

This study describes a double-blind randomized placebo-controlled phase I clinical trial in healthy adults of a new potential pandemic H7N9 live attenuated influenza vaccine (LAIV) based on the human influenza virus of Yangtze River Delta hemagglutinin lineage (ClinicalTrials.gov Identifier: NCT03739229). Two doses of H7N9 LAIV or placebo were administered intranasally to 30 and 10 subjects, respectively. The vaccine was well-tolerated and not associated with increased rates of adverse events or with any serious adverse events. Vaccine virus was detected in nasal swabs during the 6 days after vaccination or revaccination. A lower frequency of shedding was observed after the second vaccination. Twenty-five clinical viral isolates obtained after the first and second doses of vaccine retained the temperature-sensitive and cold-adapted phenotypic characteristics of LAIV. There was no confirmed transmission of the vaccine strain from vaccinees to placebo recipients. After the two H7N9 LAIV doses, an immune response was observed in 96.6% of subjects in at least one of the assays conducted.


2017 ◽  
Vol 4 (4) ◽  
pp. e367 ◽  
Author(s):  
Christopher LaGanke ◽  
Lawrence Samkoff ◽  
Keith Edwards ◽  
Lily Jung Henson ◽  
Pavle Repovic ◽  
...  

Objective:To evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of VX15/2503 in a randomized, single-dose, dose-escalation, double-blind, placebo-controlled study enrolling adult patients with MS.Methods:Single IV doses of VX15/2503 or placebo were administered. Ten patients each were randomized (4:1 randomization ratio) into 5 ascending dose cohorts of 1, 3, 6, 10, or 20 mg/kg. Safety, immunogenicity, PK/PD, MRI, ECG, and lymphocyte subset levels were evaluated. A Dose Escalation Safety Committee (DESC) approved each dose escalation.Results:VX15/2503 was well tolerated, and all participants completed the study. Antibody treatment–related adverse events were primarily grade 1 or 2 and included urinary tract infection (12.5%) and muscle weakness, contusion, and insomnia (each 7.5%). No dose-limiting toxicities were observed, and no maximum tolerated dose was determined. One subject (20 mg/kg) experienced disease relapse 3 months before study entry and exhibited a grade 3 (nonserious) increase in brain lesions by day 29, possibly related to VX15/2503. Twenty-nine patients exhibited human anti-humanized antibody responses; 5 with titer ≥100. No anti-VX15/2503 antibody responses were fully neutralizing. VX15/2503 Cmax, area under the time-concentration curve, and mean half-life increased with dose level; at 20 mg/kg, the T1/2 was 20 days. Cellular SEMA4D saturation occurred at serum antibody concentrations ≤0.3 μg/mL, resulting in decreased cSEMA4D expression. At 20 mg/kg, cSEMA4D saturation persisted for ≥155 days. Total sSEMA4D levels increased with dose level and declined with antibody clearance.Conclusions:These results support the continued investigation of VX15/2503 in neurodegenerative diseases.ClinicalTrials.gov identifier:NCT01764737.Classification of evidence:This study provides Class III evidence that anti-semaphorin 4D antibody VX15/2503 at various doses was safe and well tolerated vs placebo, although an increase in treatment-emergent adverse events in the treatment group could not be excluded (risk difference −0.7%, 95% CI −28.0% to 32.7%).


2020 ◽  
Author(s):  
Wendy P. Painter ◽  
Wayne Holman ◽  
Jim A. Bush ◽  
Firas Almazedi ◽  
Hamzah Malik ◽  
...  

AbstractMolnupiravir, EIDD-2801/MK-4482, the prodrug of the ribonucleoside analog ß-d-N4-hydroxycytidine (NHC), has activity against a number of RNA viruses including severe acute respiratory syndrome coronavirus 2, severe acute respiratory syndrome coronavirus, Middle East respiratory syndrome coronavirus, seasonal and pandemic influenza viruses, and respiratory syncytial virus.Single and multiple doses of molnupiravir were evaluated in this first-in-human, phase 1, randomized, double-blind, placebo-controlled study in healthy volunteers, which included evaluation of the effect of food on pharmacokinetics.EIDD-1931 appeared rapidly in plasma, with a median time of maximum observed concentration of 1.00 to 1.75 hours, and declined with a geometric half-life of approximately 1 hour, with a slower elimination phase apparent following multiple doses or higher single doses (7.1 hours at the highest dose tested). Mean maximum observed concentration and area under the concentration versus time curve increased in a dose-proportional manner, and there was no accumulation following multiple doses. When administered in a fed state, there was a decrease in the rate of absorption, but no decrease in overall exposure.Molnupiravir was well tolerated. Fewer than half of subjects reported an adverse event, the incidence of adverse events was higher following administration of placebo, and 93.3% of adverse events were mild. One discontinued early due to rash. There were no serious adverse events and there were no clinically significant findings in clinical laboratory, vital signs, or electrocardiography. Plasma exposures exceeded expected efficacious doses based on scaling from animal models; therefore, dose escalations were discontinued before a maximum tolerated dose was reached.Clinical trial identifierThis study was registered at ClinicalTrials.gov with the identifier NCT04392219.


Author(s):  
Wendy P. Painter ◽  
Wayne Holman ◽  
Jim A. Bush ◽  
Firas Almazedi ◽  
Hamzah Malik ◽  
...  

Molnupiravir, EIDD-2801/MK-4482, the prodrug of the active antiviral ribonucleoside analog ß-d-N4-hydroxycytidine (NHC; EIDD-1931), has activity against a number of RNA viruses including severe acute respiratory syndrome coronavirus 2, severe acute respiratory syndrome coronavirus, Middle East respiratory syndrome coronavirus, and seasonal and pandemic influenza viruses. Single and multiple doses of molnupiravir were evaluated in this first-in-human, phase 1, randomized, double-blind, placebo-controlled study in healthy volunteers, which included evaluation of the effect of food on pharmacokinetics. EIDD-1931 appeared rapidly in plasma, with a median time of maximum observed concentration of 1.00 to 1.75 hours, and declined with a geometric half-life of approximately 1 hour, with a slower elimination phase apparent following multiple doses or higher single doses (7.1 hours at the highest dose tested). Mean maximum observed concentration and area under the concentration versus time curve increased in a dose-proportional manner, and there was no accumulation following multiple doses. When administered in a fed state, there was a decrease in the rate of absorption, but no decrease in overall exposure. Molnupiravir was well tolerated. Fewer than half of subjects reported an adverse event, the incidence of adverse events was higher following administration of placebo, and 93.3% of adverse events were mild. One discontinued early due to rash. There were no serious adverse events and there were no clinically significant findings in clinical laboratory, vital signs, or electrocardiography. Plasma exposures exceeded expected efficacious doses based on scaling from animal models; therefore, dose escalations were discontinued before a maximum tolerated dose was reached.


2015 ◽  
Vol 59 (8) ◽  
pp. 4919-4929 ◽  
Author(s):  
Julie H. Ishida ◽  
Tracy Burgess ◽  
Michael A. Derby ◽  
Pearline A. Brown ◽  
Mauricio Maia ◽  
...  

ABSTRACTCytomegalovirus can cause debilitating and life-threatening disease in newborns infectedin uteroand immunocompromised individuals, including transplant recipients. RG7667 is a unique combination of two monoclonal antibodies that binds glycoprotein complexes on the surface of cytomegalovirus and inhibits its entry into host cells. A phase 1 first-in-human, randomized, double-blind, placebo-controlled, dose-escalation study of RG7667 given intravenously was conducted in 181 healthy adults. The study involved a single ascending dose stage (1, 3, 5, and 10 mg/kg each antibody;n= 21), a multiple ascending dose stage (5 and 10 mg/kg each antibody monthly for 3 doses;n= 10), and a multiple dose expansion stage (10 mg/kg each antibody monthly for 3 doses;n= 150). Subjects were followed for 85 to 141 days to evaluate safety, tolerability, pharmacokinetics, and immunogenicity. Most adverse events were mild, and the incidence of adverse events was similar among the RG7667 and placebo groups. RG7667 had dose-proportional pharmacokinetics in all three dosing stages, a mean terminal half-life of 20 to 30 days, and an overall pharmacokinetic profile consistent with that of a human monoclonal antibody that lacks endogenous host targets. The proportion of subjects developing an antitherapeutic antibody response was not higher in the RG7667 group than in the placebo group. In summary, single and multiple doses of RG7667 were found to be safe and well-tolerated in healthy adults and had a favorable pharmacokinetic and immunogenicity profile. This study supports further development of RG7667 as a therapy for the prevention and treatment of cytomegalovirus infection in susceptible populations. (This study has been registered at ClinicalTrials.gov under registration no. NCT01496755.)


1967 ◽  
Vol 18 (03/04) ◽  
pp. 766-778 ◽  
Author(s):  
H. J Knieriem ◽  
A. B Chandler

SummaryThe effect of the administration of warfarin sodium (Coumadin®) on the duration of platelet aggregation in vitro was studied. Coumadin was given for 4 consecutive days to 10 healthy adults who were followed over a period of 9 days. The duration of adenosine diphosphate-induced platelet aggregation in platelet-rich plasma, the prothrombin time, and the platelet count of platelet-rich plasma were measured. Four other healthy adults received placebos and participated in a double-blind study with those receiving Coumadin.Although administration of Coumadin caused a prolongation of the prothrombin time to 2 or 21/2 times the normal value, a decrease in the duration of platelet aggregation was not observed. In most individuals who received Coumadin an increase in the duration of platelet aggregation occurred. The effect of Coumadin on platelet aggregation was not consistently related to the prothrombin time or to the platelet count. In the placebo group there was a distinct relation between the duration of platelet aggregation and the platelet count in platelet-rich plasma.The mean increase in the duration of platelet aggregation when compared to the control value before medication with Coumadin was 37.7%. In the placebo group there was a mean increase of 8.4%. The difference between the two groups is significant (p <0.001). Increased duration of platelet aggregation also occurred in two individuals who received Coumadin over a period of 10 and 16 days respectively.


1985 ◽  
Vol 54 (04) ◽  
pp. 808-812 ◽  
Author(s):  
Ulf Berglund ◽  
Henning von Schenck ◽  
Lars Wallentin

SummaryThe effects of ticlopidine (T) (500 mg daily) on platelet function were investigated in a double-blind placebo-controlled study in 38 middle-aged men with stable incapacitating angina pectoris. The in vitro platelet reactivity to aggregating agents, the platelet sensitivity to prostacyclin and the plasma levels of platelet specific proteins and fibrinogen were determined before and after 4 and 8 weeks of treatment. T exerted a potent inhibitory effect on ADP- and collagen-induced platelet aggregation. The effect of T was proportional to the pretreatment reactivity to ADP and collagen. The inhibitory effect of T on the epinephrine response was less pronounced. The plasma levels of beta-thromboglobulin, platelet factor 4 and fibrinogen were not influenced by T. The platelet inhibition of prostacyclin was potentiated by T, and it was demonstrated that T and prostacyclin had synergistic inhibitory effects on platelet aggregation.


2021 ◽  
Author(s):  
Kathryn E. Stephenson ◽  
Boris Julg ◽  
C. Sabrina Tan ◽  
Rebecca Zash ◽  
Stephen R. Walsh ◽  
...  

AbstractHuman immunodeficiency virus (HIV)-1-specific broadly neutralizing monoclonal antibodies are currently under development to treat and prevent HIV-1 infection. We performed a single-center, randomized, double-blind, dose-escalation, placebo-controlled trial of a single administration of the HIV-1 V3-glycan-specific antibody PGT121 at 3, 10 and 30 mg kg–1 in HIV-uninfected adults and HIV-infected adults on antiretroviral therapy (ART), as well as a multicenter, open-label trial of one infusion of PGT121 at 30 mg kg–1 in viremic HIV-infected adults not on ART (no. NCT02960581). The primary endpoints were safety and tolerability, pharmacokinetics (PK) and antiviral activity in viremic HIV-infected adults not on ART. The secondary endpoints were changes in anti-PGT121 antibody titers and CD4+ T-cell count, and development of HIV-1 sequence variations associated with PGT121 resistance. Among 48 participants enrolled, no treatment-related serious adverse events, potential immune-mediated diseases or Grade 3 or higher adverse events were reported. The most common reactions among PGT121 recipients were intravenous/injection site tenderness, pain and headache. Absolute and relative CD4+ T-cell counts did not change following PGT121 infusion in HIV-infected participants. Neutralizing anti-drug antibodies were not elicited. PGT121 reduced plasma HIV RNA levels by a median of 1.77 log in viremic participants, with a viral load nadir at a median of 8.5 days. Two individuals with low baseline viral loads experienced ART-free viral suppression for ≥168 days following antibody infusion, and rebound viruses in these individuals demonstrated full or partial PGT121 sensitivity. The trial met the prespecified endpoints. These data suggest that further investigation of the potential of antibody-based therapeutic strategies for long-term suppression of HIV is warranted, including in individuals off ART and with low viral load.


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