Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT04357730 |
Other study ID # |
20-0880 |
Secondary ID |
|
Status |
Completed |
Phase |
Phase 2
|
First received |
|
Last updated |
|
Start date |
May 14, 2020 |
Est. completion date |
September 30, 2021 |
Study information
Verified date |
January 2022 |
Source |
Denver Health and Hospital Authority |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial Summary
The global pandemic COVID-19 has overwhelmed the medical capacity to accommodate a large
surge of patients with acute respiratory distress syndrome (ARDS). In the United States, the
number of cases of COVID-19 ARDS is projected to exceed the number of available ventilators.
Reports from China and Italy indicate that 22-64% of critically ill COVID-19 patients with
ARDS will die. ARDS currently has no evidence-based treatments other than low tidal
ventilation to limit mechanical stress on the lung and prone positioning. A new therapeutic
approach capable of rapidly treating and attenuating ARDS secondary to COVID-19 is urgently
needed.
The dominant pathologic feature of viral-induced ARDS is fibrin accumulation in the
microvasculature and airspaces. Substantial preclinical work suggests antifibrinolytic
therapy attenuates infection provoked ARDS. In 2001, a phase I trial 7 demonstrated the
urokinase and streptokinase were effective in patients with terminal ARDS, markedly improving
oxygen delivery and reducing an expected mortality in that specific patient cohort from 100%
to 70%. A more contemporary approach to thrombolytic therapy is tissue plasminogen activator
(tPA) due to its higher efficacy of clot lysis with comparable bleeding risk 8. We therefore
propose a phase IIa clinical trial with two intravenous (IV) tPA treatment arms and a control
arm to test the efficacy and safety of IV tPA in improving respiratory function and
oxygenation, and consequently, successful extubation, duration of mechanical ventilation and
survival.
Description:
As the COVID-19 pandemic accelerates, cases have grown exponentially around the world. Other
countries' experience suggests that 5-16% of COVID-19 in-patients will undergo prolonged
intensive care with 50-70% needing mechanical ventilation(MV) threatening to overwhelm
hospital capacity. ARDS has no effective treatment besides supportive care, the use of
ventilation strategies encompassing low tidal volumes that limit trans-pulmonary pressures,
and prone positioning in severe disease. Most current trials in clinicaltrials.gov for
COVID-19-induced ARDS aim at modulating the inflammatory response or test anti-viral drugs.
Sarilumab and tocilizumab that block IL-6 effects are being tested in RCT for patients
hospitalized with severe COVID-19 (NCT04317092, NCT04322773, NCT04327388). The World Health
Organization international trial SOLIDARITY will test remdesivir; chloroquine +
hydroxychloroquine; lopinavir + ritonavir; and lopinavir + ritonavir and interferon-beta
(NCT04321616). Yet studies targeting the coagulation system, which is intrinsically
intertwined with the inflammatory response are lacking.
A consistent finding in ARDS is the deposition of fibrin in the airspaces and lung
parenchyma, along with fibrin-platelet microthrombi in the pulmonary vasculature, which
contribute to the development of progressive respiratory dysfunction and right heart failure.
Similar to pathologic findings of ARDS, microthrombi have now been observed in lung specimens
from patients infected with COVID-19.
Inappropriate activation of the clotting system in ARDS results from enhanced activation and
propagation of clot formation as well as suppression of fibrinolysis. Our group has shown
that low fibrinolysis is associated with ARDS. Studies starting decades ago have demonstrated
the systemic and local effects of dysfunctional coagulation in ARDS, specifically related to
fibrin. This occurs largely because of excessive amounts of tissue factor that is produced by
alveolar epithelial cells and activated alveolar macrophages, and high levels of plasminogen
activator inhibitor-1 (PAI-1) produced and released by endothelial cells. Consistent with
this, generalized derangements of the hemostatic system with prolongation of the prothrombin
time, elevated D-dimer and fibrin degradation products have been reported in severely ill
COVID-19 patients, particularly in non-survivors. These laboratory findings, in combination
with the large clot burden seen in the pulmonary microvasculature, mirrors what is seen in
human sepsis, experimental endotoxemia, and massive tissue trauma. Targeting the coagulation
and fibrinolytic systems to improve the treatment of ARDS has been proposed for at least the
past two decades. In particular, the use of plasminogen activators to limit ARDS progression
and reduce ARDS-induced death has received strong support from animal models, and a phase 1
human clinical trial. In 2001, Hardaway and colleagues showed that administration of either
urokinase or streptokinase to patients with terminal ARDS reduced the expected mortality from
100% to 70% with no adverse bleeding events. Importantly, the majority of patients who
ultimately succumbed died from renal or hepatic failure, rather than pulmonary failure.
Consideration of therapies that are widely available but not recognized for this indication
and traditionally considered "high-risk" such as fibrinolytic agents is warranted in this
unprecedented public health emergency, since the risk of adverse events from tPA is far
outweighed by the extremely high risk of death in the patient's meeting the eligibility
criteria for this trial. While the prior studies by Hardaway et al evaluating fibrinolytic
therapy for treatment of ARDS used urokinase and streptokinase, the more contemporary
approach to thrombolytic therapy involves the use of tissue-type plasminogen activator (tPA)
due to higher efficacy of clot lysis with comparable bleeding risk to the other fibrinolytic
agents.