3K3A-APC

PURPOSE OF REVIEW: Activated protein C (APC) is a homeostatic coagulation protease with anticoagulant and cytoprotective activities. Focusing on APC's effects in the brain, this review discusses three different scenarios that illustrate how APC functions are intimately affecting the physiology and pathophysiology of the brain. RECENT FINDINGS: Cytoprotective APC therapy holds promise for the treatment of ischemic stroke, and a recently completed trial suggested that cytoprotective-selective 3K3A-APC reduced bleeding in ischemic stroke patients...

Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease with diverse etiologies. Therefore, the identification of common disease mechanisms and therapeutics targeting these mechanisms could dramatically improve clinical outcomes. To this end, we developed induced motor neuron (iMN) models from C9ORF72 and sporadic ALS (sALS) patients to identify targets that are effective against these types of cases, which together comprise ~90% of patients. We find that iMNs from C9ORF72 and several sporadic ALS patients share two common defects - impaired autophagosome formation and the aberrant accumulation of glutamate receptors...

3K3A-activated protein C (APC), a cell-signaling analogue of endogenous blood serine protease APC, exerts vasculoprotective, neuroprotective, and anti-inflammatory activities in rodent models of stroke, brain injury, and neurodegenerative disorders. 3K3A-APC is currently in development as a neuroprotectant in patients with ischemic stroke. Here, we report that 3K3A-APC inhibits BACE1 amyloidogenic pathway in a mouse model of Alzheimer's disease (AD). We show that a 4-mo daily treatment of 3-mo-old 5XFAD mice with murine recombinant 3K3A-APC (100 µg/kg/d i...

OBJECTIVE: Agonism of protease-activated receptor (PAR) 1 by activated protein C (APC) provides neuro- and vasculoprotection in experimental neuroinjury models. The pleiotropic PAR1 agonist, 3K3A-APC, reduces neurological injury and promotes vascular integrity; 3K3A-APC proved safe in human volunteers. We performed a randomized, controlled, blinded trial to determine the maximally tolerated dose (MTD) of 3K3A-APC in ischemic stroke patients. METHODS: The NeuroNEXT trial, RHAPSODY, used a novel continual reassessment method to determine the MTD using tiers of 120, 240, 360, and 540 μg/kg of 3K3A-APC...

Neonatal hypoxic ischemic encephalopathy (HIE) resulting from intrapartum asphyxia is a global problem that causes severe disabilities and up to 1 million deaths annually. A variant form of activated protein C, 3K3A-APC, has cytoprotective properties that attenuate brain injury in models of adult stroke. In this study, we compared the ability of 3K3A-APC and APC (wild-type (wt)) to attenuate neonatal brain injury, using the spiny mouse (Acomys cahirinus) model of intrapartum asphyxia. Pups were delivered at 38 days of gestation (term = 39 days), with an intrapartum hypoxic insult of 7...

Protein C is a plasma serine protease zymogen whose active form, activated protein C (APC), exerts potent anticoagulant activity. In addition to its antithrombotic role as a plasma protease, pharmacologic APC is a pleiotropic protease that activates diverse homeostatic cell signaling pathways via multiple receptors on many cells. Engineering of APC by site-directed mutagenesis provided a signaling selective APC mutant with 3 Lys residues replaced by 3 Ala residues, 3K3A-APC, that lacks >90% anticoagulant activity but retains normal cell signaling activities...

In the management of acute ischemic stroke, vessel recanalization correlates with functional status, mortality, cost, and other outcome measures. Thrombolysis with intravenous tissue plasminogen activator has many limitations that restrict its applicability, but recent advances in the development of mechanical thrombectomy devices as well as improved systems of stroke care have resulted in greater likelihood of vessel revascularization. Nonetheless, there remains substantial discrepancy between rates of recanalization and rates of favorable outcome...

BACKGROUND AND PURPOSE: The advent of intra-arterial neurothrombectomy (IAT) for acute ischemic stroke opens a potentially transformative opportunity to improve neuroprotection studies. Combining a putative neuroprotectant with recanalization could produce more powerful trials but could introduce heterogeneity and adverse event possibilities. We sought to demonstrate feasibility of IAT in neuroprotectant trials by defining IAT selection criteria for an ongoing neuroprotectant clinical trial...

APC (activated protein C), derived from the plasma protease zymogen, is antithrombotic and anti-inflammatory. In preclinical injury models, recombinant APC provides neuroprotection for multiple injuries, including ischemic stroke. APC acts directly on brain endothelial cells and neurons by initiating cell signaling that requires multiple receptors. Two or more major APC receptors mediate APC's neuroprotective cell signaling. When bound to endothelial cell protein C receptor, APC can cleave protease-activated receptor 1, causing biased cytoprotective signaling that reduces ischemia-induced injury...

Activated protein C (APC) is a blood protease with anticoagulant activity and cell-signaling activities mediated by the activation of protease-activated receptor 1 (F2R, also known as PAR1) and F2RL1 (also known as PAR3) via noncanonical cleavage. Recombinant variants of APC, such as the 3K3A-APC (Lys191-193Ala) mutant in which three Lys residues (KKK191-193) were replaced with alanine, and/or its other mutants with reduced (>90%) anticoagulant activity, engineered to reduce APC-associated bleeding risk while retaining normal cell-signaling activity, have shown benefits in preclinical models of ischemic stroke, brain trauma, multiple sclerosis, amyotrophic lateral sclerosis, sepsis, ischemic and reperfusion injury of heart, kidney and liver, pulmonary, kidney and gastrointestinal inflammation, diabetes and lethal body radiation...

Activated protein C (APC) is a plasma serine protease that is capable of antithrombotic, anti-inflammatory, anti-apoptotic, and cell-signaling activities. Animal injury studies show that recombinant APC and some of its mutants are remarkably therapeutic for a wide range of injuries. In particular, for neurologic injuries, APC reduces damage caused by ischemia/reperfusion in the brain, by acute brain trauma, and by chronic neurodegenerative conditions. For these neuroprotective effects, APC requires endothelial cell protein C receptor...

The homeostatic blood protease, activated protein C (APC), can function as (1) an antithrombotic on the basis of inactivation of clotting factors Va and VIIIa; (2) a cytoprotective on the basis of endothelial barrier stabilization and anti-inflammatory and antiapoptotic actions; and (3) a regenerative on the basis of stimulation of neurogenesis, angiogenesis, and wound healing. Pharmacologic therapies using recombinant human and murine APCs indicate that APC provides effective acute or chronic therapies for a strikingly diverse range of preclinical injury models...

Despite years of research and efforts to translate stroke research to clinical therapy, ischaemic stroke remains a major cause of death, disability, and diminished quality of life. Primary and secondary preventive measures combined with improved quality of care have made significant progress. However, no novel drug for ischaemic stroke therapy has been approved in the past decade. Numerous studies have shown beneficial effects of activated protein C (APC) in rodent stroke models. In addition to its natural anticoagulant functions, APC conveys multiple direct cytoprotective effects on many different cell types that involve multiple receptors including protease activated receptor (PAR) 1, PAR3, and the endothelial protein C receptor (EPCR)...

BACKGROUND AND PURPOSE: Activated Protein C (APC) stimulates multiple cytoprotective pathways via the protease activated receptor-1 (PAR-1) and promotes anticoagulation. 3K3A-APC was designed for preserved activity at PAR-1 with reduced anticoagulation. This Phase 1 trial characterized pharmacokinetics and anticoagulation effects of 3K3A-APC. METHODS: Subjects (n=64) were randomly assigned to receive 3K3A-APC (n=4) at 6, 30, 90, 180, 360, 540 or 720 µg/kg or placebo (n=6) and were observed for 24 hr...

BACKGROUND AND PURPOSE: 3K3A-activated protein C (APC) protects young, healthy male rodents after ischemic stroke. 3K3A-APC is currently under development as a neuroprotectant for acute ischemic stroke in humans. Stroke Therapy Academic Industry Roundtable recommends that after initial studies in young, healthy male animals, further studies should be performed in females, aged animals, and animals with comorbid conditions. Here, we studied the effects of delayed 3KA-APC therapy alone and with tissue-type plasminogen activator (tPA) in aged female mice and spontaneously hypertensive rats...

Activated protein C (APC) is a protease with anticoagulant and cell-signaling activities. In the CNS, APC and its analogs with reduced anticoagulant activity but preserved cell signaling activities, such as 3K3A-APC, exert neuroprotective, vasculoprotective, and anti-inflammatory effects. Murine APC promotes subependymal neurogenesis in rodents in vivo after ischemic and traumatic brain injury. Whether human APC can influence neuronal production from resident progenitor cells in humans is unknown. Here we show that 3K3A-APC, but not S360A-APC (an enzymatically inactive analog of APC), stimulates neuronal mitogenesis and differentiation from fetal human neural stem and progenitor cells (NPCs)...

Wild type (WT) activated protein C (APC) and cytoprotective-selective APC variants such as 3K3A-APC (<10% anticoagulant but normal cytoprotective activity) are neuroprotective in murine focal ischemic stroke models. Here we compared the neuroprotective effects of the anticoagulant-selective E149A-APC variant (>3-fold increased anticoagulant activity but defective cytoprotective activities) to those of the cytoprotective-selective 5A-APC variant (<10% anticoagulant activity). After transient distal middle cerebral artery occlusion, mice received a vehicle, E149A-APC or 5A-APC at 0...

3K3A-APC is a recombinant analog of activated protein C (APC) which is an endogenous protease with multiple functions in the body. Compared to APC, 3K3A-APC has reduced anticoagulant activity but preserved cell signaling activities. In the brain, 3K3A-APC exerts neuroprotective effects after an acute or chronic injury. 3K3A-APC is currently under clinical assessment as a neuroprotective agent following acute ischemic stroke. Whether 3K3A-APC can influence post-ischemic neurogenesis and improve neurological outcome by promoting brain repair remains unknown...

BACKGROUND AND PURPOSE: Tissue plasminogen activator (tPA) is the only approved therapy for acute ischemic stroke. However, tPA has a brief therapeutic window. Its side effects include intracerebral bleeding and neurotoxicity. Therefore, a combination therapy with tPA and agents that can extend the therapeutic window of tPA and/or counteract its side effects are warranted. Here, we studied whether 3K3A-APC, a neuroprotective analog of activated protein C with reduced anticoagulant activity, can enhance the therapeutic effects of tPA in models of ischemic stroke in rodents...

Activated protein C (APC), a protease with anticoagulant and cytoprotective activities, protects neurons and cerebrovascular endothelium from ischemic injury. A recombinant APC, drotrecogin alfa (activated) (DrotAA) (Xigris®), was approved by the Food and Drug Administration for the treatment of sepsis; however, serious bleeding was a dose-limiting side effect. A modified APC, containing 405 amino acid residues, 3K3A-APC, was designed to possess significantly reduced anticoagulant activity ( < 10 %) while maintaining full cytoprotective properties...