Final Results of the RHAPSODY Trial: A Multi-Center, Phase 2 Trial Using a Continual Reassessment Method to Determine the Safety and Tolerability of 3K3A-APC, A Recombinant Variant of Human Activated Protein C, in Combination with Tissue Plasminogen Activator, Mechanical Thrombectomy or both in Moderate to Severe Acute Ischemic Stroke

Ann Neurol. 2019 Jan;85(1):125-136. doi: 10.1002/ana.25383. Epub 2019 Jan 7.


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. After intravenous tissue plasminogen activator, intra-arterial mechanical thrombectomy, or both, patients were randomized to 1 of the 4 doses or placebo. Vasculoprotection was assessed as microbleed and intracranial hemorrhage (ICH) rates.

Results: Between January 2015 and July 2017, we treated 110 patients. Demographics resembled a typical stroke population. The MTD was the highest-dose 3K3A-APC tested, 540 μg/kg, with an estimated toxicity rate of 7%. There was no difference in prespecified ICH rates. In exploratory analyses, 3K3A-APC reduced ICH rates compared to placebo from 86.5% to 67.4% in the combined treatment arms (p = 0.046) and total hemorrhage volume from an average of 2.1 ± 5.8 ml in placebo to 0.8 ± 2.1 ml in the combined treatment arms (p = 0.066).

Interpretation: RHAPSODY is the first trial of a neuroprotectant for acute ischemic stroke in a trial design allowing thrombectomy, thrombolysis, or both. The MTD was 540 μg/kg for the PAR1 active cytoprotectant, 3K3A-APC. A trend toward lower hemorrhage rate in an exploratory analysis requires confirmation.

Clinical trial registration: Clinical Trial Registration-URL: Unique identifier: NCT02222714. ANN NEUROL 2019;85:125-136.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Aged
  • Aged, 80 and over
  • Brain Ischemia / diagnostic imaging
  • Brain Ischemia / drug therapy*
  • Brain Ischemia / surgery*
  • Combined Modality Therapy / methods
  • Drug Therapy, Combination
  • Female
  • Humans
  • Male
  • Middle Aged
  • Protein C / administration & dosage*
  • Recombinant Proteins / administration & dosage*
  • Severity of Illness Index
  • Single-Blind Method
  • Stroke / diagnostic imaging
  • Stroke / drug therapy*
  • Stroke / surgery*
  • Thrombectomy / methods*
  • Tissue Plasminogen Activator / administration & dosage*


  • 3K3A-APC protein
  • Protein C
  • Recombinant Proteins
  • Tissue Plasminogen Activator

Associated data