A Randomized, Double−blind, Placebo−controlled, Clinical Outcome Study of ARC1779 Injection in Patients with Thrombotic Microangiopathy.

INTERVENTION: Product Name: ARC1779 Product Code: ARC1779 Pharmaceutical Form: Solution for infusion CAS Number: 934868‐74‐3 Current Sponsor code: ARC1779 Other descriptive name: Poly(oxy‐1,2‐ethanediyl), a‐hydro‐?‐methoxy‐, 5’‐ester with RNA (Gm‐Cm‐Gm‐Um‐dG‐dCdA‐ Concentration unit: mg/ml milligram(s)/millilitre Concentration type: equal Concentration number: 10‐ Pharmaceutical form of the placebo: Solution for infusion Route of administration of the placebo: Intravenous use CONDITION: Thrombotic microangiopathy (TMA) disorders ; MedDRA version: 9.1 Level: LLT Classification code 10009731 Term: Coagulation disorder PRIMARY OUTCOME: Main Objective: • To evaluate the ability of ARC1779 Injection to improve clinical outcome by; protecting brain, heart, and kidney from damage due to formation of disseminated; platelet thrombi in the microcirculation;; • To evaluate the overall safety and tolerability of ARC1779 Injection;; • To assess the concentration‐response of ARC1779 for efficacy‐ and safety‐related; effects;; • To assess the concentration‐response relationships among ARC1779; pharmacokinetic (PK) and pharmacodynamic (PD) parameters. Primary end point(s): Composite of clinical events and biomarker evidence for injury to the target organs commonly affected by TMA, i.e., brain, heart, and kidney. Secondary Objective: INCLUSION CRITERIA: • Male or female; • =18 to =75 years of age; • Diagnosis of TMA based on presence of: ‐ Thrombocytopenia, defined as a platelet count <100 x 109 per liter; ‐ Microangiopathic hemolytic anemia, defined by negative findings on direct antiglobin test, and evidence of accelerated red blood cell (RBC) production and destruction); AND ‐ Absence of a clinically apparent alternative explanation for thrombocytopenia and anemia, e.g., disseminated intravascular coagulation (DIC), eclampsia, HELLP syndrome, Evans syndrome); • Females: non‐pregnant and commit to use of effective, redundant methods of contraception (i.e., for both self and male partner) throughout the study and for at least 30 days after discontinuation of study drug treatment; • Males: commit to use of a medically acceptable contraceptive (abstinence or use of a condom with spermicide) throughout the study and for at least 30 days after discontinuation of study drug tr