A Phase I study to evaluate the safety, tolerance and pharmacokinetics
of anti-Shiga toxin hyperimmune equine F(ab’)2 fragments
in healthy volunteers
Authors
Yanina
Hiriart1-2#,
Paula Scibona3, Augusto Ferraris5,
Waldo H. Belloso4, Valeria
Beruto3,
Facundo Garcia Bournissen6, Vanesa
Zylberman1-2, Luciana Muñoz2,
Fernando Goldbaum1,2,7, Linus
Spatz2, Mariana
Colonna2, Santiago Sanguineti2,
Ventura A. Simonovich3.
1-National Scientific and Technological Research Council, CONICET, Godoy
Cruz 2290 (C1425FQB) CABA, Argentina
2-Inmunova S.A Av. 25 de Mayo 1021 (CP1650), San Martín, Buenos Aires,
Argentina
3-Clinical Pharmacology Section,
Hospital Italiano de Buenos
Aires, Tte. Gral. Juan Domingo Perón 4190, CP (C1181ACH), CABA,
Argentina
4-Terra Nova Innovation Unit. Hospital Italiano de Buenos Aires, Tte.
Gral. Juan Domingo Perón 4190, CP (C1181ACH) CABA, Argentina
5-Internal Medicine Section, Hospital Italiano de Buenos Aires, Tte.
Gral. Juan Domingo Perón 4190, CP (C1181ACH), CABA, Argentina
6-Division of Pediatric Clinical Pharmacology, Department of Pediatrics,
Schulich School of Medicine & Dentistry, University of Western Ontario,
London, Ontario, Canada
7-CRIP, Centro de rediseño e ingeniería de proteínas, 25 de Mayo y
Francia (CP 1650) San Martín, Buenos Aires, Argentina
YH and PS equally contributed to this work
* Correspondence to:
Ventura.simonovich@hospitalitaliano.org.ar
*Cover title: Safety of anti-Stx (Fab’)2 fragments
The authors confirm that the Principal Investigator for this paper is
Ventura Simonovich and that he had direct clinical responsibility for
patients.
Word count: The main text has 2961 words, three figures, two tables and
three supplementary tables as appendix
11# Actually, Instituto de estudios
Inmunológicos y Fisiopatológicos, CONICET, UNLP, Boulevard 120 1489,
CP 1900, La Plata, Buenos Aires, ArgentinaABSTRACT
Shiga toxin-producing Escherichia coli -associated hemolytic
uremic syndrome STEC-HUS is considered a toxemic disorder in which early
intervention with neutralizing antibodies may have therapeutic benefits.
We developed a novel therapy, INM004, composed of
F(ab’)2 fragments from equine immunoglobulins that
neutralizes Stx1/Stx2, potentially preventing the onset of HUS.
A single-center, randomized, Phase 1, single-blind, placebo-controlled
clinical trial to evaluate INM004 safety, tolerance, and
pharmacokinetics (PK) in healthy adult volunteers, was conducted in two
stages; In Stage I, eight subjects were divided in two cohorts (n=4) to
receive a single INM004 dose of 2 or 4 mg.kg-1, or placebo
(INM004:placebo rate 3:1). In Stage II six study subjects received
either three INM004 doses of 4 mg.kg-1 repeated every 24 h, or placebo
(INM004:placebo rate of 5:1). Hospital discharged was 24 hours after the
last infusion. INM004 was quantified by ELISA in serum samples obtained
at predefined times. Safety and tolerability were assessed in both
Stages by monitoring adverse events (AEs), laboratory test values, and
vital signs. Eight subjects (57.1%) experienced treatment-emergent AEs
(TEAEs), that resolved within 24 hours without requiring changes in
treatment or additional intervention. No serious AEs were reported. Most
TEAEs were of mild or moderate intensity, and four were possibly
drug-related. Peak concentrations of INM004 occurred within 2 hours
after infusion, with median Cmax values of 45.1 µg.mL-1 and 77.7 µg.mL-1
for different doses. The serum concentration of INM004 declined in a
biphasic manner (t1/2 range 30.7-52.9 hours). Systemic exposures
increased with each subsequent dose in a dose-proportional manner,
exhibiting accumulation. Geometric median Cmax and AUC values were 149
µg.mL-1 and 10300 µg.h.mL-1, respectively, in the repeated dose regimen.
The results obtained in this First in Human Study supporting progression
into the phase 2 trial in children with hemolytic uremic syndrome.
Keywords: HUS treatment, F(ab´)2 fragments,
pharmacokinetics, anti-shiga toxins, INM004
What is already known about this subject:
STEC-HUS is a serious foodborne disease worldwide for which there are
currently no specific therapeutic options availables.
STEC-HUS is considered a toxemic disorder more than a bacterial
disease, suggesting that treatment with neutralizing antibodies may
have a therapeutic benefit.
What this study adds
Equine Anti Shiga Toxin F(ab’)2 immunoglobulins
fragments (INM004) is a novel therapy for STEC infections which have
an excellent profile of safety.
In this phase I study, INM004 showed adequate tolerability and safety
in healthy volunteers, providing information on the pharmacokinetics
of this novel passive immunotherapy to support further clinical
development, including clinical trials in children suffering HUS.
Introduction
Shiga toxin-producing Escherichia coli -associated hemolytic
uremic syndrome (STEC-HUS) is a disease characterized by
microangiopathic hemolytic anemia, thrombocytopenia and acute renal
compromise of varying extent, occurring after an episode of E.
coli diarrhea with or without blood1. STEC-HUS
affects predominantly pediatric patients. STEC-HUS poses a high social
and economic burden, particularly due to the frequent need for long-term
renal replacement therapy and renal transplantation2.
STEC-HUS was described for the first time in 1955 by Gasser et. al, and
30 years later Karmali et al. demonstrated the association between this
syndrome and diarrhea caused by bacteria producing
cytotoxins3. These cytotoxins, called Shiga-type
toxins or shigatoxins (Stx) can cause renal, neurological, intestinal or
heart complications leading in some cases to chronic renal impairment,
and even death. The development of effective treatments for STEC-HUS
remains a priority. Polyclonal antibodies (pAbs) and specifically equine
polyclonal antibodies (EpAbs) present an interesting therapeutic
option4. Their safety and effectiveness have been
widely demonstrated in rabies virus or botulinum toxin exposures, and in
the treatment of venomous snake and scorpion
bites5–8. Furthermore, EpAbs present several
advantages over mAbs. First, they are composed of
F(ab)’2 fragments generated by pepsin digestion that
retain the bivalent binding capacity of IgG immunoglobulins but lack the
constant region (Fc) potentially responsible for Fc-triggered side
effects. Second, EpAbs recognize a vast array of epitopes and tend to
develop greater avidity than mAbs for their cognate antigens. Finally,
EpAbs are considerably easier than mAbs to produce, allowing
manufacturers to rapidly achieve large-scale production.
We developed a novel therapy composed of F(ab’)2fragments from equine immunoglobulins that efficiently neutralizes eight
variants of Stx1 and Stx2 in vitro and in vivo in an
animal model of STEC-HUS potentially preventing the onset of
HUS9. No significant toxicity was observed in
preclinical studies, both in single-dose and repeated-dose toxicity
studies in mice and rabbits10.
The aim of this phase I study was to evaluate the safety, tolerance, and
pharmacokinetics (PK) of INM004 in human volunteers. In addition, the
Stx neutralizing capacity of INM004 in the plasma of volunteers was
evaluated in vitro .
Methods