Phase 2/3 Study to Evaluate PK, Safety & Efficacy of INM004 in STEC Positive Pediatric Patients for Prevention of HUS
Phase 2/3 Study to Evaluate PK, Safety & Efficacy of INM004 in STEC Positive Pediatric Patients for Prevention of HUS
The investigational medicinal product (IMP), INM004, proposes to neutralize the toxin in the
 bloodstream to prevent the interaction of the Stx with the specific receptor, by means of a
 polyclonal antibody to be administered upon the appearance of symptoms (bloody diarrhea) and
 diagnosis of infection by STEC, thereby preventing the action of the toxin in the body. Thus,
 the initial hypothesis for examination is for the prevention of the full expression of HUS,
 based upon presumptive clinical, biochemical, and other biological evidence suggesting a risk
 of HUS at the time of treatment application. The polyclonal antibody (F(ab')2 fragment) is
 obtained by processing the serum of equine animals previously immunized against engineered
 Stx1B and Stx2B immunogens.

 INM004 could be administered at the earlier stages of STEC disease since subjects with STEC
 diarrhea are more likely to benefit from Stx neutralizing antibodies before the development
 of extra-intestinal manifestations and HUS. Neutralizing equine anti-Stx F(ab')2 antibodies
 (INM004) have the objective of preventing the development of HUS by blocking the circulating
 toxins in patients infected with STEC. Therefore, INM004 may be used in patients with a
 clinical manifestation of bloody diarrhea and a positive Stx result in feces. Early
 interruption of the Stx mediated cascade is expected to prevent the development of HUS,
 alleviate the severity of the illness, the rate of complications and the incidence/duration
 of hospitalizations. Therefore, patients in the early phases of the disease will be targeted
 in this study, ie, children who seek medical care due to diarrhea associated with STEC
 infection before HUS development.
Hemolytic uremic syndrome (HUS) is a form of thrombotic microangiopathy, characterized by
 microangiopathic hemolytic anemia, thrombocytopenia, and acute renal impairment of varying
 severity, which may be preceded by an episode of diarrhea with or without blood. Karmali et
 al. showed the relationship between this syndrome and diarrhea caused by Shiga
 toxin-producing bacteria such as Escherichia coli. These cytotoxins, called Shiga-like toxins
 or Shiga toxins (Stx), are also called verotoxins, due to the characteristic cytopathic
 effect they cause on Vero cell cultures.

 HUS is often classified into 3 primary types: 1) HUS due to infections associated with
 Shiga-toxin producing E. coli (STEC) or Shigella dysenteriae Type 1, often associated with
 diarrhea, with the rare exception of HUS due to a severe disseminated infection caused by
 Streptococcus pneumoniae, 2) HUS related to complement abnormalities or related to factor
 ADAMTS13 deficit, such HUS is also known as "atypical HUS" and is not associated with
 diarrhea, and 3) HUS of unknown etiology that usually occurs in the course of systemic
 diseases or physio-pathologic conditions such as pregnancy, after transplantation or after
 drug use.

 E. coli bacteria normally live in the intestines of people and animals. Cattle and sheep are
 the main reservoirs of STEC, and the major transmission route is believed to be food
 contaminated with animal feces. Contaminated water has also been recognized as a source, and
 direct human-to-human and animal-to-human transmission have been reported.

 E. coli consists of a diverse group of bacteria. Most of them are harmless and an important
 part of a healthy human intestinal tract. However, some E. coli are pathogenic, that can
 cause either diarrhea or illness outside of the intestinal tract. Diarrheagenic E. coli
 strains are categorized into 6 pathotypes: 1) Enterotoxigenic E. coli, 2) Enteropathogenic E.
 coli, 3) Enteroaggregative E. coli, 4) Enteroinvasive E. coli, 5) diffusely adherent E. coli,
 and 6) STEC. STEC may also be referred to as verocytotoxin-producing E. coli (VTEC). This
 last pathotype is the one most commonly associated with foodborne outbreaks.

 Treatment of STEC HUS renal damage caused by Stx is available. The investigational medicinal
 product (IMP), INM004, proposes to neutralize the toxin in the bloodstream to prevent the
 interaction of the Stx with the specific receptor, by means of a polyclonal antibody to be
 administered upon the appearance of symptoms (bloody diarrhea) and diagnosis of infection by
 STEC, thereby preventing the action of the toxin in the body. Thus, the initial hypothesis
 for examination is for the prevention of the full expression of HUS, based upon presumptive
 clinical, biochemical, and other biological evidence suggesting a risk of HUS at the time of
 treatment application. The polyclonal antibody (F(ab')2 fragment) is obtained by processing
 the serum of equine animals previously immunized against engineered Stx1B and Stx2B
 immunogens.

 INM004 could be administered at the earlier stages of STEC disease since subjects with STEC
 diarrhea are more likely to benefit from Stx neutralizing antibodies before the development
 of extra-intestinal manifestations and HUS. Neutralizing equine anti-Stx F(ab')2 antibodies
 (INM004) have the objective of preventing the development of HUS by blocking the circulating
 toxins in patients infected with STEC. Therefore, INM004 may be used in patients with a
 clinical manifestation of bloody diarrhea and a positive Stx result in feces. Early
 interruption of the Stx mediated cascade is expected to prevent the development of HUS,
 alleviate the severity of the illness, the rate of complications and the incidence/duration
 of hospitalizations. Therefore, patients in the early phases of the disease will be targeted
 in this study, ie, children who seek medical care due to diarrhea associated with STEC
 infection before HUS development.

 Pediatric subjects between 1 and 10 years (y) of age at the time of screening with an
 increased risk for development of HUS defined by the presence of bloody diarrhea based upon
 history or presentation and positive screen for Stx2 in the stool will be enrolled.

 Bloody diarrhea and positive screen for Stx2 have been included as inclusion criteria as
 these factors have been identified as risk factor for HUS development and will serve to
 enrich the patient population within the study to those most likely to benefit from this
 therapy.

 Case of Bloody Diarrhea Any person with an increase in the number of daily stools and
 alteration in the stool consistency, with presence of visible blood, which may include
 episodes of stool formed with blood in the form of streaks on its surface or blood visible
 only under a microscope, which may be accompanied by other symptoms such as vomiting, nausea,
 abdominal pain, or fever.

 Case of Shiga Toxin producing Escherichia coli Infection

 Identification of the etiological agent by at least 1 of the following laboratory criteria:

 -  Isolation of an E. coli strain that produces Stx or harbors stx1 or stx2 gene(s);

 -  Direct detection of stx1 or stx2 gene(s) nucleic acid (without strain isolation);

 -  Direct detection of free Stx in feces (without strain isolation). The surveillance of
 the STEC strains is performed using subtyping techniques: 1) genotyping of stx and eae
 by polymerase chain reaction (PCR)-restriction fragment length polymorphism and 2)
 pulsed-field gel electrophoresis. STEC O157 and non O157 strains are recovered from the
 clinic, animal, food and environmental samples, and E. coli O157:H7, a Stx2a/Stx2c
 producer, harboring eae and ehxA genes, is the most common serotype.

 Case of Hemolytic Uremic Syndrome Patient of any age who presents in an acute form with
 microangiopathic hemolytic anemia, thrombocytopenia, and renal compromise.

 Case of Hemolytic Uremic Syndrome with Confirmed Diagnosis of Shiga Toxin producing
 Escherichia coli

 Case of HUS with identification of the etiological agent by at least 1 of the laboratory
 criteria:

 -  Screening of stx1 and/or stx2 by PCR/isolation of STEC

 -  Detection of free Stx in stool

 -  Detection of serogroup-specific O antigen antibodies O157, O145, O121
Inclusion Criteria:

 1. Age of ≥ 1 to < 10 y.

 2. Signed informed consent from the parent(s)/legal guardian with assent from the subject
 as appropriate by age and regulatory guidance.

 3. Bloody diarrhea based upon history or presentation (by visual inspection).

 4. Detection of Stx2 in stool based on enzyme immunoassay (EIA) and/or stx2 based on PCR
 before randomization.

 NOTE: The basis for accepting a positive test for stx2 by EIA is based on taking as
 valid the results yielded from an EIA whose sensitivity and specificity are greater
 than 98.7% and 100%, respectively (according to the description in the insert) as per
 recommendation given by the NRL. The Sponsor will select the investigational sites
 that have in their laboratory such EIA test used in the STEC diagnostic routine
 algorithm. (Appendix 6).

 5. For children between 1 to 5 years old: weight for length/height between percentiles 3
 (< 2 z score) and 97 (> 2 z score) corresponding to age (according to the reference
 tables "WHO Child Growth Standards".

 6. For children ≥ 5 years: Body mass index (BMI) between percentiles 3 (<2 z score) and
 97 (> 2 z score) corresponding to age (according to the reference tables "WHO Child
 Standards, Appendix 4)

 Exclusion Criteria:

 1. Any laboratory findings compatible with the development of HUS:

 -  Microangiopathic hemolytic anemia defined as LDH above the ULN for age with the
 finding of schistocytes on peripheral smear and a negative Coomb's test, and/or

 -  Thrombocytopenia: platelet count < 150 × 103/μL, and/or

 -  Renal failure: serum creatinine > ULN adjusted for age and gender criteria
 despite correction of hypovolemia, and/or hematuria, and/or proteinuria (Table
 7.1)11 NOTE: Laboratory results must be obtained within 24 h before the 1st study
 drug administration; there must be no clinical signs and symptoms of HUS at the
 time laboratory assessments are obtained. If there is any change in clinical
 presentation in the 24 h before the 1st study drug administration, laboratory
 assessments are to be repeated and results reviewed before study drug
 administration.

 NOTE: Laboratory and physical examination results must indicate normal hydration
 before the 1st study drug administration.

 2. A history of chronic/recurrent hemolytic anemia, thrombocytopenia, or chronic renal
 failure.

 3. A family history of aHUS.

 4. Anuria or oliguria after hypovolemia is corrected.

 5. Evidence of clinically significant chronic active disease not medically controlled.

 6. History of anaphylaxis, prior administration of equine serum (eg, antitetanus serum or
 anti-ophidic serum, or anti-arachnid toxin serum), or allergic reaction to contact
 with, or exposure to, horses.

 7. Family relation or work relation with a member of the personnel of the research group.

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