A Double-Blind, Placebo-Controlled, Randomized, Multicenter, Proof of Concept and Dose-Finding Phase II Clinical Trial to Investigate the Safety, Tolerability and Efficacy of ADRECIZUMAB in Patients with Septic Shock and Elevated Adrenomedullin

Sepsis is defined as life-threatening organ dysfunction caused by a
dysregulated host response to infection. Organ dysfunction can be identified as
an acute change in 2 total SOFA score points subsequent to the infection.
Septic shock is a subset of sepsis in which underlying circulatory and
cellular/metabolic abnormalities are profound enough to substantially increase
mortality. Patients with septic shock can be identified with a clinical
construct of sepsis with persisting hypotension requiring vasopressors to
maintain MAP > 65 mm Hg and having a serum lactate level >2 mmol/L (18 mg/dL)
despite adequate volume resuscitation. With these criteria, hospital mortality
is in excess of 40%.

One important factor in the pathogenesis of sepsis and septic shock seems to be
Adrenomedullin (ADM). It could also be demonstrated that ADM influences the
stability of the circulation directly and indirectly: it has direct
chronotropic, inotropic and vasodilatory effects. Several in-vitro and in-vivo
studies have shown that ADM seems also to be a key regulator of endothelial
permeability in sepsis.

A possible mode of action for the anti-ADM antibody ADRECIZUMAB is described as
follows:
Due to its small size (about 6 kDa), ADM is supposed to be able to freely
diffuse between the blood circulation and the interstitium. The inner wall of
blood vessels is composed of endothelial cells. Smooth muscle cells, on the
contrary, have no direct contact to the blood circulation, as they are located
distal at the basal site of the endothelial cell layer of arteries. Thus, it
can be assumed that ADM located in the blood circulation can act on endothelial
cells to stabilize endothelial permeability, but from this compartment cannot
directly exert its vasodilatory activity on smooth muscle cells. Rather, smooth
muscle cells are accessible for ADM, when it is located in the interstitium.
When the anti-ADM antibody ADRECIZUMAB (HAM8101) is administered in the blood
circulation at high concentrations by far exceeding those of plasma ADM, the
compartmental distribution of ADM is altered. ADRECIZUMAB, an IgG with a
molecular weight of more than 150 kDa, is too large to freely diffuse from the
blood circulation to the interstitium.
With its fast association kinetics ADRECIZUMAB quickly binds to ADM in the
blood circulation and *pulls* ADM, which has been initially located in the
interstitium, from this compartment to the blood circulation. The more
ADRECIZUMAB is applied, the stronger is the *pulling* effect and the higher the
resulting concentrations of ADRECIZUMAB-bound ADM in the blood circulation. As
a consequence of this redistribution, the ADM concentration in the interstitium
decreases, and less ADM is able to act on smooth muscle cells to exert its
vasodilatory activity. In the progression to septic shock, when it comes to
excessive vasodilation and hypotension, administration of ADRECIZUMAB thus can
reduce vasodilation by substracting excessive levels of interstitially located
ADM.

At the same time levels of ADRECIZUMAB-bound ADM increase in the blood
circulation, and it is assumed that this can be functionally relevant: due to
its epitope specificity for the N-terminal moiety of ADM, ADRECIZUMAB is a
special anti-ADM antibody. While it is a high-affinity antibody, its binding to
ADM does not completely block the function of ADM, but rather only partially
reduces its capacity to elicit a second messenger response.
The net effect of an increase of ADRECIZUMAB-bound ADM in the blood circulation
on the one hand, and an only partial functional inhibition of ADM brought about
by the binding of ADRECIZUMAB on the other hand, is that more ADM activity is
present in the blood circulation after administration of ADRECIZUMAB than
without administration of ADRECIZUMAB. The increased net activity in the blood
circulation could promote stabilization of endothelial permeability.

An additional effect of binding of ADRECIZUMAB to ADM in the blood circulation
could be an * at least partial and/or temporal * protection from otherwise
occurring proteolytic decay of ADM. Proteolytic degradation of ADM occurs at
its N-terminus. It is exactly this site, where ADRECIZUMAB binds to ADM.
In accordance with the proposed mode of action, the dosing goal for ADRECIZUMAB
is as follows: ADRECIZUMAB in septic shock is intended to be efficacious for at
least 7 days after single administration (T/2 ~ 15 days). Therefore, a dose of
ADRECIZUMAB should be chosen, which leads to
a) elevation (compared to baseline) of plasma ADM immunoreactivity,
as measured by the bio-ADM assay, for up to minimally 7 days, and
b) plasma levels of ADRECIZUMAB for up to minimally 7 days, which are
in considerable excess over endogenous ADM.

While an initial increase of plasma ADM immunoreactivity has been observed
after administration of a minimal dose of 0.2-0.4 mg/kg (healthy mice; Study
No. Safety-06), at least 2 mg/kg were required to achieve an elevation of
plasma ADM immunoreactivity over baseline for 7 days after administration of
ADRECIZUMAB (Phase Ia Study). With this dose of 2 mg/kg, the concentration of
free ADRECIZUMAB was above 10 µg/mL. Similarly, in a CLP mouse model (Study No.
CLP-09/3), by using the same dose (2 mg/kg), both plasma ADM immunoreactivity
and levels of free ADRECIZUMAB were elevated 7 days after administration of
ADRECIZUMAB. Thus, it is concluded that 2 mg/kg ADRECIZUMAB should be chosen as
the minimum dose for the planned Phase II study.

Patients will be evaluated for safety and tolerability of the therapy, but also
for signs of clinical efficacy. As long as the patients are on the ICU,
measurements of clinical signs and laboratory data will be collected for safety
reasons and for determination of SOFA score as long as arterial line is in
place for determination of PaO2/FiO2. Additional blood samples for laboratory
analyses will be taken prior to start of IMP infusion (day 1) and within the
timeframe of 24 hours (+/- 10 hours) after end of IMP infusion (day 2), 48
hours, 96 hours and 144 hours after the end of infusion (+/- 10 hours) or
between scheduled assessments, if discharged earlier from Intensive Care
(whatever comes first) for determination of ADM (prior to infusion) and the
biomarker MR-proADM and inflammatory biomarkers PCT, IL-6 and penKid.

Primary aim of this phase II study is to demonstrate safety and tolerability as
well as efficacy of ADRECIZUMAB in patients with septic shock. The current
phase II study is underpowered to detect a relevant reduction of 28-day
mortality by ADRECIZUMAB; on the other hand, there is evidence from our animal
models that ADRECIZUMAB can improve organ function. The improvement in organ
function is measurable using days with relevant organ support (cardiac, renal,
respiratory) while on ICU. Therefore, a composite endpoint of days with organ
support AND all-cause of mortality will be used: the *Sepsis Support
Index* (SSI). Further, it is intended to determine pharmacodynamics and
pharmacokinetics of ADRECIZUMAB.

This is a double-blind, placebo-controlled, dose-finding, multicenter
randomized proof of concept phase II study using two doses of ADRECIZUMAB in
patients with early septic shock and a bio-ADM plasma concentration at
admission of > 70 pg/ml.

*Early* septic shock is defined as a life-threatening organ dysfunction due to
dysregulated host response to a proven or suspected infection which leads to a
decline of MAP < 65mm Hg which is refractory to fluid resuscitation and
requires vasopressors. Early is defined as a maximum of < 12 hours between
onset of the cardiovascular organ-dysfunction (start of vasopressor use) and
administration of ADRECIZUMAB. Refractoriness to fluid resuscitation is defined
as a lack of response to the administration of 30 ml of fluid per kilogram of
body weight or is determined according to a clinician*s assessment of
inadequate hemodynamic results.

In this phase II study 300 patients with early septic shock and a plasma
concentration of bio-ADM > 70 pg/mL from surgical, medical and mixed ICU at
multiple centers in Europe will be randomized. This concept is based on the
observation of the clinical observation study AdrenOSS-1, in which 201 out of
291 patients with septic shock and a bio-ADM concentration > 70 pg/mL had a
28-day mortality rate of approximately 35% compared with 84 out of 291 patients
with a bio-ADM concentration < 70 pg/mL who had a 28-day mortality rate of 23 %.

All patients will be treated according to *International Guidelines for
Management of Severe Sepsis and Septic Shock*.
300 patients with early septic shock will be randomized into two treatment arms
and one control group. After informed consent has been signed by patient or
legally designated representative and the result from plasma-ADM concentration
(> 70 pg/ml) is available, inclusion and exclusion criteria will be checked via
a centralized procedure. After fulfilling the inclusion and exclusion criteria
patients will be assigned randomly (randomization 1:1:2; four * block
randomization per center) to the treatment arms (2 mg/kg or 4 mg/kg) or to the
placebo control group.

Patients assigned to the treatment arms will be administered a single dose of
ADRECIZUMAB as i.v. infusion over approximately 1 hour; patients assigned to
the control group will be administered placebo as i.v. infusion over
approximately 1 hour.

Patients will be evaluated for safety and tolerability of the therapy, but also
for signs of clinical efficacy. As long as the patients are on the ICU,
measurements of clinical signs and laboratory data will be collected for safety
reasons and for determination of SOFA score as long as arterial line is in
place for determination of PaO2/FiO2.
Additional blood samples will be taken prior to start of IMP infusion (day 1)
and within the timeframe of 24 hours (+/- 10 hours) after end of IMP infusion
(day 2), at 48 hours, 96 hours and 144 hours after the end of infusion (+/- 10
hours) or between scheduled assessments, if discharged earlier from Intensive
Care (whatever comes first) for determination of ADM (prior to infusion) and
the biomarker MR-proADM and inflammatory biomarkers PCT, IL-6 and penKid.

Patient accrual is expected to be completed within 24 months.

An interim analysis is planned after 50% of patients (n= 150) have completed
the study after day 28.

All patients will be treated according to *International Guidelines for
Management of Severe Sepsis and Septic Shock*.

Eligible patients (confirmed by central verification) will be randomized
(1:1:2) to ADRECIZUMAB treatment arm A
(2 mg/kg) or to ADRECIZUMAB treatment arm B (4 mg/kg) or to placebo as control
group. Patients assigned to the treatment arm A or B will be administered a
single dose of ADRECIZUMAB as intravenous infusion over approximately 1 hour;
patients assigned to the control group will be administered placebo as
intravenous infusion over approximately 1 hour.

As long as the patients are on the ICU, daily measurements of clinical signs
and laboratory data will be collected for safety reasons and for determination
of SOFA score. Additional blood samples for central laboratory analyses will be
taken prior to start of IMP infusion (day 1) and 24 hours, 48 hours, 96 hours
and 144 hours after end of infusion (+/- 10 hours) or between scheduled
assessments, if discharged earlier from the ICU (whatever comes first) after
the end of infusion for measurement of biomarkers.


The SOFA score and its components will be determined for all patients over the
entire stay on the ICU (28 days or until discharge whatever comes first). Two
preconditions need to be fulfilled for this: Daily measurement of platelets and
daily assessment of blood gas analysis (BGA) from arterial blood. Safety
monitoring for each patient will begin at the time of signing the Informed
Consent Form and continue for 90 days after end of short-term infusion of study
medication.

At selected study centers a PK substudy will be performed to determine the
profile of ADRECIZUMAB in 80 randomized patients.

Study procedures are scheduled for screening, administration of study
medication and for assessment of the safety and tolerability of the
investigational treatment, as well as until the end of the study as outlined in
the flow-chart (Protocol p 14 Figure 1, page 16 Figure 2, and page 17 Figure
3).
The procedures on particular study days are described in more detail as from
page 40 onwards.

As long as the patients are on the ICU, measurements of clinical signs and
laboratory data will be collected for safety reasons and for determination of
SOFA score as long as arterial line is in place for determination of PaO2/FiO2.
Additional blood samples for central laboratory analyses will be taken prior to
start of IMP infusion (day 1) and within the time frame of 24 hours (+/- 10
hours) after end of IMP infusion (day 2). Further timepoints for blood sampling
will follow at 48 hours, 96 hours and 144 hours after end of infusion (+/- 10
hours) or between scheduled assessments, if discharged earlier from the ICU
(whatever comes first) for determination of ADRECIZUMAB, inflammatory biomarker
and cardiac biomarkers.
The SOFA score and its components will be determined daily for all patients
over the entire stay on the ICU until day 28 or discharge (whatever comes
first). Safety monitoring for each patient will begin at the time of signing
the Informed Consent Form and continue for 90 days after end of short-term
infusion of study medication.

Blood samples will be taken for determination of the following biomarkers prior
to start of IMP infusion (day 1) and within the timeframe of 24 hours (+/- 10
hours) after end of IMP infusion (day 2), as well as at 48 hours, 96 hours and
144 hours after end of infusion (+/- 10 hours) or between scheduled
assessments, if discharged earlier from ICU (whatever comes first): bio-ADM,
MR-pro-ADM, inflammatory biomarkers PCT, IL-6 and penKid.
EDTA blood, 2 samples of 7 ml content (resulting in approximately half the
volume of plasma) are collected at each time point.

At selected study centers a PK substudy will be performed to determine the
profile of ADRECIZUMAB in 80 randomized patients.
Blood samples (2 ml EDTA blood at each time point) will be obtained prior to
ADRECIZUMAB dosing and after 30 minutes as well as 24 hours, 48 hours, 96
hours, 144 hours and 648 hours after end of infusion (+/- 10 hours) or between
scheduled assessments, if discharged earlier from the ICU (whatever comes
first) (during stay in ICU or on day 28 follow-up, if patient is discharged
from ICU prior to day 28).

No patient diaries will need to be completed.

Euro-QoL * 5 Quality of Life Short Form will be completed at the day of
discharge from ICU (day 2 to day 28 or discharge, whatever comes first), and on
follow-up day 28. patients will be called from the investigator's site on
follow-up day 90 after end of infusion of study medication for completion of
the paper telephone Euro-Qol - 5 Quality of Life Short Form.