Prevention of Infection and Incidence of COVID-19 in Medical Personnel Assisting Patients With New Coronavirus Disease: a Randomised Controlled Trial
Phase: PHASE4
Conditions: Increased Risk of SARS-CoV-2 Infection
Sponsor: Federal State Budgetary Institution, V. A. Almazov Federal North-West Medical Research Centre, of the Ministry of Health

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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Bromhexine Hydrochloride Prophylaxis of COVID-19 for Medical Personnel: A Randomized 
Open-Label Study 
by Mikhaylov EN, Lyubimtseva TA, Vakhrushev AD, Stepanov D, Lebedev DS, Vasilieva EYu, 
Konradi AO, Shlyakhto EV 
 
SUPPLEMENTS. STUDY PROTOCOL 
 
 
_____________________________________________________________ 
 
 
 
Almazov National Medical Research Centre 
 
 
 
 
 
CLINICAL STUDY PROTOCOL 
 
«Prophylaxis of SARS-CoV-2 infection and COVID-19 among medical 
personnel managing patients with the novel coronavirus disease » 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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Contents 
1. Rationale ...................................................................................................................................... 3 
2. Purpose ........................................................................................................................................ 4 
3. Study type .................................................................................................................................... 4 
4. Inclusion criteria .......................................................................................................................... 4 
5. Exclusion criteria ......................................................................................................................... 4 
6. Drop out criteria ........................................................................................................................... 5 
7. Study design ................................................................................................................................ 5 
8. Study endpoints ........................................................................................................................... 6 
9. Randomization and sample size estimation ................................................................................. 7 
10. Bromhexine hydrochloride dosing and administration rules ..................................................... 8 
11. Study timeline ............................................................................................................................ 8 
12. Subject exclusion ....................................................................................................................... 9 
13. Replacement of subjects when excluded from the study ........................................................... 9 
14. Preliminary study termination ................................................................................................... 9 
15. Safety reports ............................................................................................................................. 9 
16. Ethics ......................................................................................................................................... 9 
Investigators ................................................................................................................................... 11 
 
 
 
 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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1. Rationale 
Several independent scientific laboratories have analyzed data on the mechanism of action 
of drugs that block the transmembrane protease (TMPRSS2), which is necessary for the activation 
of the S protein of the coronavirus when it binds to the ACE2 receptor on the surface of epithelial 
cells. Currently, two drugs, potential TMPRSS2 inhibitors, are of particular interest: Camostat 
mesylate and Bromhexine hydrochloride [D. Stepanov, P. Lierz; Frenxiv, April 23, 2020; Markus 
Hoffmann, Hannah Kleine-Weber, Simon Schroeder et al. Cell 181, 271-280 April 16, 2020; 
Kailas Sonawane Sagar S. Barale Maruti J. Dhanavade et al. ChemRxiv April 22, 2020]. 
These drugs are effective chemical TMPRSS2 blockers in vitro. According to the available 
data on severe acute respiratory syndrome caused by the SARS-CoV type coronavirus, the 
mechanism of entry into the cell of the new SARS-CoV-2 coronavirus is similar: it has been 
demonstrated in animal models that the introduction of SARS-CoV-2 into epithelial cells can be 
blocked by Camostat mesylate. In mice, Camostat, dosed at concentrations similar to clinically 
achievable concentrations in humans, reduced mortality after infection with SARS-CoV from 
100% to 30-35% [Yanchen Zhou, Punitha Vedantham, Kai Lu et al. Protease inhibitors targeting 
coronavirus and filovirus entry. Antiviral Research 116 (2015) 76-84; Hoffmann M, Kleine-Weber 
H, Schroeder S et al. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked 
by a Clinically Proven Protease Inhibitor. Cell. 2020; 181: 1-10]. 
Bromhexine, a well known pharmacological drug, is an alkaloid derived from Adhatoda 
vasca used as a secretolytic expectorant for the treatment of respiratory diseases with excessive or 
viscous mucus. Bromhexine stimulates the activity of the ciliated epithelium, enhances lysosomal 
activity and causes hydrolytic depolymerization of mucous protein fibers [Bhagat A, Rachana R. 
Bromhexine: A Comprehensive Review. Int J Bio Med Res. 2018; 9 (3): 6455-9]. The 
concentration of Bromhexine in the pulmonary parenchyma two hours after administration is 2.4-
5.9 times higher than in the blood plasma. The drug demonstrates first-order pharmacokinetics and 
is almost completely metabolized to a variety of hydroxylated metabolites; the most famous of 
these is Ambroxol, also available as a licensed mucolytic drug. 
Like Camostat, Bromhexine inhibits the activity of TMPRSS2, thus preventing the SARS-
CoV-2 virus from entering the cell. Bromhexine blocks the ability of TMPRSS2 to activate the 
tissue zymogen precursor, plasminogen activator in vitro [Lucas JM, Heinlein C, Kim T, 
Hernandez SA, Malik MS, True LD et al. The Androgen-Regulated Protease TMPRSS2 Activates 
a Proteolytic Cascade Involving Components of the Tumor Microenvironment and Promotes 
Prostate Cancer Metastasis. Cancer Discovery. 2014; 4: 1310-25]. 
It is important to note that only minor side effects of Bromhexine have been described, 
such as nausea (a common effect), rash, bronchospasm, vomiting, diarrhea, and fever (noted as a 
rare effect). Severe complications, such as Stevens-Johnson syndrome, or toxic epidermal 
necrolysis, possibly associated with the metabolite Ambroxol, are casuistic (no more than 0.16 
cases per million patients). 
There are currently no results of prospective studies of the use of Bromhexine 
hydrochloride as a preventive measure. There is one known study planned in China (Evaluating 
the Efficacy and Safety of Bromhexine Hydrochloride Tablets Combined With Standard 
Treatment / Standard Treatment in Patients With Suspected and Mild Novel Coronavirus 
Pneumonia (COVID-19) clinicaltrials.gov: NCT04273763; sample of 60 patients, start date studies 
02/16/2020 Two prospective placebo-controlled studies are also known to study the effect of 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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Camostat on reducing the severity of the incidence of COVID19: The Effect of Camostat Mesylate 
on COVID-19 Infection in Ambulatory Patients: An Investigator-Initiated Randomized, Placebo-
Controlled, Phase IIa Trial, clinicaltrials.gov: NCT04353284, sample of 114 patients, study start 
date 04/30/2020 (Yale University, USA); The Impact of Camostat Mesilate on COVID-19 
Infection: An Investigator-initiated Randomized, Placebo-controlled, Phase IIa Trial; 
clinicaltrials.gov: NCT04321096, sample of 180 patients, study start date - 03/31/2020 (Dani me, 
9 participating centers).  
We suggest, that when SARS-CoV-2 has already entered the cells, the effect of 
Bromhexine hydrochloride therapy will be low or insufficient. About 20-30% of medical 
personnel are infected with SARS-Cov-2. At the same time, there are similar data on the potential 
effectiveness of Bromhexine hydrochloride in the prevention of a new infection in risk groups 
from several independent groups of authors. According to data from personal communication with 
specialists in Germany, there were no cases of infection among those who took the drug 
prophylactically [Department of Anesthesiology, Intensive Care, Pain Management and Palliative 
Care, Marienkrankenhaus, Soest, Germany]. It can be assumed that there is a preventive effect of 
taking Bromhexine among medical personnel to reduce the risk of infection and COVID 19 
disease, despite the use of personal protective equipment. 
2. Purpose  
To evaluate the efficacy and safety of oral administration of Bromhexine hydrochloride for the 
prevention of SARS-CoV-2 infection and COVID-19 disease in medical personnel managing 
patients with COVID-19 
3. Study type 
Prospective randomized open-label study with a control group, which assesses the superiority of 
prophylactic therapy  
 
4. Inclusion criteria 
1. Age ≥18 years; 
2. Negative test (PCR) for SARS-CoV-2 infection; 
3. Absence of clinical manifestations of a respiratory infection; 
4. Presumptive management of patients with laboratory and/or clinically confirmed COVID-
19; 
5. Signed informed consent to participate in the study. 
5. Exclusion criteria 
1. Intolerance to Bromhexine hydrochloride; 
2. Work outside of contact with SARS-CoV-2 infection; 
3. Pregnancy (positive laboratory test for pregnancy or ultrasound confirmation of pregnancy) 
and breastfeeding period; 
4. Other circumstances that the researcher considers inappropriate to participate in this study. 
5. Peptic ulcer or duodenal ulcer, incl. in anamnesis 
6. Documented contact with a SARS-CoV-2 carrier or a COVID-19 patient within 14 days prior 
to randomization 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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6. Drop out criteria 
1. Failure to comply with the rules for the use of personal protective equipment when working 
with SARS-CoV-2 infection (the rules for the use of PPE in accordance with the 
recommendations of the Ministry of Health of Russia and internal orders of the General Director 
of the V.A. research; control of the use of PPE - independent); 
2. Any acute illness not associated with SARS-CoV-2 that occurred during the study period 
7. Study design 
 
This is single-center study. Location of the study center: 
Almazov National Medical Research Centre; 2, Akkuratova str., Saint-Petersburg 197341, 
Russian Federation 
Study design is present on Figure 1. 
 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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Figure 1. Study design 
 
 
• When COVID-19 is expected clinically or SARS-CoV-2 infection is verified with a positive 
PCR test, the endpoint is reached and the drug may be canceled; 
• However, the drug can be continued at the request of the participant for mild and moderate 
forms of the disease, since, theoretically, a decrease in viral load is possible; patients with 
continued therapy will continue to be followed, but outside the study protocol. 
 
The same test systems for PCR (SARS-CoV-2 infection) will be used during the study. 
8. Study endpoints 
8.1 Primary endpoint 
• Combined endpoint: a positive PCR swab test to SARS-CoV-a2 and/or clinically 
suspected COVID-19 at 4 weeks and/or after 14 days after the last contact with a SARS-
CoV-2 positive person  
 
8.2 Secondary endpoints 
• The time to the onset of clinical symptoms of a respiratory infection with positive SARS-
CoV-2 PCR from the moment of the first contact with COVID-19; 
• Time to a positive swab PCR SARS-CoV-2; 
• Number of symptomatic cases of SARS-CoV-2 infection in both study groups; 
• The number of mild, moderate and severe forms of COVID-19; 
• The presence and type of side effects of Bromhexine hydrochloride 
 
8.3 Methods for assessing primary and secondary endpoints 
1. Clinical assessment of study participants for the presence of symptoms of respiratory 
infection 
2. Laboratory diagnostics of the presence of SARS-CoV-2: swab PCR test; 
3. Chest computed tomography, pulse oximetry - to assess the severity of the disease; 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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4. Laboratory diagnostics of SARS-CoV-2 infection: plasma IgG; 
5. Laboratory diagnostics of the severity of COVID-19: clinical blood test with leukocyte 
count, C-reactive protein, D-dimer, ALT, AST, bilirubin fraction; creatinine, urea, protein 
fractions; amylase; glucose; 
6. The need for oxygen support and its type in the treatment of COVID-19; the duration of the 
need for oxygen therapy; duration of mechanical ventilation. 
7. Working hours (hours) with patients with confirmed / suspected SARS-CoV-2 infection; 
8. Additional observation of all study participants up to 8 weeks from the date of 
randomization. 
 
Methodology for calculating the time of work with SARS-CoV-2 infection 
1. Units of time calculation - hours; 
2. Separately taken into account: a) the time of work in the therapeutic department, including the 
emergency room where patients with suspected / confirmed SARS-CoV-2 infection are located; 
b) the time of work in the intensive care unit, where patients with suspected / confirmed SARS-
CoV-2 infection are located; c) the time of work in a "clean" area, outside the presence of patients 
with suspected / confirmed SARS-CoV-2 infection; 
3. Working hours in the hospital without personal protective equipment in accordance with the 
regulations of Almazov National Medical Research Centre. 
9. Randomization and sample size estimation 
Randomization method: 1:1, allocation by minimization method to the preventive therapy 
group with Bromhexine hydrochloride and to the control group, taking into account the following 
factors: age (ranges 18-45, 45-64, 65-74, 75-79); type of contact with SARS-CoV-2 infection: 
("red zone"; "green" zone); taking hydroxychloroquine to prevent COVID-19. 
• "Red" zone: the closest and longest contact with SARS-CoV-2 infection associated with 
an infected aerosol (work in intensive care units and intensive care units; in operating and 
intervention laboratories; work with biological material of infected patients); 
• Green Zone: work outside direct contact with patients with confirmed / suspected SARS-
CoV-2 infection. 
 
Known statistics: 
• The incidence rate of medical personnel working with SARS-CoV-2 infection: ranges 
between 
20 
and 
50% 
(https://www.cdc.gov/mmwr/volumes/69/wr/mm6915e6.htm?deliveryName=USCDC_425-
DM25898); 
• Frequency of serious side effects of bromhexine hydrochloride: no more than 0.16 cases 
per million patients (Ambroxol and bromhexine containing medicinal products. EMA / PRAC / 
800767/2015, 10/09/2015); 
 
Estimated effect of preventive therapy: 
Empirically, it is suggested that prophylactic drug administration can reduce the incidence 
of the primary endpoint by 20%. 
 
Calculation of the study sample size: 
• Power: 80% 
• Confidence level - alpha error: 5% 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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• The incidence of the primary endpoint in the control group is estimated 30%; the 
incidence of the primary endpoint in the study group is estimated 10%; 
• Thus, the target sample size: 118 people (59 subjects in each group) 
• Estimated dropout rate from study protocol (dropout after randomization, non-SARS-
CoV-2 incidence) 15%; thus, the required number of participants in the study will be 139 people; 
 
10. Bromhexine hydrochloride dosing and administration rules 
The drug is administered orally, after meals, without chewing, with plenty of liquid: 
3 times a day, 8 mg. 
In case of impaired renal function (creatinine clearance <30 ml / min / 1.73 m2) and / or liver 
insufficiency (an increase in the level of hepatic transaminases by 2 or more times), the drug 
should be discontinued in this study. 
11. Study timeline 
 
Table 1.  Schedule of evaluations and prophylactic measures 
 
Evaluations 
0 
7 days  
14 days 
21 days 
28 days 
5-8 weeks 
Test (PCR) SARS-
CoV-2 
+ 
+ 
+ 
+ 
+ 
+ 
Enzyme 
immunoassay  - 
IgG to SARS-
CoV-2 
+* 
 
 
 
 
 
Clinical follow-up, 
daily 
+ 
+ 
+ 
+ 
+ 
+ 
Bromhexine 
hydrochloride 
administration, 
daily (8 mg 3 
times a day) 
+ 
+ 
+ 
+ 
+ 
+ 
Individual 
protective 
equipment; daily 
+ 
+ 
+ 
+ 
+ 
+ 
Concomitant 
pharmacological 
treatment record 
+ 
+ 
+ 
+ 
+ 
+ 
Participant’s 
questionnaire 
maintaining 
+ 
+ 
+ 
+ 
+ 
+ 
Laboratory 
diagnostics when 
SARS-CoV-2 is 
expected 
 
When indicated 
Chest computed 
tomography when 
SARS-CoV-2 
infection is 
expected  
 
When indicated 
*Plasma biobanking with subsequent IgG analysis when it is possible 
 

COVID-19 prophylaxis in medical personnel – Ver. 1.2 from 12.05.2020 
 
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12. Subject exclusion 
Participants in the study can leave at any time, for any reason, without any consequences. A 
participant might be excluded from the study for a medical emergency. 
Study participant specific withdrawal criteria: 
• The presence of side effects of the use of Bromhexine hydrochloride, which complicates its 
further safe use and / or any other intolerance to the drug; 
• The onset of pregnancy; 
• Suspected / confirmed SARS-CoV-2 infection; 
• Period of disability and / or hospitalization associated with SARS-CoV-2 infection. 
13. Replacement of subjects when excluded from the study 
Participants excluded from the study will not be replaced. 
 
14. Preliminary study termination 
The study may be terminated prematurely if there is a significant difference in the safety endpoints 
between groups after enrollment of 20 subjects, which indicates unacceptable safety. If the 
superiority of the treatment method is found early, there will be no reason for early termination of 
the study. 
 
15. Safety reports 
 
15.1 Adverse events (AE). 
 
Adverse event is any unwanted event that may occur to a study subject during the study course, 
whether or not associated with bromhexine hydrochloride treatment. All adverse events reported 
by an investigator should be recorded. 
Examples of adverse events based on studies in patients taking bromhexine: 
Significant: allergic reaction in the form of anaphylactic shock; 
Minor: nausea, vomiting, diarrhea, allergic reaction in the form of urticaria 
 
15.2 Severe adverse events (SAE) 
SAE 
– 
is 
any 
unwanted 
event, 
which 
in 
any 
from 
or 
duration 
may: 
- cause death; 
- is life-threatening (when it develops); 
- requires unscheduled hospitalization or prolongs hospitalization period; 
- leads to permanent or severe disability; 
- any other important medical event that does not lead to death, is not life-threatening and does not 
require hospitalization, but may be interpreted (according to a specialist’s opinion) as an event 
with risk to a subject or needs an additional medical intervention for the prevention of an event. 
 
When SAE is expected, an investigator must immediately inform the study coordinator and the 
primary investigator. The study coordinator and primary investigator are responsible for 
notification of the ethics committee. 
 
16. Ethics 
 

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The study will be conducted in accordance with the principles of the Declaration of Helsinki 
(version 59 review of the WMA article, Seoul, Korea, October 2008). 
 
15.1 Study enrollment and informed consent 
All individuals who meet the inclusion and exclusion criteria are enrolled after they have given 
their consent. Information about the study will be provided by a physician-investigator, signed 
before the procedure begins, with the examination. The research participant will be given enough 
time to consider and decide on whether to participate or decline. The informed consent form has 
been reviewed and approved by the Ethics Committee of the Almazov National Medical Research 
Centre. Informed consent has been developed according to the ICH / GCP guidelines. Potential 
risks and participation in the study will be explained orally. A copy of the signed consent is issued 
to the research participant. 
 
 
 
 

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Investigators 
 
Primary investigator 
Prof. Evgeny V. Shlyakhto, MD, PhD,  
Director general, Almazov National Medical Research Centre 
e.shlyakhto@almazovcentre.ru 
 
Executive committee 
Evgeny N. Mikhaylov, MD, PhD, Vice director, Institute of heart and vessels, Almazov National 
Medical Research Centre; 
Prof. Alexandra O. Konradi, MD, PhD, vice-director, Almazov National Medical Research 
Centre; 
Prof. Dmitry S. Lebedev, MD, PhD, head, arrhythmia department, Almazov National Medical 
Research Centre; 
Tamara A. Lyubimtseva, MD, PhD, senior researcher, arrhythmia department, Almazov National 
Medical Research Centre 
 
Study coordinator 
Tamara A. Lyubimtseva, MD, PhD, senior researcher, arrhythmia department, Almazov National 
Medical Research Centre 
 
Co-investigators 
Dmitry Stepanov 
Novikova, Anna N. 
Vasilieva, Elena Yu. 
Garkina, Svetlana V. 
Orshanskaya, Viktoria S. 
Vakhrushev, Aleksandr D. 
Gasimova, Nigar Z. 
Semenov, Andrey P.