The current study is a multi-center, double arm, adjuvant, randomized control trial
(RCT), double-blind clinical trial, to analyze the differences in the usefulness and
safety of Exosome-MSC intravenous injection therapy in moderate-grade COVID-19 patients
with hyper-inflammation (Evans S.R, 2010).

This study used 2 groups (double arm) of study participants:

Treatment Group (Intervention Arm): received treatment in the form of standard therapy
and injection of Exosomes-MSC.

Control Group (Control Arm): received treatment in the form of standard therapy and
injection placebo.

The time interval for the implementation of the study protocol was 14 days. For each
group (Treatment and Control) the minimum target number of participating patients and
according to the inclusion criteria in this study were 30 people. The minimum total
number of participants with 2 groups (Treatment and Control) is 60 people. (Rohrig B.,
2010)

Random sample selection was carried out nationally from patients who entered the
treatment room with a positive diagnosis of COVID-19 at the three Multi-Center Research
Implementation Hospitals (RSPAD Gatot Soebroto Jakarta, RSUP Dr. Sardjito Yogyakarta and
RSUP M. Djamil Padang) in the period 3 months after the issuance of Ethical Clearance and
Approval for Implementation of Clinical Trials from BPOM.

The sample size is calculated using the following formula:

n1 = n2 = 2(Za+Z1-β)^2/ Δ^2

n1: the number of participants in the Exosome-MSC group n2: the number of participants in
the control group Zα: standard deviation of type I error, 95% confidence interval (1.96)
Zβ: standard deviation of type II error, power 80% (0.84) SD: standard deviation of
duration of recovery on standard therapy (5.90). (Voinsky I, 2020)

Minimum expected difference in duration of healing (in days) when using Exosome-MSC
compared to standard therapy (5) From the above calculation, the results of the
calculation are N1 = N2 = 21.83 with rounding up each = 22 participants . To anticipate
the adequacy of the number of participants , each group was added 8 participants , 30
participants each in the Exosome-MSC group and the control group so that the total number
of participants was 60 participants.

Participants can be discontinued before the study is completed (drop-out) if they
experience significant side effects and/or adverse events, both treatment related and non
treatment related. Participants can also be discontinued before the study is completed
(drop-out) if it worsens to a severe degree. All Participants will be discontinued from
the study when the treatment and examination are completed according to the procedure.

Randomization of patients into the intervention group or control group was made for each
study site through the block 4 randomization technique. This process will be coordinated
by the Team who will carry out the Research Management/CRO function.

The double-blind procedure is a procedure to avoid bias of researchers and research
participants that will affect the results of data analysis. To apply this procedure, the
Exosome-MSC test material specimen in the Treatment Group was dissolved in 0.9% Nacl. The
dosage form will be disguised so that it is similar to Nacl 0.9% in the Control Group.
Research participants and local researchers implementing in hospitals do not have
knowledge about the status of the research group (arm). During the study, patients
continued to take their usual routine medications, such as antihypertensive drugs,
antidiabetic drugs, calcium, or folic acid. The treatment will be included as a
confounding factor.

Research participants will be monitored closely. CLINICAL examinations are carried out
EVERY DAY, starting from the baseline (day 0) to day 14.

The clinical examination consists of:

1. body temperature,

2. oxygen saturation,

3. respiratory rate,

4. breath difficulties,

5. cough with phlegm,

6. RT-PCR results

7. standard therapy.received

8. allergic reactions,

9. secondary infection

10. side effects/ adverse events (AE) that are life threatening.

11. Remission score assessment based on 8 ordinal scales to determine Time to Clinical
Improvement (TTCI).

TTCI is the number of days until clinical improvement can be observed, as indicated by a
score of 1-3 out of 8 ordinal scales.

Laboratory examinations will be carried out on days 0, 1, 3, 7, 10 and 14 (unless they
have been discharged/recovered first) . On days 0 and 7 when the Exosomes-MSC injection
therapy is administered, laboratory examinations were performed before therapy.

Laboratory examinations consist of:

1. C-Reactive Protein,

2. ferritin,

3. D-Dimer,

4. LDH

5. Fibrinogen,

6. Routine blood, type count (including lymphocyte count)

7. PT and APTT

8. SGOT/SGPT,

9. urea/creatinine,

10. electrolyte K/Na/Cl,

Measures of intervention outcomes must be documented in a standardized Case Report Form
(CRF) for each patient participating in the study.

Adverse Events are any events, whether predicted or not, which can be related to the test
material or not, this includes worsening of the clinical condition previously owned by
the participant.

Serious Adverse Events (SAE), include

1. Dead

2. Life threatening Inpatient / Participant requires treatment as an inpatient

3. Additional length of stay *

4. Permanent / significant disability

5. Congenital abnormalities

Additional length of stay, defined as length of stay at any time. Hospitalization due to
routine administration of standard therapy is not included in this definition. If the
participant experiences an adverse event during the hospitalization period, the condition
must be reported as an adverse event.

All adverse events identified from the start of the study (day 0) to day 14 will be
recorded in the adverse event form in the case report form (CRF).

In the event of a Serious Adverse Events (SAE), researchers at the research site must
report it to Dermama Biotechnology Laboratorium within 24 hours after it is known as the
initial report, the report is addressed to: Dr. dr. Indah Hidajati Kampono, Sp.DV(K)
Dermama Biotechnology Laboratory Jl. Kelengkeng No. 8 Surakarta Phone/Fax Number:
0271-727007 E-mail: Indahhidajati01@gmail.com Telephone/Mobile Number: +62 811-2632-086

Written reports of serious adverse events must be sent to the Ethics Committee within 3
calendar days and to Indonesian National Agency of Food and Drugs Control (BPOM) within 7
calendar days for SAE that are fatal or life threatening, and within 15 calendar days for
other SAE according to BPOM Regulation No. 21/201514.