TURN-COVID Biobank:
The Dutch cohort study for the evaluation of the use of neutralizing monoclonal antibodies and other antiviral agents against SARS-CoV-2

2. INTRODUCTION AND RATIONALE
New SARS-CoV-2 specific therapies
From the beginning of the worldwide pandemic till now no effective specific
anti-SARS-CoV-2 treatment was available1,2. In June 2021 the use of SARS-CoV-2
monoclonal antibodies as early treatment for SARS-CoV-2 infected individuals
became available in the Netherlands after an emergency use authorisation of the
FDA and EMA. First large phase-III randomised controlled clinical trials have
showed that SARS-CoV-2 monoclonal antibodies, when given early after the onset
of symptoms, bind the SARS-CoV-2 spike protein effectively and prevent hospital
admission and death3-7. Additionally, promising SARS-CoV-2 compounds such as
the oral antivirals molnupiravir8,9 and nirmatrelvir/ritonavir10 recently
received an emergency use authorization of the FDA in patients with Covid-19 at
high risk of hospitalization and death. EMA's human medicines committee (CHMP)
has also started a rolling review of the oral antiviral medicine molnupiravir
and gave an emergency auhorisation for nirmatrelvir/ritonavir. Recently, the
EMA gave an emergency authorization for and tixagevimab/cilgavimab for the
prevention of COVID-19 before potential exposure to the SARS-CoV-2 virus11.

Pathophysiology
SARS-CoV-2 monoclonal antibodies
SARS-CoV-2 monoclonal antibodies recognize a single and unique epitope on the
SARS-CoV-2 spike proteins and are derived from donor B-lymphocytes. The donor
B-lymphocytes can be derived either from patients who had Covid-19 or humanized
mice who were exposed to SARS-CoV-23,12. The SARS-CoV-2 monoclonal antibodies
inhibit the entry of the virus into the host cells (neutralization).
Furthermore, antibody binding results in opsonization and is the first step of
phagocytosis, eventually resulting in apoptosis and necrosis of the infected
cells3. Monoclonal antibodies can be altered artificially in the laboratory to
combat emerging variants of SARS-CoV-23. Frequently investigated combinations
are casirivimab with imdevimab, sotrovimab and balanivimab with etesevimab4-
7,13. Tixagevimab/cilgavimab (Evusheld) is the first monoclonal antibody
authorised by the EMA for the prevention of COVID-1911

Oral anti-SARS-CoV-2 agents
At present, many candidate small-molecule therapeutics have been developed that
can inhibit both the infection and replication of SARS-CoV-2 and even
potentially relieve cytokine storms and other related complications. As
SARS-CoV-2 infects cells, reproduces itself, and spreads, the coronavirus
relies on dozens of viral and host proteins to complete its life cycle. The new
oral pill nirmatrelvir/ritonavir (Phizer) inhibits the main viral protease used
to create other proteins for the virus10. The oral pill molnupiravir (Merck)
inserts a defective RNA building block when the virus uses an enzyme known as a
polymerase to copy its genome.8

The role of new SARS-CoV-2 therapies
There are a number of factors that most probably will lead to seasonally peaks
of infection and hospital admissions for SARS-CoV-2 infections14-16. First,
there will remain a group within our population that remains willingly
unvaccinated. Second, it is shown that numerous immunocompromised patients have
inadequate antibody response to vaccinations and do not produce long-term
protection17,18. At last, with new emerging viral variants arising with
expected higher viral spread, it is assumed that outbreaks of SARS-CoV-2
infections will remain prevalent in the coming years14-16,19.
With regard to immunocompromised patients, even with the most effective mRNA
SARS-CoV-2 vaccines show reduced or even absent humoral responses in patients
with solid organ transplants or for instance in patients treated with anti-CD20
for an hematologic malignancy17,18. The fact that immunocompromised patients
have inadequate immune response to vaccinations underscores the need of
treatment options essential for a subpopulation to slow or stop the
replications of the SARS-CoV-2 virus. Especially for these immunocompromised
patients the novel SARS-CoV-2 therapies could become a real game changer.

First results of phase-III studies
SARS-CoV-2 monoclonal antibodies
The first results of several phase III placebo-controlled randomized controlled
clinical trials of monoclonal antibodies of SARS-CoV-2 are now
available4,5,7,13. The studies were designed to analyze the effect of these
monoclonal antibodies when given early after symptom onset to prevent disease
progression, hospital admission and mortality. Two other studies presented the
interim analysis regarding the treatment of casirivimab with imdevimab4
combination and the sotrovimab alone5. These two studies investigated a single
intravenously administration of monoclonal antibodies within 3-7 days after the
start of symptoms and demonstrated a relative reduction of 70-85% in Covid-19
related hospital admission and death within four weeks4,20.

Due to the abovementioned evidence, the Dutch medical guideline for the
treatment of SARS-CoV-2 patients updated on July 2022. The Dutch Working Party
on Antibiotic Policy (Stichting Werkgroep AntibioticaBeleid, SWAB) now
considers to treat high-risk patients, with or without a prior antibody
response (that means no vaccination response and no seroconversion) and with a
high risk of Covid-19 disease progression to start treatment with neutralizing
monoclonal SARS-CoV-2 antibodies and oral antiviral agents
(nirmatrelvir/ritonavir) 21. Patients with a high risk to develop severe
Covid-19 are defined as follows in the Dutch guidelines:

Post organ or bone marrow/stem cell transplantation, hematological malignicany,
solid tumor <= 3 months chemotherapy or immunotherapy; severe kidney
failure/dialysis, primary immunodeficiency, using immunosuppressive
medication21,22.

At the moment (July 2022), there are no SARS-CoV-2 monoclonal antibody agents
available in the Netherlands which have potent neutralisation against the
dominant B.1.1.529 (Omicron) variant of concern (VOC). However,
tixagevimab/cilgavimab (Evusheld) will become available in the Netherlands in
Q3, 2022. The EMA evaluated data from a study in over 5,000 people showing that
Evusheld, given as two injections of 150 mg tixagevimab and 150 mg cilgavimab,
reduced the risk of COVID-19 infection by 77%, with the duration of protection
from the virus estimated to be at least six months11.

Oral anti-SARS-CoV-2 agents
The mechanism of action of the nucleoside analogue molnupiravir and the
protease inhibitor nirmatrelvir/ritonavir are independent of mutations in the
spike protein, which can affect the efficacy of monoclonal antibody treatments.
The first results of a phase III placebo-controlled randomized controlled
clinical trials of molnupiravir are now available9.
Both oral antivirals are developed to be taken within the first few days of
Covid-19 infection and are reported to reduce the risk of hospitalization and
death by approximately 30% for molnupiravir and even up tot 89% for
nirmatrelvir/ritonavir, without evident safety concerns9-11.

The need for an independent Dutch cohort to evaluate the clinical use of new
SARS-CoV-2 specific therapies
After the results of these first results of phase-III studies4,5, neutralizing
monoclonal SARS-CoV-2 antibodies have been given an emergency use authorisation
and - since late June 2021 - have become available in the Netherlands to treat
SARS-CoV-2 infected patients who are at high risk to develop severe disease.
Further randomized controlled trials investigating the effect SARS-CoV-2
antibody in immunocompromised patients are expected to be deemed unethical due
to the clear effect seen in the phase-III trials and the already limited
existing immune response. Of interest, there are currently intravenous and
intramuscular antibodies treatment regimens available, although the shift to
different routes, most notably subcutaneous, is underway and will possi

This study has been transitioned to CTIS with ID 2024-515263-60-00 check the CTIS register for the current data.

- A. What are the SARS-CoV-2 viral load kinetics during and after treatment
with neutralizing monoclonal antibodies and other antiviral agents against
SARS-CoV-2?
- B. What is the risk of SARS-CoV-2 infection after prophylactic use of
monoclonal antibodies or other antiviral agents?
- C. Do variants, spike mutations and immune escape during treatment with
neutralizing monoclonal antibodies and other antiviral agents against
SARS-CoV-2?
- D. What are the viral antibody and inflammatory response kinetics during and
after treatment with neutralizing monoclonal antibodies and other antiviral
agents against SARS-CoV-2?

The TURN-COVID biobank will be a prospective cohort study designed in
accordance with international standards25. The study population will consist
out of all patients treated with neutralizing monoclonal antibodies and
antivirals against SARS-CoV-2. Clinical data will be obtained throughout the
electronic patient dossier. In addition, control patients with similar
comorbidities will be included.

In addition, patients with a high risk to develop severe Covid-19 and who are
not treated with monoclonal antibodies or other antiviral agents against
SARS-CoV-2 will be included as controls.
*
Scheme 1: SARS-CoV-2 infected patients treated with neutralizing monoclonal
antibodies or/and other antiviral agents
Blood samples as detailed below will be sampled at day 0, 7, 28 and 90.
Nasopharyngeal swabs will be sampled at day 0, 2, 5, 7, 28 and 90. The design
is further visualized schematically in Figure 1. Patients will be asked to
perform provided antigen-self test in the first 14 days of their SARS-CoV-2
infection. All self tests will be saved on room temperature for genetic
characterization35.

Scheme 2: Patients treated with prophylactic neutralizing monoclonal antibodies
or/and other antiviral agents
Blood samples and nasopharyngeal swabs as detailed below will be sampled at day
0, 28, 90, 180 and 360. In case patients experience symptoms that could
indicate COVID-19 they are also asked to perform provided self-tests. A
positive self test will be confirmed with an extra nasopharyngeal swab in order
to perform a PCR. If a patient is infected with SARS-CoV-2 (= positive PCR)
during the study period, they will also be included in Scheme 1 from the moment
of confirmed SARS-CoV-2 infection. Patients will be asked to save their antigen
test on room-temperature (self-tests), in order to perform genetic
characterization and genomic surveillance for SARS-CoV-2.
The design is further visualized schematically in Figure 2. A three day
deviation before and after the appointment is deemed acceptable for day 0, 2, 5
and day 7. For day 28 a seven day deviation is deemed acceptable, for day 90
and 180 a fourteen day deviation is deemed acceptable and for day 360 a
twenty-eight day deviation is deemed acceptable. Samples will be stored in the
Amsterdam UMC, location AMC.

Patients will be seen multiple times during follow-up. Venous blood and
naso-oropharyngeal swabs will be obtained. The total burden and risk is deemed
low.

Due to the fact that the METC classified this observational research as a
medication study (non-registred) we also describe the risks associated with the
monoclonal antibody and antiviral agents treatment, namely allergic reactions
and local reacties.