What is Sotrovimab?
Sotrovimab is an antibody drug specifically designed to treat covid-19. It has been approved since the end of 2021 for the treatment of adult and adolescent high-risk patients with pre-existing conditions who do not require hospitalization – but who are at increased risk for a severe course.
Within the group of antibody drugs, it is characterized by high efficacy against both the delta and omicron variants of the coronavirus. It is effective in protecting against severe disease when used in a timely manner within the first five days of a confirmed Covid 19 diagnosis.
Once circulating in the body, Sotrovimab specifically binds the spike protein of the Sars-CoV-2 pathogen, preventing coronaviruses from docking and invading human cells. In this way, the reproduction of the coronavirus in the human body can be slowed down or, in the best case, prevented.
How well does sotrovimab work?
Sotrovimab is effective against a wide range of different coronavirus variants. The most important of these are delta (B.1.617.2) and omicron (B.1.1.529). The protective effect against the Delta variant is very high.
Sotrovimab thus closes a supply gap in the field of antibody-based therapies against covid-19.
Sotrovimab was tested in three pivotal studies, with the COMET-ICE study providing the first robust efficacy data. This was a multi-center study that included a total of 1057 study participants.
Adults with a confirmed laboratory diagnosis of covid-19 and mild covid-19 symptoms were included. Neither did study participants require supplemental oxygen at treatment initiation, nor did they require inpatient hospital care.
However, risk factors for a severe course were present in all participants – such as:
- diabetes mellitus
- overweight (obesity with a BMI greater than 30)
- chronic kidney disease
- Heart disease
- chronic lung disease (COPD), asthma or were older than 55 years of age
Study participants were divided into two groups – one group received a single 500-milligram standard treatment dose with sotrovimab (528 patients), and the other received placebo (529 patients).
Comparing the two groups, there was a 79 percent reduction in the (relative) risk of hospitalization when sotrovimab was administered.
What are the side effects?
However, the administration of sotrovimab is also associated with side effects in a certain proportion of treated patients. Common adverse effects are (moderate) allergic reactions affecting one in ten individuals.
Typically, allergic reactions are manifested by:
- reddened skin areas and itching (pruritus)
- swollen areas of skin on the face (angioedema)
- shortness of breath or cough (bronchospasm)
- general feeling of malaise – possibly with a feeling of weakness, nausea or headache
- feeling of heat, feverish reactions or chills
- rarely individually pronounced cardiovascular complaints (hypo and hypertension, tachycardia and bradycardia)
Only in extremely rare cases have severe hypersensitivity reactions (anaphylaxis) been observed following treatment.
How is sotrovimab used?
Sotrovimab is administered as a single intravenous infusion through a drip. This is usually done in a medical facility or as an inpatient in a hospital.
Treatment should be started as soon as possible after a confirmed Covid 19 diagnosis in order to have the best possible effect – ideally within five days of symptom onset.
Use in pregnancy only after risk-benefit assessment.
No data are available on the use of sotrovimab in pregnancy. It should therefore only be considered after individual risk-benefit assessment. Data from animal models are also not available.
Since antibodies (IgG antibodies) are able to pass from the placenta into the unborn child, a certain residual risk for the fetus cannot be completely excluded. In addition, no reliable statements can be made as to whether sotrovimab in particular passes into the breast milk – it is at least suggested.
It has not been investigated whether this means that the protection is also transferred to the infant or whether possible rare adverse reactions could occur. Therefore, use should be individualized according to a physician’s risk-benefit assessment.
When is sotrovimab not used?
The earlier sotrovimab is applied, the higher the efficacy. If treatment is started too late, efficacy decreases sharply.
Thus, sotrovimab shows little additional benefit in patients who have already had to be hospitalized. This is also the reason why the drug does not hold approval for use in hospitalized patients.
