Discussion:
This study included 62 subjects who tested positive for COVID-19 and received Sotrovimab infusion within an average of 4 days of symptoms onset between November 2021 and March 2022 at AUBMC. To our knowledge, this study is the second one from the Middle East, the first one was conducted in United Arab Emirates (UAE) [16], describing real-life experience with Sotrovimab as treatment in patients with COVID-19. And it is the first study that includes a high proportion of cancer patients.
Most of our subjects were classified as tier 1 priority as per NIH criteria as patients in this tier were at the highest risk for disease progression. As compared to other cohorts in the earlier Sotrovimab clinical trials [12, 16-17], more patients in our study had hematological malignancies and/or were receiving active chemotherapy. Moreover, more than 50% (63.4%=27.9+35.5) of our patient population had cancer, whether hematological malignancy or solid organ malignancy and those are considered high-risk subjects and at risk for severe COVID-19 disease and death [18]. In the study from UAE only 1% of the subjects in the Sotrovimab group were immunosuppressed [16]. Whereas in the study by Aggarwal et al 24.9% of the subjects who received Sotrovimab were immunosuppressed [19].
Before the use of Sotrovimab, COVID-19 was associated with serious complications in cancer patients. In fact, the percentage of hospitalization among cancer patients who were infected with COVID-19 in the U.S varied between 25.2% and 33.7% [20]. And, in a study from China, the percentage of clinical deterioration and intensive care unit (ICU) admission in this patient population was reported as 39% [21].
In our cohort, we found that 21% of the subjects required hospitalization after receiving Sotrovimab, and 21 % had clinical deterioration within 24 hours of Sotrovimab infusion even though most of our subjects were cancer patients. Those rates were higher compared to the previously published trials [12, 19]. In the study from UAE, the overall hospitalization was 3.9%, and the percentage of critical disease progression was 0% [16]. However, patients who received Sotrovimab in the UAE study were selected based on a risk stratification criterion with at least one risk factor for disease progression, and the most prevalent risk factor for disease progression among patient who received Sotrovimab infusion was overweight 36% followed by HTN 20 % [16] and both percentages were much lower than the risk factors percentages in our cohort where 63.2 % of our subjects were obese and 56.5 % had HTN.
In a recent study from Sao Paulo Brazil the mortality rate among cancer patients who were hospitalized for COVID-19 was 49% without Sotrovimab [22]. The mortality rate in our study was much lower at 6.5% but still higher than the mortality rate among patients who received Sotrovimab in the studies that included less cancer patients such as the study from UAE [16] and that from Aggarwal et al [19].
The difference in the findings is mainly due to the overall proportion of immune suppressed subjects in the various studies and whether the NIH prioritization criteria were applied or not.
In our series, no adverse events related to Sotrovimab infusion were reported compared to 2% Sotrovimab related adverse events in the COMET ICE clinical trial and 10% in the TICO trial [12, 17].
Another point of relevance in this study is the very high compliance with the set criteria for use of Sotrovimab developed at our institution by the concerned stakeholders including ID specialists and pharmacists. Despite the chaos in Lebanon and the many challenges faced in all health care institutions [14], the Antimicrobial Stewardship Program at AUBMC has high level expertise in developing institutional policies, and guidelines for various diseases including COVID-19 with a tight control on the use of various agents including the monoclonal antibodies. The program follows patients closely to ensure adherence and compliance to various medications use.
Our study has several limitations. First, it is a retrospective study and not all the data needed was available in the reviewed charts. Also, the sample size is small, given the limited number of available Sotrovimab doses. It included vaccinated patients, and vaccination was not homogenous among the cohort and the subjects received different types of vaccines. In addition, our study was not homogenous in terms of management and treatment options for COVID-19 infection (concomitant use of remdesivir, steroids, and tocilizumab). As a result, the generalizability of the findings of the study is limited. Another limitation is the fact that the SARS-CoV-2 variant type of each subject was not identified; this information would have been important in light of several reports of a decreased efficacy of Sotrovimab against Omicron variants of COVID-19 [13].