A Single-center Experience in Treating Young Children at High Risk For Severe COVID-19 With Sotrovimab.

To the Editors:

In Italy, the B.1.1.529 (Omicron) variant of concern (VOC) of Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is now dominant[1] and sotrovimab is thought to retain activity against it.[2,3]

To the best of our knowledge, there are few data on its use in children less than 12 years old and weighing less than 40 kg.[4] European Medicine Agency (EMA) and Italian Medicine Agency (AIFA) both authorized sotrovimab for treating COVID-19 in adults and adolescents (from 12 years of age and weighing at least 40 kilograms) who do not require supplemental oxygen and who are at increased risk of the disease becoming severe.

We describe a series of 5 children less than 12 years old, treated with sotrovimab in the Department of Pediatric and Public Health Sciences, Infectious Diseases Unit, Regina Margherita Children’s Hospital, Turin. All 5 patients were admitted for reasons other than COVID-19 and tested positive for SARS-CoV-2 infection. They were hospitalized to ensure clinical observation because they all fulfilled the criteria for high risk of progression to severe COVID-19 (Table 1) and they all met AIFA’s indications for treatment with sotrovimab, with the exception of age and weight.[5] None of them had received vaccination for SARS-CoV-2 (4 out 5 were less than 5 years old). As required by the hospital’s policy, off-label monoclonal antibodies (mAb) use for age and weight was prescribed after Hospital Drug Committee approval and once we obtained the informed parental consent.

TABLE 1.

Demographic and COVID-19 Related Symptoms in Our Pediatric Patients

Subjects	Age	Weight	Sex	Ethnicity	Comorbidity	First positive test for SARS-CoV-2	COVID-19 related symptoms	Sotrovimab infusion
Patient 1	2 months	5.5 kg	F	Caucasian	ALL at onset	27 January 2022	Fatigue	29 January 2022
Patient 2	1 year	12.5 kg	M	African	Mucopolysaccharidosis type I, sleep apnea syndrome with nocturnal NIV, AHSCT complicated with reactivation of CMV and EBV infection, immunosuppressive treatment with anti–B lymphocyte monoclonal antibodies (rituximab)	2 January 2022	Rhinitis, sore throat	8 January 2022
Patient 3	1 year	10 kg	F	African	Embryonal rhabdomyosarcoma and neutropenia (ongoing chemotherapeutic agents)	27 January 2022	Fever	29 January 2022
Patient 4	2 years	14 kg	M	Caucasian	ALL (ongoing chemotherapeutic agents)	27 January 2022	Fever	29 January 2022
Patient 5	8 years	18 kg	M	Hispanic	Chronic pulmonary graft versus host disease after AHSCT in ALL	1 January 2022	Headache, rhinitis	8 January 2022

AHSCT indicates allogeneic hematopoietic stem cell transplant; ALL, acute lymphoblastic leukemia; CMV, cytomegalovirus; EBV, epstein barr virus; F, female; M, male; NIV, noninvasive ventilation.

Since pediatric clinical trials on SARS-CoV-2 treatment with sotrovimab are lacking in children, there are no formal guidelines and recommendations about the dosage in patients younger than 12 years of age and weighing less than 40 kg. Considering that the recommended dose in adults and adolescents (weighing at least 40 kg) is a single 500 mg intravenous administration,[3] we established a dose based on anthropometric values of 12.5 mg/kg for our patients.

There were no significant adverse events and reactions that required the cessation of infusion. None of the treated patients required either intensive care admission or oxygen supplementation, except for 1, who presented pulmonary worsening the day after Sotrovimab infusion and recovered with a short course of steroids.

Among the first 2 patients treated, none was readmitted for reasons related to COVID-19 or Multisystem Inflammatory Syndrome in children (MIS-C) within 30 days of follow-up. Of the other 3, 1 was discharged the day after sotrovimab infusion and another 5 days later; the last is still hospitalized for reasons other than COVID-19. These 3 children did not develop COVID-19 related symptoms at the 7-day follow-up.

In conclusion, the administration of sotrovimab in the initial phase of SARS-CoV-2 infection might be considered also in young children with risk factors for severe COVID-19.

Although our data are limited, this report provides preliminary information on the use, weight-based dosage and tolerability of sotrovimab in young children at high risk for unfavourable and complicated COVID-19 evolution.