Pfizer has commenced a Phase 2/3 clinical trial to evaluate the antiviral treatment Paxlovid in children and adolescents aged 6 to 17 years with confirmed COVID-19 infection. The study focuses on assessing the safety and efficacy of Paxlovid in non-hospitalized children who are symptomatic and at high risk of progressing to severe disease.
The trial, which has begun enrolling approximately 140 participants, is designed to determine the optimal dosing regimen for pediatric patients. Participants are divided into two cohorts based on weight. The first cohort, consisting of children weighing at least 88 pounds (40 kg), will receive 300 mg of nirmatrelvir and 100 mg of ritonavir orally twice daily for five days – the same dosage currently authorized for adults and adolescents 12 years and older meeting the weight requirement. The second cohort includes children weighing between 44 and 88 pounds (20-40 kg) and will receive a reduced dose of 150 mg of nirmatrelvir and 100 mg of ritonavir orally twice daily for five days.
Addressing Unmet Needs in Pediatric COVID-19 Treatment
Dr. Mikael Dolsten, Pfizer’s chief scientific officer, emphasized the significant unmet need for outpatient treatments suitable for children and adolescents to prevent the progression of COVID-19 to severe illness, including hospitalization or death. While vaccines are available for children as young as 5, treatment options remain limited, highlighting the importance of this trial.
The FDA's Dr. John Farley acknowledged the eagerness of physicians for more treatment options during an American Medical Association webinar, noting the importance of safety data and understanding how drugs move through the body in pediatric populations.
Paxlovid's Efficacy in Adults
Data from adult trials have demonstrated Paxlovid's effectiveness in reducing the risk of hospitalization or death by 89% when administered to high-risk adults within a few days of symptom onset. The current authorization for individuals 12 and older weighing at least 88 pounds is based on modeling data suggesting similar effects in children. The ongoing trial aims to provide further data to support dose recommendations and potentially expand the indication to younger age groups and lower weights.
COVID-19 Impact on Children
Although children are less likely than adults to be hospitalized with COVID-19, they can still experience serious illness. Recent data from the American Academy of Pediatrics indicates a decline in new COVID-19 cases among US children, with cases dropping below 100,000 last week for the first time since early August.
