With oral treatment with simnotrelvir/ritonavir in a vaccinated population, COVID-19 symptoms resolved approximately 1. 5 days earlier and SARS-CoV-2 virality decreased significantly, according to a Chinese placebo-controlled phase II/III trial.
In patients with mild to moderate COVID-19, the median time to sustained resolution of symptoms was especially reduced from 216 hours to approximately 180 hours when simnotrelvir/ritonavir was taken within 72 hours of treatment. symptom onset and continued twice daily for five days (P = 0. 006), reported Dr. Bin Cao, of the China-Japan Friendship Hospital in Beijing, and colleagues.
Also by day 5, simnotrelvir/ritonavir significantly decreased the SARS-CoV-2 viral load from baseline when compared to placebo (mean difference -1.51 log10 copies/mL, 95% CI -1.79 to -1.24). Viral load reductions at day 7 and day 9 were also greater in the simnotrelvir/ritonavir group, the authors detailed in the New England Journal of Medicine.
In the subgroup of the trial with risk points for severe COVID-19, simnotrelvir reduced the median time to symptom resolution by 60. 4 hours. The researchers found no protective problems, adverse events occurred in a higher proportion of patients in the simnotrelvir group.
The antivirals that are currently available for COVID outpatients, namely nirmatrelvir-ritonavir (Paxlovid) and remdesivir (Veklury), are for high-risk groups based on studies demonstrating their ability to reduce the risk of COVID-related hospitalization or death. It has been linked to the highest prices since the U. S. ended universal access to free COVID treatments last year.
“Due to high drug prices and unequal drug distribution, more drug features are needed to improve symptom resolution in patients with mild to moderate COVID-19,” Cao and his co-authors wrote.
Simnotrelvir, an oral protease type 3-CL inhibitor, has been granted conditional emergency authorization in China for the treatment of mild to moderate COVID-19, although plans for regulatory approval in the U. S. have been finalized. UU. no are clear.
“I think we have to be interested, and even a little excited, about those results, but we also want to see them implemented in the population that we’re most interested in,” said William Schaffner, MD, of Vanderbilt University in Nashville, Tennessee. in an interview with MedPage Today.
Schaffner, who wasn’t concerned about the study, noted that the trial participants were young, healthy and vaccinated. “Some of them had cardiovascular disease, but that wasn’t the population we were most concerned about because they’re older and have one or more serious underlying chronic diseases. “
And the trial was not designed to provide data on the effects of simnotrelvir on the maximum clinically applicable outcomes, Schaffner noted: COVID-related hospitalizations, ICU admissions or mortality.
That said, he stressed the importance of devising new COVID-19 remedies that can overcome some of the limitations of nirmatrelvir-ritonavir. “Having a choice is a smart thing to do,” he said.
The trial enrolled more than 1,200 patients from 35 sites in China from August to December 2022. Participants were adults with mild to moderate symptoms of COVID-19, most commonly sore or dry throat, cough, stuffy or runny nose, headache and fever. Half were randomly assigned to receive 750 mg simnotrelvir/100 mg ritonavir and the other half to receive a matching placebo, twice over five days.
For this research, Cao’s organization relied on the other 1,007 people in the intention-to-treat modified cohort who obtained their assigned treatment within 72 hours of symptom onset. Almost one part won the test drug or placebo within 48 hours.
Patients were quarantined, observed, and evaluated for compliance with remedies at designated hospitals. Patients self-rated COVID-19-related symptoms and symptoms on a subjective scale. The researchers quantified SARS-CoV-2 RNA from nasal or oropharyngeal samples received at normal periods up to day 29.
The study authors reported that the population had a median age of 35 years, of which 59% were men. The majority (53. 5%) had some threat of severe COVID-19, adding being obese or obese (35. 7%), smoking or more (22. 7%) and cardiovascular disease (4. 5%). Approximately 96% have been vaccinated against COVID-19 and 77% have received a booster dose.
Other secondary endpoints showed that treatment with simnotrelvir/ritonavir reduced the median time to sustained symptom improvement by approximately 48 hours and accelerated the resolution of respiratory symptoms by approximately 41 hours.
Adverse events occurred in 17. 5% of patients in the simnotrelvir group and 10. 2% in the placebo group. The three most common drug-related adverse events were higher triglyceride levels (4. 3%), decreased neutrophil count (1. 9%), and diarrhea (1. 7%). No patients died during the trial period.
Katherine Kahn is a staff writer at MedPage Today, covering the infectious diseases beat. She has been a medical writer for over 15 years.
The study was funded by Jiangsu Simcere Pharmaceutical.
Cao and some co-authors reported consulting with Jiangsu Simcere Pharmaceutical. The co-authors also included workers at the company.
Schaffner reported on any ties to the industry.