More patients SARS-CoV-2 RNA negative
By day 7, 80% of patients in the peginterferon lambda group were negative for SARS-CoV-2 RNA, compared with 63% in the placebo group (P = .15). After baseline load adjustment, however, the peginterferon lambda treatment was significantly associated with day 7 clearance (OR 4·12 [95% CI 1·15-16·73]; P = .029).
Respiratory symptoms improved faster
Most symptoms in both groups were mild to moderate, without difference in frequency or severity. While symptom improvement was generally similar over time for both groups, respiratory symptoms improved faster with peginterferon lambda, with the effect more pronounced in the high baseline viral load group (OR 5·88 (0·81-42·46; P =. 079).
Laboratory adverse events, similar for both groups, were mild.
“Peginterferon lambda has potential to prevent clinical deterioration and shorten duration of viral shedding,” the investigators concluded.
“This clinical trial is important” because it suggests that a single intravenous dose of peginterferon lambda administered to outpatients with a positive SARS-CoV-2 nasopharyngeal swab speeds reduction of SARS-CoV-2 viral load, David L. Bowton, MD, FCCP, professor emeritus, Wake Forest Baptist Health, Winston-Salem, N.C., said in an interview. He observed that the smaller viral load difference observed at day 14 likely reflects host immune responses.
Dr. David L. Bowton
Dr. Bowton also noted that two placebo group baseline characteristics (five placebo group patients with anti-SARS-CoV-2 S protein IgG antibodies; two times more undetectable SARS-CoV-2 RNA at baseline assessment) would tend to reduce differences between the peginterferon lambda and placebo groups. He added that the study findings were concordant with another phase 2 trial of hospitalized COVID-19 patients receiving inhaled interferon beta-1a.
“Thus, interferons may find a place in the treatment of COVID-19 and perhaps other severe viral illnesses,” Dr. Bowton said.
The study was funded by the Toronto COVID-19 Action Initiative, University of Toronto, and the Ontario First COVID-19 Rapid Research Fund, Toronto General & Western Hospital Foundation.
Dr. Bowton had no disclosures. Disclosures for Dr. Feld and coauthors are listed on the Lancet Respiratory Medicine website.