Use of a daily interferon-α nasal spray could significantly reduce the risk of COVID-19 infection among adult patients with cancer, according to the results of a multicenter, randomized trial published in Clinical Infectious Diseases.
The results suggest that the nasal spray could be a potential new tool for protecting vulnerable populations from the virus.
“This is the first randomized, controlled trial to show that an intranasal interferon-α spray can safely and effectively prevent COVID-19 in this group," stated lead study author Michelle K. Yong, MBBS, PhD, FRACP, MPH, Associate Professor and Infectious Disease Researcher at Peter MacCallum Cancer Centre, Victoria, Australia. “Even with vaccination, cancer patients remain more vulnerable to COVID-19 and its complications. It’s an additional layer of defense, especially for those who can’t mount strong responses to vaccines."
Study Methods and Key Findings
A total of 433 participants were enrolled in the multicenter, randomized, double-blinded, placebo-controlled trial and randomized 1:1 to receive either daily 40,000 IU of an interferon-α nasal spray or a saline placebo. All patients with influenza-like symptoms took self-collected nasal swabs for polymerase chain reaction testing.
Rates of COVID-19 infection were lower in the interferon-α spray arm, at 8.3%, compared with 14.4% in the placebo arm (relative risk [RR] = 0.60; 95% credible interval [CrI] = 0.33‒0.97). Other respiratory viral infections were reported at a rate of 5.1% in both groups (RR = 1.12; 95% CrI = 0.43‒2.34).
In the per-protocol cohort of 389 patients, the incidence rates for COVID-19 infection were 7.7% in the interferon-α nasal spray arm and 16.0% in the placebo arm (RR = 0.50; 95% CrI = 0.26‒0.84). Other respiratory viruses were reported at a rate of 4.6% in the interferon-α arm and 5.7% in the placebo arm.
Subgroup analyses showed that COVID-19 infection rates were lower in the interferon-α group for patients younger than age 65 years (RR = 0.48; 95% CrI = 0.20‒0.92); women (RR = 0.44; 95% CrI = 0.19‒0.85), and those that were vaccinated against COVID-19 (RR = 0.50; 95% CrI = 0.26‒0.82). No differences were observed according to underlying malignancy.
No differences were noted between the arms in regard to severity of COVID-19 infection, hospitalization, or mortality.
The nasal spray was considered safe and well tolerated.
“A safe, easy-to-use nasal spray with broad antiviral activity could benefit not just cancer patients, but other high-risk groups such as transplant recipients, people with chronic illnesses, and the elderly,” said senior author Monica Slavin, MBBS, FRACP, MD, FAAHMS, FECMM, Professor, Head of Infectious Diseases Department and National Centre for Infections in Cancer and Transplantation, Peter MacCallum Cancer Centre. “While it’s not a replacement for vaccination, it adds to our prevention toolkit and could help reduce illness, treatment delays, and hospitalizations.”
Disclosure: For full disclosures of the study authors, visit academic.oup.com.
