COVID-19 less prevalent among patients with asthma taking biologics

SAN ANTONIO — Patients taking biologics for severe asthma experienced a lower rate of COVID-19 than those who were not taking biologics, according to data presented at the American Academy of Allergy, Asthma & Immunology Annual Meeting.

“Biologics are thought to suppress the immune system, so we wanted to see how this would interact with COVID,” Sofia Tovar, a student in public health at the University of Texas, Austin, told Healio.

Study design, results

Hypothesizing that the use of biologics would lead to higher rates of COVID-19 due to this effect, Tovar and colleagues studied 62 patients with asthma treated at five clinics in the Greater Austin Allergy, Asthma, and Immunology (GAAAI) network between March 1, 2020, and February 28, 2022.

The cohort included 29 patients treated with biologics (mean age = 45 years; 21 men), with one patient reporting mild persistent asthma, 10 patients reporting moderate persistent asthma and 10 patients reporting severe persistent asthma. Three of these patients developed COVID-19.

As controls, the cohort included 33 patients who were not treated with biologics (mean age = 38 years; 17 men), with 15 patients reporting mild intermittent asthma, 13 reporting mild persistent asthma and five reporting moderate persistent asthma. Twelve of these patients developed COVID-19.

Also, eight of the patients in the biologic group and five in the control group were unvaccinated. Inhaled corticosteroids (ICS) were used by six of the biologic group and three of the control group. Seventeen of the biologic patients and 10 of the controls used both ICS and long-acting beta agonists (LABA). None of the patients used LABA alone.

Biologic use included seven patients on benralizumab (Fasenra, AstraZeneca), seven on dupilumab (Dupixent, Sanofi Genzyme/Regeneron), four on mepolizumab (Nucala, GlaxoSmithKline) and 11 on omalizumab (Xolair; Genetech, Novartis).

COVID-19 was less prevalent among the patients on biologics compared with the control group (P = .02016). However, the patients on biologics and the control group did not experience any difference in severity of COVID-19 symptoms.

Possible mechanism

“This was contrary to our initial hypothesis because we were expecting that immunosuppressive effect,” Alyssa Osheim, BBA, lead medical scribe and research assistant at GAAAI, told Healio.

“But what we’re finding is that there is actually this alternate anti-inflammatory pathway that’s overpowering that immunosuppressive effect,” she continued.

As omalizumab binds with IgE, it inhibits cross-linking with high-affinity Fc epsilon receptors, which already are high among patients with asthma, Osheim said.

“There’s an inverse relationship between those receptors and interferon alpha,” she said. “Whatever is preventing that cross-linking with the receptors is causing that upregulation of interferon alpha.”

This indirectly affects interactions between dendritic cells and viruses when the immune system is attacking foreign invaders, Osheim said, calling this action specific to virus-induced exacerbations in patients with asthma. 

The researchers also suggested that the lower rates of COVID-19 among patients on biologics may be due to their behavior.

“They tend to be maybe more cautious about COVID and they care about their health, taking precautions,” Osheim said.

However, Osheim and Tovar cautioned that their study had a limited sample size and that COVID-19 incidence was based on positivity by report. They also noted that this anti-inflammatory effect may not be distributed evenly among all biologics.

“There might be concern for those patients who are on biologics if they can have more susceptibility to COVID, but this data indicates that might not be the case,” Tovar said. “So, severe asthmatic patients can continue their biologic.”

Noting that studies into the effects of biologics on COVID-19 prevalence are still in their early stages, Tovar and Osheim called for further investigations into how biologics and other anti-IgE therapies impact this mechanism in patients with asthma.

Further, the researchers noted that since only three of the patients in the study group developed COVID-19, it was difficult to analyze any subcategorization based on COVID-19 severity.

They added that they are expanding this research to include approximately 500 patients on biologics and will analyze subcategories of biologics in this analysis.