Omalizumab (Xolair) maintained efficacy for chronic rhinosinusitis with nasal polyps, a researcher reported.

In an open-label extension study of two, 24-week clinical trials, omalizumab was associated with significant improvements in nasal polyp scores (mean change -0.97, 95% CI -1.25 to -0.69), nasal congestion scores (mean change -0.99, 95% CI -1.14 to -0.83), and Sino-Nasal Outcome Test (SNOT) scores (mean change -22.39, 95% CI -25.39 to -19.40) through 1 year, according to Philippe Gevaert, MD, PhD, of Ghent University in Belgium.

“Scores worsened following omalizumab withdrawal, but remained above pre-treatment levels at week 76,” Gevaert said during a presentation at the American College of Allergy, Asthma & Immunology virtual meeting.

Omalizumab is thought to bind to free local immunoglobulin E (IgE), reducing inflammation that occurs with nasal polyps, Gevaert said.

Currently, dupilumab (Dupixent) is the only FDA-approved therapy to treat chronic rhinosinusitis with nasal polyps, and omalizumab is approved for treating moderate to severe persistent asthma.

The FDA did accept a supplemental biologics license application for this indication in 2019, but the application has not yet been reviewed due to the COVID-19 pandemic, noted Joseph Han, MD, of the Eastern Virginia Medical School in Norfolk, during a discussion of the findings.

Han added that he suspects “we may be able to find a decision soon.”

The European Commission approved omalizumab as an add-on therapy to intranasal corticosteroids for treating severe and persistent chronic rhinosinusitis with nasal polyps in August 2020.

Patients on either omalizumab or placebo in the original POLYP 1 and POLYP 2 studies were enrolled in this extension trial after 24 weeks. All patients then received 28 weeks of treatment followed by another 24 weeks of follow-up, during which they were only receiving background nasal spray.

The most common adverse event during the treatment period was nasopharyngitis, which occurred in 4.8% of patients. Otherwise the drug was well-tolerated, Gevaert said.

Overall, 95.6% of patients completed the extension treatment period and 92.8% completed the follow-up. Patients originally on placebo showed a similar treatment response to patients who continued omalizumab treatment from the previous study.

Many patients in the trial had surgery before entering the trial, but there was no difference in any of the outcomes when comparing patients with or without surgery, Gevaert said.

“In order to be included in the trial, you had to have a combined nasal polyp score of at least 5,” Gevaert said. “So although patients had surgery before, there was a regrowth of polyp large enough for them to be included in the trial.”