The analysis reviewed the safety and efficacy among patients in Japan to confirm the findings of the overall study population.
A post hoc analysis of a subgroup of patients in Japan confirmed that dupilumab is well tolerated, safe, and efficacious for the treatment of chronic rhinosinusitis with nasal polyps (CRSwNP), according to a study published in The Laryngoscope.
The study analyzed 49 patients enrolled in the SINUS-52 study in Japan. According to the researchers, studying this subgroup is important because in Asian populations, patients are more likely to have type 1 and type 3 inflammation; in comparison, Western populations are more likely to have disease driven by type 2 inflammation.
Patients in the SINUS-52 study received 100 µg mometasone furate nasal spray twice daily during a 4-week run-in period and the entirety of the trial. After the run-in period, patients received either dupilumab 300 mg every 2 weeks (q2w) for 52 weeks (Arm A; n = 16), dupilumab 300 mg q2w for 24 weeks and then every 4 weeks for the remaining 28 weeks (Arm B; n = 17), or placebo (Arm C; n = 16).
As a subgroup analysis, the end points were the same as for the entire study population. For all end points, the researchers were looking at change from baseline by week 24 for pooled Arms A and B vs placebo for nasal polyp score (NPS), nasal congestion (NC), and Lund-Mackay computed tomography (LMK-CT) score.
The participants in the Japan subgroup had a lower body mass index than the overall study population, but the rest of the baseline demographics and disease characteristics were similar.
A total of 49 patients were randomized at Japanese centers, but only 45 completed the study. Compared with the placebo group, patients who received dupilumab had significantly greater improvements in NPS, NC, and sinus opacification LMK-CT score. Arm A had the greatest changes (P < .001) at all time points compared with placebo.
The first few weeks of the study had the greatest improvements in daily loss of smell and University of Pennsylvania Smell Identification Test. These differences remained significant compared with placebo through week 52 of the study.
Compared with the placebo arm, patients with comorbid asthma who were in the dupilumab arms had significant improvements by week 24 in forced expiratory volume in 1 second (least squares [LS] mean: 0.34; 95% CI: 0.05-0.63) and 6-item Asthma Control Questionnaire score (LS mean: –1.45; 95% CI: –2.09 to –0.82).
At week 52, only 9.1% of the patients who received dupilumab required systemic corticosteroid rescue use of NP surgery (actual or planned) compared with 31.3% of patients in the placebo arm.
Nearly all of the patients reported a treatment-emergent adverse event (TEAE): 14 patients in the placebo arm (87.5%), 16 patients in Arm A (81.3%), and 17 patients in Arm B (100%). Infections and infestations were the most common TEAE in all 3 arms: 56.3% in Arm A, 82.4% in Arm B, and 68.8% in the placebo arm. Respiratory, thoracic, and mediastinal disorders were also common: 25.0% in Arm A, 35.3% in Arm B, and 50.0% in the placebo arm.
Overall, the results in the Japan subgroup were comparable to the overall population, the researchers determined. However, they did note that the small population of the subgroup of patients in Japan was a limitation to the study findings.
“Treatment effects were noted as early as week 4 and were maintained throughout the 52-week study period,” they wrote. “TEAEs were also similar to those reported by the overall study population, indicating no ethnicity/race differences in safety profiles.”
Fujieda S, Matsune S, Takeno S, et al. The effect of dupilumab on intractable chronic rhinosinusitis with nasal polyps in Japan. Laryngoscope. Published online November 23, 2020. doi:10.1002/lary.29230