Improved clinical effectiveness of adalimumab when initiated with clindamycin and rifampicin in hidradenitis suppurativa

Background: Adalimumab monotherapy for hidradenitis suppurativa (HS) is often insufficient with a maximum clinical efficacy of 60% in Hidradenitis Suppurativa Clinical Response (HiSCR) and limited effect on draining tunnels. Data suggest that adalimumab therapy could be improved by concomitant antibiotics.Objective: To compare the clinical effectiveness of adalimumab with clindamycin and rifampicin versus adalimumab monotherapy after 12 weeks.Methods: This retrospective study included patients who started adalimumab with additional clindamycin and rifampicin and patients treated with adalimumab monotherapy, matched on sex and refined Hurley score. The primary outcome measure was the difference in change in the International Hidradenitis Suppurativa Severity Score System (IHS4) at 12 weeks.Results: In total, 62 patients were included in the combination therapy group (n = 31) and adalimumab monotherapy group (n = 31), showing comparable IHS4 scores; 32.5 versus 29, p = 0.87 at baseline respectively. The combination therapy demonstrated greater clinical effectiveness expressed in median IHS4 improvement (-20 vs. -9, p < 0.001), IHS4-55 (74% vs. 36%, p = 0.002), median draining tunnel reduction (-4 vs. -2, p < 0.001) and pain response (47% vs. 27%, p = 0.02).Conclusion: Adalimumab initiated with clindamycin and rifampicin shows greater clinical effectiveness than adalimumab monotherapy. An important difference in effect was observed in the decrease of draining tunnels, addressing a serious limitation of adalimumab monotherapy.