Reply to ‘Effectiveness, safety and drug survival of oral roflumilast for hidradenitis suppurativa’ by Holgersen et al.

We have read with great interest the article recently published on your journal entitled 'Effectiveness, safety and drug survival of oral roflumilast for hidradenitis suppurativa' by Holgersen et al.1 The authors examined the effectiveness, safety and drug survival of oral roflumilast in 32 adult outpatients with hidradenitis suppurativa (HS). There was a significant reduction in paired mean differences for the IHS4 score, 9.7 (2.4–17.0), p = 0.015; DLQI, 6.3 (1.3–11.2), p = 0.021; and overall VAS10, 2.0 (0.3–3.7), p = 0.027. Among patients who completed the follow-up, five (50%) and seven (70%) achieved HiSCR50 and IHS4-55, respectively.1 Follow up period was 6 months. We have some comments regarding these data presented by the authors. As rightly stated by the authors there are studies in the literature regarding both roflumilast as a single reported case2; but in particular there are long-term studies on other PDE-4 inhibitors such as apremilast3 and orismilast.4 Specifically, for apremilast, 2-year follow-up data have confirmed its effectiveness5; however, it is important to emphasize that the sampling in these studies is highly selective and limited in size, highlighting the need for larger scale studies to validate these promising results. Additionally, it has been reported that apremilast does not produce significant changes in inflammatory biomarkers in the lesional skin of HS patients.6 Upon a detailed review of the data presented by Holgersen et al., several critical elements are missing. Notably, the study lacks information about the patients' comorbidities and does not provide details regarding any prior treatments they may have received, such as adalimumab and/or secukinumab. This absence of information is significant, as it limits our understanding of how these factors could influence the study's outcomes. Incorporating data on comorbid conditions and prior biologic therapies would greatly enhance the authors' findings. It prompts an important inquiry: does the medication show greater efficacy in bio-naive patients, or does it offer more benefits to those who have previously failed biologic treatments? Addressing these questions would yield a deeper understanding of the drug's potential and help tailor treatment approaches to better meet the needs of diverse patient populations. In conclusion, we definitely agree with the authors on the potential use of these drugs in the therapeutic management of HS. However, we believe that it is still too early to define them as a novel therapeutic option for HS due to the lack of long-term studies and inadequate sampling. As the authors noted, large-scale studies will be necessary to support this assertion. To date, adalimumab, secukinumab and bimekizumab remain the drugs that have demonstrated real efficacy and long-term safety.7-9 Looking ahead, we await new studies that can confirm the initial data published for both JAK inhibitors and PDE-4 inhibitors.10 None. The authors reported no conflict of interest. Not required. The patients gave the consent for publication. The data that support the findings of this study are available on request from the corresponding author.