Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by the inflammation of hair follicles. It typically emerges after puberty and manifests as painful lesions, affecting the axilla, inguinal, perianal, and gluteal regions.1,2 In Spain, according to different estimations the prevalences is estimated to be around 0.5%.3

Treatment for HS aims to control the inflammation and reduce pain through changes in lifestyle and medical and surgical therapies.4 Traditional therapies includes topical keratolytics, antiseptics, and antibiotics, alongside systemic treatment involving antibiotics, retinoids, and corticosteroids.5,6 Biological therapies have been incorporated into the therapeutic arsenal, being of special relevance for patients with moderate-to-severe HS.5,7 Up to 2023 adalimumab was the only biologic treatment approved for HS treatment based on the results of the PIONEER studies.8,9 However, the efficacy profile of adalimumab in the routine clinical practice is variable and primary or secondary lack of efficacy may occur.7 In February 2023 the European Medicines Agency (EMA) approved secukinumab, a monoclonal antibody that binds to IL-17A, as a therapeutic alternative. Secukinumab has already been approved for psoriasis, psoriatic arthritis, and axial spondylarthritis.10 The SUNSHINE and SUNRISE trials, conducted with patients with HS, demonstrated that a higher proportion of patients on secukinumab achieved a clinical response in HS clinical response (HiSCR50) vs patients on placebo 52-weeks into therapy.11 Based on this, secukinumab was approved for the treatment of HS.10

Former studies have shown that the use of biological therapies results in an increased cost of the treatment for HS.12,13 In this regard, financial assessments are essential to provide patients with HS with the best therapeutic approach available. To date, no economic evaluations on the use of secukinumab for HS have been published.

Considering the above, the main goal of the study was to estimate the difference between secukinumab and adalimumab regarding the pharmacological cost and the cost per responding patient one year after treatment initiation from the perspective of the Spanish National Health System (NHS).

In this study, we conducted a pharmaco-economic evaluation of the secukinumab use for the treatment of moderate-to-severe HS vs the use of adalimumab from the perspective of the Spanish NHS, using a cost-consequence analysis.

The analysis showed that, based on previously published efficacy rates, initiating treatment for hidradenitis suppurativa with secukinumab resulted in a higher number of responders compared with initiation of adalimumab. Notably, treatment with secukinumab could be exclusive, without the need for dose escalation or switching, whereas treatment with adalimumab may require rescue therapy with secukinumab. In addition, initiation with secukinumab was associated with lower total pharmacologic costs and lower cost per responder compared with initiation with adalimumab. However, when a 45.0% discount was applied to the cost of adalimumab, a lower cost per responder was observed.

Our results are consistent with those from previously published studies in other conditions such as psoriasis21 and psoriatic arthritis22 in which secukinumab demonstrated to be the most efficient treatment from the Spanish NHS perspective vs other biological agents. This was attributed to its efficacy profile and persistence of the effect, resulting in the greatest number of responders with a cost containment, which translates into the lowest cost per responder. Of note, for HS management, the standard dose for adalimumab is administered every week, which doubles the dose and cost vs other diseases as psoriasis, psoriatic arthritis, or axial spondylopathies.

The efficacy data for both treatments were obtained from previous clinical trials. However, clinical trials for adalimumab did not consider the 52-week timepoint and for this, clinical response rates were assumed to be the same as for secukinumab. In this context, the model developed for this study was conservative for secukinumab, as real-life studies have reported clinical responses rates for adalimumab at 52 weeks from 53.9%23 to 72.1%,24 which is lower than that assumed for this study (78.6%).

The management of HS not only inflicts a significant financial strain on patients but also affects their work productivity.25,26 Former European studies have indicated that the predominant contributors to HS-related costs are treatment expenses, time off work due to sickness and decline in work productivity.12,13 Given the higher number of responders with secukinumab compared with adalimumab, both direct costs related to hospital-based patient management and indirect costs, including those associated with reduced work productivity, may be decreased.

Similarly, HS has a significant negative impact on patients’ HRQoL, including high levels of pain, anxiety, and depression, being higher in those with moderate-to-severe HS.27 In this regard, a recently published study showed that, compared with placebo, secukinumab improved patients’ HRQoL.28 This, along with the results of our study showing that the early use of secukinumab results in a higher number of responders, suggests that using secukinumab as a first-line therapy could help achieve a better disease control and ultimately reduce the disease burden.

For the management of HS, the concept of “window of opportunity” was proposed and defined as that period in the disease course in which efforts to control the disease are more effective and patients can obtain the best results.29 In this regard, the results of our study show that starting HS therpy with secukinumab would be beneficial, as a higher proportion of patients in this treatment group were considered responders and resulted in lower treatment costs vs patients treated with adalimumab.

Our study has some limitations. First, due to the lack of long-term efficacy data for adalimumab in clinical trials, we assumed the clinical response rates from SUNRISE and SUNSHINE clinical trials. Second, the model assumes that patients who do not achieve a response discontinue treatment, because partial responses could not be incorporated owing to a lack of data. Third, in the absence of data on patients who fail biologic therapy and subsequently receive rescue treatment with another biologic or treatment intensification, efficacy estimates from the corresponding clinical trials in biologic-naïve patients were assumed. Further research is warranted to evaluate treatment sequencing when local comparative studies in similar populations become available.

Fourth, for the model in our study, we assumed timepoints for efficacy evaluation slightly different from those in the clinical trials to compare both treatments. Fifth, inclusion criteria for clinical trials assessing the efficacy secukinumab and adalimumab were not the same thus, this could have influenced clinical response rates. Sixth, discontinuation rates were not considered in the decision tree due to the short-term follow-up of our analysis, as they should have minimal impact. Finally, due to the nature of the model used, only the cost of pharmacological treatment is considered, although the total cost of patient management would include other costs such as surgery. However, it has been shown that there is a correlation between good pharmacological control and the need for fewer surgical interventions when patients are treated with secukinumab. Despite the above-mentioned limitations, we tried to address them in the most conservative approach not overestimating the efficacy and persistence data for secukinumab and giving adalimumab its best possible results published or estimated.

Secukinumab has been approved in Spain as second-line therapy after failure of adalimumab. This analysis suggests that, when considering that adalimumab is not providing enough efficacy for the patients, there are no economical reason for delaying the switch to secukinumab. The results of our economic evaluation can help decision makers in selecting the most efficient therapeutic approach for treating patients with moderate-to-severe HS and poses secukinumab as a suitable therapeutic option for the Spanish NHS.

All authors of the manuscript (AMC, AML, AJM and CB) have contributed to the conception and design of the model and the interpretation of the data; they have participated in the critical review of the intellectual content of the manuscript and have approved its final version prior to publication.

The authors declare no conflict of interest.