We have read with great interest the article by Martorell Calatayud et al., “Cost-consequence analysis of secukinumab vs adalimumab in moderate-to-severe hidradenitis suppurativa”, recently published in Actas Dermo-Sifiliográficas.1 The authors present a detailed and methodologically structured economic analysis comparing different therapeutic sequences with secukinumab and adalimumab from the perspective of the Spanish National Health System (SNS), providing relevant information for clinical decision-making and healthcare management. We agree on the need for rigorous economic evaluations in hidradenitis suppurativa (HS), a chronic, highly disabling disease associated with a significant clinical, social, and economic burden.

In addition, we acknowledge the inherent complexity of any pharmacoeconomic modeling in the absence of direct comparative trials between active biological treatments. In this context, we consider it of interest to complement the cost-consequence approach presented by the authors with an alternative, simpler, and more transparent approach based on the number needed to treat (NNT) vs placebo, with the aim of exploring the relationship between the magnitude of clinical benefit observed in pivotal trials and the annual cost of treatment.

This approach is not intended to replace or invalidate the analysis by Martorell et al., but rather to provide an additional interpretative framework that may be useful for clinicians and decision-makers. Although NNT does not allow direct comparisons between active treatments and is conditioned by the comparator, trial design, and included population, it constitutes a reproducible and easily verifiable measure of the magnitude of clinical benefit. In the absence of head-to-head studies or adjusted indirect comparisons, its use may facilitate a preliminary approximation of the economic impact of efficacy demonstrated against placebo.

In the PIONEER I and II trials,2 adalimumab demonstrated HiSCR response rates close to 50% vs approximately 26–27% with placebo. This translates into an absolute risk reduction (ARR) of around 23% and a point estimate NNT of 4.3 (95%CI, 3.1–7.1). For its part, in the SUNSHINE and SUNRISE studies,3 secukinumab achieved response rates of 41–46%, compared with 27–28% with placebo, with an approximate ARR of 14% and a point estimate NNT of 7.1 (95%CI, 4.8–14.3).

By combining these values with annual treatment costs in Spain, estimates of cost per additional responder (cost per NNT) can be obtained. Using net hospital acquisition prices, the approximate annual cost of biosimilar adalimumab (80mg, approved regimen in HS with induction and biweekly maintenance) is around €4448.6 per patient, whereas that of secukinumab (300mg, monthly regimen after induction) rises to approximately €17,594.9 annually, according to public procurement sources.4,5

Applying these costs to the NNT derived from pivotal trials, the cost per additional responder would be on the order of €19,000 for adalimumab vs approximately €125,000 for secukinumab in the base-case scenario, with wide ranges derived from the uncertainty of the NNT confidence intervals (Table 1). These differences should not be interpreted as a direct recommendation for therapeutic positioning nor as a comprehensive assessment of the relative efficiency of both drugs. They simply reflect that, from a strictly quantitative perspective based on efficacy versus placebo, the magnitude of clinical benefit observed with adalimumab is achieved at a lower cost per additional responder.

Of note, this approach does not incorporate relevant aspects that are at least partially considered in more complex models, such as therapeutic sequences, persistence, rescue treatments, delayed response, safety, quality of life, or patient preferences. Therefore, both approaches should be considered complementary rather than mutually exclusive.

In conclusion, the analysis based on point estimate NNT provides an additional, simple, and transparent perspective, highlighting how the choice of methodological framework may influence economic conclusions. We believe that integrating different approaches—cost-consequence analyses, NNT-based evaluations, and, in the future, adjusted indirect comparisons or direct comparative trials—will enrich the debate and contribute to more informed decision-making in the treatment of hidradenitis suppurativa.