'Cosentyx' reimb changes hidradenitis suppurativa strategy

Starting this month, expanded reimbursement is provided…biological agent has been added

Patients can choose medicine depending on their individual condition and the mechanisms of actions

The treatment landscape for hidradenitis suppurativa (HS) in South Korea is at a turning point following approval of 'Cosentyx' for insurance reimbursement.

In December 2023, the expanded indication for Novartis Korea's interleukin-17A inhibitor Cosentyx (secukinumab) was approved, making it a new biologic treatment option after approximately 8 years.

However, Cosentyx has remained a non-reimbursed drug until now, while Humira has been the only biological agent patients can practically choose.

Two years after approval, as of December 1, 2025, the reimbursement criteria for Cosentyx were set to treat adult patients with severe HS. Consequently, a reimbursement option is now available to the domestic HS market in approximately 10 years.

The process of expanding reimbursement for Cosentyx has not been easy. The reimbursement application for Cosentyx was submitted soon after receiving indication approval in December 2023. However, the reimbursement review had been delayed due to an external issue. The company voluntarily withdrew the application and resubmitted an expanded reimbursement application in November 2024.

Even after that, the review process was challenged by various external issues, including changes to the domestic drug pricing policy and discussions on Most Favored Nations (MFN). Given the evidence, such as large-scale global clinical data, international guideline recommendations, and unmet needs of domestic patients, the company succeeded in expanding reimbursement criteria 1 year after reapplication.

Cosentyx is drawing attention for having different mechanisms of action compared with Humira. Whereas Humira blocks Tumor Necrosis Factor-alpha (TNF-α) to inhibit the inflammatory response, Cosentyx works by directly inhibiting IL-17A, which plays a key role in inflammatory immune diseases, thereby inhibiting the release of proinflammatory cytokines and chemokines. This drug reduces abscess and inflammatory lesions in HS.

Improved treatment access to a new medicine with a mechanistic difference is meaningful because it not only provides a new option for patients in terms of treatment response conditions and drug tolerance, but also establishes a setting for potentially elaborate personalized treatment plans.

Furthermore, it is encouraging that the reimbursement criteria for biological agents were updated during the Cosentyx review. Previously, reimbursement for biological agents in HS was limited to severe patients (Hurley Stage 3). The scope has now expanded to include patients with moderate-to-severe disease (Hurley Stage 2).

Another significant change resulting from this expanded reimbursement is improved patient access and a broader range of treatment options. When the Special Case Medical Expense Coverage criteria are applied, the out-of-pocket cost for a single 300mg dose of Cosentyx is KRW 113,482. Cosentyx is administered once weekly for the first month of initiation, followed by dosing every 4 weeks thereafter. Excluding the initial month, patients will pay KRW 113,482 per month during the maintenance phase.

In comparison, the out-of-pocket cost for a single 40mg dose of Humira is KRW 28,640, and it is administered every week or every two weeks. The monthly price (4 doses) is approximately KRW 114,560. During the maintenance period, the patient's financial burden is nearly identical for both medications, allowing patients to select and maintain therapies with different mechanisms of action without significant cost disparities.

Professor Min Soo Jang, General Affairs Head of the Korean Acne and Rosacea Society (Professor of Dermatology at Kosin University Gospel Hospital), explained, "HS is a difficult disease to cure. There are cases in which the disease does not improve with conventional treatment, or symptoms progressively worsen. Strategic management is possible if a systematic treatment plan is established through biological agents."

Professor Jang added, "However, unlike psoriasis or atopic dermatitis, where various biological agents with different mechanisms of action are available, HS treatment options have been limited to a single mechanism. With the expanded reimbursement of Cosentyx, treatment options have widened for patients who had insufficient responses to existing therapies or had to discontinue treatment due to side effects."

Meanwhile, in the recently announced 4-year (204-week) extension of the SUNNY study, patients who achieved HiSCR at Week 52 and continued Cosentyx treatment showed a HiSCR achievement rate of 83.2% at Week 204. It was confirmed that the symptom-improvement effect is maintained for up to 4 years after starting treatment.