Hidradenitis Suppurativa and Anakinra: Clinical Efficacy, Safety, and Future Directions

HS severely impairs quality of life due to painful abscesses, sinus tracts, and scarring, commonly affecting apocrine-rich areas such as the axillae and groin. Conventional therapies (antibiotics, hormonal agents, surgery, TNF-α inhibitors) variably address disease severity. The search for novel interventions has focused on cytokine blockade, with IL-1 inhibition offering targeted immunomodulation for inflammatory pathways distinct from those addressed by TNF-α inhibitors.

·        HS is characterized by follicular occlusion, rupture, and secondary immune activation.

·        Dysregulation of the IL-1 pathway leads to overproduction of IL-1β, which drives neutrophilic infiltration and tissue destruction.

·        Elevated IL-1β and related cytokines have been detected in lesional and systemic samples from patients with HS, supporting IL-1 as a key driver of chronic inflammation^[1][2].

·        Anakinra is a recombinant, non-glycosylated form of human IL-1 receptor antagonist that competitively inhibits the binding of IL-1α and IL-1β to the IL-1 type I receptor.

·        By blocking this pathway, anakinra suppresses downstream inflammatory cascades implicated in HS pathogenesis, providing a rationale for therapeutic use in moderate to severe disease^[1].

Key Clinical Trials and Results

Double-Blind, Placebo-Controlled RCT

A pivotal randomized controlled trial (RCT) evaluated anakinra (100mg/day subcutaneously) for 12 weeks in 20 patients with Hurley stage II or III HS:

·        Clinical response (as defined by Hidradenitis Suppurativa Clinical Response, HiSCR) reached 78% (7/9) in the anakinra group vs 30% (3/10) in placebo at 12 weeks (P = .04)^[1][3][4].

·        Disease activity score decreased in 67% of the anakinra group vs 20% in placebo.

·        Time to new exacerbation was significantly prolonged in the anakinra-treated group.

·        Cytokine changes: Reduced interferon-γ and increased interleukin-22 production.

·        No serious adverse events were reported, though mild injection site reactions and occasional mild infections occurred^[1][3][4].

Open-label Studies

·        An 8-week study of 6 patients with moderate to severe HS showed significant reductions in Sartorius score (mean decrease of 34.8 points), physician and patient global assessments, and Dermatology Life Quality Index scores^[2][5][6].

Subjective and objective improvements persisted into the follow-up period, with no participant experiencing severe adverse events^[2].

·        Reviews indicate that anakinra provides HiSCR clinical responses at week 24 in up to 10%, with notable improvements earlier in therapy for some patients^[7][8].

·        Effect size varies; studies emphasize individualized selection and close monitoring, as well as the need for enhanced predictive markers of response.

Table: Summary of Major Clinical Outcomes

Real-World Efficacy

·        Observed effectiveness is typically robust among patients with moderate to severe HS, especially after failure of first-line agents.

·        Some real-world studies report cases of limited efficacy or relapse post discontinuation, highlighting need for selection criteria and possible combination therapy^[9].

·        Most patients and clinicians report improved quality of life, reduced pain, and extended time to flare during active treatment.

Safety Profile

·        Common adverse effects: Mild injection site reactions and transient upper respiratory tract infections.

·        Serious adverse events: Rare; studies consistently report no increased incidence of serious infections or organ toxicity.

·        Tolerability: Daily subcutaneous administration may limit adherence for some patients, and discomfort can prompt discontinuation in select cases^[9].

Comparative Efficacy

·        Systematic evidence ranks anti-TNF agents (e.g., adalimumab) and lasers as highly effective for HS, but anakinra is detailed as a valuable adjunct or alternative—particularly for refractory or biologic-experienced patients.

·        The personalization of care is emphasized, with anakinra providing a non-TNF-based alternative suited to select patient populations^[7][10].

Clinical Response to Anakinra vs Placebo at 12 Weeks

This illustrates the improved rates of disease control with anakinra relative to placebo, as reported by leading RCTs^[1][3][4].

Anakinra represents a targeted, biologically plausible, and generally well-tolerated therapy for HS. Its efficacy is supported by reductions in lesion count, inflammatory markers, and patient-reported outcomes across both controlled and observational studies. Barriers include the need for daily injections, variable individual response, and the long-term safety and durability of remission upon withdrawal.

Limitations and Areas for Future Research

·        Limited sample sizes and short trial durations are recurring concerns.

·        Lack of direct comparison with other biologic agents in head-to-head trials.

·        Uncertainty about long-term remission rates and ideal therapy duration.

·        Further elucidation of biomarkers predictive of IL-1 pathway blockade responsiveness is needed^[7][3].

Anakinra is a promising, IL-1-targeted immunomodulator for moderate to severe HS, demonstrating significant efficacy and safety in clinical trials and real-world practice. Ongoing studies will define its optimal use within a broader therapeutic algorithm, preferentially for patients not responding to conventional or anti-TNF therapies.

1.      Kanni, T., et al. "Safety and Efficacy of Anakinra in Severe Hidradenitis Suppurativa." JAMA Dermatology, vol. 152, no. 1, 2016, pp. 52-59.

2.      Leslie, K.S., et al. "An open-label study of anakinra for the treatment of moderate to severe hidradenitis suppurativa." Journal of the American Academy of Dermatology, vol. 70, no. 2, 2014, pp. 243-251.

3.      Leslie, K.S., et al. "An open-label study of anakinra for the treatment of moderate to severe hidradenitis suppurativa." ScienceDirect, 2013.

4.      Bisen, R., et al. "A Systematic Review of Pharmacological Interventions for Hidradenitis Suppurativa." ISPOR Europe 2024, Nov. 2024.

5.      Shivsingwale, G., et al. "A Systematic Review of Pharmacological Interventions for Hidradenitis Suppurativa." ISPOR Europe 2024, Nov. 2024.

6.      "An open-label study of anakinra for the treatment of moderate to severe hidradenitis suppurativa." Profiles.WUSTL, 2014.

7.      Wasko, A.L., et al. "Failure of Anakinra in a Case of Severe Hidradenitis Suppurativa." J Drugs Dermatol, 2016; 15(6):772-774.

8.      "Safety and Efficacy of Anakinra in Severe Hidradenitis Suppurativa: A Randomized Clinical Trial." Dialnet, 2016.

9.      "Hidradenitis Suppurativa: A Systematic Review and Meta-analysis of Therapeutic Interventions." IJDVL, 2019.

10.   "Safety and Efficacy of Anakinra in Severe Hidradenitis Suppurativa." JAMA Dermatology, 2016.