Therapeutic Drug Monitoring in Patients with Suboptimal Response to Adalimumab for Hidradenitis Suppurativa: A Retrospective Case Series

Dose Escalation of Adalimumab in Patients with Hidradenitis Suppurativa: A Retrospective Case Series

BACKGROUND

Adalimumab is a central treatment for moderate-to-severe hidradenitis suppurativa (HS). However, half of patients treated with adalimumab for HS do not achieve a clinically significant response. Data on non-immunological factors correlating clinical response and adalimumab blood concentration are scarce.

OBJECTIVES

To determine whether increasing adalimumab dose to 80 mg weekly can improve the clinical outcome of patients unresponsive to adalimumab 40 mg weekly. To identify parameters influencing disease activity and those modifying serum adalimumab concentration.

METHODS

This is a retrospective case series from a tertiary dermatology clinic, comprising 40 patients with moderate-to-severe HS with suboptimal response to the FDA-approved dose of adalimumab. All patients had a measurement of blood adalimumab concentration. Depending on their dosage, some patients had their adalimumab dose increased to 80 mg weekly while others stayed at 40 mg dose weekly. Chi-squared and ANOVA tests were used for data analysis.

RESULTS

43.8% of patients who increased to a weekly dose of 80 mg clinically improved at their follow-up, compared with 33.3% of those who stayed at a weekly dose of 40 mg. The dose increase led to a statistically significant increase in serum concentration of adalimumab (P < .001). Higher serum adalimumab concentration is associated with lower disease activity (P = .043). Normal-weight patients had significantly higher concentrations than overweight patients (P = .011).

CONCLUSIONS

An increase in the weekly dose of adalimumab led to a nonstatistically significant improvement in clinical response but led to a statistically significant increase in serum concentration.

Adalimumab Therapeutic Drug Monitoring Improves Treatment Outcome in Patients with Psoriasis

Therapeutic drug monitoring (TDM) or the measurement of drug concentrations (ideally at trough level) and antidrug antibodies are important tools for optimizing biologic therapy. Limited studies evaluated TDM in dermatological indications. A retrospective study of 170 patients with psoriasis who were treated with adalimumab and received TDM reported that adalimumab TDM is practical and promising in routine psoriasis care. However, TDM interpretation requires careful attention to the clinical context to address the controversies and challenges.

Perifolliculitis capitis abscedens et suffodiens treatment with tumor necrosis factor inhibitors and baricitinib: A case report and literature review

Rationale

Perifolliculitis capitis abscedens et suffodiens (PCAS), also known as dissecting cellulitis of the scalp (DCS), is a part of the “follicular occlusion tetrad” that also includes acne conglobate (AC), hidradenitis suppurativa (HS), and pilonidal sinus, which share the same pathogenic mechanism, such as follicular occlusions, follicular ruptures, and follicular infections.

Patient concerns

A 15-year-old boy had multiple rashes on the scalp accompanied by pain.

Diagnosis

The patient was diagnosed with PCAS or DCS based on the clinical manifestations and laboratory examinations.

Interventions

The patient was initially administered adalimumab 40 mg biweekly and oral isotretinoin 30 mg daily for 5 months. Because the initial results were insufficient, the interval between adalimumab injections was extended to 4 weeks, and isotretinoin was changed to baricitinib 4 mg daily for 2 months. When the condition became more stable, adalimumab 40 mg and baricitinib 4 mg were administered every 20 and 3 days, respectively, for two more months until now.

Outcomes

After 9 months of treatment and follow-up, the original skin lesions of the patient were almost cured, and most inflammatory alopecia patches disappeared.

Conclusion

Our literature review did not find any previous reports on treating PCAS with TNF-α inhibitors and baricitinib. Accordingly, we presented the first successful treatment of PCAS with this regimen.

New and Emerging Targeted Therapies for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease deriving from the hair follicles. The formation of inflammatory nodules, abscesses, fistulas, and sinus tracts is characterized by a large inflow of key pro-inflammatory mediators, such as IFN-γ, TNF-α, IL-1, IL-17, and IL-12/23. Adalimumab is currently the only Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved biologic therapy for moderate to severe HS in adults and adolescents. However, the long-term effectiveness of this TNF-α inhibitor in HS patients has shown to be highly variable. This review aims to review the evidence for emerging therapies that target the main pro-inflammatory cytokines in HS pathogenesis. A review of the literature was conducted, using the PubMed and Google Scholar repositories, as well as Clinicaltrials.gov. Presently, the most promising biologics in phase III trials are anti-IL-17 antibodies, secukinumab, and bimekizumab. Furthermore, an anti-IL-1 biologic, bermekimab, is currently in phase II trials, and shows encouraging results. Overall, the clinical efficacies of all new targeted therapies published up to this point are limited. More studies need to be performed to clarify the precise molecular pathology, and assess the efficacy of biological therapies for HS.

Clinical Implementation of Biologics and Small Molecules in the Treatment of Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, auto-inflammatory skin disease originating from the hair follicles. The typical inflammatory nodules, abscesses, and draining sinus tracts (tunnels) are characterized by a massive influx of neutrophils, macrophages, B-cells, plasma cells, T helper (Th)1, Th17 cells and upregulation of pro-inflammatory cytokines such as IL-1, IL-17, IL-12/23, and TNF-α. Over the last decades, several clinical trials evaluated the clinical efficacy of different biologics targeting these pro-inflammatory cytokines, in particular TNF-α and IL-1. However, adalimumab is still the only registered drug for HS. This review discusses biologics and small molecules with high level of evidence for their clinical application, provides guidance on when and how to use these biologics and small molecules in clinical practice, and elaborates on the combination with medical and surgical treatment options beyond the current guidelines. Furthermore this review provides an overview of potential biologics and small molecules currently under investigation for novel targets in HS such as IL-36, C5a, Janus kinase family members, CD-40, LTA4 and CXCR1/2.

Is There a Role for Therapeutic Drug Monitoring in Patients with Hidradenitis Suppurativa on Tumor Necrosis Factor-α Inhibitors?

Tumor necrosis factor-α inhibitors, adalimumab and infliximab, are at the forefront of biologic therapy for the management of moderate-to-severe hidradenitis suppurativa, with adalimumab as currently the only approved medication for this condition. In treating patients, primary or secondary lack of response (also termed suboptimal response) is a major burden for both patients and healthcare systems and is a challenge with biologics in part owing to the development of anti-drug antibodies following treatment. To overcome this, therapeutic drug monitoring may be conducted proactively or reactively to a patient's suboptimal response guided by measurements of trough serum drug concentrations and levels of anti-drug antibodies. While strong evidence to support the utility of therapeutic drug monitoring exists in patients with inflammatory bowel disease, current information is limited in the context of hidradenitis suppurativa. We sought to summarize the available evidence and to present the role of therapeutic drug monitoring and other dose optimization strategies in improving clinical response in patients with hidradenitis suppurativa treated with tumor necrosis factor-α inhibitors.