THESEUS II

THESEUS II is a UK-wide randomised controlled trial investigating whether adding laser/light hair treatment to standard adalimumab therapy improves outcomes for adults with moderate-to-severe hidradenitis suppurativa.

Hidradenitis suppurativa (HS) is a long-term inflammatory skin condition that causes painful lumps, abscesses and tunnels under the skin. These commonly occur in areas such as the armpits, groin, buttocks and under the breasts. HS can have a major impact on daily activities, work, relationships and overall quality of life.

Adalimumab is a commonly prescribed treatment for people with moderate to severe HS. Although many people benefit from adalimumab, symptoms often persist and additional treatment options are needed.

Laser and light-based hair removal treatments have shown promise in HS and are already used in some clinical settings. These treatments target hair follicles, which are thought to play an important role in the development and progression of HS. However, it is not yet known whether adding laser or light treatment to adalimumab provides greater benefit than adalimumab treatment alone.

THESEUS II (Treatment of Hidradenitis Suppurativa Evaluation Study II) is a UK-wide research study designed to answer this important question.

The study will recruit 500 adults with moderate to severe HS from hospitals across the United Kingdom. Participants will be randomly allocated to one of two groups:

• Adalimumab plus laser/light hair treatment; or
• Adalimumab alone.

Participants allocated to the combination treatment group will receive four laser or light treatment sessions approximately one month apart, in addition to their adalimumab treatment. Participants in both groups will be followed for 18 months.

The study will assess whether combining laser/light treatment with adalimumab improves disease severity, symptoms, quality of life and long-term disease control compared with adalimumab alone. Researchers will also evaluate whether the combined approach represents good value for the NHS.

Alongside the main trial, a process evaluation will explore how laser and adalimumab combination treatment can best be delivered within different healthcare settings across the UK. This will help researchers understand how treatment can be implemented effectively in routine clinical practice if it proves beneficial.

THESEUS II is funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment (HTA) Programme and is sponsored by Cardiff University. The study is coordinated by the Centre for Trials Research (CTR) at Cardiff University.

The findings will help inform future HS treatment and may improve care and outcomes for people living with this challenging condition.