Clinical studies in dermatology require a post-treatment observation phase to define the impact of the intervention on the natural history of the complaint

Time to relapse after tildrakizumab withdrawal in patients with moderate-to-severe psoriasis who were responders at week 28: post hoc analysis through 64 weeks from reSURFACE 1 trial

BACKGROUND

As treatment interruptions occur during psoriasis management in clinical practice, it is important to know the duration of clinical response after treatment withdrawal.

OBJECTIVES

To report time to and predictors of relapse in patients who were tildrakizumab 100 and 200 mg responders (≥75% improvement in Psoriasis Area and Severity Index, PASI 75) at week 28 re-randomized to placebo from reSURFACE 1 trial.

METHODS

Post hoc analysis of adult patients with moderate-to-severe plaque psoriasis from a 64-week phase 3 trial. Relapse was primarily defined as loss of PASI 75 response. Both relapses defined as loss of PASI 90 and loss of absolute PASI < 2 response were included as sensitivity analyses. PASI 75, PASI 90 and PASI < 2 responders re-randomized to placebo at week 28 and followed up until week 64 were included. The Kaplan-Meier (KM) estimates of the 64-week relapse rate were calculated. The log-rank test to compare KM curves from responders to tildrakizumab 100 and 200 mg was used. Independent predictors of relapse were explored.

RESULTS

Median time to loss of PASI 75/PASI 90/PASI < 2 response from week 28 was 142/111/112 days with tildrakizumab 100 mg and 172/140/113 days with tildrakizumab 200 mg, respectively (all not significant). Around 20% of patients did not relapse (either maintained a PASI 75 response or were lost to follow-up) during the 36-week period. Increase in body mass index (BMI) (hazard ratio, HR [95% confidence interval, CI] for loss of PASI 75 response: 1.0345 [1.0112-1.0582]) and increase in disease duration (HR [95% CI]: 1.0151 [1.0028-1.0275] for loss of PASI 75 response) were associated with an increased risk of relapse, regardless of the relapse definition.

CONCLUSIONS

When treatment is interrupted, tildrakizumab provides durable maintenance of efficacy with a median time to loss of PASI 75 response of 5-6 months, irrespective of the dose. Interventions on modifiable risk factors for relapse, such as BMI, may improve personalized long-term psoriasis management.

The diversity and abundance of fungi and bacteria on the healthy and dandruff affected human scalp

Dandruff is a skin condition that affects the scalp of up to half the world's population, it is characterised by an itchy, flaky scalp and is associated with colonisation of the skin by Malassezia spp. Management of this condition is typically via antifungal therapies, however the precise role of microbes in the aggravation of the condition are incompletely characterised. Here, a combination of 454 sequencing and qPCR techniques were used to compare the scalp microbiota of dandruff and non-dandruff affected Chinese subjects. Based on 454 sequencing of the scalp microbiome, the two most abundant bacterial genera found on the scalp surface were Cutibacterium (formerly Propionibacterium) and Staphylococcus, while Malassezia was the main fungal inhabitant. Quantitative PCR (qPCR) analysis of four scalp taxa (M. restricta, M. globosa, C. acnes and Staphylococcus spp.) believed to represent the bulk of the overall population was additionally carried out. Metataxonomic and qPCR analyses were performed on healthy and lesional buffer scrub samples to facilitate assessment of whether the scalp condition is associated with differential microbial communities on the sampled skin. Dandruff was associated with greater frequencies of M. restricta and Staphylococcus spp. compared with the healthy population (p<0.05). Analysis also revealed the presence of an unclassified fungal taxon that could represent a novel Malassezia species.

Dimethyl fumarate (DMF) vs. monoethyl fumarate (MEF) salts for the treatment of plaque psoriasis: a review of clinical data

Fumarates (fumaric acid esters, FAEs) are orally administered systemic agents used for the treatment of psoriasis and multiple sclerosis. In 1994, a proprietary combination of FAEs was licensed for psoriasis by the German Drug Administration for use within Germany. Since then, fumarates have been established as one of the most commonly used treatments for moderate-to-severe psoriasis in Germany and other countries. The licensed FAE formulation contains dimethyl fumarate (DMF), as well as calcium, zinc, and magnesium salts of monoethyl fumarate (MEF). While the clinical efficacy of this FAE mixture is well established, the combination of esters on which it is based, and its dosing regimen, was determined empirically. Since the mid-1990s, the modes of action and contribution of the different FAEs to their overall therapeutic effect in psoriasis, as well as their adverse event profile, have been investigated in more detail. In this article, the available clinical data for DMF are reviewed and compared with data for the other FAEs. The current evidence substantiates that DMF is the main active compound, via its metabolic transformation to monomethyl fumarate (MMF). A recent phase III randomized and placebo-controlled trial including more than 700 patients demonstrated therapeutic equivalence when comparing the licensed FAE combination with DMF alone, in terms of psoriasis clearance according to the Psoriasis Area and Severity Index (PASI) and Physician's Global Assessment (PGA). Thus, DMF as monotherapy for the treatment of psoriasis is as efficacious as in combination with MEF, making the addition of such fumarate derivatives unnecessary.