Deucravacitinib Improves Psoriasis Symptoms in Japanese Patients

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Psoriasis affects approximately 0.3% of the Japanese population, with plaque psoriasis (PP) is the most common subtype, accounting for 97.4% of cases. Generalized pustular psoriasis (GPP) and erythrodermic psoriasis (EP) are rarer, comprising 1.1% and 0.4% of cases, respectively.¹ Deucravacitinib, an oral TYK2 inhibitor, is approved for moderate to severe PP globally and for GPP and EP in Japan for patients with inadequate responses to conventional therapies.² The phase 3 POETYK PSO-4 trial (NCT04036435) investigated the efficacy of deucravacitinib in Japanese patients, focusing on its impact on patient-reported outcomes (PROs) through the Psoriasis Symptoms and Signs Diary (PSSD) and Dermatology Life Quality Index (DLQI) over 52 weeks.³

“At week 52, approximately two-thirds of patients in each group achieved a DLQI score of 0 or 1, indicating no impact of disease on quality of life,” researchers reported. “These results demonstrate improvements in psoriasis symptoms and signs and in quality of life with deucravacitinib treatment in Japanese patients with plaque, generalized pustular, or erythrodermic psoriasis.”

Methods

The open-label, single-arm trial enrolled 74 Japanese patients (PP: n=63; GPP: n=3; EP: n=8) aged ≥18 years. All patients received deucravacitinib6 mg daily. PRO assessments included the PSSD, which evaluates psoriasis symptoms (e.g., itch, pain) and signs (e.g., redness, scaling) on a 0–10 scale, and the DLQI, which measures the quality-of-life impact of psoriasis using a 0–30 scale. Data were analyzed for meaningful changes in scores (PSSD: ≥2-point improvement; DLQI: ≥4-point improvement) and response rates at weeks 16 and 52.

Results

PSSD

In PP patients, researchers noted significant reductions in symptom and sign scores were observed at week 16 (−25.8 and −31.9, respectively) and further improved by week 52 (−32.4 and −38.2, respectively). Meaningful symptom improvements at week 52 included itch (73.0%) and flaking (87.3%). In GPP, the study reported reductions in mean symptom and sign scores at week 52 were −16.4 and −22.9, respectively, though variability was high due to small sample size. It found EP patients reported comparable improvements in symptom (−27.3) and sign (−31.4) scores by week 52.

DLQI

Baseline DLQI scores were reported to be 9.1, 9.7, and 7.5 in the PP, GPP, and EP groups, respectively, indicating moderate impairment. By week 52, researchers reported mean improvements were −7.6, −8.3, and −7.8. Response rates for meaningful changes were 83.3%, 100%, and 66.7% across the 3 groups. Over 66% of patients in each group reportedly achieved DLQI scores of 0 or 1, reflecting no significant impact of psoriasis on quality of life.

Discussion

The study found deucravacitinib demonstrated significant improvements in PROs across all psoriasis subtypes, particularly in reducing bothersome symptoms like itch and flaking, which are often associated with emotional distress and stigma. While the PP group provided robust data, researchers noted smaller GPP and EP groups limited the generalizability of findings for rarer phenotypes. Additional limitations included the open-label design and lack of a control group, which could introduce bias.

Conclusion

Overall, researchers found that deucravacitinib effectively reduces psoriasis symptoms and enhances quality of life in Japanese patients with PP, GPP, and EP. These results affirm its clinical utility, particularly for patients with insufficient response to standard therapies. They stated further research is warranted to validate findings in larger cohorts of patients with GPP and EP.

References

1. Kubota K, Kamijima Y, Sato T, et al. Epidemiology of psoriasis and palmoplantar pustulosis: a nationwide study using the Japanese national claims database. BMJ Open. 2015;5(1):e006450. Published 2015 Jan 14. doi:10.1136/bmjopen-2014-006450
2. Sotyktu [package insert]. Tokyo, Japan: Bristol Myers Squibb K.K; 2022.
3. Tada Y, Armstrong AW, Imafuku S, et al. Deucravacitinib in Japanese patients with plaque, generalized pustular, or erythrodermic psoriasis: Patient-reported outcomes in the POETYK PSO-4 study. J Dermatol. 2024. doi:10.1111/1346-8138.17570