How is IHS4 calculated?

IHS4 = (nodule count x1) + (abscess count x2) + (draining tunnel count x4). Severity: mild =11. IHS4 enables quantitative monitoring unlike ordinal Hurley staging.

What is IHS4-55 as a treatment endpoint?

IHS4-55 response (55% reduction in IHS4 from baseline) is used as a treatment endpoint in HS clinical trials, analogous to PASI 75 for psoriasis. Used in secukinumab and bimekizumab trials.

What is the HiSCR endpoint in HS trials?

HiSCR (Hidradenitis Suppurativa Clinical Response): >=50% reduction in total abscess and nodule count with no increase in abscess count or draining fistula count. HiSCR was the primary endpoint in adalimumab PIONEER trials.

HS IHS4 International Hidradenitis Scoring

Calculate IHS4 (International Hidradenitis Suppurativa Severity Score System) from nodule count x1, abscess count x2, and draining tunnels x4. Score >=11 indicates severe HS.

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HS Hurley Stage

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HS IHS4 International Hidradenitis Scoring

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Frequently Asked Questions

How is IHS4 calculated?

What is IHS4-55 as a treatment endpoint?

What is the HiSCR endpoint in HS trials?