Evaluating HiSCR50 Outcomes in HS

Dr. Martina Porter explains that in STOP HS 1, about 40% of patients on either 45 mg or 75 mg povorcitinib achieved HiSCR50 at week 12 versus just under 30% on placebo; in STOP HS 2, HiSCR50 rates were ~42% on both active doses versus 28.6% on placebo. She notes that placebo rates vary widely across HS trials, which complicates cross‑trial comparisons and the debate over whether the “delta” vs the absolute response matters. Even though both placebo and active arms are slightly lower than in some biologic studies, she views these results as being in the same overall range, with roughly half of patients achieving ≥50% improvement by 12 weeks.

By week 24, after all patients are on active drug in the open‑label phase, HiSCR50 rates rise further: just over 50% for those continuously on drug in STOP HS 1, and ~57–58% in STOP HS 2, with >60% among those who switched from placebo. The panel stresses that longer time on treatment generally yields better outcomes in HS. They also address the apparent lack of dose separation between 45 mg and 75 mg at week 12, suggesting that when a very heterogeneous population (from relatively mild Hurley II to very severe Hurley III disease) is pooled, dose–response differences get diluted, and may only become clear in subgroup and post‑hoc analyses. Finally, they remind clinicians that dropout over time changes the denominator, so rising percentages at later time points must be interpreted alongside forthcoming longer‑term data on patient disposition and durability of response.

Our next episode further explores HS, highlighting the clinical implications for high-level treatment responses, such as HiSCR75, HiSCR90, and HiSCR100.