HS-IGA may overcome ‘important limitations’ in other hidradenitis suppurativa measures
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Key takeaways:
- In a large cohort of patients with hidradenitis suppurativa (HS), HS-IGA score strongly correlated with existing measures of the condition.
- HS-IGA score also strongly correlated with HS clinical response.
The hidradenitis suppurativa-IGA score strongly correlated with other measures of the condition’s activity and may be more useful for clinicians, according to a study.
“This disease is quite complex in its presentation, which makes accurate identification and counting of lesions in clinical trials a challenge,” Amit Garg, MD, professor and founding chair of the department of dermatology at the Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, told Healio. “Poor quality in lesion rating represents a significant threat to drug development in [hidradenitis suppurativa (HS)], so we need easier to use measures in trials which will support getting effective treatments to patients with hidradenitis suppurativa.”
Garg and colleagues assessed psychometric properties of the HS-IGA score using previously published clinical trial data.
This retrospective analysis included patients randomly assigned to bimekizumab (Bimzelx, UCB), adalimumab or placebo at baseline. The phase 2 randomized double-blind, active-reference arm trial included adults with moderate to severe HS.
The aim was to assess the utility of the HS-IGA score at prespecified time points up to 12 weeks after randomization.
“We were fortunate to collaborate with sponsors of large-scale clinical trials in HS, which allowed us to use very robust data to develop and validate the HS-IGA,” Garg said. “We achieved in 2 years what would have otherwise taken perhaps 7 or 8 years to complete if we took a more conventional approach.”
According to the study, the score demonstrated “strong convergent validity,” both at baseline and at week 12, with International HS Severity Scoring System (Spearman correlation = 0.86 and 0.73, respectively) and HS-Physician Global Assessment scores (Spearman rank correlation = 0.74 and 0.64; P < .001 for all).
In addition, the HS-IGA scores gathered prior to dosing demonstrated strong test-retest reliability (intraclass correlation coefficient = 0.92), according to the findings.
Data from week 12 indicated that patients who showed HS-IGA response demonstrated a significant association with HS Clinical Response (HiSCR) at 50%, 75% and 90% reduction from baseline (P < .001 for all).
Moreover, HS-IGA score predicted HiSCR at 50%, 75% and 90% response as well, with corresponding area under the curve values of 0.69, 0.73 and 0.85, respectively.
“When applying the HS-IGA, investigators demonstrated very high consistency in rating lesions for study patients,” Garg told Healio. “Study patients meeting the HS-IGA endpoint experienced very high efficacy.”
However, when patients were assessed for disease activity and patient-reported outcomes at 12 weeks, HS-IGA demonstrated low predictive validity.
“The HS-IGA appears to overcome important limitations of existing disease severity and response instruments, including requirements to distinguish among and accurately count various lesions,” Garg concluded. “The HS-IGA is easy for investigators to use and demonstrated good operational performance, and thus it should be considered for use as a primary end point in clinical trials for HS.”