The PHASE3 study NCT03895203, which included Adalimumab as an active comparator, completed its primary phase on 2021-08-17. This trial investigated the efficacy and safety of Bimekizumab in subjects with active Psoriatic Arthritis. Key results showed that Bimekizumab 160 mg Q4W achieved an ACR50 response of 43.9% at Week 16, significantly higher than placebo's 10.0%, and comparable to Adalimumab's 45.7%.

Background

Adalimumab is a well-established medication, and it was included as an active comparator in this study. The trial focused on Psoriatic Arthritis (PsA), a chronic inflammatory disease affecting joints and skin.

Trial design

The PHASE3 study, identified as NCT03895203, enrolled 852 participants with active Psoriatic Arthritis (PsA). The study aimed to demonstrate the clinical efficacy, safety, and tolerability of Bimekizumab administered subcutaneously compared with placebo. An active comparator arm utilized Adalimumab 40 mg Q2W.

Key results

Key efficacy outcomes at Week 16 included:

  • For Percentage of Participants With an American College of Rheumatology (ACR) 50 Response:
    • The placebo group showed a 10.0% response.
    • The Bimekizumab 160 mg Q4W group achieved a 43.9% response.
    • The Adalimumab 40 mg Q2W group achieved a 45.7% response.
  • For Change From Baseline in Health Assessment Questionnaire-Disability Index (HAQ-DI):
    • The placebo group showed a mean change of -0.0881 (Standard Error: 0.0273).
    • The Bimekizumab 160 mg Q4W group showed a mean change of -0.2567 (Standard Error: 0.0208).
  • In the subgroup of participants with Psoriasis (PSO) involving at least 3% Body Surface Area (BSA) at baseline, for Percentage of Participants With a Psoriasis Area Severity Index (PASI) 90 Response at Week 16:
    • The placebo group showed a 2.9% response.
    • The Bimekizumab 160 mg Q4W group achieved a 61.3% response.
    • The Adalimumab 40 mg Q2W group achieved a 41.2% response.
  • For Percentage of Participants With a PASI 90 Response at Week 4 in the same subgroup:
    • The placebo group showed a 4.3% response.
    • The Bimekizumab 160 mg Q4W group achieved a 19.8% response.
    • The Adalimumab 40 mg Q2W group achieved a 7.4% response.
  • For Change From Baseline in the Short Form 36-item Health Survey (SF-36) Physical Component Summary (PCS) at Week 16:
    • The placebo group showed a mean change of 2.326 (Standard Error: 0.478).

Key statistical analyses included:

  • For ACR50 response, a logistic regression analysis showed an Odds Ratio (OR) of 7.082 (95.0% CI: 4.583, 10.943) with a p-value of 0.001.
  • For HAQ-DI change from baseline, an ANCOVA analysis showed a Least square (LS) mean difference of -0.187 (95.0% CI: -0.249, -0.125) with a p-value of 0.001.
  • For PASI90 response at Week 16, a logistic regression analysis showed an Odds Ratio (OR) of 63.039 (95.0% CI: 22.211, 178.918) with a p-value of 0.001.
  • For PASI90 response at Week 4, a logistic regression analysis showed an Odds Ratio (OR) of 5.447 (95.0% CI: 3.668, 8.088) with a p-value of 0.001.
  • For SF-36 PCS change from baseline, an ANCOVA analysis showed an LS mean difference of 4.337 (95.0% CI: 3.229, 5.444) with a p-value of 0.001.
  • An ANOVA analysis reported an LS mean difference of -0.327 (95.0% CI: -0.524, -0.13) with a p-value of 0.001.

What this means

The results from the PHASE3 study NCT03895203 indicate that Bimekizumab demonstrated significant efficacy in treating active Psoriatic Arthritis, including both joint and skin manifestations, compared to placebo. The observed ACR50 response of 43.9% for Bimekizumab and 45.7% for Adalimumab suggests comparable efficacy between the investigational drug and the established active comparator for joint symptoms. Furthermore, Bimekizumab showed a strong PASI90 response of 61.3% at Week 16, outperforming Adalimumab's 41.2% in the psoriasis subgroup, highlighting its potential benefit for skin involvement in PsA patients.

Source

This information was sourced from ClinicalTrials.gov, documenting the primary completion of trial NCT03895203 on 2021-08-17. The study details and results are available on clinicaltrials.gov.