Ixekizumab Citrate-Free Formulation: Results from Two Clinical Trials

Adv Ther. 2022 Jun;39(6):2862-2872. doi: 10.1007/s12325-022-02126-0. Epub 2022 Apr 21.


Introduction: Subcutaneous (SC) injection is a common route of drug administration; however, injection site pain (ISP) might create a negative patient experience. We evaluated ISP, bioequivalence, and overall safety of the citrate-free (CF) formulation of ixekizumab, a high-affinity monoclonal antibody that selectively targets interleukin-17A.

Methods: Two phase 1, single-blind studies were conducted in healthy participants. The crossover study A (NCT03848403) evaluated pain intensity on injection as measured by visual analog scale of pain (VAS) scores. Subjects (N = 70) were randomized 1:1:1 at the beginning to three possible treatment sequences and received a 1 mL SC injection of the three formulations sequentially in the abdomen on days 1, 8, and 15, respectively. A mixed-effects repeated measures analysis model was used to analyze VAS score by time post-injection. Study B (NCT04259346) evaluated the bioequivalence of a single 80 mg dose of CF formulation compared to the original commercial formulation. Subjects (N = 245) were randomized 1:1 to either commercial or CF formulation and received a single SC injection into the abdomen, arm, or thigh.

Results: Primary endpoint was achieved in both studies. In study A, least-squares mean (LSM) difference of VAS scores immediately post injection between commercial (n = 61) and CF formulation (n = 63) was - 21.7 (p < 0.0001), indicating a lower degree of pain associated with CF formulation. In study B, bioequivalence of the CF formulation was established as 90% CIs for the ratio of geometric LSM AUC0-tlast, AUC0-∞, and Cmax between treatments were contained within the prespecified limits of 0.8 and 1.25. Except for less ISP in the CF formulation, overall safety profile was comparable.

Conclusion: Ixekizumab CF formulation proved to be bioequivalent, was associated with less ISP, and had no other notable differences in the safety profile compared to the original commercial formulation.

Trail registration: ClinicalTrials.gov identifier NCT03848403, NCT04259346.

Keywords: Bioequivalence; Citrate-free; Injection site pain; Ixekizumab.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal, Humanized
  • Area Under Curve
  • Citric Acid*
  • Cross-Over Studies
  • Humans
  • Injection Site Reaction*
  • Pain
  • Single-Blind Method
  • Therapeutic Equivalency


  • Antibodies, Monoclonal, Humanized
  • Citric Acid
  • ixekizumab

Associated data

  • ClinicalTrials.gov/NCT03848403
  • ClinicalTrials.gov/NCT04259346