The study was structured as a two-period design:
* A 2-year Core Period, followed by
* A 3-year Extension Period, consisting of 2 years of continued treatment and 1 year of follow-up, totaling 5 years.
Participants were randomized in a 1:1:1:1:1 ratio into five treatment arms:
* LNA043 20 mg Q4w ×3, repeated every 6 months.
* LNA043 40 mg ×1 and placebo Q4w ×2, repeated every 6 months.
* LNA043 40 mg Q4w ×3 followed six months later by placebo Q4w ×3, repeated every 12 months.
* LNA043 40 mg Q4w ×3, repeated every 6 months.
* Placebo Q4w ×3, repeated every 6 months.
All injections were administered intra-articularly (i.a.) to the target knee. Placebo injections (saline solution) were used throughout the study to maintain blinding and ensure consistency in injection frequency across arms.
During the Extension Period:
* Participants from the 6-month cycle arms continued with a single injection of the same LNA043 dose every 6 months.
* Participants from the 12-month cycle arm received LNA043 40 mg every 12 months and placebo every other 6 months.
* Participants who received placebo during the Core Period continued with a single injection of the same placebo every 6 months.
The final year of the Extension Period was a no-treatment follow-up phase for all participants.
The study was terminated early following the Week 104 primary endpoint analysis due to lack of effect.There was no safety related reasons for early termination or safety concerns for the subjects in the study.
