NCT06839222: KOALA

Randomized Controlled Single-Blind Multi-Centre Evaluation of the Safety and Performance of an Injection of Hydrogel OA 2% in Subjects With Knee Osteoarthritis

Withdrawn NA Last updated 7 April 2026

What this trial tests

NA trial testing Hydrogel OA 2% in Knee Osteoarthritis (Knee OA). Withdrawn.

Timeline

1 May 2025

Primary endpoint
1 November 2026

1 November 2026

Quick facts

Lead sponsor	Allegro NV/SA
Phase	NA
Status	Withdrawn
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	single
Primary purpose	treatment
Start date	1 May 2025
Primary completion	1 November 2026
Estimated completion	1 November 2026
Sites	5 locations across Belgium

Drugs / interventions tested

• Hydrogel OA 2%
• Hyaluronic Acid (Durolane)

Conditions studied

• Knee Osteoarthritis (Knee OA) — all drugs for Knee Osteoarthritis (Knee OA) →

Sponsor

Allegro NV/SA

Who can join

Adults 35 to 75, any sex, with Knee Osteoarthritis (Knee OA). Patients with the condition only — healthy volunteers not accepted.

What's being measured

Primary outcomes are the specific endpoints the trial is designed to prove or disprove.

• Safety of Hydrogel OA 2% in subjects with symptomatic KOA
  Time frame: From the treatment to the end of the follow up at 26 weeks
  The primary aim of this study is to test the safety of Hydrogel OA 2% in patients with symptomatic KOA. Specifically, the aim is to demonstrate that the proportion of patients experiencing Hydrogel OA 2%-related AEs is equal to the the proportion of patients experiencing Durolane-related AEs .

Sponsor's own description

The goal of this clinical study is to learn if Hydrogel OA 2% injection is safe and whether it works to improve symptoms of diagnosed knee osteoarthritis in adults when compared to Hyaluronic Acid (Durolane), a treatment that is currently often used for treatment of knee osteoarthritis. The main question it aims to answer is:

\- How many study participants will experience side effects related to Hydrogel OA 2% during the study when compared to Hyaluronic Acid (Durolane)?

All study participants will receive either one Hydrogel OA 2% or Hyaluronic Acid (Durolane) injection in their knee during the clinical study. Study participants will not know which treatment they have received. Study participants will also receive a call from the researchers and visit the clinic three times to report whether they have experienced any side effects, and complete a questionnaire that will ask questions on whether their symptoms have improved since they received an injection.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Tuning mechanical softness as a design principle in drug delivery: A biomechanical perspective.
   Qi K, Zhang S, Bi X, Zhang Z, et al · · 2026 · cited 1× · PMID 41909730 · DOI 10.1016/j.apsb.2025.11.037