This goal of this open label study is to evaluate the safety and tolerability of a single intra-articular administration of ABR1 in adults with knee osteoarthritis with a KL grade from 2 to 4. The primary questions it aims to answer are:

1. Is ABR1 safe to use as an intraarticular injection for participants with knee osteoarthritis?
2. What medical problems do participants have after receiving a single injection of ABR1?

Participants will receive a single injection of ABR1 to the knee with osteoarthritis. Participants will

1. Keep a stable pain treatment regimen
2. Visit the clinic at 1 week, 4 weeks, 8 weeks, and 12 weeks post injection
3. Keep a diary of their symptoms and number of times they use a rescue medication for their knee pain.

This first-in-human study is a single-site, open-label, single-arm investigation in adults with knee osteoarthritis from KL grade 2 to 4 evaluating safety and tolerability of a single, ultrasound-guided intra-articular injection of ABR1, while also observing any signals of symptom improvement over 24 weeks post-injection. All enrolled participants will receive a single administration of ABR1 intraarticularly in the target knee and will be followed per protocol for safety monitoring and clinical assessments. Participants should continue to take their medications for pre-existing medical conditions as usual during the trial. Participants will be advised that they may use study allowed rescue medication to treat worsening pain. Participants will record any rescue medication use in their Participant Diary.

Researchers will assess the incidence of adverse events, its relatedness to the device, and the incidence of any treatment-related serious adverse events through Week 12. Patient reported outcomes related to knee osteoarthritis pain will be observed up to Week 24 post injection.

Inclusion Criteria:

1. Male or female at least 40years of age

2. Knee OA with Kellgren-Lawrence (KL) Grade 2 to 4 of the target knee on X-ray

3. Inadequate pain relief with 1st line treatment, consisting of any of the following

   1. conservative non-pharmacological treatment AND/OR
   2. stable dose NSAIDs for at least the past 30 days OR
   3. use of NSAID treatment is contraindicated

4. Target knee pain on most days (at least 15 days per month in the preceding month)

5. Symptomatic knee OA with moderate to severe pain (NRS ≥4 and <9 on Numeric Rating Scale (NRS) with target knee significantly worse than the other knee with a minimum difference of 2-point between knees.

6. Possess cognitive and language ability to complete informed consent and questionnaires

7. Willingness to follow protocol instructions and maintain appointment schedule of the study

8. Willingness to maintain their existing stable regimen (defined as the same regimen for at least the past 30 days) of complementary and non-pharmacological knee OA treatments for trial duration (if any)

9. If participant is taking a stable regimen of NSAIDs - they are willing to maintain their existing stable regimen (defined as taking the same dose for at least the past 30 days) of NSAIDs and not anticipate to change for the duration of the study.

10. Willingness to stop any 'as needed' (PRN) NSAIDs or paracetamol or opioids (except for protocol-permitted rescue pain medication) for the duration of the trial

11. Willingness to stop taking any rescue pain meds 24 hours prior to scheduled follow up clinic visits (except for their stable NSAIDs therapy)

Exclusion Criteria:

1. Pregnant or lactating
2. Other significant knee pathologies of target knee from medical history or radiographic method(s)
3. Severe malalignment > 10 degree in the target knee (either varus or valgus) measured using standardized knee x-ray at screening or based on previous medical records
4. Severe inflammatory arthritis or other joint disease with warm, red, and swollen knee in the target knee
5. History of knee surgery or significant knee trauma of target knee in the past 12 months
6. Received intraarticular injection in the targeted knee joint within the past 6 months
7. Knee surgery or intraarticular injection in the target knee planned in the next 8 months
8. Allergy to rescue pain medication (paracetamol)
9. Unstable/ poorly controlled coagulopathy[CH1.1][LC1.2]
10. Severe anxiety, depression or psychiatric disorder based on self -reported medical history
11. Chronic pain conditions other than knee OA (e.g. cancer, fibromyalgia, pain due to hip OA, etc.) which may interfere with the outcomes of the study, at the discretion of the investigator
12. History of or current substance abuse, self-reported
13. Significant systemic medical comorbidities, e.g. uncontrolled diabetes or hypertension, immunocompromised, cancer, severe cardiovascular disease, neuropathic pain/disorder, etc.
14. ModifiedPainDETECT Questionnaire (mPDQ) >18
15. Current use of any non-opioids centrally acting analgesics including gabapentin, pregabalin, duloxetine, tricyclic antidepressants (e.g. amitriptyline) for pain management within 12 weeks prior to screening.
16. Started taking oral or injectable GLP-1 products in the past 6 months as new regimen. Current use of a GLP-1 product is permitted if the participant has been on the product for > 6 months and plans to continue the product at its current stable dose for the duration of the trial.
17. Started taking another concomitant medication within the past 12 weeks or changed dose of a concomitant medication within the past 12 weeks which could, in the opinion of the Principal Investigator or delegate, impact the participant's safety on the trial or the reliability of the outcome assessments.
18. Participate in another clinical trial and received study intervention currently or in the past 3 months