Can a pill regrow knee cartilage? new trial tests RHH646

NCT ID NCT05816395

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed This study
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 25, 2026 · Last updated Jun 27, 2026 · Updated 1 time

Summary

This Phase 2 trial tested whether an oral drug called RHH646 can help regrow cartilage in the knee for people with osteoarthritis. 82 adults aged 35 to 75 with knee osteoarthritis took either RHH646 or a placebo. The study measured changes in cartilage volume using MRI and tracked any side effects.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
RHH646 (oral capsule)
What this could lead to
If successful, this could point toward a treatment that helps regenerate knee cartilage in people with osteoarthritis.
What could go wrong
This is an early Phase 2 trial with only 82 participants. The results may not show significant cartilage growth or symptom improvement, and side effects are possible.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 2

Tests whether the treatment actually works, and watches for side effects, in a larger group.

Participants

82 people

The number who actually took part.

Started

May 2023

Finished

Feb 2025

Lead sponsor

A company

The lead sponsor is a pharmaceutical, biotech, or medical-device company.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

35 to 75 years

Sex

Anyone

Healthy volunteers

Not accepted

This study is not open to healthy volunteers. The entry requirements below say who it is open to.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Participant is ≥35 and ≤75 years old, at time of screening * Participants must weigh at least 50 kg to participate in the study and must have a body mass index (BMI) ≤35 kg/m2. BMI = Body weight (kg) / \[Height (m)\]2 * Diagnosis of tibiofemoral OA in at least one knee by standard American College of Rheumatology clinical and radiographic criteria (Altman et al 1986) at screening * K\&L grade 2 to 3 OA in the target knee evaluated with X-Ray by the Central Reader at screening * Predominantly medial tibiofemoral compartment involvement defined as medial Joint Space Narrowing (medJSN) 1-2 (Altman et al 1995; Altman, Gold 2007) and medJSN \> lateral Joint Space Narrowing (latJSN) in the target knee evaluated with X-Ray by the Central Reader at screening * Symptomatic disease, defined as having pain in the target knee at least 3 days per week during the last 3 months from screening that is relieved by analgesic therapy (e.g. acetaminophen or non-steroidal anti-inflammatory drugs), according to the investigator's evaluation and judgment of the patient's history Exclusion Criteria: * Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they are using highly effective methods of contraception. In EEA countries, women of child-bearing potential will be excluded from participation in this trial, irrespective of the use of highly effective methods of contraception. * Arthroscopy of the target knee within the 6 months prior to screening or planned arthroscopy during the study * Previous surgical treatment of the target knee using mosaicplasty, microfracture, meniscectomy \>50% or osteotomy; planned surgery for either knee during the study * Unstable target knee joint (including, but not limited to, post-traumatic or congenital laxity) or insufficiently reconstructed ligaments based on medical history and/or physical examination by the investigator * Participant has severe malalignment (valgus or varus deformity) in the target knee \>7.5° based on X-ray evaluation by the Central Reader at screening. * K\&L grade 4 OA in either knee * Presence of severe hip OA that either (i) alters lower limb function to a degree that increases or abnormally changes the mechanical forces in the knee while walking, according to investigator's evaluation or (ii) currently requires or is likely to require specific medical or surgical management during the study period * Other pathologies affecting the knee, including subchondral insufficiency fractures, bone fracture (acute or subacute within the 6 months prior to screening) or bone bruise, osteonecrosis, malignant bone marrow infiltration, solid tumors, and/or patellofemoral dysplasia based on clinical assessment, or imaging * Known autoimmune disease with inflammatory arthritis (including but not limited to rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, systemic lupus erythematosus), crystal-induced arthritides (gout or pseudogout arthritis), active acute or chronic infection of the knee joint, Lyme disease involving the knee, reactive arthritis, systemic cartilage disorders, moderate to severe fibromyalgia, a known systemic connective tissue disease or a widespread pain index \>4. * Inability to undergo MRI (e.g., claustrophobia, body size, leg not fitting in the coil) or contraindications to MRI (e.g., non MRI-compatible metallic implants, metallic foreign bodies, pacemaker, defibrillator)

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Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Clinical Trial Network

    Houston, Texas, 77074, United States

  • Clinical Trials Research

    Lincoln, California, 95648, United States

  • Conquest Research

    Winter Park, Florida, 32789, United States

  • Novartis Investigative Site

    Buenos Aires, C1055AAF, Argentina

  • Novartis Investigative Site

    Caba, C1015ABO, Argentina

  • Novartis Investigative Site

    Gandrup, 9362, Denmark

  • Novartis Investigative Site

    Herlev, 2730, Denmark

  • Novartis Investigative Site

    Warsaw, 00-874, Poland

  • Novartis Investigative Site

    Santiago, A Coruna, 15705, Spain

  • Pioneer Research Solutions

    Sugar Land, Texas, 77479, United States

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