A Phase 2 interventional study of MK-8690 and Placebo in Rheumatoid Arthritis, sponsored by Merck Sharp & Dohme LLC. Not yet recruiting. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-26.
Sponsored by Merck Sharp & Dohme LLC (part of Merck & Co., Inc) · Phase 2, Interventional, and Treatment
Researchers are looking for new ways to treat rheumatoid arthritis (RA). Methotrexate (MTX) is a standard (usual) treatment for RA. However, MTX and other current treatments may not work well to treat RA symptoms for many people. Researchers are doing this trial to learn if a trial medicine called MK-8690 can treat symptoms of active RA in people who are taking MTX.
The goal of this study is to learn if MK-8690 works better than placebo to improve RA symptoms.
2,963 studies on the registry are indexed under Arthritis, Rheumatoid; 396 are open to participants now.
This study's planned enrollment of 60 is below the median of 94 across 2,027 interventional studies indexed under Arthritis, Rheumatoid.
Browse Arthritis, Rheumatoid studies →Merck Sharp & Dohme LLC is the lead sponsor of 2,160 studies on the registry; 134 are open to participants now.
Of its 497 completed or terminated interventional studies of FDA-regulated products, 369 (74%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
The main inclusion criteria include but are not limited to the following:
Exclusion Criteria:
The main exclusion criteria include but are not limited to the following:
Participant will receive MK-8690 subcutaneous (SC) for 12 weeks
Combination Product: MK-8690 · Drug: Methotrexate (MTX)
Participant will receive placebo SC for 12 weeks
Combination Product: Placebo · Drug: Methotrexate (MTX)
After completing Period 1 participants will receive MK-8690 SC for 40 weeks.
Combination Product: MK-8690 · Drug: Methotrexate (MTX)
Solution for SC injection
Also known as: PRA052
Solution for SC injection
Background therapy - variable dose strength with route of administration per approved product label
Percentage of Participants Achieving American College of Rheumatology 50% Response Criteria (ACR50) at Week 12
ACR response is a well-established composite measure used in clinical trials to evaluate clinical response in rheumatoid arthritis (RA). ACR50 response is defined as 50% or greater improvement in tender joint count (TJC) based on 68 joints, swollen joint count (SJC) based on 66 joints, and ≥3 of the 5 remaining components of Health Assessment Questionnaire-Disability Index (HAQ-DI), Physician Global Assessment of Disease Activity (PGA), Patient Global Assessment of Disease Activity (PtGA), Patient Assessment of Pain Severity, and high-sensitivity C-reactive protein (hsCRP). ACR50 is an accepted measure by the FDA to demonstrate reduction in RA disease activity and is defined as the proportion of participants achieving 50% improvement in the composite measure. The percentage of participants achieving ACR50 at Week 12 will be presented.
Time frame: Week 12
Number of Participants Who Experience One or More Adverse Events (AEs)
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who experience 1 or more AEs will be presented.
Time frame: Up to approximately 70 weeks
Number of Participants Who Discontinue Study Intervention Due to an AE
An AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. The number of participants who discontinue study intervention due to an AE will be presented.
Time frame: Up to approximately 48 weeks
Percentage of Participants Achieving American College of Rheumatology 20% Response Criteria (ACR20) at Week 12
ACR20 response is defined as 20% or greater improvement in TJC based on 68 joints, SJC based on 66 joints, and ≥3 of the 5 remaining components of HAQ-DI, PGA, PtGA, Patient Assessment of Pain Severity, and hsCRP. ACR20 is an accepted measure by the FDA to demonstrate reduction in RA disease activity and is defined as the proportion of participants achieving 20% improvement in the composite measure. The percentage of participants achieving ACR20 at Week 12 will be presented.
Time frame: Week 12
Percentage of Participants Achieving American College of Rheumatology 70% Response Criteria (ACR70) at Week 12
ACR70 response is defined as 70% or greater improvement in TJC based on 68 joints, SJC based on 66 joints, and ≥3 of the 5 remaining components of HAQ-DI, PGA, PtGA, Patient Assessment of Pain Severity, and hsCRP. ACR70 is an accepted measure by the FDA to demonstrate reduction in RA disease activity and is defined as the proportion of participants achieving 70% improvement in the composite measure. The percentage of participants achieving ACR70 at Week 70 will be presented.
Time frame: Week 12
Percentage of Participants Achieving Low Disease Activity (LDA) based on Disease Activity Score 28 Using C-Reactive Protein (DAS28-CRP) at Week 12
The DAS28-CRP is a continuous composite measure of RA activity that includes the following components: * TJC (out of a total of 28 joints) * SJC (out of a total of 28 joints) * hsCRP * PtGA The 28 anatomical joints for inclusion in the TJC and SJC scoring are the shoulders, elbows, wrists, first through fifth metacarpophalangeals, second through fifth proximal interphalangeals, thumb interphalangeals, and knees. The DAS28-CRP score ranges from 0 to 10, with higher scores indicating a higher degree of disease activity. LDA is indicated by a DAS28-CRP score of ≤3.2. The percentage of participants achieving LDA at Week 12 will be presented.
Time frame: Week 12
Change from Baseline in DAS28-CRP
The DAS28-CRP is a continuous composite measure of RA activity that includes the following components: * TJC (out of a total of 28 joints) * SJC (out of a total of 28 joints) * hsCRP * PtGA The 28 anatomical joints for inclusion in the TJC and SJC scoring are the shoulders, elbows, wrists, first through fifth metacarpophalangeals, second through fifth proximal interphalangeals, thumb interphalangeals, and knees. The DAS28-CRP score ranges from 0 to 10, with higher scores indicating a higher degree of disease activity. The change from Baseline at designated timepoints up to Week 52 in the DAS28-CRP will be presented.
Time frame: Baseline and at designated timepoints up to Week 52
Percentage of Participants Achieving LDA based on DAS28-CRP
The DAS28-CRP is a continuous composite measure of RA disease activity that includes the following components: * TJC (out of a total of 28 joints) * SJC (out of a total of 28 joints) * hsCRP * PtGA The 28 anatomical joints for inclusion in the TJC and SJC scoring are the shoulders, elbows, wrists, first through fifth metacarpophalangeals, second through fifth proximal interphalangeals, thumb interphalangeals, and knees. The DAS28-CRP score ranges from 0 to 10, with higher scores indicating a higher degree of disease activity. Remission is indicated by a DAS28-CRP score of \<2.6 and LDA by a DAS28-CRP score of ≤3.2. The percentage of participants achieving LDA at designated timepoints up to Week 52 based on DAS28-CRP will be presented.
Time frame: At designated timepoints up to Week 52
Percentage of Participants Achieving Clinical Remission Based on DAS28-CRP
The DAS28-CRP is a continuous composite measure of RA disease activity that includes the following components: * TJC (out of a total of 28 joints) * SJC (out of a total of 28 joints) * hsCRP * PtGA The 28 anatomical joints for inclusion in the TJC and SJC scoring are the shoulders, elbows, wrists, first through fifth metacarpophalangeals, second through fifth proximal interphalangeals, thumb interphalangeals, and knees. The DAS28-CRP score ranges from 0 to 10, with higher scores indicating a higher degree of disease activity. Remission is indicated by a DAS28-CRP score of \<2.6 and LDA by a DAS28-CRP score of ≤3.2. The percentage of participants achieving clinical remission at designated timepoints assessed up to Week 52 based on DAS28-CRP will be presented.
Time frame: At designated timepoints assessed up to Week 52
Change From Baseline in the HAQ-DI Score
HAQ-DI is measure of physical function in RA clinical trials and is a 20-item questionnaire completed by the participant. The measure includes 8 domains assessing "dressing and grooming," "arising," "eating," "walking," "hygiene," "reach," "grip," and "activities." Participants respond on a 4-point scale ranging from 0 = "without ANY difficulty" to 3 = "UNABLE to do." The measure also captures the use of aids or devices and need for help from another person. The overall disability score is a summation of the highest score from each domain divided by the number of domains completed and ranges from 0 to 3 (worst disability). Clinically meaningful improvement in HAQ-DI for RA has been determined to be ≥0.22 points. The change from Baseline to Week 12 in the HAQ-DI will be presented.
Time frame: Baseline and Week 12
No study locations are listed for this record.
Plan to share: Yes — https://trialstransparency.msdclinicaltrials.com/pdf/ProcedureAccessClinicalTrialData.pdf
Data sharing details ↗ · externaldatasharing-msd.com
Start is estimated for Nov 2026; primary completion for Oct 2027, 10 months later.
Of 114 industry-sponsored phase 2 interventional studies under Arthritis, Rheumatoid, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 13 and three quarters within 24. This study's planned 10 months is below that.
Counting every sponsor, half of 154 studies reached it within 18 months; a quarter within 13 and three quarters within 26.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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