A Phase 2 interventional study of ATI-450 50 mg oral tablet BID and Placebo oral tablet in Rheumatoid Arthritis, sponsored by Aclaris Therapeutics, Inc.. Completed at 50 sites in 4 countries. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-09-28.
Sponsored by Aclaris Therapeutics, Inc. · Phase 2, Interventional, and Treatment
This study evaluates ATI-450 plus MTX versus placebo plus MTX in participants with moderate to severe active RA who have had an inadequate response to MTX alone.
This is a Phase 2b, randomized, multicenter, double-blind, parallel group, placebo controlled, dose ranging study to investigate the efficacy, safety, tolerability, pharmacokinetics, and pharmacodynamics of multiple doses of ATI-450 plus MTX versus placebo plus MTX in participants with moderate to severe active RA who have had an inadequate response to MTX alone.
3,332 studies on the registry are indexed under Arthritis, Rheumatoid; 443 are open to participants now.
This study's enrollment of 251 is above the median of 96 across 2,220 interventional studies indexed under Arthritis, Rheumatoid.
Browse Arthritis, Rheumatoid studies →Aclaris Therapeutics, Inc. is the lead sponsor of 33 studies on the registry; none are open to participants now.
Of its 25 completed or terminated interventional studies of FDA-regulated products, 22 (88%) 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.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ATI-450 20 mg oral tablet twice daily (BID) with a stable weekly dose of methotrexate for 12 weeks
Drug: Methotrexate · Drug: ATI-450 20 mg oral tablet BID
ATI-450 50 mg oral tablet BID with a stable weekly dose of methotrexate for 12 weeks
Drug: ATI-450 50 mg oral tablet BID · Drug: Methotrexate
Placebo oral tablet BID with a stable weekly dose of methotrexate for 12 weeks
Drug: Placebo oral tablet · Drug: Methotrexate
Oral, small molecule MK2 inhibitor
Also known as: zunsemetinib
Placebo tablet manufactured to match ATI-450 in appearance
15 mg to 25 mg weekly
Oral, small molecule MK2 inhibitor
Also known as: zunsemetinib
Percentage of Participants Achieving ACR20 at Week 12
Participants achieving American College of Rheumatology (ACR) 20 (responders) were defined as having ≥20% improvement in both the number of swollen and tender joints (66/68 joint counts) and ≥20% improvement in ≥3 of the following 5 measures: Patient's Global Assessment of Disease Activity (VAS), Patient's Assessment of Arthritis Pain (VAS), Health Assessment Questionnaire-Disability Index (HAQ-DI), Physician's Global Assessment of Disease Activity (VAS), and acute phase reactant as measured by hsCRP. Model-based estimates and 95% confidence intervals (CIs) were produced.
Time frame: Week 12
Percentage of Participants Achieving ACR50 at Week 12
Participant achieving ACR50 (responders) were defined as having ≥50% improvement in both the number of swollen and tender joints (66/68 joint counts) and ≥50% improvement in ≥3 of the following 5 measures: Patient's Global Assessment of Disease Activity (VAS), Patient's Assessment of Arthritis Pain (VAS), HAQ-DI, Physician's Global Assessment of Disease Activity (VAS), Acute phase reactant as measured by hsCRP. Model-based estimates and 95% CIs were produced.
Time frame: Week 12
Percentage of Participants Achieving ACR70 at Week 12
Participants achieving ACR70 (responders) were defined as having ≥70% improvement in both the number of swollen and tender joints (66/68 joint counts) and ≥70% improvement in ≥3 of the following 5 measures: Patient's Global Assessment of Disease Activity (VAS), Patient's Assessment of Arthritis Pain (VAS), HAQ-DI, Physician's Global Assessment of Disease Activity (VAS), Acute phase reactant as measured by hsCRP. Model-based estimates and 95% CIs were produced.
Time frame: Week 12
Change From Baseline in DAS28-CRP at Week 12
The DAS28-CRP consists of a composite score of the following variables: TJC28, SJC28, CRP (hsCRP was used for the purposes of this study), and Patient's Global Assessment of Disease Activity. Interpretation of the DAS28-CRP is on a scale of 0 to 9.4, where \<2.6 is considered remission, ≥2.6 to \<3.2 is considered low/minimal disease activity, ≥3.2 to ≤5.1 is considered moderate disease activity, and \>5.1 is considered high/severe disease activity. The least square (LS) mean change from baseline in DAS28-CRP at Week 12 was estimated from the Mixed Model Repeated Measures (MMRM) model.
Time frame: Baseline, Week 12
Percentage of Participants Achieving DAS28-CRP Remission (Score <2.6) at Week 12
The Disease Activity Score using 28 Joint Count-C-reactive protein (DAS28-CRP) consists of a composite score of the following variables: TJC28, SJC28, CRP (hsCRP is used for the purposes of this study), and Patient's Global Assessment of Disease Activity. Interpretation of the DAS28-CRP is on a scale of 0 to 9.4, where \<2.6 is considered remission, ≥2.6 to \<3.2 is considered low/minimal disease activity, ≥3.2 to ≤5.1 is considered moderate disease activity, and \>5.1 is considered high/severe disease activity. Model-based estimates and 95% CIs were produced.
Time frame: Week 12
Percentage of Participants Achieving DAS28-CRP Low Disease Activity (Score ≤ 3.2) at Week 12
The DAS28-CRP consists of a composite score of the following variables: TJC28, SJC28, CRP (hsCRP is used for the purposes of this study), and Patient's Global Assessment of Disease Activity. Interpretation of the DAS28-CRP is on a scale of 0 to 9.4, where \<2.6 is considered remission, ≥2.6 to \<3.2 is considered low/minimal disease activity, ≥3.2 to ≤5.1 is considered moderate disease activity, and \>5.1 is considered high/severe disease activity. Model-based estimates and 95% CIs were produced.
Time frame: Week 12
Change From Baseline in HAQ-DI Score at Week12
The HAQ-DI (standard disability method calculation) was utilized to assess the participant's physical function or disability according to the participant. The HAQ-DI is a 20-item, validated questionnaire used to assess the degree of difficulty a person has in accomplishing tasks in 8 functional areas (dressing, arising, eating, walking, hygiene, reaching, gripping, and activities \[errands and chores\]). Responses in each functional area are scored from 0 (no difficulty) to 3 (inability to perform a ask in that area). Overall score was computed as the sum of category scores and divided by the number of categories answered, ranging from 0 to 3. A lower score demonstrated less disability. LS mean change from baseline in HAQ-DI score at Week 12 was estimated from the MMRM model.
Time frame: Baseline, Week 12
Change From Baseline in CDAI Score at Week 12
The Clinical Disease Activity Index (CDAI) was the sum of 4 outcome parameters: * Tender joint count out of 28 joints (TJC28) * Swollen joint count out of 28 joints (SJC28) * Patient's Global Assessment of Disease Activity; and * Physician's Global Assessment of Disease Activity. Interpretation of the CDAI disease activity was measured on a scale of 0 to 76, where ≤2.8 was considered remission, \>2.8 to ≤10 was considered low/minimal disease activity, \>10 to ≤22 was considered moderate disease activity, and \>22.0 was considered high/severe disease activity. LS mean change from baseline in CDAI score at Week 12 was estimated from the MMRM model.
Time frame: Baseline, Week 12
Percentage of Participants Achieving CDAI Remission (Score ≤ 2.8)
The CDAI was the sum of 4 outcome parameters: * Tender joint count out of 28 joints (TJC28) * Swollen joint count out of 28 joints (SJC28) * Patient's Global Assessment of Disease Activity; and * Physician's Global Assessment of Disease Activity. Interpretation of the CDAI disease activity was measured on a scale of 0 to 76, where ≤2.8 was considered remission, \>2.8 to ≤10 was considered low/minimal disease activity, \>10 to ≤22 was considered moderate disease activity, and \>22.0 was considered high/severe disease activity. Model-based estimates and 95% CIs were produced.
Time frame: Week 12
Percent Change From Baseline in hsCRP Level at Week 12
Blood samples were evaluated to measure levels of hsCRP.
Time frame: Baseline, Week 12
Change From Baseline in Short Form Health Survey SF-36 Physical Component Summary (PCS) Score at Week 12
The PCS is composed of 4 scales of the Short Form-36 Health Status Survey Questionnaire (SF-36) version 2 assessing physical function, role limitations caused by physical problems, bodily pain, and general health. The range of the SF-36 PCS is between 0 and 100, where higher scores represent better physical functioning. A 2.5 to 5-point change from baseline is established as the minimum clinically-important difference for the PCS in RA participants. LS mean change from baseline in SF-36 PCS score at Week 12 was estimated from the MMRM model.
Time frame: Baseline, Week 12
Change From Baseline in Functional Assessment of Chronic Illness Therapy - Fatigue Scale (FACIT-Fatigue) Score at Week 12
The FACIT-Fatigue is a 13-item questionnaire that measures an individual's level of fatigue during their usual daily activities over the past week. The level of fatigue is measured on a 4 point Likert scale (4 = not at all fatigued to 0 = very much fatigued). The total score range is from 0 to 52. The higher the score, the lower the fatigue level. LS mean change from baseline in FACIT-Fatigue score at Week 12 was estimated from the MMRM model.
Time frame: Baseline, Week 12
ATI-450 and Metabolite (CDD-2164) Concentrations
Time frame: 2 hours postdose on Days 1, 8, and 85
| Milestone | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Started | 83 | 84 | 84 |
| Itt population | 83 | 84 | 84 |
| Safety population | 82 | 85 | 83 |
| Completed | 66 | 63 | 73 |
| Not completed | 17 | 21 | 11 |
| Withdrew: Adverse event | 3 | 8 | 0 |
| Withdrew: Lack of efficacy | 1 | 0 | 5 |
| Withdrew: Lost to follow-up | 3 | 2 | 1 |
| Withdrew: Protocol violation | 1 | 0 | 0 |
| Withdrew: Withdrawal by subject | 9 | 11 | 4 |
| Withdrew: Did not meet inclusion criteria; discontinued prior to dosing | 0 | 0 | 1 |
Participants achieving American College of Rheumatology (ACR) 20 (responders) were defined as having ≥20% improvement in both the number of swollen and tender joints (66/68 joint counts) and ≥20% improvement in ≥3 of the following 5 measures: Patient's Global Assessment of Disease Activity (VAS), Patient's Assessment of Arthritis Pain (VAS), Health Assessment Questionnaire-Disability Index (HAQ-DI), Physician's Global Assessment of Disease Activity (VAS), and acute phase reactant as measured by hsCRP. Model-based estimates and 95% confidence intervals (CIs) were produced.
| percentage of participants | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percentage of Participants Achieving ACR20 at Week 12 | 42.2 (31.5 to 52.9) | 34.7 (24.2 to 44.9) | 46.5 (35.7 to 57.2) |
Participant achieving ACR50 (responders) were defined as having ≥50% improvement in both the number of swollen and tender joints (66/68 joint counts) and ≥50% improvement in ≥3 of the following 5 measures: Patient's Global Assessment of Disease Activity (VAS), Patient's Assessment of Arthritis Pain (VAS), HAQ-DI, Physician's Global Assessment of Disease Activity (VAS), Acute phase reactant as measured by hsCRP. Model-based estimates and 95% CIs were produced.
| percentage of participants | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percentage of Participants Achieving ACR50 at Week 12 | 20.9 (12.1 to 29.7) | 20.7 (12.0 to 29.4) | 27.7 (18.1 to 37.3) |
Participants achieving ACR70 (responders) were defined as having ≥70% improvement in both the number of swollen and tender joints (66/68 joint counts) and ≥70% improvement in ≥3 of the following 5 measures: Patient's Global Assessment of Disease Activity (VAS), Patient's Assessment of Arthritis Pain (VAS), HAQ-DI, Physician's Global Assessment of Disease Activity (VAS), Acute phase reactant as measured by hsCRP. Model-based estimates and 95% CIs were produced.
| percentage of participants | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percentage of Participants Achieving ACR70 at Week 12 | 8.9 (2.8 to 15.1) | 7.6 (1.9 to 13.3) | 14.7 (7.1 to 22.3) |
The DAS28-CRP consists of a composite score of the following variables: TJC28, SJC28, CRP (hsCRP was used for the purposes of this study), and Patient's Global Assessment of Disease Activity. Interpretation of the DAS28-CRP is on a scale of 0 to 9.4, where \<2.6 is considered remission, ≥2.6 to \<3.2 is considered low/minimal disease activity, ≥3.2 to ≤5.1 is considered moderate disease activity, and \>5.1 is considered high/severe disease activity. The least square (LS) mean change from baseline in DAS28-CRP at Week 12 was estimated from the Mixed Model Repeated Measures (MMRM) model.
| units on a scale | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Change From Baseline in DAS28-CRP at Week 12 | -1.66 ± 0.170 | -1.64 ± 0.167 | -1.60 ± 0.162 |
The Disease Activity Score using 28 Joint Count-C-reactive protein (DAS28-CRP) consists of a composite score of the following variables: TJC28, SJC28, CRP (hsCRP is used for the purposes of this study), and Patient's Global Assessment of Disease Activity. Interpretation of the DAS28-CRP is on a scale of 0 to 9.4, where \<2.6 is considered remission, ≥2.6 to \<3.2 is considered low/minimal disease activity, ≥3.2 to ≤5.1 is considered moderate disease activity, and \>5.1 is considered high/severe disease activity. Model-based estimates and 95% CIs were produced.
| percentage of participants | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percentage of Participants Achieving DAS28-CRP Remission (Score <2.6) at Week 12 | 19.8 (11.1 to 28.4) | 14.8 (7.2 to 22.4) | 21.9 (13.0 to 30.8) |
The DAS28-CRP consists of a composite score of the following variables: TJC28, SJC28, CRP (hsCRP is used for the purposes of this study), and Patient's Global Assessment of Disease Activity. Interpretation of the DAS28-CRP is on a scale of 0 to 9.4, where \<2.6 is considered remission, ≥2.6 to \<3.2 is considered low/minimal disease activity, ≥3.2 to ≤5.1 is considered moderate disease activity, and \>5.1 is considered high/severe disease activity. Model-based estimates and 95% CIs were produced.
| percentage of participants | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percentage of Participants Achieving DAS28-CRP Low Disease Activity (Score ≤ 3.2) at Week 12 | 24.1 (14.8 to 33.4) | 19.1 (10.7 to 27.6) | 29.8 (19.9 to 39.7) |
The HAQ-DI (standard disability method calculation) was utilized to assess the participant's physical function or disability according to the participant. The HAQ-DI is a 20-item, validated questionnaire used to assess the degree of difficulty a person has in accomplishing tasks in 8 functional areas (dressing, arising, eating, walking, hygiene, reaching, gripping, and activities \[errands and chores\]). Responses in each functional area are scored from 0 (no difficulty) to 3 (inability to perform a ask in that area). Overall score was computed as the sum of category scores and divided by the number of categories answered, ranging from 0 to 3. A lower score demonstrated less disability. LS mean change from baseline in HAQ-DI score at Week 12 was estimated from the MMRM model.
| units on a scale | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Change From Baseline in HAQ-DI Score at Week12 | -0.24 ± 0.072 | -0.33 ± 0.067 | -0.37 ± 0.063 |
The Clinical Disease Activity Index (CDAI) was the sum of 4 outcome parameters: * Tender joint count out of 28 joints (TJC28) * Swollen joint count out of 28 joints (SJC28) * Patient's Global Assessment of Disease Activity; and * Physician's Global Assessment of Disease Activity. Interpretation of the CDAI disease activity was measured on a scale of 0 to 76, where ≤2.8 was considered remission, \>2.8 to ≤10 was considered low/minimal disease activity, \>10 to ≤22 was considered moderate disease activity, and \>22.0 was considered high/severe disease activity. LS mean change from baseline in CDAI score at Week 12 was estimated from the MMRM model.
| units on a scale | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Change From Baseline in CDAI Score at Week 12 | -18.39 ± 1.595 | -17.79 ± 1.669 | -17.89 ± 1.524 |
The CDAI was the sum of 4 outcome parameters: * Tender joint count out of 28 joints (TJC28) * Swollen joint count out of 28 joints (SJC28) * Patient's Global Assessment of Disease Activity; and * Physician's Global Assessment of Disease Activity. Interpretation of the CDAI disease activity was measured on a scale of 0 to 76, where ≤2.8 was considered remission, \>2.8 to ≤10 was considered low/minimal disease activity, \>10 to ≤22 was considered moderate disease activity, and \>22.0 was considered high/severe disease activity. Model-based estimates and 95% CIs were produced.
| percentage of participants | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percentage of Participants Achieving CDAI Remission (Score ≤ 2.8) | 6.6 (1.3 to 12.0) | 6.6 (1.2 to 11.9) | 7.7 (2.0 to 13.5) |
Blood samples were evaluated to measure levels of hsCRP.
| percent change | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Percent Change From Baseline in hsCRP Level at Week 12 | -28.274 (-89.766 to 1121.053) | -22.779 (-86.392 to 528.571) | 1.546 (-93.280 to 838.047) |
The PCS is composed of 4 scales of the Short Form-36 Health Status Survey Questionnaire (SF-36) version 2 assessing physical function, role limitations caused by physical problems, bodily pain, and general health. The range of the SF-36 PCS is between 0 and 100, where higher scores represent better physical functioning. A 2.5 to 5-point change from baseline is established as the minimum clinically-important difference for the PCS in RA participants. LS mean change from baseline in SF-36 PCS score at Week 12 was estimated from the MMRM model.
| units on a scale | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Change From Baseline in Short Form Health Survey SF-36 Physical Component Summary (PCS) Score at Week 12 | 6.48 ± 1.025 | 7.08 ± 1.057 | 7.01 ± 0.935 |
The FACIT-Fatigue is a 13-item questionnaire that measures an individual's level of fatigue during their usual daily activities over the past week. The level of fatigue is measured on a 4 point Likert scale (4 = not at all fatigued to 0 = very much fatigued). The total score range is from 0 to 52. The higher the score, the lower the fatigue level. LS mean change from baseline in FACIT-Fatigue score at Week 12 was estimated from the MMRM model.
| units on a scale | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Change From Baseline in Functional Assessment of Chronic Illness Therapy - Fatigue Scale (FACIT-Fatigue) Score at Week 12 | 4.21 ± 1.296 | 6.93 ± 1.313 | 6.53 ± 1.168 |
| ng/milliliters (mL) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| ATI-450 Day 1 | 79.289 ± 46.0493 | 177.627 ± 120.9491 | 0.398 ± 0.7727 |
| ATI-450 Day 8 | 104.032 ± 41.8903 | 245.377 ± 113.5619 | 0.272 ± 0.1887 |
| ATI-450 Day 85 | 94.615 ± 58.6913 | 244.670 ± 127.9654 | 0.303 ± 0.3185 |
| CDD-2164 Day 1 | 30.609 ± 18.8977 | 66.602 ± 47.0467 | 0.407 ± 0.9181 |
| CDD-2164 Day 8 | 36.375 ± 15.6280 | 89.692 ± 48.0216 | 0.261 ± 0.0890 |
| CDD-2164 Day 85 | 33.219 ± 21.5870 | 89.196 ± 50.6267 | 0.285 ± 0.2916 |
Collected over Day 1 (after dosing) through Week 16. Non-serious events are listed at a 2% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| ATI-450 20 mg Plus MTX | 0/83 (0%) | 0/82 (0%) | 20/82 (24.4%) |
| ATI-450 50 mg Plus MTX | 0/84 (0%) | 3/85 (3.5%) | 31/85 (36.5%) |
| Placebo Plus MTX | 0/84 (0%) | 1/83 (1.2%) | 12/83 (14.5%) |
| Event | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Rheumatoid arthritisMusculoskeletal and connective tissue disorders | 0/82 | 1/85 | 1/83 |
| Hepatic cirrhosisHepatobiliary disorders | 0/82 | 1/85 | 0/83 |
| Gastrointestinal bacterial infectionInfections and infestations | 0/82 | 1/85 | 0/83 |
| PyelonephritisInfections and infestations | 0/82 | 1/85 | 0/83 |
| Ultrasound ovary abnormalInvestigations | 0/82 | 1/85 | 0/83 |
| Event | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX |
|---|---|---|---|
| Upper respiratory tract infectionInfections and infestations | 5/82 | 2/85 | 1/83 |
| NauseaGastrointestinal disorders | 2/82 | 4/85 | 1/83 |
| NasopharyngitisInfections and infestations | 2/82 | 3/85 | 3/83 |
| DiarrhoeaGastrointestinal disorders | 1/82 | 3/85 | 1/83 |
| Blood creatine phosphokinase increasedInvestigations | 2/82 | 3/85 | 1/83 |
| AnaemiaBlood and lymphatic system disorders | 2/82 | 0/85 | 0/83 |
| Ventricular extrasystolesCardiac disorders | 2/82 | 0/85 | 0/83 |
| Abdominal pain upperGastrointestinal disorders | 2/82 | 2/85 | 0/83 |
| Urinary tract infectionInfections and infestations | 2/82 | 2/85 | 1/83 |
| DizzinessNervous system disorders | 2/82 | 1/85 | 1/83 |
ITT Population: All participants who were randomized.
| Age, Continuous(years) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| Mean | 55.9 ± 10.28 | 55.8 ± 10.79 | 55.5 ± 11.86 | 55.8 ± 10.96 |
| Sex: Female, Male(Participants) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| Female | 62 | 64 | 72 | 198 |
| Male | 21 | 20 | 12 | 53 |
| Ethnicity (NIH/OMB)(Participants) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| Hispanic or Latino | 7 | 14 | 12 | 33 |
| Not Hispanic or Latino | 72 | 61 | 67 | 200 |
| Unknown or Not Reported | 4 | 9 | 5 | 18 |
| Race/Ethnicity, Customized(Participants) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| Black or African American | 3 | 2 | 3 | 8 |
| White | 76 | 73 | 75 | 224 |
| Asian | 0 | 1 | 0 | 1 |
| Not reported | 4 | 8 | 6 | 18 |
| High-sensitivity C-reactive protein (hsCRP)(mg/L) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| Median | 5.58 (0.17 to 74.63) | 6.22 (0.15 to 127.53) | 4.40 (0.46 to 74.58) | 5.29 (0.15 to 127.53) |
| Disease Activity Score using 28 Joint Count-C-reactive Protein (DAS28-CRP)(units on a scale) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| Mean | 5.43 ± 0.769 | 5.47 ± 0.866 | 5.45 ± 0.806 | 5.45 ± 0.812 |
| DAS28-CRP (Categorical)(Participants) | ATI-450 20 mg Plus MTX | ATI-450 50 mg Plus MTX | Placebo Plus MTX | Total |
|---|---|---|---|---|
| ≥ 3.2 to ≤ 5.1 (Moderate Disease Activity) | 27 | 30 | 27 | 84 |
| > 5.1 (High/Severe Disease Activity) | 56 | 54 | 56 | 166 |
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Studies of the drug tested here: Zunsemetinib