A Study to Assess the Efficacy, Safety and Tolerability of DDY391 in Participants With Moderate to Severe Psoriatic Arthritis

August 31, 2026 updated by: Novartis Pharmaceuticals

A Randomized, Double-blind, Placebo-controlled, Multicenter Phase 2a/b Study Assessing the Efficacy, Safety and Tolerability of DDY391 in Participants With Active Moderate to Severe Psoriatic Arthritis

The purpose of this Phase 2a/b study is:

  1. to evaluate the efficacy, safety and tolerability of DDY391 in participants with psoriatic arthritis (PsA).
  2. to determine the dose-response relationship of DDY391 in participants with PsA to support dose selection for Phase 3.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

This study is a Phase 2a/b, randomized, double-blind, placebo-controlled, multicenter trial designed to evaluate the efficacy, safety, tolerability and dose-response relationship of DDY391 in participants with active moderate to severe PsA.

The study is composed of two sequential parts:

  • Part A to evaluate efficacy, safety and tolerability of DDY391 compared with placebo.
  • Part B to determine the dose-response relationship of multiple doses of DDY391 compared with placebo.

Study Type

Interventional

Enrollment (Estimated)

220

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Novartis Pharmaceuticals
  • Phone Number: +41613241111

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Key Inclusion Criteria:

  • Female or male participants at least 18 years of age.
  • Diagnosis of PsA and meeting classification criteria for Psoriatic arthritis (CASPAR) at screening.
  • Moderate to severe PsA at screening and baseline.

Key Exclusion Criteria:

  • Presence of inflammatory conditions other than psoriasis or PsA including but not limited to those associated with arthralgia or arthritis (e.g., rheumatoid arthritis, systemic lupus erythematosus, scleroderma, sarcoidosis) or presence of fibromyalgia or osteoarthritis with articular symptoms.
  • Use of bDMARD treatment within 4 weeks or 5 half-lives of randomization, whichever is longer
  • Prior use of JAK inhibitors or TYK2 inhibitors (e.g., deucravacitinib). Prior use of apremilast is allowed but must not be taken within 4 weeks of baseline.
  • Previous treatment with any cell-depleting therapies, including but not limited to anti-CD20, unless ≥ 12 months prior to baseline.
  • History of lymphoproliferative disease or any known malignancy or history of malignancy of any organ system within the past 5 years (except for basal cell carcinoma or actinic keratosis that have been treated with no evidence of recurrence in the past 3 months, carcinoma in situ of the cervix or non-invasive malignant colon polyps that have been removed).
  • Any active viral, bacterial or other infections at the time of screening or randomization, or history of recurrent clinically significant infection or of recurrent bacterial infections.

Other protocol-defined inclusion/exclusion criteria may apply.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Sequential Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Part A: DDY391-Schedule 1 Dose A
Participants will receive DDY391 Schedule 1 Dose A.
Drug: DDY391
DDY391
Placebo Comparator: Part A: Placebo Schedule 1
Participants will receive matching placebo Schedule 1.
Drug: Placebo
Matching placebo
Experimental: Part B: DDY391- Schedule 1 Dose A
Participants will receive DDY391 Schedule 1 Dose A. Based on treatment response, participants will then either continue receiving DDY391 or switch to local standard of care (SOC).
Drug: DDY391
DDY391
Experimental: Part B: DDY391- Schedule 1 Dose B
Participants will receive DDY391 Schedule 1 Dose B. Based on treatment response, participants will then either continue receiving DDY391 or switch to local SOC.
Drug: DDY391
DDY391
Experimental: Part B: DDY391- Schedule 1 Dose C
Participants will receive DDY391 Schedule 1 Dose C. Based on treatment response, participants will then either continue receiving DDY391 or switch to local SOC.
Drug: DDY391
DDY391
Experimental: Part B: Placebo Schedule 1
Participants will receive matching placebo Schedule 1. Based on treatment response, participants will then either switch to DDY391 Schedule 1 Dose A or receive local SOC.
Drug: Placebo
Matching placebo
Experimental: Part B: DDY391- Schedule 2 Dose C
Participants will receive DDY391 Schedule 2 Dose C. Based on treatment response, participants will then either switch to DDY391 Schedule 1 Dose A or receive local SOC.
Drug: DDY391
DDY391
Experimental: Part B: Placebo Schedule 2
Participants will receive matching placebo Schedule 2. Based on treatment response, participants will then either switch to DDY391 Schedule 1 Dose A or receive local SOC.
Drug: Placebo
Matching placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Part A: Number of participants achieving American College of Rheumatology 50 (ACR50) response
Time Frame: Week 12
To evaluate the efficacy of DDY391 versus placebo through achievement of ACR 50. ACR 50 is a validated tool for assessing RA disease activity.
Week 12
Part A and B: Number of participants achieving American College of Rheumatology 50 (ACR50) response
Time Frame: Week 12
To demonstrate the dose-response relationship of DDY391 compared to placebo in bDMARD-IR participants.
Week 12

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Part B: Number of participants achieving American College of Rheumatology 50 (ACR50) response
Time Frame: Week 12
To demonstrate the dose-response relationship of DDY391 compared to placebo in participants.
Week 12
Part A and Part B: Incidence and severity of Adverse Events (AEs) and Serious Adverse Events (SAEs)
Time Frame: From first dose through Week 12
Number of participants with AEs and SAEs, including changes in vital signs, electrocardiograms (ECGs) and laboratory values qualifying and reported as AEs.
From first dose through Week 12

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Novartis Pharmaceuticals

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

October 14, 2026

Primary Completion (Estimated)

December 13, 2028

Study Completion (Estimated)

January 12, 2029

Study Registration Dates

First Submitted

August 31, 2026

First Submitted That Met QC Criteria

August 31, 2026

First Posted (Actual)

September 3, 2026

Study Record Updates

Last Update Posted (Actual)

September 3, 2026

Last Update Submitted That Met QC Criteria

August 31, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CDDY391A12201
  • 2025 (U.S. NIH Grant/Contract: Faculty of Social Sciences Scientific Grant at the University of Gdańsk)
  • 2025-524512-10 (Other Identifier: EU CTIS)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Novartis is committed to sharing with qualified external researchers, access to patient-level data and supporting clinical documents from eligible studies. These requests are reviewed and approved by an independent review panel on the basis of scientific merit. All data provided is anonymized to respect the privacy of patients who have participated in the trial in line with applicable laws and regulations.

This trial data availability is according to the criteria and process described on www.clinicalstudydatarequest.com

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Subscribe