Last Update: Sep 17, 2026 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 ClinicalTrials.gov Identifier: [NCT07801495](https://clinicaltrials.gov/ct2/show/NCT07801495) Novartis Reference Number:CDDY391A12201 [See if you Pre-qualify](#trial-eligibility "See if you Pre-qualify") All compounds are either investigational or being studied for (a) new use(s). Efficacy and safety have not been established. There is no guarantee that they will become commercially available for the use(s) under investigation. ## Study Description 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. 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. Condition Moderate to Severe Psoriatic Arthritis Phase Phase2 Overall Status Recruiting Number of Participants220 Start Date Oct 14, 2026 Completion Date Jan 12, 2029 Gender All Age(s) 18 Years - 100 Years (Adult, Older Adult) ## Interventions Drug ### DDY391 DDY391 Drug ### Placebo Matching placebo ## Eligibility Criteria 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. United States #### Rheumatology Associates of South Texas Recruiting San Antonio,Texas,78251,United States ###### Jane Barbosa Ayala ###### Veronica Gonzales Email: ## Worldwide Contacts If the location of your choosing does not feature any contact detail, please reach out using the information below. #### Novartis Pharmaceuticals Phone: [ +41613241111](tel:+41613241111) Email: [](mailto:) #### Novartis Pharmaceuticals Phone: [ 1-888-669-6682](tel:1-888-669-6682) Email: