BOSTON, Massachusetts, United States — October 28, 2026
Monte Rosa Therapeutics, Inc., a clinical-stage biotechnology company developing molecular glue degrader medicines, announced that Novartis has initiated a second Phase 2 clinical study of MRT-6160, also known as DDY391, in participants with active moderate to severe psoriatic arthritis (PsA). Under their global exclusive development and commercialization agreement, Monte Rosa will receive a $37.5 million milestone payment associated with the first patient visit in the study. The Phase 2a/b trial follows the initiation of a separate Phase 2 study in Sjögren’s disease in August 2026 and forms part of a broader development program evaluating VAV1-directed molecular glue degraders across immune-mediated diseases. MRT-6160 is an investigational oral therapy designed to selectively degrade VAV1, a signaling protein involved in T-cell and B-cell receptor pathways. Novartis is responsible for conducting and funding the Phase 2 studies, while Monte Rosa remains eligible for additional development, regulatory and commercial milestones under the collaboration.
Phase 2a/b Trial Evaluates MRT-6160 in Moderate to Severe Psoriatic Arthritis
The newly initiated study is a randomized, double-blind, placebo-controlled, multicenter Phase 2a/b trial designed to evaluate the efficacy, safety, tolerability and dose-response relationship of MRT-6160 in participants with active moderate to severe psoriatic arthritis. PsA is a chronic inflammatory disease associated with psoriasis that can cause joint pain, stiffness, swelling, tendon inflammation and potentially irreversible joint damage. Despite available treatment options, some patients continue to experience active disease, creating a need for additional therapeutic approaches. The study will assess whether targeting VAV1 can provide clinical benefit by modulating immune signaling pathways implicated in inflammatory disease. Monte Rosa Chief Executive Officer Markus Warmuth said the trial reflects the biological rationale for VAV1-directed degradation in PsA and represents continued progress under the Novartis collaboration. The study is registered on ClinicalTrials.gov under identifier NCT07801495. As the program remains in Phase 2, clinical data will be needed to determine the candidate’s effectiveness, optimal dosing and safety profile in this patient population.
MRT-6160 Targets VAV1 to Modulate Immune Signaling
MRT-6160 is an investigational, orally bioavailable molecular glue degrader designed to selectively eliminate VAV1, a key signaling protein downstream of both T-cell and B-cell receptors. By degrading this protein, the therapy aims to alter immune-cell signaling rather than block a single inflammatory mediator. According to Monte Rosa, Phase 1 data showed sustained, dose-dependent VAV1 degradation of more than 90% in peripheral blood T cells following single and multiple doses, alongside suppression of key inflammatory biomarkers. The company also reported that MRT-6160 was generally well tolerated in the Phase 1 study, with no serious adverse effects observed. These early findings support continued investigation but do not establish clinical efficacy in psoriatic arthritis or other immune-mediated conditions. The ongoing Phase 2 studies are intended to assess whether the observed biological activity translates into meaningful improvements in disease activity and whether treatment can be administered safely over longer periods.
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Novartis Collaboration Supports Global Development of Molecular Glue Degraders
Under the global exclusive license agreement, Novartis holds worldwide rights to develop, manufacture and commercialize MRT-6160 and other VAV1-directed molecular glue degraders and is responsible for clinical development and commercialization beginning with Phase 2. Monte Rosa is eligible to receive up to $2.1 billion in aggregate development, regulatory and sales milestones, in addition to the newly triggered $37.5 million payment. The agreement also provides for Monte Rosa to co-fund any Phase 3 clinical development, share 30% of profits and losses associated with U.S. manufacturing and commercialization of MRT-6160, and receive tiered royalties on net sales outside the United States. The program is part of Monte Rosa’s broader molecular glue degrader pipeline, supported by its QuEEN™ discovery engine, which combines AI-guided chemistry, structural biology, chemical libraries and proteomics to design selective protein degraders. Initiation of the second Phase 2 study expands the clinical evaluation of VAV1 targeting across different immune-mediated diseases, while future trial results will determine the approach’s therapeutic potential.
Source:Monte Rosa Therapeutics, Press release
