Announcement • Jun 12
Cullinan Therapeutics Shares New Clinical Data Across Its Portfolio of T Cell Engager Programs Targeting Cd19 and Bcma in Autoimmune Diseases
Cullinan Therapeutics, Inc. reported clinical data and outlined global clinical development plans for CLN-978, a CD19xCD3 T cell engager, and velinotamig, a BCMAxCD3 T cell engager. CLN-978 (CD19xCD3 T cell engager): Treatment-refractory moderate to severe SLE and difficult-to-treat RA. Data cutoff: May 20, 2026. New multi-dose data in the Phase 1 OUTRACE RA clinical trial demonstrate the robust efficacy profile of CLN-978 observed in two heavily pre-treated, poly-refractory patients, including a DAS28-ESR remission in one patient. A patient refractory to immediate prior rituximab experienced a DAS28-ESR remission, with a baseline disease score of 4.0 quickly reduced to 2.2 at week 4 and maintained through the latest follow-up at week 8. Achievement of clinical remission was associated with rapid reduction in RA-associated autoantibodies. Safety data for the first three patients with SLE treated with a multi-dose regimen in the Phase 1 OUTRACE SLE clinical trial are consistent with the favorable safety profile observed in the initial RA multi-dose cohort presented at the European Alliance of Associations for Rheumatology (EULAR) 2026 Congress. Clinical observations in SLE patients with nephritis, notably rapid improvement in proteinuria, support planned evaluation of CLN-978 in patients with lupus nephritis, with Phase 2a expansion expected to begin in early 2027. The Company plans to report additional multi-dose regimen data for RA in Third Quarter 2026 and SLE in Fourth Quarter 2026. CLN-978 is a novel, differentiated and highly potent CD19xCD3 bispecific T cell engager. CLN-978 triggers T cell–redirected lysis of CD19-expressing target cells in vitro and in vivo. CLN-978 is engineered to achieve very high affinity binding to CD19 to efficiently target B cells, including those with very low CD19 levels. Small in molecular size (65 kDa), CLN-978 contains two single-chain variable fragments, one binding with very high affinity to the CD19 target and the other binding to CD3 on T cells, and a single-domain antibody binding to human serum albumin to extend half-life. CLN-978 was developed by an internal Cullinan team and is a wholly owned asset. CLN-978 has the potential to offer a convenient, off-the-shelf, subcutaneously delivered therapeutic option for patients with autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus, and Sjögren’s disease. OUTRACE RA and OUTRACE SLE are global Phase 1 studies of CLN-978 evaluating safety, as well as effects on disease activity and the immune system. Both studies are currently recruiting. OUTRACE RA enrolls patients with active rheumatoid arthritis (DAS28-ESR =3.2) who have been treated with =2 prior targeted treatments and have evidence of B cell–driven disease. Assessments include DAS28, synovial ultrasound, and optional synovial and lymph node biopsies. OUTRACE SLE enrolls patients with active systemic lupus erythematosus (hSLEDAI =6) who have been treated with at least one biologic or immunosuppressive agent and are seropositive. Assessments include hSLEDAI, CLASI, and physician global assessment. Velinotamig (BCMAxCD3 T cell engager): Treatment-refractory autoimmune diseases driven by long-lived plasma cells. Data cutoff: May 15, 2026. In the first two patients with refractory SLE who had completed treatment with four intravenous doses of velinotamig (3 µg/kg on day 1 followed by three doses of 10 µg/kg), at the time of the data cut-off, both patients experienced rapid and marked reductions in SLEDAI-2K scores and proteinuria and both achieved complete renal response. SLEDAI-2K scores were 16 and 14 at baseline, respectively, and at the latest follow-up at week 8 were 0 and 2, respectively. Clinical improvements correlated with pharmacodynamic changes consistent with the mechanism of action of velinotamig. Velinotamig demonstrated a favorable safety profile in both patients, with no cytokine release syndrome (CRS) or immune effector cell–associated neurotoxicity syndrome (ICANS) observed. Additional multi-dose regimen data in patients with SLE from the Genrix Bio clinical trial in China expected to be shared in Fourth Quarter 2026. Cullinan plans to initiate a Phase 1/2a clinical trial in First Quarter 2027 in patients with autoimmune cytopenias, including immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA), autoantibody-mediated diseases with high unmet need. Velinotamig is a BCMAxCD3 bispecific T cell engager designed to redirect cytotoxic T cells to target BCMA-expressing cells including pathogenic, autoantibody-producing plasma cells. Velinotamig is engineered with high-affinity binding to BCMA and lower affinity binding to CD3, with the goal of enhancing target cell depletion while minimizing non-specific T cell activation and associated toxicity. By targeting BCMA-expressing cells, velinotamig has the potential to address autoimmune diseases driven by pathogenic autoantibodies. Cullinan holds a global (ex-Greater China), all indication, exclusive license to velinotamig from Genrix Bio. Genrix Bio is currently evaluating velinotamig in a Phase 1b/2a clinical trial in patients with refractory systemic lupus erythematosus (SLE) in China, with additional autoimmune indications under consideration. Cullinan Therapeutics plans to initiate a global basket trial of velinotamig in autoimmune cytopenias, including immune thrombocytopenia (ITP) and autoimmune hemolytic anemia (AIHA).
