Velinotamig (BCMAxCD3) (T Cell Engager)

June 06, 2026 — Cullinan Therapeutics, Inc. (Nasdaq: CGEM) reported initial interim Phase 1 clinical data for CLN-978, a subcutaneous CD19xCD3 bispecific T cell engager, presented at the EULAR 2026 Congress (poster POS1179). Data reflect 29 patients across two ongoing global Phase 1 studies (OUTRACE SLE: n=18; OUTRACE RA: n=11) with a May 15, 2026 cutoff.

In SLE, among 14 patients with ≥4 weeks follow-up after a single target dose, 10/14 (71%) achieved ≥4-point hSLEDAI reduction and 5 achieved DORIS remission; disease activity labs (anti-dsDNA, UPCR, C3/C4) improved where abnormal. Peripheral B cells fell >80% in 14/17 (82%), and B-cell depletion below quantification occurred in 7/14 (50%) at ≥20 µg.

In RA, 5/7 (71%) improved disease activity, including one DAS28-ESR remission after a single 30 µg dose; autoantibodies decreased without affecting vaccine titers. BLOQ B-cell depletion occurred in 4/6 (67%) at ≥20 µg, with dose-dependent depletion also in lymph node and synovial tissue.

Safety was favorable up to 30 µg; most CRS was Grade 1, with one Grade 3 CRS at 45 µg leading to discontinuation of that cohort; no ICANS observed. Cullinan will present additional multi-dose RA cohort data and initial velinotamig (BCMAxCD3) data at an Immunology Day on June 10.