CARsgen Therapeutics Holdings Limited announced that the initial results from the ongoing first-in-human study of CT071 have been presented at the 29th Annual Congress of the European Hematology Association (EHA). As of February 28, 2024, 10 patients were dosed with CT071?7 patients at 1.0×105 cells/kg and 3 patients at 3.0×105 cells/kg. Among them, 80% had high-risk cytogenetics, 30% had one or more extramedullary plasmacytomas (EMD), and 40% were at R-ISS stage III.

This was a heavily pre-treated population with a median of 5 prior lines of therapy, including 90% double-class refractory, 70% triple-class refractory, 40% penta-drug refractory, 50% having received autologous stem cell transplantation, and 20% had previously been treated with BCMA/CD19 dual-targeting CAR T cells. None of the patients on the study required bridging therapy due to rapid manufacturing turnaround. The median follow-up at the time of data cut-off was 4.07 months (range: 2.8-7.4).

There were no Grade 3 or higher cytokine release syndrome (CRS) events. No immune effector cell-associated neurotoxicity syndrome (ICANS) was observed. No adverse events of special interest or dose limiting toxicity (DLT) occurred.

Four patients experienced treatment-related SAE, including pneumonia (n=1), decreased appetite (n=1) and thrombocytopenia (n=2), and all recovered. The overall response rate was 90%, including 5 patients (50%) with stringent complete response (sCR), 2 patients (20%) with very good partial response (VGPR), and 2 patients (20%) with partial response (PR). All the 9 patients with evaluable MRD assessment at Week 4 achieved MRD negativity (10-6 threshold)), including all 5 patients with sCR/CR.

The pharmacokinetic analysis demonstrated robust cell expansion and persistence, with median Tmax of 14 days (range: 12-28) and median Cmax of 32280.5 copies/µg gDNA (range: 8372-106060).