Immix Biopharma (Nasdaq: IMMX) reported a 95% complete response rate in an interim update from a clinical trial assessing BCMA-targeted chimeric antigen receptor (CAR) T cell therapy NXC-201 in AL (amyloid light chain) amyloidosis. In the Phase II NEXICART-2 study, a total 19 of 20 evaluable patients achieved complete response — a result that, if sustained in a larger cohort, could position NXC-201 as a leading option in a disease with limited treatment options.
NEXICART-2 (NCT06097832) is a multi-site US Phase II study of NXC-201 (formerly HBI0101) in relapsed/refractory AL amyloidosis, enrolling up to 45 patients and designed with a potentially registrational intent. The interim data cover the first 20 patients, who had received a median of four prior lines of therapy, making NXC-201 a fifth-line intervention in a heavily pretreated population.
All four patients who were MRD-negative at the time of the ASH 2025 data presentation have since converted to complete response, bringing the overall complete response rate to 95%. Every complete response was achieved within one year of follow-up post-dosing, and no relapses have been observed to date among patients who reached complete response. Additionally, all subsequently enrolled patients for whom MRD results are available are MRD-negative at the one-month mark, a directional finding that suggests early and deep responses may be consistent across the broader enrollment cohort. No safety data were included in this interim update.
The MRD-negative amyloidosis findings carry particular weight in this disease context. AL amyloidosis is driven by clonal plasma cells that secrete misfolded light chains, which deposit in organs including the heart, kidney, and liver, causing progressive organ failure. Achieving MRD negativity implies near-complete elimination of the underlying plasma cell clone, and conversion from MRD negativity to hematologic complete response is the deepest measurable endpoint in this disease. The absence of relapses among complete responders, while observed in a small cohort with limited follow-up, is a notable early signal.
NXC-201: mechanism and competitive context
NXC-201 is an autologous BCMA-targeted CAR-T cell therapy in which patient-derived T cells are transduced ex vivo with a retroviral vector encoding an anti-BCMA chimeric antigen receptor. The company describes the construct as "sterically optimized," incorporating what it terms a "digital filter" designed to reduce non-specific T cell activation.
NXC-201 holds Breakthrough Therapy Designation and Regenerative Medicine Advanced Therapy designation from the US FDA, as well as Orphan Drug Designation from both the US FDA and the European Medicines Agency. These designations reflect the unmet need in relapsed/refractory AL amyloidosis.