Immix Biopharma’s CAR-T NXC-201 Effects Deep Hematologic Responses in Light Chain Amyloidosis

Heather Landau, MD
Credit: MSKCC

Immix Biopharma and its subsidiary Nexcella's NXC-201, an investigational autologous BCMA-directed chimeric antigen receptor T-cell (CAR-T) therapy, has generated deep hematologic responses in patients with relapsed/refractory (r/r) light chain (AL) amyloidosis who were treated in the phase 1b/2 NEXICART-2 clinical trial (NCT06097832), which is taking place in the United States.¹ The data are being presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting, held May 30 to June 3, in Chicago, Illinois.

The results reported in the ASCO abstract included 7 patients treated in the trial, whose follow-up ranged from 7 to 209 days (median, 97). Following treatment with NXC-201, all 7 patients (100%) showed normalized pathological disease markers. Furthermore, 6 of the 7 patients showed normalized free light chains (FLCs) at 7 to 14 days posttreatment (median, 7) and a decrease in their dFLC to less than 1 mg/dL. At Day 25 or Day 26 posttreatment, 5 of the 7 patients showed minimal residual disease (MRD) negativity in the bone marrow at a sensitivity of 10^-6. One patient did not have MRD data available at the data cutoff. First author Heather Landau, MD, the MSKCC Amyloidosis Program director and the NEXICART-2 principal study investigator, and colleagues also noted that at 15 days posttreatment 1 patient achieved a renal organ response along with resolution of the m-spike. It was additionally stated that as of the abstract’s data cut-off, all of the 7 patients were in a state of complete response or very good partial response, and no relapses had occurred. In addition, at 14 days posttreatment 1 patient achieved an improvement in New York Heart Association (NYHA) class from II to I.

With regard to safety, 4 patients experienced grade 1 cases of cytokine release syndrome (CRS) and 1 patient experienced a case of grade 2 CRS. In 3 patients CRS onset began at Day 1 and in 2 patients CRS onset began at Day 3. All cases lasted less than 24 hours after administration of tocilizumab. No neurotoxicity, febrile neutropenia, treatment-related infections, cardiac toxicity, or deaths occurred in the study. Three patients experienced grade 3 cases of neutropenia and 2 patients experienced grade 4 cases of neutropenia. A grade 4 case of acute on chronic kidney injury occurred in a patient who had preexisting stage 4 chronic kidney disease before being enrolled in the study.

“In this first reported US CAR-T clinical trial experience in r/r AL amyloidosis, we demonstrate that NXC-201 can be given safely and resulted in rapid and deep hematologic responses in all patients treated,” Landau and colleagues wrote in the ASCO abstract.¹ “Our data suggests that the novel antiBCMA CAR-T NXC-201 may become a valuable treatment option for r/r AL patients.”

The ages of the 7 patients in the trial ranged from 56 to 82 years (median, 66), with 4 women and 3 men included. The patients had received from 2 to 9 previous lines of therapy (median, 4), with 4 of the patients (57%) having previously undergone autologous stem cell transplant. At enrollment, dFLC ranged from 2.4 to 12.1 mg/dL (median, 5.4). Four of the patients (57%) had cardiac involvement, 2 patients had NYHA class II heart failure, and 5 patients had NYHA class I heart failure. Kidney involvement was present in 2 of the 7 patients.

“We are beyond thrilled with the strength of these results,” Ilya Rachman, MD, PhD, the chief executive officer of Immix Biopharma, said in a May 22, 2025, statement.² “I believe these results could transform the paradigm of relapsed/refractory AL Amyloidosis treatment.”

Notably, NXC-201 recently received regenerative medicine advanced therapy (RMAT) designation from the FDA for r/r AL amyloidosis in February 2025.³ NEXICART-2 is expected to enroll approximately 40 patients in total and is taking place at study sites in California, Michigan, New York, and Ohio.

“Recent NXC-201 FDA RMAT designation and ASCO interim readout demonstrate our progress toward completion of NEXICART-2 enrollment and biologics license application submission,” Gabriel Morris, the chief financial officer of Immix Biopharma, added to the statement.²

REFERENCES
1. Landau H. Safety and efficacy data from Nexicart-2, the first US trial of CAR-T in R/R light chain (AL) amyloidosis, NXC-201. Presented at the 2025 ASCO Annual Meeting, held May 30 to June 3, in Chicago, Illinois. Abstract #7508
2. Immix Biopharma announces positive results for NXC-201 at ASCO oral presentation, enabling pathway to best-in-class therapy for relapsed/refractory AL amyloidosis. News release. Immix Biopharma, Inc. May 22, 2025. Accessed June 3, 2025. https://immixbio.com/immix-biopharma-announces-positive-results-for-nxc-201-at-asco-oral-presentation-enabling-pathway-to-best-in-class-therapy-for-relapsed-refractory-al-amyloidosis/
3. Immix Biopharma receives FDA regenerative medicine advanced therapy (RMAT) designation for NXC-201, sterically-optimized CAR-T for relapsed/refractory AL amyloidosis. News release. Immix Biopharma, Inc. February 10, 2025. Accessed June 3, 2025. https://immixbio.com/immix-biopharma-receives-fda-regenerative-medicine-advanced-therapy-rmat-designation-for-nxc-201-sterically-optimized-car-t-for-relapsed-refractory-al-amyloidosis/