Immix Biopharma Reports Positive NXC-201 Data for Relapsed AL Amyloidosis at ASGCT 2024

Immix Biopharma, Inc., a clinical-stage biopharmaceutical company specializing in cell therapies for autoimmune diseases, recently disclosed clinical data from its Phase 1b/2a NEXICART-1 study. This study focuses on NXC-201, a novel, autologous, BCMA-targeted chimeric antigen receptor T (CAR-T) cell therapy for patients with relapsed/refractory AL Amyloidosis (R/R ALA). The data were presented at the 27th Annual Meeting of The American Society of Gene and Cell Therapy (ASGCT) in Baltimore, Maryland. All patients involved were resistant to the standard Dara-CyBorD treatment, which combines daratumumab, cyclophosphamide, bortezomib, and dexamethasone.

Dr. Polina Stepensky, the principal investigator of NEXICART-1, highlighted the ongoing need for effective treatments for relapsed/refractory AL Amyloidosis, emphasizing the promising response rates and durability of NXC-201, particularly in patients without significant pre-existing cardiac damage.

Dr. Ilya Rachman, CEO of Immix Biopharma, expressed enthusiasm about the clinical data, which will inform the design of the upcoming NEXICART-2 clinical trial in the United States, set to commence in mid-2024. Gabriel Morris, the company's CFO, noted that NXC-201's tolerability, especially its lack of neurotoxicity, positions it as a potential new treatment option for these patients.

The presentation at ASGCT featured data from 13 patients, including three recent additions, involved in the ongoing NEXICART-1 study. The patients received varying doses of CAR+T cells: one at 150 x 10^6, two at 450 x 10^6, and ten at 800 x 10^6.

Patient characteristics revealed significant involvement of cardiac issues, with 85% (11 out of 13) having cardiac involvement and 38% (5 out of 13) suffering from New York Heart Association (NYHA) stage 3 or 4 heart failure. Additionally, 38% (5 out of 13) were at Mayo stage 3 of AL amyloidosis disease, and patients had been refractory to a median of four prior lines of therapy.

The safety and efficacy results were notable. The overall response rate (ORR) for the 13 relapsed/refractory AL Amyloidosis patients was 92%. All 12 patients who had not been exposed to prior BCMA-targeted bispecific treatments responded to NXC-201, resulting in a 100% ORR, with 75% achieving complete response (CR). Conversely, the one patient with previous exposure to BCMA-targeted treatment did not respond. The best responder maintained a duration of response of 28.0 months as of May 10, 2024, with the response still ongoing.

Importantly, there were no incidences of immune effector cell-associated neurotoxicity syndrome (ICANS). The median duration of cytokine release syndrome (CRS) was two days, with no grade 4 CRS events reported. The breakdown of CRS severity included no CRS in two patients, grade 1 CRS in three patients, grade 2 CRS in six patients, and grade 3 CRS in two patients.

NEXICART-1 is an ongoing Phase 1b/2a open-label study aimed at evaluating the safety and efficacy of NXC-201 in adults with relapsed/refractory multiple myeloma and AL amyloidosis. The successful completion of the Phase 1b portion has established a recommended Phase 2 dose (RP2D) of 800 million CAR+T cells.

The upcoming NEXICART-2 trial will be an open-label, single-arm, multi-site Phase 1b dose expansion study in the United States, targeting relapsed/refractory AL Amyloidosis with CAR-T NXC-201. The trial aims to enroll 40 patients over 18 months, focusing on those with adequate cardiac function who have not been previously exposed to BCMA-targeted therapy. The primary endpoints will include complete response rate and overall response rate.

NXC-201 is a sterically-optimized BCMA-targeted CAR-T cell therapy, potentially delivering a "Single-Day CRS" approach. It is currently undergoing extensive clinical development for relapsed/refractory AL amyloidosis and other autoimmune diseases. The therapy has received Orphan Drug Designation (ODD) from both the FDA and the EMA for multiple myeloma and AL amyloidosis.

AL amyloidosis is a systemic disorder resulting from abnormal plasma cells producing misfolded amyloid proteins, leading to progressive organ damage. The U.S. observed prevalence of relapsed/refractory AL Amyloidosis is increasing at 12% per year, projected to reach 33,277 patients by 2024, with the market expected to grow from $3.6 billion in 2017 to $6 billion by 2025.