FDA Grants RMAT and Fast Track Status to Prizlon-Cel in R/R LBCL

The FDA has granted regenerative medicine advanced therapy (RMAT) and fast track designations to prizloncabtagene autoleucel (prizlon-cel), an investigational anti-CD20/CD19 bispecific chimeric antigen receptor (CAR) T-cell therapy, for the treatment of patients with relapsed or refractory (r/r) large B-cell lymphoma (LBCL), according to an announcement from AbelZeta Inc.¹

Prizlon-cel is a second-generation 4-1BB-costimulated CAR T-cell product engineered to recognize both CD19 and CD20 on malignant B cells.² The designations were issued under AbelZeta's investigational new drug application, which the FDA cleared in August 2026, roughly 1 month after the company reclaimed all global development, regulatory, manufacturing, and commercialization rights to the agent. RMAT status opens the door to intensive FDA guidance throughout clinical development, while fast track status can allow more frequent agency meetings and rolling review of portions of a future biologics license application.¹

"These dual FDA designations are important milestones for Prizlon-cel and support our strategy to develop it across multiple treatment settings in r/r LBCL," Tony Liu, chief executive officer, AbelZeta, stated in a press release. "Our near-term development strategy includes patients whose disease has progressed following prior CAR T-cell therapy, a population with substantial unmet medical need, while we are also preparing to evaluate Prizlon-cel earlier in the treatment course through a randomized second-line program. We look forward to working closely with the FDA as we advance both elements of this development strategy."¹

The most mature clinical evidence for prizlon-cel comes from a phase 1 program conducted in China, the results of which were published in Blood in April 2025. Of 48 patients with CD19- and/or CD20-positive r/r B-cell non-Hodgkin lymphoma (B-NHL) who received an infusion, 44 had LBCL. In the overall population, the overall response rate (ORR) was 91.5%, and 85.1% of patients achieved a complete response (CR). Among those with LBCL, the ORR was 90.7%, with a CR rate of 86.0%.³

At a median follow-up of 30.0 months, the median duration of response (DOR), progression-free survival (PFS), and overall survival (OS) had not been reached. Kaplan-Meier analysis estimated 2-year DOR, PFS, and OS rates of 66.0%, 62.6%, and 76.5%, respectively.³ An earlier analysis of the program presented at the 2023 American Society of Hematology Annual Meeting, at a median follow-up of 23.9 months, reported a median time to first response of 1.0 month and a median time to CR of 1.1 months.⁴

Prizlon-Cel Safety Profile in B-Cell Lymphoma

No dose-limiting toxicities occurred in the phase 1 study. Cytokine release syndrome was reported in 93.8% of patients, with a single grade 3 event. Immune effector cell-associated neurotoxicity syndrome developed in 6.3% of patients, and none of these events reached grade 3 or higher. The most frequent grade 3 or worse treatment-emergent adverse events were neutropenia (83.3%) and leukopenia (50%).³

Phase 1 Design and Ongoing Prizlon-Cel Trials in LBCL

The open-label phase 1 study enrolled patients with CD19- and/or CD20-positive r/r B-NHL across 4 sites (NCT04317885, NCT04655677, NCT04696432, NCT04693676). Participants underwent 3 days of lymphodepletion with cyclophosphamide at 300 mg/m² per day plus fludarabine at 30 mg/m² per day, followed by a single intravenous dose of prizlon-cel. Primary end points were dose-limiting toxicity and the incidence and severity of treatment-emergent adverse events, and secondary end points included ORR, DOR, PFS, and OS.³^,⁴

In the United States, AbelZeta plans to launch ABZT-121 (NCT07875413), a multicenter, single-arm phase 2 study enrolling approximately 55 adults with r/r LBCL whose disease has progressed after at least 2 lines of standard therapy, including a commercially available, FDA-approved CAR T-cell therapy given at least 3 months earlier. Prior allogeneic transplant or investigational CAR T-cell therapy is not permitted. Participants will receive fludarabine/cyclophosphamide lymphodepletion followed by a single prizlon-cel infusion.¹^,⁵

Primary end points for ABZT-121 are ORR per Lugano 2014 criteria and the incidence and severity of adverse events through month 24. Secondary end points include DOR, CR rate, PFS, OS, and CAR T-cell expansion and persistence. The trial is not yet recruiting, with enrollment expected to begin in May 2027. AbelZeta intends to assess whether ABZT-121 results could support an accelerated approval pathway, pending the data and future discussions with the FDA.¹^,⁵

The company is also preparing ABZT-131, a randomized study of prizlon-cel in the second-line setting designed to define its role relative to established CAR T-cell therapies.¹ Separately, the phase 1b/2 ELEVATION trial (NCT05800977) is recruiting approximately 112 patients with r/r LBCL in China, with ORR at 3 months serving as the phase 2 primary end point.²

References

1. AbelZeta receives FDA RMAT and fast track designations for prizlon-cel in relapsed or refractory large B-cell lymphoma. News release. AbelZeta Inc. November 10, 2026. Accessed November 12, 2026. https://tinyurl.com/2t9nkzbx

2. A study of C-CAR039 (prizloncabtagene autoleucel) in patients with relapsed/refractory large B-cell lymphoma (ELEVATION). ClinicalTrials.gov identifier: NCT05800977. Updated December 31, 2025. Accessed November 12, 2026. https://clinicaltrials.gov/study/NCT05800977

3. Yu W, Li P, Zhou L, et al. A phase 1 trial of prizloncabtagene autoleucel, a CD19/CD20 CAR T-cell therapy for relapsed/refractory B-cell non-Hodgkin lymphoma. Blood. 2025;145(14):1526-1535. doi:10.1182/blood.2024026401

4. Li P, Yu WJ, Zhou L, et al. C-CAR039, a novel anti-CD20/CD19 bi-specific CAR T-cell therapy shows deep and durable clinical benefits in patients with relapsed or refractory (r/r) B-cell non-Hodgkin lymphoma (B-NHL) in long term follow up. Blood. 2023;142(suppl 1):1025. doi:10.1182/blood-2023-182817

5. Prizloncabtagene autoleucel (prizlon-cel) for the treatment of relapsed or refractory large B-cell lymphoma post FDA approved CAR T-cell therapy. ClinicalTrials.gov identifier: NCT07875413. Updated October 15, 2026. Accessed November 12, 2026. https://clinicaltrials.gov/study/NCT07875413