Results from real-world populations of patients with relapsed or refractory mantle cell lymphoma (MCL) treated with the chimeric antigen receptor (CAR) T therapy lisocabtagene maraleucel (liso-cel) show high response rates that are consistent with those seen in clinical trials involving the same treatment.

In one new analysis, which involved 121 patients with relapsed or refractory MCL treated with liso-cel, the overall response rate (ORR) was 89%, and the complete response (CR) rate was 79% over a median follow-up of 6 months. Cytokine release syndrome (CRS) occurred in more than half of the participants in this analysis and in another, smaller real-world analysis presented at the Society of Hematologic Oncology (SOHO) 2026.

“Liso-cel was associated with high response rates in a broad population of patients with [relapsed or refractory MCL], with early signs of durable benefit and safety profile consistent with the TRANSCEND NHL 001 trial,” reported co-author of the larger analysis, Elise A. Chong, MD, at the meeting.

Among patients with MCL who relapse following conventional treatments, outcomes can be poor, according to studies — including a 2015 paper. While significant improvements have been observed with the first CAR T-cell therapy for relapsed or refractory MCL (brexucabtagene autoleucel), targeting CD19 and CD28, treatment-related toxicity with that drug is a concern.

Liso-cel, which is a CD19-directed product, has shown high efficacy and lower rates of adverse events than brexucabtagene autoleucel. It was approved by the FDA in 2024 for use in patients with relapsed or refractory MCL treated with at least two prior lines of therapy, on the basis of results from the TRANSCEND MCL trial.

Chong, assistant professor of medicine at the Hospital of the University of Pennsylvania in Philadelphia, and her colleagues conducted the new retrospective study utilizing data from the Center for International Blood and Marrow Transplant Research (CIBMTR).

The median age of patients was 71 years, 73% were men, and 66% had at least one clinically significant comorbidity. Patients who were treated with liso-cel in the US between May 2024 and December 2025 had a median of 4 prior lines of therapy, ranging from 2 to 12 lines, including stem cell transplant lines, and 72.5% had received bridging therapy.

The median duration of response, progression-free survival (PFS), and overall survival (OS) were not reached. The corresponding 6-month rates were 81%, 79%, and 92%, respectively. Sixty-four (53%) patients in the study would have been ineligible for the TRANSCEND MCL trial due to comorbidities, and among them, the rates of response were similar to those in the larger cohort, with an ORR of 86% and a CR rate of 75%, Chong reported.

While 65% of patients had any-grade CRS, only 2% of cases were grade ≥ 3, which was similar to the any-grade rate of 61% reported in the TRANSCEND NHL 001 trial, in which 1% were grade 3 or 4 CRS. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 36% of patients, with 14% being grade ≥ 3. About a quarter of patients (24%) developed clinically significant infections compared with 15% in the TRANSCEND NHL 001 trial. Cytopenia occurred in 17% of patients in the current study compared with a reported rate of prolonged cytopenia of 40% in the TRANSCEND NHL 001 trial.

Overall, there were 14 deaths (12%) in the current study, with 10 deaths (8%) related to the persistence or progression of disease. Of the 47 (39%) patients who received outpatient infusions, 28 (60%) were hospitalized following infusion, with a median time to hospitalization of 5.5 days.

Further Real-World Results Are ‘Remarkably Consistent’

In a separate, smaller real-world assessment also presented at the meeting, involving 34 adults with relapsed or refractory MCL treated with liso-cel at 10 institutions in the US between January 2023 and December 2025, similar outcomes were observed.

With similar patient profiles (average age, 74 years at the time of liso-cel infusion; 64% men; median of 2 prior lines of therapy), the ORR in the cohort was 85.3%, and the CR rate was 82.4%. At a median follow-up of 9 months (range, 118 months), progressive disease had occurred in five patients (14.7%), and six patients (17.6%) had died, including five from progressive disease and one from sepsis. The 6-month rates of duration of response, PFS, and OS were 79.8%, 68.9%, and 85.2%, respectively.

Any-grade CRS occurred in 20 patients (58.8%), with just one case being grade ≥ 3, and ICANS occurred in 12 patients (35.3%), with two cases being grade ≥ 3.

“Overall, our findings were remarkably consistent with both the CIBMTR analysis and the pivotal TRANSCEND NHL 001 study, particularly regarding response and acute toxicity,” senior author Aditi Saha, MD, assistant professor of medicine in the Division of Hematology and Oncology, O’Neal Comprehensive Cancer Center at The University of Alabama at Birmingham, told Medscape Medical News.

“This consistency is notable because our patients were older, with a median age of 74 years, and many had adverse biological features, including blastoid or pleomorphic morphology in 35%, high Ki-67 in 65%, TP53 abnormalities in 27%, and complex karyotype in 27%,” Saha explained.

Infections were reported in 38% of patients in Saha’s study compared with clinically significant infections reported in 24% in the CIBMTR analysis.

“This may reflect our longer follow-up, inclusion of both early and late infections, differences in infection definitions and ascertainment, or underlying patient and treatment characteristics,” Saha noted. Ten patients experienced infections beyond day 30, “emphasizing that infectious risk does not end after the initial CAR T-cell monitoring period.”

Real-world findings vs those reported in clinical trials are always insightful, but such findings are especially important in terms of the highly complex regimen involved in CAR T-cell therapy, where patients in real-world practice are often older, have more comorbidities, and/or have rapidly progressing disease vs those in clinical trials, Saha noted.

“The frequency of late infections in our study reminds us that ‘manageable toxicity’ should not be interpreted as an absence of clinically important risk,” Saha added. “Long-term infection surveillance, antimicrobial prophylaxis, immunoglobulin monitoring and replacement when appropriate, vaccination, and structured survivorship follow-up remain essential.”

The study was funded by Bristol Myers Squibb. Chong’s disclosures included relationships with AbbVie; AstraZeneca; BeiGene USA Inc.; Cargo Therapeutics; Genentech; Genmab; Ideology Health; Intellisphere, LLC; Lymphoma Research Foundation; MJH Life Sciences; Nurix; and Targeted Oncology. Saha had no disclosures to report.