A CAR-T Therapy Is Working Better Than Expected for Patients With Hard to Treat Leukemia

New findings presented at ASCO 2026 show that a CAR-T cell therapy called Breyanzi (lisocabtagene maraleucel) is producing response rates far higher in everyday practice than what was seen in the original clinical trial — offering fresh hope for patients who have run out of other options.

For patients living with relapsed or refractory chronic lymphocytic leukemia (CLL) meaning their cancer has come back or stopped responding to treatment the road ahead can feel increasingly narrow. After working through standard therapies, the options often shrink down to a short list. But new data presented at the American Society of Clinical Oncology (ASCO) Annual Meeting in 2026 is giving patients and their doctors reason to feel more hopeful about one of those options: a CAR-T cell therapy called Breyanzi (lisocabtagene maraleucel) Dr. Emily Tomasulo, an oncologist who reviewed the findings, says the results exceeded expectations.

What Did the Study Find?

The new data were collected through CIBMTR the Center for International Blood and Marrow Transplant Research Registry which tracks long-term outcomes for patients who receive cell therapies like CAR-T. Researchers looked at 59 patients with relapsed or refractory CLL who received Breyanzi in real-world clinical practice between May 2024 and December 2025.

The results were striking.

83% Overall Response Rate (vs. 48% in the original trial)
55% Complete Response Rate (vs. 18% in the original trial)
87.5% Overall Survival at 6 Months

To put that in plain terms: in the original pivotal trial that led to Breyanzi's approval for CLL, about 1 in 5 patients achieved a complete response meaning no detectable cancer. In this real-world study, more than half of patients reached that milestone. And among the 22 patients who did achieve a complete response and had measurable residual disease testing done, 18 of them, 82%, tested negative for any remaining cancer in their blood.

"Response rates are high, 84% , significantly higher than the 43% in the trial. I'm really hopeful and encouraged by these data," said Tomasulo.

Tomasulo is a Doctor of Osteopathic Medicine and oncologist who has been closely following the emerging data on CAR-T cell therapy in CLL. She spoke with CURE about the CIBMTR findings and what they could mean for patients navigating treatment decisions in the relapsed or refractory setting. Her perspective brings both clinical expertise and a deep familiarity with the real-world challenges patients face when standard therapies have stopped working.

What is CAR-T cell therapy?

CAR-T therapy is a type of immunotherapy in which doctors collect a patient's own immune cells (T cells), genetically engineer them in a laboratory to better recognize and attack cancer cells, and then infuse them back into the patient. Breyanzi (lisocabtagene maraleucel) is one such therapy that has been approved by the FDA for certain patients with CLL.

Why Are the Results So Much Better Than in the Trial?

This is a question the researchers themselves are working to understand, and one that Tomasulo says was her first reaction when reviewing the data. A few factors likely play a role.

One important difference is timing. The real-world patients were treated in an era when a newer type of targeted therapy a drug called Jaypirca (pirtobrutinib), a non-covalent BTK inhibitor was already available. About 54% of patients in this real-world study had received Jaypirca (pirtobrutinib) before their CAR-T infusion. This drug can control CLL even after other targeted therapies have stopped working, and better disease control going into CAR-T therapy is believed to lead to better outcomes after it. Tomasulo identified this as a key factor that may be driving the stronger results.

There is also the matter of sample size and follow-up time. The real-world study included 59 patients, compared to 117 in the original trial, and follow-up was shorter a median of six months versus more than 21 months in the trial. That means the full picture of how durable these responses are still needs to be filled in with more time and more patients.

What Does This Mean for Patients?

For patients who have been through multiple lines of treatment targeted therapies, chemotherapy, perhaps clinical trials and are wondering what comes next, these findings matter. CAR-T cell therapy is a significant undertaking. It requires specialized centers, a period of hospital monitoring, and carries real risks. But Tomasulo says knowing that the real-world complete response rate may be three times higher than originally reported changes the conversation significantly.

"Outside of Breyanzi, there are no other FDA-approved treatment options right now. Having real-world data that the complete response rate is 55% higher than 18% provides a lot of hope for patients," Tomasulo said.

A Note on Side Effects

The most common serious side effects of Breyanzi are cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). In this real-world study, the vast majority of CRS and ICANS events were grade 1 or 2 meaning they were relatively mild and manageable. About 15% of patients experienced low blood cell counts at day 30, and 44% experienced infections. Tomasulo noted that these rates are consistent with what was seen in the original clinical trial, suggesting the safety profile holds up in the real world.

The Importance of Early Conversations With Your Care Team

One of the most practical takeaways from Tomasulo: if you or someone you love has CLL and is being treated with targeted therapy, it is not too early to ask about Breyanzi even before you need it.

CAR-T therapy is currently administered at academic medical centers and specialized cancer programs. Access is expanding, but the referral process takes time, and patients benefit from having those conversations early before their disease has progressed further or their overall health has changed.

Tomasulo says she has patients who come to her at the time they are starting a new line of therapy, simply to understand what the path forward could look like. She welcomes it and says academic centers are eager to work alongside community oncologists to make sure patients don't miss a window.

"Don't be shy reach out to an academic center. Early referrals are the best referrals, just to have that discussion ongoing," Tomasulo said.

What Comes Next?

Tomasulo is clear that this is an early snapshot and says she has a long list of questions she hopes future research will answer including a closer look at specific chromosomal abnormalities such as deletion 17p, the extent of disease burden before treatment, and detailed patient demographics. With only six months of follow-up, questions about how long these responses last and which patients are most likely to benefit remain open.

But for now, the direction of the data is encouraging. In a disease where patients are often told the options are running out, real-world evidence that a treatment is working better than expected not worse is news worth paying attention to.

Talk to Your Doctor

If you have relapsed or refractory CLL and are curious about Breyanzi, ask your oncologist whether a referral to an academic medical center might make sense for your situation. Early conversations cost nothing and could open doors.

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