Key Clinical Summary:

• Design/Population: A retrospective observational analysis evaluated 38 adult patients who received CAR T-cell therapy between January 2024 and January 2025 at newly authorized US treatment centers, comparing inpatient vs outpatient administration across disease states including diffuse large B-cell lymphoma, multiple myeloma, follicular lymphoma, mantle cell lymphoma, and ALL.
• Key Outcomes: Outpatient CAR-T delivery was associated with lower adverse event rates and reduced healthcare utilization (fewer hospital days, ICU transfers, and ER visits) compared with inpatient treatment. All-cause medical costs were approximately $36,000 higher for inpatient-treated patients. Patients with multiple myeloma experienced fewer toxicities than those with large B-cell lymphoma, consistent with prior reports. CAR-T administration was feasible in both settings, with lengths of stay comparable to historical benchmarks.
• Clinical Relevance: These findings support the safe and effective implementation of outpatient CAR T-cell therapy at newly authorized centers, with potential benefits in toxicity burden, healthcare utilization, cost, and patient experience. Careful patient selection remains critical, and broader adoption of outpatient CAR T could expand access while optimizing resource use.

Olalekan Oluwole, MD, MBBS, Vanderbilt University Medical Center, Nashville, Tennessee, presented an analysis of CAR T-cell therapy delivery at newly authorized U.S. treatment centers, comparing inpatient versus outpatient outcomes at the 2025 American Society of Hematology (ASH) Annual Meeting & Exposition in Orlando, Florida.

Among 38 patients treated between January 2024 and January 2025, outpatient CAR T-cell therapy was associated with lower adverse event rates, reduced healthcare utilization, and lower overall medical costs compared with inpatient treatment, though patient selection likely influenced these findings. 

Transcript:

Hello, I am Olalekan Oluwole, associate professor of medicine, Vanderbilt University Medical Center. I'll be presenting at ASH and I'm glad to share this abstract, which is a work that my colleagues and I put together. The title is, "Outcomes of inpatient and outpatient chimeric antigen receptor T-cell therapy in newly authorized treatment centers in the United States."

Though CAR-T has been found to be effective in the treatment of diseases like lymphoma and multiple myeloma and in fact may be a curative option for some of our patients, there has been a push to get this new treatment to as many centers as possible. Many new centers do want to provide this care for patients, but FACT accreditation often takes time for them to get once they up and run it to provide CAR-T. 

The question we also wanted to ask is, even though these centers are new, some of them are already providing stem cell transplant, some of them know how to do outpatient therapy and the question was whether there's a difference in the quality of care between the outpatient and the inpatient setting.

The inclusion criteria for this study were the receipt of CAR-T products between January 2024 and January 2025, and the CAR-T would've been administered the newly authorized centers in the US in adult patients and continue enrollment throughout that period of time was anticipated. We were looking for specific outcomes including healthcare utilization, inpatient stays for those who were admitted. Then even up with those who started outpatient, how many hospital days they utilized. We were also looking for emergency room visits, ICU transfers and the type of adverse event, cytokine release syndrome, immune effector cell-associated neurotoxicity syndrome, all-cause mortality and medical costs.

We were able to identify a total of 38 patients in these new centers that fit these criteria. 53% received CAR-T in the inpatient setting, and most of them had diffuse large B-cell lymphoma, 29%, multiple myeloma was the majority of the others, and there were a few follicular, mantle cell, and ALL. Comorbidities were similar among all the patients treated.

What did we find? We found out that adverse events and post-CAR-T healthcare resource utilizations were generally lower in patients who are treated outpatient compared to those who are treated inpatient. This is not unexpected because the choice of inpatient versus outpatient may have been made based on the comorbidities that the patient had. Patients with multiple myeloma also had the generally lower adverse event profile compared to patients with large B-cell lymphoma. These has also been described previously.

When we looked at the medical costs, the all-cause medical costs were slightly higher by about $36,000 for patient treated in the inpatient setting compared to patients who are treated in the outpatient setting. Again, this may not tell all the story because some who were treated inpatient may have been sicker, so it may not be, it's not entirely unusual that the cost is small, but we do expect that those who can be treated outpatient will utilize less healthcare.

Now, we also found that our CAR-T administration was feasible for both inpatient and outpatients. Patients were admitted; they were treated. Length of state was reasonable compared to historical control. All course medical costs were higher by 6% in those who were treated inpatient versus outpatient. The adverse events were lower in those who were treated in the outpatient setting, potentially reflecting that all things being equal, if you were able to start outpatient and monitor patients outpatient, the quality of life and outcomes of healthcare utilization will be more favorable.

Thank you very much.

Source:

Oluwole O, Hsu H, Hong S, et al. Outcomes of inpatient and outpatient chimeric antigen receptor T-cell therapy (CAR T) in newly authorized treatment centers (ATCs) in the United States (US). 2025 American Society of Hematology (ASH) Annual Meeting & Exposition. Dec 6-9, 2025; Orlando, FL. Abstract: 6284