Outpatient CAR T: Safe, Effective, Accessible

A growing body of research suggests that clinicians can offer chimeric antigen receptor (CAR) T-cell therapy safely and effectively on an outpatient basis — a positive development as clinicians strive to expand access beyond metropolitan areas. 

In one recent study, an industry-funded phase 2 trial, researchers found similar outcomes from outpatient and inpatient CAR T-cell therapy for relapsed/refractory large B-cell lymphoma with lisocabtagene maraleucel (Breyanzi). 

Another recent study reported that outpatient treatment of B cell non-Hodgkin lymphoma with tisagenlecleucel (Kymriah) had similar efficacy to inpatient treatment. Meanwhile, a 2023 review of CAR T-cell therapy in various settings found similar outcomes in outpatient and inpatient treatment. 

“The future of CAR T-cell therapy lies in balancing safety with accessibility,” said Rayne Rouce, MD, a pediatric oncologist at Texas Children’s Cancer Center in Houston, Texas, in an interview. “Expanding CAR T-cell therapy beyond large medical centers is a critical next step.” 

Great Outcomes, Low Access

Since 2017, the FDA has approved six CAR T-cell therapies, which target cancer by harnessing the power of a patient’s own T cells. As an Oregon Health & Sciences University/Knight Cancer Center website explains, T cells are removed from the patient’s body, “genetically modified to make the chimeric antigen receptor, or CAR, [which] protein binds to specific proteins on the surface of cancer cells.”

Modified cells are grown and then infused back into the body, where they “multiply and may be able to destroy all the cancer cells.”

As Rouce puts it, “CAR T-cells have revolutionized the treatment of relapsed or refractory blood cancers.” One or more of the therapies have been approved to treat types of lymphoblastic leukemia, B-cell lymphoma, follicular lymphoma, mantle cell lymphoma, and multiple myeloma.

A 2023 review of clinical trial data reported complete response rates of 40%-54% in aggressive B-cell lymphoma, 67% in mantle cell lymphoma, and 69%-74% in indolent B cell lymphoma.

“Commercialization of CAR T-cell therapy brought hope that access would expand beyond the major academic medical centers with the highly specialized infrastructure and advanced laboratories required to manufacture and ultimately treat patients,” Rouce said. “However, it quickly became clear that patients who are underinsured or uninsured — or who live outside the network of the well-resourced institutions that house these therapies — are still unable to access these potentially life-saving therapies.”

A 2024 report estimated the cost of CAR T-cell therapy as $700,000-$1 million and said only a small percentage of those who could benefit from the treatment actually get it. For example, an estimated 10,000 patients with diffuse large B-cell lymphoma alone could benefit from CAR T therapy annually, but a survey of 200 US healthcare centers in 2021 found that 1900 procedures were performed overall for all indications. 

Distance to Treatment Is a Major Obstacle

Even if patients have insurance plans willing to cover CAR T-cell therapy, they may not be able get care. While more than 150 US centers are certified to administer the therapy, “distance to major medical centers with CAR T capabilities is a major obstacle,” Yuliya Linhares, MD, chief of lymphoma at Miami Cancer Institute in Miami, Florida, said in an interview. 

“I have had patients who chose to not proceed with CAR T therapy due to inability to travel the distance to the medical center for pre-CAR T appointments and assessments and a lack of caretakers who are available to stay nearby,” Linhares said.

Indeed, the challenges facing patients in rural and underserved urban areas can be overwhelming, Hoda Badr, PhD, professor of medicine at Baylor College of Medicine in Houston, Texas, said in an interview.

“They must take time off work, arrange accommodations near treatment sites, and manage travel costs, all of which strain limited financial resources. The inability to afford these additional expenses can lead to delays in receiving care or patients forgoing the treatment altogether,” Bahr said. She added that “the psychological and social burden of being away from family and community support systems during treatment can intensify the stress of an already difficult situation.”

A statistic tells the story of the urban/community divide. CAR T-cell therapy administration at academic centers after leukapheresis — the separation and collection of white blood cells — is reported to be at around 90%, while it’s only 47% in community-based practices that have to refer patients elsewhere, Linhares noted. 

Researchers Explore CAR T-Cell Therapy in the Community 

Linhares is lead author of the phase 2 trial that explored administration of lisocabtagene maraleucel in 82 patients with relapsed/refractory large B-cell lymphoma. The findings were published Sept. 30 in Blood Advances.

The OUTREACH trial, funded by Juno/Bristol-Myers Squibb, treated patients in the third line and beyond at community medical centers (outpatient-monitored, 70%; inpatient-monitored, 30%). The trial didn’t require facilities to be certified by the Foundation for the Accreditation of Cellular Therapy (FACT); all had to be non-tertiary cancer centers that weren’t associated with a university. In order to administer therapy on the outpatient basis, the centers had to have phase 1 or hematopoietic stem cell transplant capabilities.

As Linhares explained, 72% of participating centers hadn’t provided CAR T-cell therapy before, and 44% did not have FACT accreditation. “About 32% of patients received CAR T at CAR T naïve sites, while 70% of patients received CAR T as outpatients. Investigators had to decide whether patients qualified for the outpatient observation or had to be admitted for the inpatient observation,” she noted.

Community Outcomes Were Comparable to Major Trial

As for the results, grade 3 or higher adverse events occurred at a similar frequency among outpatients and inpatients at 74% and 76%, Linhares said. There were no grade 5 adverse events, and 25% of patients treated as outpatients were never hospitalized. 

Response rates were similar to those in the major TRANSCEND trial with the objective response rates rate of 80% and complete response rates of 54%.

“Overall,” Linhares said, “our study demonstrated that with the availability of standard operating procedures, specially trained staff and a multidisciplinary team trained in CAR T toxicity management, inpatient and outpatient CAR T administration is feasible at specialized community medical centers.”

In 2023, another study examined patients with B-cell non-Hodgkin lymphoma who were treated on an outpatient basis with tisagenlecleucel. Researchers reported that outpatient therapy was “feasible and associated with similar efficacy outcomes as inpatient treatment.”

And a 2023 systematic literature review identified 11 studies that reported outpatient vs inpatient outcomes in CAR T-cell therapy and found “comparable response rates (80-82% in outpatient and 72-80% in inpatient).” Costs were cheaper in the outpatient setting. 

Research findings like these are good news, Baylor College of Medicine’s Badr said. “Outpatient administration could help to scale the availability of this therapy to a broader range of healthcare settings, including those serving underserved populations. Findings indicate promising safety profiles, which is encouraging for expanding access​.”

Not Every Patient Can Tolerate Outpatient Care

Linhares noted that the patients who received outpatient care in the lisocabtagene maraleucel study were in better shape than those in the inpatient group. Those selected for inpatient care had “higher disease risk characteristics, including high grade B cell lymphoma histology, higher disease burden, and having received bridging therapy. This points to the fact that the investigators properly selected patients who were at a higher risk of complications for inpatient observation. Additionally, some patients stayed as inpatient due to social factors, which increases length of stay independently of disease characteristics.”

Specifically, reasons for inpatient monitoring were disease characteristics (48%) including tumor burden and risk of adverse events; psychosocial factors (32%) including lack of caregiver support or transportation; COVID-19 precautions (8%); pre-infusion adverse events (8%) of fever and vasovagal reaction; and principal investigator decision (4%) due to limited hospital experience with CAR T-cell therapy.

Texas Children’s Cancer Center’sRouse said “certain patients, particularly those with higher risk for complications or those who require intensive monitoring, may not be suited for outpatient CAR T-cell therapy. This may be due to other comorbidities or baseline factors known to predispose to CAR T-related toxicities. However, evidence-based risk mitigation algorithms may still allow closely monitored outpatient treatment, with recognition that hospital admission for incipient side effects may be necessary.”

What’s Next for Access to Therapy?

Rouce noted that her institution, like many others, is offering CAR T-cell therapy on an outpatient basis. “Additionally, continued scientific innovation, such as immediately available, off-the-shelf cell therapies and inducible safety switches, will ultimately improve access,” she said. 

Linhares noted a recent advance and highlighted research that’s now in progress. “CAR Ts now have an indication as a second-line therapy in relapsed/refractory large B-cell lymphoma, and there are ongoing clinical trials that will potentially move CAR Ts into the first line,” she said. “Some trials are exploring allogeneic, readily available off-the-shelf CAR T for the treatment of minimal residual disease positive large B-cell lymphoma after completion of first-line therapy.”

These potential advances “are increasing the need for CAR T-capable medical centers,” Linhares noted. “More and more medical centers with expert hematology teams are becoming CAR T-certified, with more patients having access to CAR T.”

Still, she said, “I don’t think access is nearly as good as it should be. Many patients in rural areas are still unable to get this life-saving treatment. “However, “it is very possible that other novel targeted therapies, such as bispecific antibodies, will be used in place of CAR T in areas with poor CAR T access. Bispecific antibody efficacy in various B cell lymphoma histologies are being currently explored.”

Rouce discloses relationships with Novartis and Pfizer. Linhares reports ties with Kyowa Kirin, AbbVie, ADC, BeiGene, Genentech, Gilead, GlaxoSmithKline, Seagen, and TG. Badr has no disclosures. 

Randy Dotinga is an independent writer and board member of the Association of Health Care Journalists.