As ciltacabtagene autoleucel (cilta-cel; Carvykti) and idecabtagene vicleucel (ide-cel; Abecma) push into earlier lines of relapsed/refractory multiple myeloma, central questions have shifted from whether CAR T-cell therapy works to when the therapy should be implanted and why so few eligible patients receive it.
“The number of people that actually get CAR T at first relapse is low but rising,” Joshua Richter, MD, an associate professor of medicine in the Division of Hematology and Medical Oncology at the Tisch Cancer Institute and director of Multiple Myeloma at the Blavatnik Family-Chelsea Medical Center at Mount Sinai in New York, New York, said during a recent OncLive® Scientific Interchange and Workshop.1
Moderated by C. Ola Landgren, MD, PhD, of the Sylvester Comprehensive Cancer Center at the University of Miami in Florida, workshop faculty traced sequencing, toxicity, and access challenges with CAR T-cell therapy in multiple myeloma and strategies to address them.
CAR T-Cell Therapy in Early Relapsed/Refractory Multiple Myeloma: Takeaways
- Many patients are eligible for CAR T-cell therapy at first relapse, yet only a small proportion receive this modality in this setting, with referral loss, patient fear, and caregiver requirements, rather than clinical contraindications, driving the shortfall.
- Sentiment has shifted toward second-line CAR T-cell therapy, partly because deeper preinfusion debulking lowers toxicity risk, and using CAR T-cell therapy first preserves a later bispecific antibody option.
- Immune effector cell–associated enterocolitis remains a poorly characterized late toxicity in need of a defined diagnostic and management pathway.
How wide Is the gap between CAR T-cell therapy eligibility and uptake at first relapse?
On April 5, 2024, the FDA approved cilta-cel for the treatment of adult patients with relapsed or refractory multiple myeloma who have received at least 1 prior line of therapy, including a proteasome inhibitor (PI) and an immunomodulatory agent (IMiD), and who are refractory to lenalidomide (Revlimid).2 On the same day, the regulatory agency also approved a new indication for ide-cel, with the CAR T-cell therapy indicated for the treatment of adult patients with relapsed or refractory multiple myeloma after 2 or more prior lines of therapy, including an IMiD, a proteasome inhibitor (PI), and an anti-CD38 monoclonal antibody.3
Updated data from the phase 3 CARTITUDE-4 trial (NCT04181827), which supported the approval of cilta-cel, showed that the CAR T-cell therapy reduced the risk of progression or death vs standard-of-care (SOC) combination regimens in patients with lenalidomide-refractory disease who had received 1 to 3 prior lines of therapy (HR, 0.29; 95% CI, 0.22-0.39).4 Data showed the 30-month progression-free survival (PFS) rate was 59.4% with cilta-cel vs 25.7% with SOC. The 30-month overall survival (OS) rates were 76.4% vs 63.8%, with a median OS that was NR in both arms (HR, 0.55; 95% CI, 0.39-0.79; P = .0009).
In the phase 3 KarMMa-3 trial (NCT03651128), which supported the third-line indication for ide-cel, updated findings demonstrated the CAR T-cell therapy (n = 254) improved PFS vs standard regimens (n = 132) at 13.8 months (95% CI, 11.8-16.1) vs 4.4 months (95% CI, 3.4-5.8), respectively (HR, 0.49; 95% CI, 0.38-0.63).5 OS outcomes were comparable at 41.4 months (95% CI, 30.9-not reached [NR]) vs 37.9 months (95% CI, 23.4-NR), respectively (HR, 1.01; 95% CI, 0.73-1.40).
Despite these data, workshop faculty estimated that although approximately 60% to 80% of patients are eligible for CAR T-cell therapy at first relapse, only 10% to 30% are treated. Several faculty who once reserved CAR T-cell therapy for later lines now favor earlier use.
“The idea of being able to cycle through a bispecific [antibody] in the next line [of therapy after CAR T-cell therapy] has made it more attractive, as opposed to the reverse, where you’re less likely to be able to go to another BCMA-targeting [agent],” said Sagar Lonial, MD, FACP, FASCO, professor and chair of the Department of Hematology and Medical Oncology, the Anne and Bernard Gray Family Chair in Cancer at Emory University School of Medicine, as well as the chief medical officer at Winship Cancer Institute of Emory University in Atlanta, Georgia.1
Bispecific combination data drew skepticism, given current frontline treatment patterns in the United States. Findings from the phase 3 MajesTEC-3 trial (NCT05083169) supported the March 2026 FDA approval of teclistamab-cqyv (Tecvayli) plus daratumumab (Darzalex) for the treatment of adult patients with relapsed/refractory multiple myeloma who have received at least 1 prior line of therapy. However, Lonial argued that “teclistamab [plus] daratumumab is [intended for] a patient population that doesn’t exist” in US practice, noting the standard frontline use of an anti-CD38 monoclonal antibody in the form of daratumumab or isatuxumab-irfc (Sarclisa).