Cell therapy anito-cel shows promise for hard-to-treat RRMM
Most patients alive 1 year after treatment in Phase 2 trial, per new data
Most people with relapsed or refractory multiple myeloma (RRMM) given the cell therapy anitocabtagene autoleucel — known as anito-cel — in a Phase 2 clinical trial are still alive and free from disease progression one year after treatment, according to new study data.
Those preliminary results were presented last week at the 66th American Society of Hematology (ASH) Annual Meeting and Exposition by Arcellx, which is developing anito-cel with Kite Pharma. Arcellx shared the data in a presentation titled “Phase 2 Registrational Study of Anitocabtagene Autoleucel for the Treatment of Patients with Relapsed and/or Refractory Multiple Myeloma: Preliminary Results from the IMMagine-1 Trial.”
“It’s exciting to reach this momentous milestone in our pivotal study and present these compelling data,” Rami Elghandour, chairman and CEO of Arcells, said in a company press release.
When added to data from an earlier Phase 1 study, these new results “continue to support our conviction that anito-cel has the potential to be a best-in-class treatment option for patients with RRMM,” Elghandour said.
Anito-cel is a CAR T-cell therapy. This type of treatment works by collecting T-cells — a type of immune cell — from patients, then engineering them with a lab-made protein called a chimeric antigen receptor, or CAR, which directs the cells to attack and kill cancer cells. The engineered cells are then infused back into the patient to go after the cancer. Anito-cel specifically uses a CAR that targets BCMA, a protein expressed by most myeloma cells.
Together, the two studies to date have “allowed us to demonstrate the potential benefit of anito-cel,” Elghandour added.
Ongoing iMMagine-1 trial expected to involve over 100 RRMM patients
The new data come from a Phase 2 study called iMMagine-1 (NCT05396885) that’s testing anito-cel in people with RRMM whose disease has progressed following treatment with at least three previous lines of therapy, including a proteasome inhibitor, an immunomodulator, and a CD38 inhibitor.
The study is expected to involve about 110 patients in total. For this presentation, the researchers shared efficacy outcomes from 86 participants who have been followed for at least two months after anito-cel treatment, with a median follow-up time of more than nine months.
The results showed that the overall response rate was 97%, meaning that nearly all patients experienced a reduction in cancer burden following treatment with anito-cel. More than 93% of evaluable patients achieved minimal residual disease, meaning virtually no cancer cells were detectable in their bodies following anito-cel treatment.
The data from the iMMagine-1 study demonstrate that this is a highly active product with impressive depth of responses achieved in patients with relapsed or refractory multiple myeloma.
Available data show that, at six months after anito-cel, more than 96% of patients were still alive, and almost all of them were free from disease progression. Among patients followed for at least one year, 96.5% were alive at one year and more than three-quarters (78.5%) were free from disease progression.
“The data from the iMMagine-1 study demonstrate that this is a highly active product with impressive depth of responses achieved in patients with relapsed or refractory multiple myeloma,” said Ciara Freeman, MD, PhD, study investigator at Moffitt Cancer Center.
Side effects with anito-cel rated as mild in most trial participants
CAR T-cell therapies like anito-cel are known to sometimes cause cytokine release syndrome, or CRS, which is an inflammatory reaction that can be serious or even deadly in severe cases. Neurological issues, most frequently immune effector cell-associated neurotoxicity syndrome, or ICANS, have also been reported with some CAR T-cell treatments.
Most of the patients treated with anito-cel in iMMagine-1 have experienced CRS. However, in the vast majority of cases, this side effect has been rated as mild in severity. ICANS has been reported in 9% of patients, with one case judged as serious; no other neurological issues have been reported to date. In slightly more than half of evaluable patients, anito-cel treatment led to low counts of blood cells that were judged as a serious side effect.
“As a physician who treats many patients both inpatient and in the outpatient setting, the emerging safety profile of anito-cel is encouraging, in particular the absence of any delayed neurotoxicities reported to date,” Freeman said.
Three deaths have been reported in the study to date: one due to CRS, one due to fungal infection, and one due to hemorrhage.
A Phase 3 trial called iMMagine-3 (NCT06413498) was launched earlier this year to test anito-cel in RRMS patients who’ve had one to three previous lines of therapy, including at least an immunomodulatory and a CD38 inhibitor. That study is actively recruiting patients at four locations across the U.S., with more sites expected to open in the future.
Elghandour, who said his own company is “just getting started,” noted the partners’ commitment to developing anito-cel.
“With iMMagine-3 underway in earlier lines in a patient population representing an unmet clinical need, we expect to further position anito-cel as a differentiated CAR-T treatment option for RRMM,” Elghandour said.
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