At ASH 2019, Dr. Madduri presented results from the phase 1b portion of the CARTITUDE-1 trial. The investigators enrolled patients with multiple myeloma with measurable diseases as assessed by M-protein or serum free light chain levels who had experienced disease progression on at least 3 prior lines of therapy, or whose disease was refractory to at least two lines of therapy with a proteasome inhibitor, immunomodulatory drug (IMiD), and an anti-CD38 antibody.
Patients underwent apheresis for T-cell collection, with bridging therapy allowed until the expanded T cells could be delivered.
Following T-cell depletion with cyclophosphamide 300 mg/m2 and fludarabine 30 mg/m2 over 3 days, patients received a single weight-based infusion (compared with fixed-dose infusions used with other CAR T cell constructs).
The dose was targeted at 0.75x106 CAR-positive cells/kg, with a target range of 0.5–1.0x106, administered 5-7 days after the start of the conditioning regimen.
A total of 29 patients, median age 60, were evaluable for the safety and efficacy endpoints. One-fourth of the patients had a high-risk cytogenetic profile. The patients had received a median of 5 prior lines of therapy, with one patient receiving 18 prior lines. Of the 29 patients, 25 (86%) had previously undergone autologous transplantation.
As noted before, the ORR after a median follow-up of 6 months was 100%, with 69% completer responses, 17% very good partial responses, and 14% partial responses. The median time to complete response was 1 month (range 1 to 9 months). All but two patients remained free of disease progression at the median 6-month follow-up.
Nearly all patients (27) developed cytokine release syndrome (CRS), and one patient with prolonged grade 4 CRS died from related complications 99 days after infusion.
The median time to onset of CRS was 7 days with more than 90% of cases occurring between days 5 and 9.
Neurotoxicities, specifically immune effector cell–associated neurotoxicity syndrome (ICANS), were infrequent in CRS, and when they did occur were generally low grade, with only 1 grade 3 ICANS event.
Asked in an interview whether the impressive response rates seen with JNJ-4528 might persist over time, Dr. Madduri acknowledged that follow-up is still relatively short.
“This product is unique in that has a CD8 central memory phenotype preferentially, and we’re hoping that this would play a central role in the durability of response because they’re memory cells, but I think at this time we don’t know,” she said.
The CARTITUDE-1 trial is funded by Janssen Research & Development. Dr. Madduri disclosed serving as a consultant to Janssen and to Takeda, Foundation Medicine, AbbVie, and Celgene.
SOURCE: Madduri D et al. ASH 2019. Abstract 577.