Tempest Therapeutics reports 100% CR rate in dual-targeting CAR-T trials
Tempest Therapeutics has presented updated clinical data on TPST-2003, its autologous CD19/BCMA dual-targeting CAR-T candidate, at the ISCT 2026 Annual Meeting in Dublin, reporting a 100% complete response rate among all 15 CAR-T-naïve efficacy-evaluable patients enrolled across two ongoing Phase 1 trials.
The dataset spans the REDEEM-1 trial in relapsed/refractory multiple myeloma and the POEMS-1 trial in POEMS syndrome, a rare plasma-cell disorder. The combined readout more than doubles the six-patient interim cohort that Tempest disclosed earlier this year, bringing the aggregate treated population to 44 patients across three studies — a figure the company describes as one of the largest CD19/BCMA dual-targeting datasets yet assembled.
Clinical data
In REDEEM-1, all 10 CAR-T-naïve patients currently evaluable for efficacy achieved a complete response according to International Myeloma Working Group criteria. Responses were observed across three dose levels, ranging from 1×10⁶ to 3×10⁶ cells/kg. Notably, 18 of the 29 CAR-T-naïve evaluable patients included across REDEEM-1 and a prior investigator-initiated trial had extramedullary disease — a subgroup historically associated with poor outcomes — yet the overall response rate across all 29 remained 100%. A single patient who had previously received a BCMA-targeting CAR-T did not respond.
The safety readout was favourable: no Grade 3 or higher cytokine release syndrome or immune effector cell-associated neurotoxicity syndrome was observed in REDEEM-1. In POEMS-1, all five evaluable patients achieved a VEGF-normalisation complete response within two months of infusion, and no dose-limiting toxicities were recorded.
Median progression-free survival in the rrMM programme stood at 23.1 months, including patients with extramedullary disease. The company says that, if replicated in a registrational trial, this figure would position TPST-2003 as a potentially class-leading therapy. Chief executive Matt Angel said the results support the view that TPST-2003 "may outperform first-generation single-targeting CAR-T therapies, in particular in patients with EMD."
Market context and regulatory path
The multiple myeloma CAR-T space is already crowded with approved single-target agents. Ciltacabtagene autoleucel and idecabtagene vicleucel — both BCMA-directed — are established in later lines, while several dual-target programmes from larger sponsors are in varying stages of development. The rationale for dual targeting rests on the premise that simultaneous engagement of CD19 and BCMA limits antigen-escape relapse, a key failure mode for earlier-generation products. Whether that architectural advantage translates into durable superiority over approved agents will require a randomised dataset that Phase 1 data cannot yet provide.
Tempest plans to seek a meeting with the FDA before the end of 2026 to discuss the design of a US registrational study. The trials to date are sponsored and conducted in China by partner Novatim Immune Therapeutics, which holds development rights in China, India, Turkey, and Russia; Tempest retains exclusive rights in all other markets. That geographic split means the registrational path outside China will depend on whether FDA accepts data generated at Novatim's Chinese sites, a question that increasingly draws regulatory scrutiny under recent guidance on foreign clinical trial data.
REDEEM-1 is targeting full enrolment of 32 patients; POEMS-1 is targeting 12. Both remain open, and further efficacy and safety data are expected as those cohorts mature.