Tempest’s TPST-2003 Shows 100% CR Rate, Plans 2026 U.S. Registrational Study
Tempest reported that TPST-2003 achieved a 100% complete response rate among six evaluable patients in its ongoing REDEEM-1 Phase 1/2a trial with no grade 3+ CRS or ICANS. A prior investigator-initiated study showed median progression-free survival of 23.1 months in 24 relapsed/refractory multiple myeloma patients, prompting plans for a U.S. registrational study in 2026.
1. Interim Efficacy Results
In the ongoing REDEEM-1 Phase 1/2a trial, all six efficacy-evaluable patients treated at dose levels of 1 x 10^6 and 2 x 10^6 cells/kg achieved complete response according to International Myeloma Working Group criteria, resulting in a 100% CR rate across evaluable cohorts.
2. Safety Profile
Across all dose levels in REDEEM-1, TPST-2003 exhibited a favorable safety profile with no grade 3 or higher cytokine release syndrome or neurotoxicity, and only one low-grade immune effector cell-associated neurotoxicity syndrome event at the highest dose of 3 x 10^6 cells/kg.
3. Prior IIT and Durability
In a prior investigator-initiated Phase 1/2 trial of 24 relapsed/refractory multiple myeloma patients, TPST-2003 achieved a 100% overall response rate, 89.5% complete response rate, and median progression-free survival of 23.1 months, with all evaluable patients remaining MRD-negative at month 12.
4. Regulatory and Development Plans
Tempest plans to submit a U.S. IND for TPST-2003 and, subject to FDA clearance, initiate a registrational study in the U.S. in 2026. The company is also exploring additional indications such as large B-cell lymphoma based on the therapy’s parallel dual-targeting CAR design.