NCT05664217

NKTR-255 vs Placebo Following CD19-directed CAR-T Therapy in Patients With Relapsed/Refractory Large B-cell Lymphoma

Terminated Phase 2, PHASE3 Last updated 13 February 2025

What this trial tests

Phase 2, PHASE3 trial testing NKTR-255 at 1.5 µg/kg in Non-Hodgkin Lymphoma in 15 participants. Terminated before completion.

Timeline

23 December 2022

Primary endpoint
22 May 2024

16 August 2024

Quick facts

Lead sponsor	Nektar Therapeutics
Phase	Phase 2, PHASE3
Status	Terminated
Study type	INTERVENTIONAL
Allocation	randomized
Design	sequential
Masking	quadruple
Primary purpose	treatment
Enrollment	15
Start date	23 December 2022
Primary completion	22 May 2024
Estimated completion	16 August 2024
Sites	22 locations across United States

Drugs / interventions tested

• NKTR-255 at 1.5 µg/kg — full drug profile →
• NKTR-255 at 3.0 μg/kg — full drug profile →
• NKTR-255 at 3.0/6.0 μg/kg — full drug profile →
• Placebo Comparator

Conditions studied

• Non-Hodgkin Lymphoma — all drugs for Non-Hodgkin Lymphoma →
• Relapsed/Refractory Diffuse Large B-cell Lymphoma — all drugs for Relapsed/Refractory Diffuse Large B-cell Lymphoma →

Sponsor

Nektar Therapeutics — full company profile →

Who can join

18 and older, any sex, with Non-Hodgkin Lymphoma or Relapsed/Refractory Diffuse Large B-cell Lymphoma. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

This study will evaluate the safety and efficacy of NKTR-255 following CD19-directed chimeric antigen (CAR)-T cell therapy in patients with relapsed or refractory (R/R) large B-cell lymphoma (LBCL).

NKTR-255 is an investigational IL-15 receptor agonist designed to boost the immune system's natural ability to fight cancer. T cells are infection fighting blood cells that can kill tumor cells. Chimeric antigen (CAR)-T cell product consists of genetically engineered T-cells, modified to recognize CD19, a protein on the surface of cancer cells. These CD19-specific T cells may help the body's immune system identify and kill CD19-positive cancer cells. Giving NKTR-255 following the treatment with CD19 CAR-T cell therapy may work better in treating large B-cell lymphoma than either drug alone.

Publications & conference data

8 peer-reviewed publications reference this trial (live from Europe PMC):

1. Targeting cytokine and chemokine signaling pathways for cancer therapy.
   Yi M, Li T, Niu M, Zhang H, et al · · 2024 · cited 264× · PMID 39034318 · DOI 10.1038/s41392-024-01868-3
2. Smart Polymeric Nanoparticles in Cancer Immunotherapy.
   Yu Z, Shen X, Yu H, Tu H, et al · · 2023 · cited 35× · PMID 36986636 · DOI 10.3390/pharmaceutics15030775
3. Lipid-based nanosystems: the next generation of cancer immune therapy.
   Cheng Z, Fobian SF, Gurrieri E, Amin M, et al · · 2024 · cited 29× · PMID 39030582 · DOI 10.1186/s13045-024-01574-1
4. Targeting γc family cytokines with biologics: current status and future prospects.
   Bick F, Blanchetot C, Lambrecht BN, Schuijs MJ. · · 2025 · cited 5× · PMID 39967341 · DOI 10.1080/19420862.2025.2468312
5. Revitalizing T cells: breakthroughs and challenges in overcoming T cell exhaustion.
   Wu Y, Wu Y, Gao Z, Yu W, et al · · 2026 · cited 2× · PMID 41484095 · DOI 10.1038/s41392-025-02327-3
6. NKTR-255 enhances complete response following CD19 CAR T-cell therapy in patients with relapsed/refractory large B-cell lymphoma.
   Ahmed S, DiPersio J, Essell J, Diefenbach C, et al · · 2025 · cited 2× · PMID 40779552 · DOI 10.1182/bloodadvances.2025016423
7. Updates on Chimeric Antigen Receptor T-Cells in Large B-Cell Lymphoma.
   Saleh K, Khalife N, Arbab A, Khoury R, et al · · 2024 · cited 2× · PMID 39767716 · DOI 10.3390/biomedicines12122810
8. Management of aggressive lymphoma after CAR T-cell therapy failure.
   Nastoupil LJ, Thiruvengadam SK. · · 2023 · cited 2× · PMID 38066908 · DOI 10.1182/hematology.2023000437