4157 - A novel affinity-enhanced NY-ESO-1-targeting TCR-redirected T cell transfer exhibited early-onset cytokine release syndrome and subsequent tumor responses in synovial sarcoma patients

Background

Adoptive transfer of TCR-redirected T cells has been reported to exhibit efficacy in some patients with melanoma and sarcoma. However, cytokine release syndrome (CRS) or its relations to tumor response has not been well documented. This study aimed to evaluate clinical responses in association with the cell kinetics and CRSs after transfer of high-affinity NY-ESO-1 TCR-gene transduced T cells in cancer patients.

Methods

We developed a novel-type affinity-enhanced NY-ESO-1-specific TCR and an originally-developed retrovirus vector that encodes siRNA to silence endogenous TCR creation. The NY-ESO-1/TCR sequence was mutated for high affinity with replacements of G50A and A51E in CDR2 region. This is a first-in-human clinical trial of the novel NY-ESO-1-specfic TCR-T cell transfer to evaluate the safety, in vivo cell kinetics and clinical responses. It was designed as a cell-dose escalation from 5 x10⁸ to 5 x10⁹ cells. NY-ESO-1-expressing refractory cancer patients were enrolled, with 3 + 3 cohort design. Cyclophosphamide (1,500mg/m²) were administered prior to the TCR-T cell transfer as pre-conditioning.

Results

Nine patients were treated with the TCR-T cells that expanded in peripheral blood with a dose-dependent manner, associated with rapid proliferation within 5 days after infusion. Three patients receiving 5x10⁹ cells developed early-onset CRSs, with elevated levels of serum IL-6, IFN-γ. The CRSs on day1 or 2 were well managed with tocilizumab treatment. Three synovial sarcoma patients exhibited tumor shrinkage and partial responses, and they all had high-expression of NY-ESO-1 in the tumor samples, namely, 75% or more. Exploratory analysis revealed that multiple chemotactic cytokines including CCL2 and CCL7, and IL-3 increased in the serum from the patients with CRS. The proportions of effector-memory phenotype T cells in the infused cell-product were significantly associated with CRS development.

Conclusions

The affinity-enhanced NY-ESO-1/TCR-T cell transfer exhibited early-onset CRS in association with in vivo cell proliferation and sequential tumor responses in the patients with high-NY-ESO-1-expressing synovial sarcoma.

Clinical trial identification

NCT02366546.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Japan Agency for Medical Research and Development.

Disclosure

All authors have declared no conflicts of interest.