Adoptive transfer of MART-1 T-cell receptor transgenic lymphocytes and dendritic cell vaccination in patients with metastatic melanoma

Abstract

Purpose: It has been demonstrated that large numbers of tumor-specific T cells for adoptive cell transfer (ACT) can be manufactured by retroviral genetic engineering of autologous peripheral blood lymphocytes and expanding them over several weeks. In mouse models, this therapy is optimized when administered with dendritic cell (DC) vaccination. We developed a short 1-week manufacture protocol to determine the feasibility, safety, and antitumor efficacy of this double cell therapy.

Experimental design: A clinical trial (NCT00910650) adoptively transferring MART-1 T-cell receptor (TCR) transgenic lymphocytes together with MART-1 peptide-pulsed DC vaccination in HLA-A2.1 patients with metastatic melanoma. Autologous TCR transgenic cells were manufactured in 6 to 7 days using retroviral vector gene transfer, and reinfused with (n = 10) or without (n = 3) prior cryopreservation.

Results: A total of 14 patients with metastatic melanoma were enrolled and 9 of 13 treated patients (69%) showed evidence of tumor regression. Peripheral blood reconstitution with MART-1-specific T cells peaked within 2 weeks of ACT, indicating rapid in vivo expansion. Administration of freshly manufactured TCR transgenic T cells resulted in a higher persistence of MART-1-specific T cells in the blood as compared with cryopreserved. Evidence that DC vaccination could cause further in vivo expansion was only observed with ACT using noncryopreserved T cells.

Conclusion: Double cell therapy with ACT of TCR-engineered T cells with a very short ex vivo manipulation and DC vaccines is feasible and results in antitumor activity, but improvements are needed to maintain tumor responses.

Figure 1. F5 study outline

A) Schedule of events for patients F5-1 to F5-11 who received cryopreserved TCR transgenic cells under amendments 1-7. B) Schedule of events for patients F5-12 to F5-14 who received freshly manufactured TCR transgenic cells after amendment 8.

Figure 2. Post-infusion peripheral blood levels of MART-1 TCR transgenic cells at various time points in patients receiving cryopreserved transgenic cells

A) F5-1 to F5-9 receiving up to 10⁹ cryopreserved transgenic cells. B) F5-10 and F5-11 receiving up to 10¹⁰ cryopreserved transgenic cells. C) Representative dot plots of MART-1 MHC tetramer analysis of infused cells and post-infusion peripheral blood PBMC in F5-7 and F5-8.

Figure 3. Pre- and post-treatment day 30 PET scans indicating initial antitumor activity

Representative scans of F5-1 and F5-3 receiving up to 10⁹ cryopreserved transgenic cells, F5-10 and F5-11 receiving up to 10¹⁰ cryopreserved transgenic cells.

Figure 4. Pre- and post-treatment day 35 PET/CT (F5-10) and CT (F5-13) showing evidence of initial antitumor activity

Representative scans of F5-10 receiving up to 10¹⁰ cryopreserved transgenic cells and F5-13 receiving up to 10¹⁰ freshly harvested transgenic cells.

Figure 5. Post-infusion peripheral blood levels of MART-1 TCR transgenic cells at various time points in patients receiving freshly harvested transgenic cells

MART-1 tetramer positive CD4+ and CD8+ levels in F5-12, F5-13 and F5-14 receiving up to 10¹⁰ freshly harvested transgenic cells.