Phase-I study of Innacell gammadelta, an autologous cell-therapy product highly enriched in gamma9delta2 T lymphocytes, in combination with IL-2, in patients with metastatic renal cell carcinoma

Abstract

Purpose: gamma9delta2 T lymphocytes have been shown to be directly cytotoxic against renal carcinoma cells. Lymphocytes T gammadelta can be selectively expanded in vivo with BrHPP (IPH1101, Phosphostim) and interleukin 2 (IL-2). A phase I Study was conducted in patients with metastatic renal cell carcinoma (mRCC) to determine the maximum-tolerated dose and safety of Innacell gammadelta, an autologous cell-therapy product based on gamma9delta2 T lymphocytes, in patients with mRCC.

Experimental design: A 1-h intravenous infusion of gamma9delta2 T lymphocytes was administered alone during treatment cycle 1 and combined with a low dose of subcutaneous interleukin-2 (IL-2, 2 MIU/m2 from Day 1 to Day 7) in the two subsequent cycles (at 3-week intervals). The dose of gamma9delta2 T lymphocytes was escalated from 1 up to 8 x 10(9) cells.

Results: Ten patients underwent a total of 27 treatment cycles. Immunomonitoring data demonstrate that gamma9delta2 T lymphocytes are initially cleared from the blood to reappear at the end of IL-2 administration. Dose-limiting toxicity occurred in one patient at the dose of 8 x 10(9) cells (disseminated intravascular coagulation). Other treatment-related adverse events (AEs) included mainly gastrointestinal disorders and flu-like symptoms (fatigue, pyrexia, rigors). Hypotension and tachycardia also occurred, especially with co-administered IL-2. Six patients showed stabilized disease. Time to progression was 25.7 weeks.

Conclusion: The data collected in ten patients with mRCC indicate that repeated infusions of Innacell gammadelta at different dose levels (up to 8 x 10(9) total cells), either alone or with IL-2 is well tolerated. These results are in favor of the therapeutic value of cell therapy with Innacell gammadelta for the treatment of cancers.

Fig. 1

Cell therapy product manufacturing and patient treatment schedule

Fig. 2

Kinetics of absolute counts (per mm³) of Vδ2 CD3+T cells in peripheral blood following multiple γ9δ2 T cell infusion (representative example of patient #5 treated with 4 × 10⁹ cells)

Fig. 3

Dose effect of Innacell γδ™ on the circulating level of γ9δ2 cells. All infusions are presented. Each histogram represents the following ratio by dose: mean + SD of fold increase of all cycles/baseline level at start of cycle 1

Fig. 4

Proportion of patients without disease progression in the 10 mRCC patients treated with Innacell γδ™, illustrated according to the Kaplan–Meier’s method. Median time to progression is 25.7 weeks. N  = 10 patients