4379 - Results of a phase I trial with MART-1 T cell receptor modified T cells in patients with metastatic melanoma

Background

Adoptive cell therapy (ACT) with T cell receptor (TCR) gene modified peripheral blood T cells creates large pools of tumor reactive T cells. Based on preclinical validation we have selected a high affinity MART-1-specific TCR for TCR gene therapy in metastatic melanoma (MM). Utilizing a novel GMP production protocol we performed a phase I trial to asses feasibility, safety and efficacy of TCR gene therapy in pts with MM.

Methods

HLA-A2*0201+ pts with irresectable stage IIIc/IV melanoma, expressing MART-1 and MHC class I, with no standard treatment options were included. Autologous T cells were isolated via apheresis and transduced with a MP-71 retroviral vector encoding the 1D3HMCys MART-1 TCR and expanded ex vivo in presence of IL-7 and IL-15. Non-myeloablative chemotherapy was given prior to one i.v. infusion of MART-1 TCR transduced T cells in a dose escalating manner after evaluation of adverse events (AEs). Feasibility, safety (CTCAE 4.0) and ORR (RECIST 1.1) were assessed.

Results

Twelve heavily pretreated metastatic cutaneous (n = 7) and uveal (n = 5) melanoma (mUM) pts were treated with MART-1 TCR transduced T cells across 4 dose cohorts. Transduction efficiency was 42-76%. Viability of the cell product was 92.9-98.5%. Pt 1 received 4.56 x 10⁹ MART-1 TCR transduced T cells but died 9 days post infusion due to multiple organ failure. Subsequent pts received 5 x 10⁷ (n = 3; cohort (c) 2), 25 x 10⁷ (n = 2; c3) and 10 x 10⁷ (n = 6; c4) cells. On-target AEs were dose-dependent and included dermatitis (10/11) max grade 3, uveitis (3/11) max grade 2 and ototoxicity (4/11) max grade 3, highest in cohort 3. Four pts (n = 2 c3; n = 2 c4) showed signs of cytokine release syndrome and 3 pts required tocilizumab. Objective PR by RECIST 1.1 was seen in 2 pts (17%), with a DOR of 4.2 (mUM, c4) and 8.4 (c3) months. Persistence of transduced T cells in peripheral blood was correlated with infused cell dose.

Conclusions

Treatment with MART-1 TCR transduced peripheral blood T cells expanded in presence of IL-7 and IL-15 led to severe dose-dependent toxicity with a maximum tolerated dose of 10 x 10⁷ transduced cells. Despite observed responses, toxicity limited further development and use of this MART-1 TCR cellular therapy in MM patients. NCT02654821.

Clinical trial identification

NCT02654821.

Editorial acknowledgement

Legal entity responsible for the study

Netherlands Cancer Institute/Antoni van Leeuwenhoek hospital (NKI-AVL).

Funding

KWF Kankerbestrijding.

Disclosure

J.H. Beijnen: Shareholder / Stockholder / Stock options, Full / Part-time employment: Modra Pharmaceuticals BV . J.V. van Thienen: Honoraria (institution), Advisory / Consultancy: Pfizer ; Honoraria (institution), Advisory / Consultancy: Novartis. C.U. Blank: Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): BMS; Honoraria (self), Advisory / Consultancy: MSD; Honoraria (self), Advisory / Consultancy: Roche; Honoraria (self), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (self), Advisory / Consultancy: Lilly; Honoraria (self), Advisory / Consultancy: Pfizer; Honoraria (self), Advisory / Consultancy: GSK; Honoraria (self), Advisory / Consultancy: GenMab; Honoraria (self), Advisory / Consultancy: Pierre Fabre ; Research grant / Funding (institution): NanoString. T.N. Schumacher: Advisory / Consultancy: Adaptive Biotechnologies; Advisory / Consultancy, Shareholder / Stockholder / Stock options: AIMM Therapeutics; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Allogene Therapeutics; Advisory / Consultancy: Amgen; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Merus; Advisory / Consultancy, Shareholder / Stockholder / Stock options: Neon Therapeutics; Advisory / Consultancy: Scenic Biotech; Advisory / Consultancy: Third Rock Ventures; Research grant / Funding (institution): Merck; Research grant / Funding (institution): Bristol-Myers Squibb; Research grant / Funding (institution): Merck KGaA; Shareholder / Stockholder / Stock options: Neogene Therapeutics; Shareholder / Stockholder / Stock options: Scenic Biotech. J.B.A.G. Haanen: Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): BMS; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): MSD; Honoraria (institution), Advisory / Consultancy: Pfizer; Honoraria (institution), Advisory / Consultancy: AZ/MedImmune; Honoraria (institution), Advisory / Consultancy: Roche/Genentech; Honoraria (institution), Advisory / Consultancy: Ipsen; Honoraria (institution), Advisory / Consultancy: Bayer; Honoraria (institution), Advisory / Consultancy: Immunocore; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Novartis; Honoraria (institution), Advisory / Consultancy: Seattle Genetics; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Neon Therapeutics; Honoraria (institution), Advisory / Consultancy: Celsius Therapeutics; Honoraria (institution), Advisory / Consultancy: Gadet ; Honoraria (institution), Advisory / Consultancy: GSK. All other authors have declared no conflicts of interest.