Clinical regressions and broad immune activation following combination therapy targeting human NKT cells in myeloma.

Natural killer T (iNKT) cells can help mediate immune surveillance against tumors in mice. Prior studies targeting human iNKT cells were limited to therapy of advanced cancer and led to only modest activation of innate immunity. Clinical myeloma is preceded by an asymptomatic precursor phase. Lenalidomide was shown to mediate antigen-specific costimulation of human iNKT cells. We treated 6 patients with asymptomatic myeloma with 3 cycles of combination of α-galactosylceramide-loaded monocyte-derived dendritic cells and low-dose lenalidomide. Therapy was well tolerated and led to reduction in tumor-associated monoclonal immunoglobulin in 3 of 4 patients with measurable disease. Combination therapy led to activation-induced decline in measurable iNKT cells and activation of NK cells with an increase in NKG2D and CD56 expression. Treatment also led to activation of monocytes with an increase in CD16 expression. Each cycle of therapy was associated with induction of eosinophilia as well as an increase in serum soluble IL2 receptor. Clinical responses correlated with pre-existing or treatment-induced antitumor T-cell immunity. These data demonstrate synergistic activation of several innate immune cells by this combination and the capacity to mediate tumor regression. Combination therapies targeting iNKT cells may be of benefit toward prevention of cancer in humans.

Immunologic activity and safety of autologous HIV RNA-electroporated dendritic cells in HIV-1 infected patients receiving antiretroviral therapy.

Immunogenicity, manufacturing feasibility, and safety of a novel, autologous dendritic cell (DC)-based immunotherapy (AGS-004) was evaluated in ten human immunodeficiency virus type 1 (HIV-1)-infected adults successfully treated with antiretroviral therapy (ART). Personalized AGS-004 was produced from autologous monocyte-derived DCs electroporated with RNA encoding CD40L and HIV antigens (Gag, Vpr, Rev, and Nef) derived from each subjects' pre-ART plasma. Patients received monthly injections of AGS-004 in combination with ART. AGS-004 was produced within a mean of 6 weeks and yielded 4-12 doses/subject Full or partial HIV-specific proliferative immune responses occurred in 7 of 9 evaluable subjects. Responses were specific for the AGS-004 presented HIV antigens and preferentially targeted CD8(+) T cells. Mild adverse events included flu-like symptoms, fatigue, and injection site reactions. No evidence of autoimmunity, changes in viral load, or significant changes in absolute CD4(+) and CD8(+) T cell counts were observed. This pilot study supports the further clinical investigation of AGS-004.

An improved RNA amplification procedure results in increased yield of autologous RNA transfected dendritic cell-based vaccine.

Use of antigen encoding RNA transfected Dendritic cells in the field of cancer immunotherapy has been well established. The use of RNA overcomes limitations inherent to other autologous DC-based vaccines as it does not require specific HLA haplotypes, identification and characterization of antigens, and captures the broadest antigen repertoire. RNA offers yet another advantage-it could be amplified minimizing the requirement of tumor mass for autologous vaccine production, and will afford the opportunity to treat patients with minimal tumor burden. The original procedure described for RNA amplification resulted in a proportion of RNA transcribed in the antisense orientation. This study also demonstrates that the presence of double-stranded RNA correlates with the presence of antisense RNA. Alternative design of oligonucleotides that removes sequence redundancy eliminates the formation of both antisense and double-stranded RNA species. We provide further evidence that amplified RNA containing antisense and double-stranded RNA species results in lower recovery of DCs post-transfection and maturation, presumably through sequence-specific gene silencing. The removal of the double-stranded species from amplified RNA results in higher recovery of mature autologous amplified RNA transfected dendritic cells. Higher DC yield will allow for reduction of cost of vaccine manufacturing and prolonged treatment of a patient.