Biomaterial Injection Combines T Cell and Cancer Vaccine Treatments

Researchers at the Harvard Wyss Institute have developed an anti-cancer biomaterial treatment that combines adoptive T cell therapy and cancer vaccine technology to treat solid tumors. The researchers have called their technique SIVET, which is short for “synergistic in situ vaccination enhanced T cell”. The approach combines local delivery of cytotoxic T cells with longer lasting cancer vaccine technology that engages with the immune system more broadly for long lasting anticancer action. The researchers hope that the technology could lead to improvements in efficacy for immune therapies in treating solid tumors.

After injection and taking action against a solid tumor, SIVETs recruit and further activate a variety of T cells that are stained with different immunofluorescence reagents in this image.

Immune therapies, such as cytotoxic T cells that have been primed to seek and destroy cancer cells, have enormous potential, but to date have been more effective against blood-based cancers rather than solid tumors. Anti-cancer T cell-based treatments can struggle to affect solid tumors, as very few of the delivered T cells end up at the tumor site. Moreover, it can be difficult for the T cells to penetrate the dense tumor mass, and variability in tumor cell biology as the tumor progresses can result in some tumor cells that lack the crucial antigens that cytotoxic T cells use to target them. This can result in a short-lived efficacy and such cell treatments can struggle to eradicate solid tumors in the long term.

Another approach is the so-called cancer vaccine. This typically involves delivering biomaterials that can assist in reprogramming dendritic cells (also called antigen-presenting cells) already present in the body into tumor fighting cells. This results in a long-lasting anti-tumor effect, but it can take time to manifest and become effective.

To achieve the best of both worlds, these researchers have combined both T cell therapy and cancer vaccines, by delivering both in one injectable biomaterial formulation that can reside near the tumor and provide fast acting and long-lasting anti-cancer effects.

“Our new platform fully leverages our expertise with adoptive T cell and cancer vaccine technologies,” said Kwasi Adu-Berchie, a researcher involved in the study. “Combining the best of these two worlds in a multi-pronged biomaterial-based approach allows the fast debulking of existing tumor masses while engaging the immune system on a much deeper level through the localized delivery, concentration, and activation of diverse tumor-fighting immune cells.”

So far, in tests with mice who had melanoma, an aggressive cancer, the system enabled rapid tumor shrinkage and long-term anti-cancer protection.

Top image: The researchers visualized the cell-permeable porous structure of an injectable SIVET immuno-material using scanning electron microscopy analysis (SEM).

Study in journal Nature Communications: Adoptive T cell transfer and host antigen-presenting cell recruitment with cryogel scaffolds promotes long-term protection against solid tumors

Via: Harvard Wyss Institute