A new experimental type of cancer treatment has shown impressive results in mice: eradicating advanced-stage ovarian and colorectal cancer in animals in as little as six days.
The new therapy has only been tested in mice so far, so let’s not get too excited just yet. However, early signs are promising and human clinical trials could be underway by the end of the year.
The treatment involves tiny ‘drug factory’ beads that are implanted in the body and deliver a continuous high dose of interleukin‑2 (IL2) — a naturally occurring compound that appeals to white blood cells in the fight against cancer .
“We only administer once, but the pharmaceutical factories continue to manufacture the dose every day, where it is needed until the cancer is eliminated,” explains bioengineer Omid Veiseh of the ‘Rice University in Texas.
“Once we determined the right dose – the number of plants we needed – we were able to eradicate tumors in 100% of the animals with ovarian cancer and in seven out of eight animals with colorectal cancer.”
Interleukin‑2 is one of a group of immune system trigger proteins called cytokines. Although cytokines are already used in the treatment of melanoma cancer and renal cell carcinoma, the problem scientists face is getting the cytokines to effectively fight tumors while avoiding dangerously high levels of inflammation elsewhere in the body. body, causing dramatic side effects.
In this study, the beads were placed in the peritoneum, a sac-like lining around the intestines, ovaries, and other abdominal organs. This allows drugs to specifically target cancer without adding bulk or weight to the body.
The dose of interleukin‑2 given by these pharmaceutical factories would be too toxic if given by intravenous infusion, but here it works because the high concentrations are concentrated on the tumor. The concentration of the protein elsewhere in the body appears to be about 30 times lower than near the tumor, according to tests.
Each bead has an outer hydrogel cell that shields cytokine-producing cells, protecting them from attack. These pearls are recognized as foreign objects by the surrounding immune system, but not as immediate threats, allowing them to do their job. They can then be programmed to turn off automatically.
“We found safe and robust foreign body reactions that turned off cytokine flux from the capsules within 30 days,” says Veiseh. “We also showed that we could safely administer a second treatment if it became necessary at the clinic.”
Drug factory beads can potentially be adopted for cancers elsewhere in the body, as long as there is a lining where they could house them, and they could be modified to deliver different types of drugs, the researchers say. It is a flexible and innovative system.
Plus, the drugs used here have already been approved as safe for use in clinical trials, which should speed up the process. The final treatment should be minimally invasive and relatively simple to administer.