Experiments with a new form of cancer treatment have shown some astonishing results in mice, including the complete eradication of advanced-stage ovarian and colorectal cancer in the animals within six days of treatment.
We shouldn’t get our hopes up just yet since the new treatment has only been tested on mice so far, so hold off on getting too thrilled. However, the early findings are encouraging, and it is possible that human clinical trials may begin before the end of the year.
It uses Interleukin-2 (IL2), a natural substance that recruits white blood cells to assist in the fight against cancer. The therapy consists of microscopic “drug factory” beads that are implanted into the body and give a continuous, high dosage of IL2 to the patient.
“We just administer once, but the drug factories keep making the dose every day, where it’s needed until the cancer is eliminated,” says bioengineer Omid Veiseh from Rice University in Texas.
“Once we determined the correct dose – how many factories we needed – we were able to eradicate tumors in 100 percent of animals with ovarian cancer and in seven of eight animals with colorectal cancer,” he continued.
Interleukin-2 is a member of the cytokine family of proteins, which are responsible for activating the immune system. However, although cytokines are already being used in cancer treatment, for example, in the treatment of melanoma and renal carcinoma, the challenge for scientists is to get cytokines to fight tumors effectively while also avoiding dangerously high levels of inflammation elsewhere in the body, which can cause dramatic side effects.
The beads were implanted in the peritoneum, which is a sac-like membrane that surrounds the intestines, ovaries, and other abdominal organs in this research. It is possible to target cancer with particular medications without putting an undue load on the body because of this.
The enormous doses of interleukin-2 provided by these drug factories would be hazardous through IV drip, yet it works here because it is focused on only the tumor. Tests show that protein concentrations elsewhere in the body are roughly 30 times lower than around the tumor.
Each bead includes a hydrogel outer cell that protects the cytokine-producing cells from assault. The immune system recognizes these beads as alien objects but not as urgent dangers, allowing them to function. Then they can be programmed to turn off.
“We found foreign body reactions safely and robustly turned off the flow of cytokine from the capsules within 30 days,” says Veiseh. “We also showed we could safely administer a second course of treatment should it become necessary in the clinic.”
The drug factory beads might be used to treat malignancies elsewhere in the body if a lining to house them is available, and they could be modified to carry other medications, the researchers said. It’s a versatile and inventive system.
“In this study, we demonstrated that the ‘drug factories’ allow regulatable local administration of interleukin-2 and eradication of tumors in several mouse models, which is very exciting,” says Amir Jazaeri, a professor of gynecologic oncology and reproductive medicine at the University of Texas. “This provides a strong rationale for clinical testing.”
The research has been published in Science Advances.
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