HOUSTON, Texas — An implantable “drug factory” the size of a pinhead could cure a patient’s cancer in less than a week! Those are the findings of a new study by bioengineers at Rice University who say the new treatment can completely eradicate late-stage ovarian and colorectal cancers in as few as six days.
The team tested this potentially groundbreaking treatment in mice, but they add that clinical trials in human cancer patients could start by fall 2022. The tiny implants continuously deliver a high dose of interleukin-2 to the tumor region in the patient. Interleukin-2 is a natural compound which activates the immune system’s white blood cells to fight the cancer.
Researchers say these drug-producing beads are capable of being implanted in a minimally invasive surgery. The bioengineers also designed the implants with a protective shell that prevents the immune system from mistakenly attacking the drug factories. They also used components that scientists already know are safe for use in humans to hopefully speed up the time it will take to get this treatment through the testing phase.
“We just administer once, but the drug factories keep making the dose every day, where it’s needed until the cancer is eliminated,” says study co-author Omid Veiseh in a university release. “Once we determined the correct dose — how many factories we needed — we were able to eradicate tumors in 100% of animals with ovarian cancer and in seven of eight animals with colorectal cancer.”
Taking the fight to cancer head-on
In tests on mice, study authors placed the beads within the peritoneum — a sac-like lining which supports the intestines, ovaries, and other abdominal organs. Placing the implants here allowed the beads to concentrate their interleukin-2 production in an area near the tumors, without exposing other regions of the body to this compound.
“A major challenge in the field of immunotherapy is to increase tumor inflammation and anti-tumor immunity while avoiding systemic side effects of cytokines and other pro-inflammatory drugs,” explains study co-author Dr. Amir Jazaeri, professor of gynecologic oncology and reproductive medicine at MD Anderson.
“In this study, we demonstrated that the ‘drug factories’ allow regulatable local administration of interleukin-2 and eradication of tumor in several mouse models, which is very exciting. This provides a strong rationale for clinical testing.”
What is interleukin-2?
The cancer-fighting compound is a cytokine, or a protein the immune system uses to both recognize and fight off diseases and infections. Although it’s already an FDA-approved cancer treatment, the new implant triggers a stronger immune response than existing interleukin-2 therapies. This is because the beads can directly expose nearby tumors to high doses of the protein, rather than using fluids to distribute it throughout the body.
“If you gave the same concentration of the protein through an IV pump, it would be extremely toxic,” says researcher Amanda Nash. “With the drug factories, the concentration we see elsewhere in the body, away from the tumor site, is actually lower than what patients have to tolerate with IV treatments. The high concentration is only at the tumor site.”
Nash adds this technique may also help patients dealing with cancerous tumors in the pancreas, liver, lungs, and other organs. Researchers believe they will be able to implant the beads next to these tumors as well, within the linings surrounding those organs, and deliver a cancer-killing dose of interleukin-2 to the tumors.
Moreover, scientists say they can also load the beads with different cytokines depending on the form of cancer a patient is dealing with.
“We found foreign body reactions safely and robustly turned off the flow of cytokine from the capsules within 30 days,” Veiseh concludes. “We also showed we could safely administer a second course of treatment should it become necessary in the clinic.”
The study is published in the journal Science Advances.