- Recently, researchers at Rice University in Houston investigated a novel way of administering anticancer medications using mice models.
- Their results show that this new experimental treatment eradicates ovarian and colorectal cancers in mice.
- The authors of the study hope to replicate their findings in humans later this year.
The World Health Organisation (WHO) estimates that 1 in 6 deaths globally occur as a result of cancer.
In 2021 alone, doctors diagnosed an estimated 1,898,160 new cases of cancer in the United States, while about 608,570 individuals died from the disease.
Although there is currently no cure for cancer, several treatment options exist. Currently, the most common types of cancer treatments include chemotherapy, radiotherapy, and tumor surgery.
However, other anticancer therapies are starting to gather momentum. Of note is immunotherapy, a type of cancer treatment that boosts the body’s natural defenses against cancer.
However, immunotherapy techniques do not fully eradicate cancer tumors without significant side effects. Scientists consider this a major challenge for immunotherapy.
Now, scientists at the Veiseh lab at Rice University in Houston have designed a first-of-its-kind drug delivery system to overcome this issue.
The study, led by graduate student Amanda Nash, appears in the journal Science Advances.
A cytokine study
The researchers built their study around cytokines. These are small proteins crucial for controlling the growth and activity of other immune system cells and blood cells.
In the study, the scientists focused on interleukin-2 (IL2), a cytokine that activates white blood cells to fight against cancer.
They designed a drug delivery system — consisting of engineered human cells — capable of delivering continuously high doses of IL2 to the cancer site itself.
This technique, they hoped, would bypass the side effects associated with intravenously administering cytokines into the body.
Using rodents and nonhuman primate models, the experimenters tested the efficacy of their drug delivery system.
First, they genetically modified the abdominal cavity of the animals to produce several types of cancers.
Next, the scientists administered IL2 directly into the animal’s peritoneum — a sac-like membrane that contains the intestines, ovaries, and abdominal organs.
Finally, the researchers harvested tissue samples from the liver, kidney, and spleen of the animals. These samples allowed them to measure the tumor-reducing capacity of the delivery system in rodents, and assess toxicity levels in nonhuman primates.
The scientists then compared all test results against a control group.
What the scientists discovered
In the rodent group, the researchers investigated the tumor-reducing ability of their drug delivery system in two types of cancers: colorectal and ovarian cancers.
They noticed that, compared with the control group, the treatment group experienced significant tumor reduction in as little as 6 days.
Furthermore, the experimenters observed that by day 15, the treatment group of the ovarian cancer group displayed at least a 90% reduction in tumor size.
Also, a significant number of the treatment group in the colorectal cancer cohort was tumor-free by day 15.
At the end of the study period, the scientists recorded a 100% tumor eradication rate in the animals with ovarian cancer, while seven out of eight animals with colorectal cancer were completely tumor-free.
For the nonhuman primate group, the scientists conducted a series of safety and toxicity tests. Here, they discovered that their drug delivery system was “well-tolerated” by the animals.
These findings led the scientists to conclude that their drug delivery system “enabled peritoneal cancer immunotherapy without systemic toxicities.”
Medical News Today spoke with lead author Amanda Nash, she said:
“We have developed a cytokine delivery platform using engineered cells, [and] this platform enables continuous delivery of cytokines such as IL-2 for defined periods of time. We believe this project will change the paradigm of how people deliver immunotherapies.”
An ‘exciting’ study
MNT also spoke with Dr. Trevan D. Fischer, MD, a surgical oncologist and assistant professor of surgical oncology for Saint John’s Cancer Institute at Providence Saint John’s Health Center in Santa Monica, CA. He said the study’s results were “exciting.”
He explained that the study builds upon many recent advancements in treating cancer with the aid of the body’s immune system:
“This is exciting as many of these [immunotherapies] have debilitating side effects or the body develops resistance to the drugs. To overcome this, [the] study uses a novel platform to deliver these therapies locally to the tumors with both good effects and limited side effects.”
He also cautions that this method has not yet been tested in humans.
“While [carrying out animal studies first] is the normal process, many therapies that show promise in mouse models do not show similar outcomes in human trials,” Dr. Fischer explained.
Thankfully, this cautious optimism is also shared by the study authors. Nash revealed to MNT their plans for human studies:
“We are encouraged by the positive results of our pre-clinical cancer models, but of course, we will have to wait and see what happens in the human clinical trials later this year.”
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